citra_android: Storage Access Framework implementation (#6313)

CMakeLists.txt

@@ -386,10 +386,11 @@ endforeach()
 
 # Boost
 if (USE_SYSTEM_BOOST)
-    find_package(Boost 1.70.0 COMPONENTS serialization REQUIRED)
+    find_package(Boost 1.70.0 COMPONENTS serialization iostreams REQUIRED)
 else()
     add_library(Boost::boost ALIAS boost)
     add_library(Boost::serialization ALIAS boost_serialization)
+    add_library(Boost::iostreams ALIAS boost_iostreams)
 endif()
 
 # SDL2

externals/CMakeLists.txt

@@ -21,6 +21,15 @@ file(GLOB boost_serialization_SRC "${CMAKE_SOURCE_DIR}/externals/boost/libs/seri
 add_library(boost_serialization STATIC ${boost_serialization_SRC})
 target_link_libraries(boost_serialization PUBLIC boost)
 
+# Boost::iostreams
+add_library(
+    boost_iostreams
+    STATIC
+    ${CMAKE_SOURCE_DIR}/externals/boost/libs/iostreams/src/file_descriptor.cpp
+    ${CMAKE_SOURCE_DIR}/externals/boost/libs/iostreams/src/mapped_file.cpp
+)
+target_link_libraries(boost_iostreams PUBLIC boost)
+
 # Add additional boost libs here; remember to ALIAS them in the root CMakeLists!
 
 # Catch2

externals/boost

@@ -1 +1 @@
-Subproject commit 66937ea62d126a92b5057e3fd9ceac7c44daf4f5
+Subproject commit 80a171a179c1f901e4f8dfc8962417f44865ceec

src/android/app/build.gradle

@@ -32,7 +32,7 @@ android {
         // TODO If this is ever modified, change application_id in strings.xml
         applicationId "org.citra.citra_emu"
         minSdkVersion 28
-        targetSdkVersion 29
+        targetSdkVersion 31
         versionCode autoVersion
         versionName getVersion()
         ndk.abiFilters abiFilter
@@ -117,22 +117,25 @@ android {
 }
 
 dependencies {
+    implementation "androidx.activity:activity:1.5.1"
+    implementation "androidx.fragment:fragment:1.5.5"
     implementation 'androidx.appcompat:appcompat:1.5.1'
     implementation 'androidx.exifinterface:exifinterface:1.3.4'
     implementation 'androidx.cardview:cardview:1.0.0'
     implementation 'androidx.recyclerview:recyclerview:1.2.1'
+    implementation "androidx.documentfile:documentfile:1.0.1"
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
     implementation 'androidx.lifecycle:lifecycle-viewmodel:2.5.1'
     implementation 'androidx.fragment:fragment:1.5.3'
     implementation "androidx.slidingpanelayout:slidingpanelayout:1.2.0"
     implementation 'com.google.android.material:material:1.6.1'
+    implementation 'androidx.core:core-splashscreen:1.0.0'
 
     // For loading huge screenshots from the disk.
     implementation 'com.squareup.picasso:picasso:2.71828'
 
     // Allows FRP-style asynchronous operations in Android.
     implementation 'io.reactivex:rxandroid:1.2.1'
-    implementation 'com.nononsenseapps:filepicker:4.2.1'
     implementation 'org.ini4j:ini4j:0.5.4'
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
     implementation 'androidx.localbroadcastmanager:localbroadcastmanager:1.1.0'
@@ -140,6 +143,10 @@ dependencies {
 
     // Please don't upgrade the billing library as the newer version is not GPL-compatible
     implementation 'com.android.billingclient:billing:2.0.3'
+
+    // To use the androidx.test.core APIs
+    androidTestImplementation "androidx.test:core:1.5.0"
+    androidTestImplementation "androidx.test.ext:junit:1.1.5"
 }
 
 def getVersion() {

src/android/app/src/androidTest/java/org/citra/citra_emu/ExampleInstrumentedTest.java

@@ -1,8 +1,8 @@
 package org.citra.citra_emu;
 
 import android.content.Context;
-import android.support.test.InstrumentationRegistry;
+import androidx.test.core.app.ApplicationProvider;
-import android.support.test.runner.AndroidJUnit4;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -19,7 +19,7 @@ public class ExampleInstrumentedTest {
     @Test
     public void useAppContext() {
         // Context of the app under test.
-        Context appContext = InstrumentationRegistry.getTargetContext();
+        Context appContext = ApplicationProvider.getApplicationContext();
 
         assertEquals("org.citra.citra_emu", appContext.getPackageName());
     }

src/android/app/src/main/AndroidManifest.xml

@@ -26,7 +26,6 @@
     <uses-feature android:glEsVersion="0x00030002" android:required="true" />
     <uses-feature android:name="android.hardware.opengles.aep" android:required="true" />
 
-    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.CAMERA" />
     <uses-permission android:name="android.permission.RECORD_AUDIO" />
@@ -44,7 +43,8 @@
 
         <activity
             android:name="org.citra.citra_emu.ui.main.MainActivity"
-            android:theme="@style/Theme.Citra.Main"
+            android:theme="@style/Theme.Citra.Splash.Main"
+            android:exported="true"
             android:resizeableActivity="false">
 
             <!-- This intentfilter marks this Activity as the one that gets launched from Home screen. -->
@@ -69,23 +69,12 @@
 
         <service android:name="org.citra.citra_emu.utils.ForegroundService"/>
 
-        <activity
-            android:name="org.citra.citra_emu.activities.CustomFilePickerActivity"
-            android:label="@string/app_name"
-            android:theme="@style/FilePickerTheme">
-            <intent-filter>
-                <action android:name="android.intent.action.GET_CONTENT" />
-                <category android:name="android.intent.category.DEFAULT" />
-            </intent-filter>
-        </activity>
-
         <activity
             android:name="org.citra.citra_emu.features.cheats.ui.CheatsActivity"
             android:exported="false"
             android:theme="@style/Theme.Citra.Main"
             android:label="@string/cheats"/>
 
-        <service android:name="org.citra.citra_emu.utils.DirectoryInitialization"/>
 
         <provider
             android:name="org.citra.citra_emu.model.GameProvider"
@@ -93,16 +82,6 @@
             android:enabled="true"
             android:exported="false">
         </provider>
-
-        <provider
-            android:name="androidx.core.content.FileProvider"
-            android:authorities="${applicationId}.filesprovider"
-            android:exported="false"
-            android:grantUriPermissions="true">
-            <meta-data
-                android:name="android.support.FILE_PROVIDER_PATHS"
-                android:resource="@xml/nnf_provider_paths" />
-        </provider>
     </application>
 
 </manifest>

src/android/app/src/main/java/org/citra/citra_emu/CitraApplication.java

@@ -12,10 +12,12 @@ import android.os.Build;
 
 import org.citra.citra_emu.model.GameDatabase;
 import org.citra.citra_emu.utils.DirectoryInitialization;
+import org.citra.citra_emu.utils.DocumentsTree;
 import org.citra.citra_emu.utils.PermissionsHandler;
 
 public class CitraApplication extends Application {
     public static GameDatabase databaseHelper;
+    public static DocumentsTree documentsTree;
     private static CitraApplication application;
 
     private void createNotificationChannel() {
@@ -39,6 +41,7 @@ public class CitraApplication extends Application {
     public void onCreate() {
         super.onCreate();
         application = this;
+        documentsTree = new DocumentsTree();
 
         if (PermissionsHandler.hasWriteAccess(getApplicationContext())) {
             DirectoryInitialization.start(getApplicationContext());

src/android/app/src/main/java/org/citra/citra_emu/NativeLibrary.java

@@ -28,6 +28,7 @@ import androidx.fragment.app.DialogFragment;
 import org.citra.citra_emu.activities.EmulationActivity;
 import org.citra.citra_emu.applets.SoftwareKeyboard;
 import org.citra.citra_emu.utils.EmulationMenuSettings;
+import org.citra.citra_emu.utils.FileUtil;
 import org.citra.citra_emu.utils.Log;
 import org.citra.citra_emu.utils.PermissionsHandler;
 
@@ -164,6 +165,10 @@ public final class NativeLibrary {
     // Create the config.ini file.
     public static native void CreateConfigFile();
 
+    public static native void CreateLogFile();
+
+    public static native void LogUserDirectory(String directory);
+
     public static native int DefaultCPUCore();
 
     /**
@@ -262,11 +267,11 @@ public final class NativeLibrary {
                             coreErrorAlertLock.notify();
                         }
                     }).setOnDismissListener(dialog -> {
-                coreErrorAlertResult = true;
+                        coreErrorAlertResult = true;
-                synchronized (coreErrorAlertLock) {
+                        synchronized (coreErrorAlertLock) {
-                    coreErrorAlertLock.notify();
+                            coreErrorAlertLock.notify();
-                }
+                        }
-            }).create();
+                    }).create();
         }
     }
 
@@ -665,4 +670,73 @@ public final class NativeLibrary {
         public static final int RELEASED = 0;
         public static final int PRESSED = 1;
     }
+    public static boolean createFile(String directory, String filename) {
+        if (FileUtil.isNativePath(directory)) {
+            return CitraApplication.documentsTree.createFile(directory, filename);
+        }
+        return FileUtil.createFile(CitraApplication.getAppContext(), directory, filename) != null;
+    }
+
+    public static boolean createDir(String directory, String directoryName) {
+        if (FileUtil.isNativePath(directory)) {
+            return CitraApplication.documentsTree.createDir(directory, directoryName);
+        }
+        return FileUtil.createDir(CitraApplication.getAppContext(), directory, directoryName) != null;
+    }
+
+    public static int openContentUri(String path, String openMode) {
+        if (FileUtil.isNativePath(path)) {
+            return CitraApplication.documentsTree.openContentUri(path, openMode);
+        }
+        return FileUtil.openContentUri(CitraApplication.getAppContext(), path, openMode);
+    }
+
+    public static String[] getFilesName(String path) {
+        if (FileUtil.isNativePath(path)) {
+            return CitraApplication.documentsTree.getFilesName(path);
+        }
+        return FileUtil.getFilesName(CitraApplication.getAppContext(), path);
+    }
+
+    public static long getSize(String path) {
+        if (FileUtil.isNativePath(path)) {
+            return CitraApplication.documentsTree.getFileSize(path);
+        }
+        return FileUtil.getFileSize(CitraApplication.getAppContext(), path);
+    }
+
+    public static boolean fileExists(String path) {
+        if (FileUtil.isNativePath(path)) {
+            return CitraApplication.documentsTree.Exists(path);
+        }
+        return FileUtil.Exists(CitraApplication.getAppContext(), path);
+    }
+
+    public static boolean isDirectory(String path) {
+        if (FileUtil.isNativePath(path)) {
+            return CitraApplication.documentsTree.isDirectory(path);
+        }
+        return FileUtil.isDirectory(CitraApplication.getAppContext(), path);
+    }
+
+    public static boolean copyFile(String sourcePath, String destinationParentPath, String destinationFilename) {
+        if (FileUtil.isNativePath(sourcePath) && FileUtil.isNativePath(destinationParentPath)) {
+            return CitraApplication.documentsTree.copyFile(sourcePath, destinationParentPath, destinationFilename);
+        }
+        return FileUtil.copyFile(CitraApplication.getAppContext(), sourcePath, destinationParentPath, destinationFilename);
+    }
+
+    public static boolean renameFile(String path, String destinationFilename) {
+        if (FileUtil.isNativePath(path)) {
+            return CitraApplication.documentsTree.renameFile(path, destinationFilename);
+        }
+        return FileUtil.renameFile(CitraApplication.getAppContext(), path, destinationFilename);
+    }
+
+    public static boolean deleteDocument(String path) {
+        if (FileUtil.isNativePath(path)) {
+            return CitraApplication.documentsTree.deleteDocument(path);
+        }
+        return FileUtil.deleteDocument(CitraApplication.getAppContext(), path);
+    }
 }

src/android/app/src/main/java/org/citra/citra_emu/activities/CustomFilePickerActivity.java

@@ -1,38 +0,0 @@
-package org.citra.citra_emu.activities;
-
-import android.content.Intent;
-import android.os.Environment;
-
-import androidx.annotation.Nullable;
-
-import com.nononsenseapps.filepicker.AbstractFilePickerFragment;
-import com.nononsenseapps.filepicker.FilePickerActivity;
-
-import org.citra.citra_emu.fragments.CustomFilePickerFragment;
-
-import java.io.File;
-
-public class CustomFilePickerActivity extends FilePickerActivity {
-    public static final String EXTRA_TITLE = "filepicker.intent.TITLE";
-    public static final String EXTRA_EXTENSIONS = "filepicker.intent.EXTENSIONS";
-
-    @Override
-    protected AbstractFilePickerFragment<File> getFragment(
-            @Nullable final String startPath, final int mode, final boolean allowMultiple,
-            final boolean allowCreateDir, final boolean allowExistingFile,
-            final boolean singleClick) {
-        CustomFilePickerFragment fragment = new CustomFilePickerFragment();
-        // startPath is allowed to be null. In that case, default folder should be SD-card and not "/"
-        fragment.setArgs(
-                startPath != null ? startPath : Environment.getExternalStorageDirectory().getPath(),
-                mode, allowMultiple, allowCreateDir, allowExistingFile, singleClick);
-
-        Intent intent = getIntent();
-        int title = intent == null ? 0 : intent.getIntExtra(EXTRA_TITLE, 0);
-        fragment.setTitle(title);
-        String allowedExtensions = intent == null ? "*" : intent.getStringExtra(EXTRA_EXTENSIONS);
-        fragment.setAllowedExtensions(allowedExtensions);
-
-        return fragment;
-    }
-}

src/android/app/src/main/java/org/citra/citra_emu/activities/EmulationActivity.java

@@ -6,6 +6,7 @@ import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
+import android.util.Pair;
 import android.util.SparseIntArray;
 import android.view.InputDevice;
 import android.view.KeyEvent;
@@ -20,6 +21,8 @@ import android.widget.CheckBox;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.activity.result.ActivityResultCallback;
+import androidx.activity.result.ActivityResultLauncher;
 import androidx.annotation.IntDef;
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
@@ -30,6 +33,7 @@ import androidx.fragment.app.FragmentActivity;
 import org.citra.citra_emu.CitraApplication;
 import org.citra.citra_emu.NativeLibrary;
 import org.citra.citra_emu.R;
+import org.citra.citra_emu.contracts.OpenFileResultContract;
 import org.citra.citra_emu.features.cheats.ui.CheatsActivity;
 import org.citra.citra_emu.features.settings.model.view.InputBindingSetting;
 import org.citra.citra_emu.features.settings.ui.SettingsActivity;
@@ -84,6 +88,18 @@ public final class EmulationActivity extends AppCompatActivity {
     private static final int EMULATION_RUNNING_NOTIFICATION = 0x1000;
     private static SparseIntArray buttonsActionsMap = new SparseIntArray();
 
+    private final ActivityResultLauncher<Boolean> mOpenFileLauncher =
+        registerForActivityResult(new OpenFileResultContract(), result -> {
+            if (result == null)
+                return;
+            String[] selectedFiles = FileBrowserHelper.getSelectedFiles(
+                result, getApplicationContext(), Collections.singletonList("bin"));
+            if (selectedFiles == null)
+                return;
+
+            onAmiiboSelected(selectedFiles[0]);
+        });
+
     static {
         buttonsActionsMap.append(R.id.menu_emulation_edit_layout,
                 EmulationActivity.MENU_ACTION_EDIT_CONTROLS_PLACEMENT);
@@ -453,9 +469,7 @@ public final class EmulationActivity extends AppCompatActivity {
                 break;
 
             case MENU_ACTION_LOAD_AMIIBO:
-                FileBrowserHelper.openFilePicker(this, REQUEST_SELECT_AMIIBO,
+                mOpenFileLauncher.launch(false);
-                        R.string.select_amiibo,
-                        Collections.singletonList("bin"), false);
                 break;
 
             case MENU_ACTION_REMOVE_AMIIBO:
@@ -548,20 +562,8 @@ public final class EmulationActivity extends AppCompatActivity {
     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent result) {
         super.onActivityResult(requestCode, resultCode, result);
-        switch (requestCode) {
+        if (requestCode == StillImageCameraHelper.REQUEST_CAMERA_FILE_PICKER) {
-            case StillImageCameraHelper.REQUEST_CAMERA_FILE_PICKER:
+            StillImageCameraHelper.OnFilePickerResult(resultCode == RESULT_OK ? result : null);
-                StillImageCameraHelper.OnFilePickerResult(resultCode == RESULT_OK ? result : null);
-                break;
-            case REQUEST_SELECT_AMIIBO:
-                // If the user picked a file, as opposed to just backing out.
-                if (resultCode == MainActivity.RESULT_OK) {
-                    String[] selectedFiles = FileBrowserHelper.getSelectedFiles(result);
-                    if (selectedFiles == null)
-                        return;
-
-                    onAmiiboSelected(selectedFiles[0]);
-                }
-                break;
         }
     }
 

src/android/app/src/main/java/org/citra/citra_emu/adapters/GameAdapter.java

@@ -15,15 +15,15 @@ import androidx.recyclerview.widget.RecyclerView;
 
 import com.google.android.material.color.MaterialColors;
 
+import org.citra.citra_emu.CitraApplication;
 import org.citra.citra_emu.R;
 import org.citra.citra_emu.activities.EmulationActivity;
 import org.citra.citra_emu.model.GameDatabase;
+import org.citra.citra_emu.utils.FileUtil;
 import org.citra.citra_emu.utils.Log;
 import org.citra.citra_emu.utils.PicassoUtils;
 import org.citra.citra_emu.viewholders.GameViewHolder;
 
-import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.stream.Stream;
 
 /**
@@ -86,8 +86,14 @@ public final class GameAdapter extends RecyclerView.Adapter<GameViewHolder> impl
                 holder.textGameTitle.setText(mCursor.getString(GameDatabase.GAME_COLUMN_TITLE).replaceAll("[\\t\\n\\r]+", " "));
                 holder.textCompany.setText(mCursor.getString(GameDatabase.GAME_COLUMN_COMPANY));
 
-                final Path gamePath = Paths.get(mCursor.getString(GameDatabase.GAME_COLUMN_PATH));
+                String filepath = mCursor.getString(GameDatabase.GAME_COLUMN_PATH);
-                holder.textFileName.setText(gamePath.getFileName().toString());
+                String filename;
+                if (FileUtil.isNativePath(filepath)) {
+                    filename = CitraApplication.documentsTree.getFilename(filepath);
+                } else {
+                    filename = FileUtil.getFilename(CitraApplication.getAppContext(), filepath);
+                }
+                holder.textFileName.setText(filename);
 
                 // TODO These shouldn't be necessary once the move to a DB-based model is complete.
                 holder.gameId = mCursor.getString(GameDatabase.GAME_COLUMN_GAME_ID);

src/android/app/src/main/java/org/citra/citra_emu/contracts/OpenFileResultContract.java

@@ -0,0 +1,24 @@
+package org.citra.citra_emu.contracts;
+
+import android.content.Context;
+import android.content.Intent;
+import android.util.Pair;
+
+import androidx.activity.result.contract.ActivityResultContract;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+public class OpenFileResultContract extends ActivityResultContract<Boolean, Intent> {
+    @NonNull
+    @Override
+    public Intent createIntent(@NonNull Context context, Boolean allowMultiple) {
+        return new Intent(Intent.ACTION_OPEN_DOCUMENT)
+            .setType("application/octet-stream")
+            .putExtra(Intent.EXTRA_ALLOW_MULTIPLE, allowMultiple);
+    }
+
+    @Override
+    public Intent parseResult(int i, @Nullable Intent intent) {
+        return intent;
+    }
+}

src/android/app/src/main/java/org/citra/citra_emu/dialogs/CitraDirectoryDialog.java

@@ -0,0 +1,91 @@
+package org.citra.citra_emu.dialogs;
+
+import android.app.Dialog;
+import android.content.SharedPreferences;
+import android.net.Uri;
+import android.os.Bundle;
+import android.preference.PreferenceManager;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.CheckBox;
+import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.fragment.app.DialogFragment;
+import androidx.fragment.app.FragmentActivity;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import java.util.Objects;
+import org.citra.citra_emu.R;
+import org.citra.citra_emu.utils.FileUtil;
+import org.citra.citra_emu.utils.PermissionsHandler;
+
+public class CitraDirectoryDialog extends DialogFragment {
+    public static final String TAG = "citra_directory_dialog_fragment";
+
+    private static final String MOVE_DATE_ENABLE = "IS_MODE_DATA_ENABLE";
+
+    TextView pathView;
+
+    TextView spaceView;
+
+    CheckBox checkBox;
+
+    AlertDialog dialog;
+
+    Listener listener;
+
+    public interface Listener {
+        void onPressPositiveButton(boolean moveData, Uri path);
+    }
+
+    public static CitraDirectoryDialog newInstance(String path, Listener listener) {
+        CitraDirectoryDialog frag = new CitraDirectoryDialog();
+        frag.listener = listener;
+        Bundle args = new Bundle();
+        args.putString("path", path);
+        frag.setArguments(args);
+        return frag;
+    }
+
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(Bundle savedInstanceState) {
+        final FragmentActivity activity = requireActivity();
+        final Uri path = Uri.parse(Objects.requireNonNull(requireArguments().getString("path")));
+        SharedPreferences mPreferences = PreferenceManager.getDefaultSharedPreferences(activity);
+        String freeSpaceText =
+            getResources().getString(R.string.free_space, FileUtil.getFreeSpace(activity, path));
+
+        LayoutInflater inflater = getLayoutInflater();
+        View view = inflater.inflate(R.layout.dialog_citra_directory, null);
+
+        checkBox = view.findViewById(R.id.checkBox);
+        pathView = view.findViewById(R.id.path);
+        spaceView = view.findViewById(R.id.space);
+
+        checkBox.setChecked(mPreferences.getBoolean(MOVE_DATE_ENABLE, true));
+        if (!PermissionsHandler.hasWriteAccess(activity)) {
+            checkBox.setVisibility(View.GONE);
+        }
+        checkBox.setOnCheckedChangeListener(
+            (v, isChecked)
+                    // record move data selection with SharedPreferences
+                -> mPreferences.edit().putBoolean(MOVE_DATE_ENABLE, checkBox.isChecked()).apply());
+
+        pathView.setText(path.getPath());
+        spaceView.setText(freeSpaceText);
+
+        setCancelable(false);
+
+        dialog = new MaterialAlertDialogBuilder(activity)
+                     .setView(view)
+                     .setIcon(R.mipmap.ic_launcher)
+                     .setTitle(R.string.app_name)
+                     .setPositiveButton(
+                         android.R.string.ok,
+                         (d, v) -> listener.onPressPositiveButton(checkBox.isChecked(), path))
+                     .setNegativeButton(android.R.string.cancel, null)
+                     .create();
+        return dialog;
+    }
+}

src/android/app/src/main/java/org/citra/citra_emu/dialogs/CopyDirProgressDialog.java

@@ -0,0 +1,61 @@
+package org.citra.citra_emu.dialogs;
+
+import android.app.Dialog;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.fragment.app.DialogFragment;
+import androidx.fragment.app.FragmentActivity;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import org.citra.citra_emu.R;
+
+public class CopyDirProgressDialog extends DialogFragment {
+    public static final String TAG = "copy_dir_progress_dialog";
+    ProgressBar progressBar;
+
+    TextView progressText;
+
+    AlertDialog dialog;
+
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(Bundle savedInstanceState) {
+        final FragmentActivity activity = requireActivity();
+
+        LayoutInflater inflater = getLayoutInflater();
+        View view = inflater.inflate(R.layout.dialog_progress_bar, null);
+
+        progressBar = view.findViewById(R.id.progress_bar);
+        progressText = view.findViewById(R.id.progress_text);
+        progressText.setText("");
+
+        setCancelable(false);
+
+        dialog = new MaterialAlertDialogBuilder(activity)
+                     .setView(view)
+                     .setIcon(R.mipmap.ic_launcher)
+                     .setTitle(R.string.move_data)
+                     .setMessage("")
+                     .create();
+        return dialog;
+    }
+
+    public void onUpdateSearchProgress(String msg) {
+        requireActivity().runOnUiThread(() -> {
+            dialog.setMessage(getResources().getString(R.string.searching_direcotry, msg));
+        });
+    }
+
+    public void onUpdateCopyProgress(String msg, int progress, int max) {
+        requireActivity().runOnUiThread(() -> {
+            progressBar.setProgress(progress);
+            progressBar.setMax(max);
+            progressText.setText(String.format("%d/%d", progress, max));
+            dialog.setMessage(getResources().getString(R.string.copy_file_name, msg));
+        });
+    }
+}

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/SettingsActivityPresenter.java

@@ -3,9 +3,9 @@ package org.citra.citra_emu.features.settings.ui;
 import android.content.IntentFilter;
 import android.os.Bundle;
 import android.text.TextUtils;
-
 import androidx.appcompat.app.AppCompatActivity;
-
+import androidx.documentfile.provider.DocumentFile;
+import java.io.File;
 import org.citra.citra_emu.NativeLibrary;
 import org.citra.citra_emu.features.settings.model.Settings;
 import org.citra.citra_emu.features.settings.utils.SettingsFile;
@@ -15,8 +15,6 @@ import org.citra.citra_emu.utils.DirectoryStateReceiver;
 import org.citra.citra_emu.utils.Log;
 import org.citra.citra_emu.utils.ThemeUtil;
 
-import java.io.File;
-
 public final class SettingsActivityPresenter {
     private static final String KEY_SHOULD_SAVE = "should_save";
 
@@ -62,8 +60,8 @@ public final class SettingsActivityPresenter {
     }
 
     private void prepareCitraDirectoriesIfNeeded() {
-        File configFile = new File(DirectoryInitialization.getUserDirectory() + "/config/" + SettingsFile.FILE_NAME_CONFIG + ".ini");
+        DocumentFile configFile = SettingsFile.getSettingsFile(SettingsFile.FILE_NAME_CONFIG);
-        if (!configFile.exists()) {
+        if (configFile == null || !configFile.exists()) {
             Log.error("Citra config file could not be found!");
         }
         if (DirectoryInitialization.areCitraDirectoriesReady()) {

src/android/app/src/main/java/org/citra/citra_emu/features/settings/utils/SettingsFile.java

@@ -1,6 +1,10 @@
 package org.citra.citra_emu.features.settings.utils;
 
+import android.content.Context;
+import android.net.Uri;
+
 import androidx.annotation.NonNull;
+import androidx.documentfile.provider.DocumentFile;
 
 import org.citra.citra_emu.CitraApplication;
 import org.citra.citra_emu.NativeLibrary;
@@ -18,10 +22,11 @@ import org.citra.citra_emu.utils.Log;
 import org.ini4j.Wini;
 
 import java.io.BufferedReader;
-import java.io.File;
 import java.io.FileNotFoundException;
-import java.io.FileReader;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
 import java.util.HashMap;
 import java.util.Set;
 import java.util.TreeMap;
@@ -145,13 +150,15 @@ public final class SettingsFile {
      * @param view         The current view.
      * @return An Observable that emits a HashMap of the file's contents, then completes.
      */
-    static HashMap<String, SettingSection> readFile(final File ini, boolean isCustomGame, SettingsActivityView view) {
+    static HashMap<String, SettingSection> readFile(final DocumentFile ini, boolean isCustomGame, SettingsActivityView view) {
         HashMap<String, SettingSection> sections = new Settings.SettingsSectionMap();
 
         BufferedReader reader = null;
 
         try {
-            reader = new BufferedReader(new FileReader(ini));
+            Context context = CitraApplication.getAppContext();
+            InputStream inputStream = context.getContentResolver().openInputStream(ini.getUri());
+            reader = new BufferedReader(new InputStreamReader(inputStream));
 
             SettingSection current = null;
             for (String line; (line = reader.readLine()) != null; ) {
@@ -166,11 +173,11 @@ public final class SettingsFile {
                 }
             }
         } catch (FileNotFoundException e) {
-            Log.error("[SettingsFile] File not found: " + ini.getAbsolutePath() + e.getMessage());
+            Log.error("[SettingsFile] File not found: " + ini.getUri() + e.getMessage());
             if (view != null)
                 view.onSettingsFileNotFound();
         } catch (IOException e) {
-            Log.error("[SettingsFile] Error reading from: " + ini.getAbsolutePath() + e.getMessage());
+            Log.error("[SettingsFile] Error reading from: " + ini.getUri() + e.getMessage());
             if (view != null)
                 view.onSettingsFileNotFound();
         } finally {
@@ -178,7 +185,7 @@ public final class SettingsFile {
                 try {
                     reader.close();
                 } catch (IOException e) {
-                    Log.error("[SettingsFile] Error closing: " + ini.getAbsolutePath() + e.getMessage());
+                    Log.error("[SettingsFile] Error closing: " + ini.getUri() + e.getMessage());
                 }
             }
         }
@@ -212,17 +219,23 @@ public final class SettingsFile {
      */
     public static void saveFile(final String fileName, TreeMap<String, SettingSection> sections,
                                 SettingsActivityView view) {
-        File ini = getSettingsFile(fileName);
+        DocumentFile ini = getSettingsFile(fileName);
 
         try {
-            Wini writer = new Wini(ini);
+            Context context = CitraApplication.getAppContext();
+            InputStream inputStream = context.getContentResolver().openInputStream(ini.getUri());
+            Wini writer = new Wini(inputStream);
 
             Set<String> keySet = sections.keySet();
             for (String key : keySet) {
                 SettingSection section = sections.get(key);
                 writeSection(writer, section);
             }
-            writer.store();
+            inputStream.close();
+            OutputStream outputStream = context.getContentResolver().openOutputStream(ini.getUri());
+            writer.store(outputStream);
+            outputStream.flush();
+            outputStream.close();
         } catch (IOException e) {
             Log.error("[SettingsFile] File not found: " + fileName + ".ini: " + e.getMessage());
             view.showToastMessage(CitraApplication.getAppContext().getString(R.string.error_saving, fileName, e.getMessage()), false);
@@ -262,14 +275,16 @@ public final class SettingsFile {
         return generalSectionName;
     }
 
-    @NonNull
+    public static DocumentFile getSettingsFile(String fileName) {
-    private static File getSettingsFile(String fileName) {
+        DocumentFile root = DocumentFile.fromTreeUri(CitraApplication.getAppContext(), Uri.parse(DirectoryInitialization.getUserDirectory()));
-        return new File(
+        DocumentFile configDirectory = root.findFile("config");
-                DirectoryInitialization.getUserDirectory() + "/config/" + fileName + ".ini");
+        return configDirectory.findFile(fileName + ".ini");
     }
 
-    private static File getCustomGameSettingsFile(String gameId) {
+    private static DocumentFile getCustomGameSettingsFile(String gameId) {
-        return new File(DirectoryInitialization.getUserDirectory() + "/GameSettings/" + gameId + ".ini");
+        DocumentFile root = DocumentFile.fromTreeUri(CitraApplication.getAppContext(), Uri.parse(DirectoryInitialization.getUserDirectory()));
+        DocumentFile configDirectory = root.findFile("GameSettings");
+        return configDirectory.findFile(gameId + ".ini");
     }
 
     private static SettingSection sectionFromLine(String line, boolean isCustomGame) {

src/android/app/src/main/java/org/citra/citra_emu/fragments/CustomFilePickerFragment.java

@@ -1,120 +0,0 @@
-package org.citra.citra_emu.fragments;
-
-import android.net.Uri;
-import android.os.Bundle;
-import android.os.Environment;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.TextView;
-
-import androidx.annotation.NonNull;
-import androidx.appcompat.widget.Toolbar;
-import androidx.core.content.FileProvider;
-
-import com.nononsenseapps.filepicker.FilePickerFragment;
-
-import org.citra.citra_emu.R;
-
-import java.io.File;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-
-public class CustomFilePickerFragment extends FilePickerFragment {
-    private static String ALL_FILES = "*";
-    private int mTitle;
-    private static List<String> extensions = Collections.singletonList(ALL_FILES);
-
-    @NonNull
-    @Override
-    public Uri toUri(@NonNull final File file) {
-        return FileProvider
-                .getUriForFile(getContext(),
-                        getContext().getApplicationContext().getPackageName() + ".filesprovider",
-                        file);
-    }
-
-    @Override
-    public void onActivityCreated(Bundle savedInstanceState) {
-        super.onActivityCreated(savedInstanceState);
-
-        if (mode == MODE_DIR) {
-            TextView ok = getActivity().findViewById(R.id.nnf_button_ok);
-            ok.setText(R.string.select_dir);
-
-            TextView cancel = getActivity().findViewById(R.id.nnf_button_cancel);
-            cancel.setVisibility(View.GONE);
-        }
-    }
-
-    @Override
-    protected View inflateRootView(LayoutInflater inflater, ViewGroup container) {
-        View view = super.inflateRootView(inflater, container);
-        if (mTitle != 0) {
-            Toolbar toolbar = view.findViewById(com.nononsenseapps.filepicker.R.id.nnf_picker_toolbar);
-            ViewGroup parent = (ViewGroup) toolbar.getParent();
-            int index = parent.indexOfChild(toolbar);
-            View newToolbar = inflater.inflate(R.layout.filepicker_toolbar, toolbar, false);
-            TextView title = newToolbar.findViewById(R.id.filepicker_title);
-            title.setText(mTitle);
-            parent.removeView(toolbar);
-            parent.addView(newToolbar, index);
-        }
-        return view;
-    }
-
-    public void setTitle(int title) {
-        mTitle = title;
-    }
-
-    public void setAllowedExtensions(String allowedExtensions) {
-        if (allowedExtensions == null)
-            return;
-
-        extensions = Arrays.asList(allowedExtensions.split(","));
-    }
-
-    @Override
-    protected boolean isItemVisible(@NonNull final File file) {
-        // Some users jump to the conclusion that Dolphin isn't able to detect their
-        // files if the files don't show up in the file picker when mode == MODE_DIR.
-        // To avoid this, show files even when the user needs to select a directory.
-        return (showHiddenItems || !file.isHidden()) &&
-                (file.isDirectory() || extensions.contains(ALL_FILES) ||
-                        extensions.contains(fileExtension(file.getName()).toLowerCase()));
-    }
-
-    @Override
-    public boolean isCheckable(@NonNull final File file) {
-        // We need to make a small correction to the isCheckable logic due to
-        // overriding isItemVisible to show files when mode == MODE_DIR.
-        // AbstractFilePickerFragment always treats files as checkable when
-        // allowExistingFile == true, but we don't want files to be checkable when mode == MODE_DIR.
-        return super.isCheckable(file) && !(mode == MODE_DIR && file.isFile());
-    }
-
-    @Override
-    public void goUp() {
-        if (Environment.getExternalStorageDirectory().getPath().equals(mCurrentPath.getPath())) {
-            goToDir(new File("/storage/"));
-            return;
-        }
-        if (mCurrentPath.equals(new File("/storage/"))){
-            return;
-        }
-        super.goUp();
-    }
-
-    @Override
-    public void onClickDir(@NonNull View view, @NonNull DirViewHolder viewHolder) {
-        if(viewHolder.file.equals(new File("/storage/emulated/")))
-            viewHolder.file = new File("/storage/emulated/0/");
-        super.onClickDir(view, viewHolder);
-    }
-
-    private static String fileExtension(@NonNull String filename) {
-        int i = filename.lastIndexOf('.');
-        return i < 0 ? "" : filename.substring(i + 1);
-    }
-}

src/android/app/src/main/java/org/citra/citra_emu/model/CheapDocument.java

@@ -0,0 +1,36 @@
+package org.citra.citra_emu.model;
+
+import android.net.Uri;
+import android.provider.DocumentsContract;
+
+/**
+ * A struct that is much more "cheaper" than DocumentFile.
+ * Only contains the information we needed.
+ */
+public class CheapDocument {
+    private final String filename;
+    private final Uri uri;
+    private final String mimeType;
+
+    public CheapDocument(String filename, String mimeType, Uri uri) {
+        this.filename = filename;
+        this.mimeType = mimeType;
+        this.uri = uri;
+    }
+
+    public String getFilename() {
+        return filename;
+    }
+
+    public Uri getUri() {
+        return uri;
+    }
+
+    public String getMimeType() {
+        return mimeType;
+    }
+
+    public boolean isDirectory() {
+        return mimeType.equals(DocumentsContract.Document.MIME_TYPE_DIR);
+    }
+}

src/android/app/src/main/java/org/citra/citra_emu/model/GameDatabase.java

@@ -5,8 +5,10 @@ import android.content.Context;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteOpenHelper;
+import android.net.Uri;
 
 import org.citra.citra_emu.NativeLibrary;
+import org.citra.citra_emu.utils.FileUtil;
 import org.citra.citra_emu.utils.Log;
 
 import java.io.File;
@@ -64,10 +66,12 @@ public final class GameDatabase extends SQLiteOpenHelper {
 
     private static final String SQL_DELETE_FOLDERS = "DROP TABLE IF EXISTS " + TABLE_NAME_FOLDERS;
     private static final String SQL_DELETE_GAMES = "DROP TABLE IF EXISTS " + TABLE_NAME_GAMES;
+    private final Context mContext;
 
     public GameDatabase(Context context) {
         // Superclass constructor builds a database or uses an existing one.
         super(context, "games.db", null, DB_VERSION);
+        mContext = context;
     }
 
     @Override
@@ -151,9 +155,10 @@ public final class GameDatabase extends SQLiteOpenHelper {
         while (folderCursor.moveToNext()) {
             String folderPath = folderCursor.getString(FOLDER_COLUMN_PATH);
 
-            File folder = new File(folderPath);
+            Uri folder = Uri.parse(folderPath);
             // If the folder is empty because it no longer exists, remove it from the library.
-            if (!folder.exists()) {
+            CheapDocument[] files = FileUtil.listFiles(mContext, folder);
+            if (files.length == 0) {
                 Log.error(
                         "[GameDatabase] Folder no longer exists. Removing from the library: " + folderPath);
                 database.delete(TABLE_NAME_FOLDERS,
@@ -161,7 +166,7 @@ public final class GameDatabase extends SQLiteOpenHelper {
                         new String[]{Long.toString(folderCursor.getLong(COLUMN_DB_ID))});
             }
 
-            addGamesRecursive(database, folder, allowedExtensions, 3);
+            addGamesRecursive(database, files, allowedExtensions, 3);
         }
 
         fileCursor.close();
@@ -173,33 +178,28 @@ public final class GameDatabase extends SQLiteOpenHelper {
         database.close();
     }
 
-    private static void addGamesRecursive(SQLiteDatabase database, File parent, Set<String> allowedExtensions, int depth) {
+    private void addGamesRecursive(SQLiteDatabase database, CheapDocument[] files,
+                                   Set<String> allowedExtensions, int depth) {
         if (depth <= 0) {
             return;
         }
 
-        File[] children = parent.listFiles();
+        for (CheapDocument file : files) {
-        if (children != null) {
+            if (file.isDirectory()) {
-            for (File file : children) {
+                Set<String> newExtensions = new HashSet<>(Arrays.asList(
-                if (file.isHidden()) {
+                        ".3ds", ".3dsx", ".elf", ".axf", ".cci", ".cxi", ".app"));
-                    continue;
+                CheapDocument[] children = FileUtil.listFiles(mContext, file.getUri());
-                }
+                this.addGamesRecursive(database, children, newExtensions, depth - 1);
+            } else {
+                String filename = file.getUri().toString();
 
-                if (file.isDirectory()) {
+                int extensionStart = filename.lastIndexOf('.');
-                    Set<String> newExtensions = new HashSet<>(Arrays.asList(
+                if (extensionStart > 0) {
-                            ".3ds", ".3dsx", ".elf", ".axf", ".cci", ".cxi", ".app"));
+                    String fileExtension = filename.substring(extensionStart);
-                    addGamesRecursive(database, file, newExtensions, depth - 1);
-                } else {
-                    String filePath = file.getPath();
 
-                    int extensionStart = filePath.lastIndexOf('.');
+                    // Check that the file has an extension we care about before trying to read out of it.
-                    if (extensionStart > 0) {
+                    if (allowedExtensions.contains(fileExtension.toLowerCase())) {
-                        String fileExtension = filePath.substring(extensionStart);
+                        attemptToAddGame(database, filename);
-
-                        // Check that the file has an extension we care about before trying to read out of it.
-                        if (allowedExtensions.contains(fileExtension.toLowerCase())) {
-                            attemptToAddGame(database, filePath);
-                        }
                     }
                 }
             }

src/android/app/src/main/java/org/citra/citra_emu/ui/main/MainActivity.java

@@ -1,25 +1,30 @@
 package org.citra.citra_emu.ui.main;
 
 import android.content.Intent;
-import android.content.pm.PackageManager;
+import android.net.Uri;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.widget.Toast;
-
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
-
+import androidx.core.splashscreen.SplashScreen;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import java.util.Collections;
 import org.citra.citra_emu.NativeLibrary;
 import org.citra.citra_emu.R;
 import org.citra.citra_emu.activities.EmulationActivity;
+import org.citra.citra_emu.contracts.OpenFileResultContract;
 import org.citra.citra_emu.features.settings.ui.SettingsActivity;
 import org.citra.citra_emu.model.GameProvider;
 import org.citra.citra_emu.ui.platform.PlatformGamesFragment;
 import org.citra.citra_emu.utils.AddDirectoryHelper;
 import org.citra.citra_emu.utils.BillingManager;
+import org.citra.citra_emu.utils.CitraDirectoryHelper;
 import org.citra.citra_emu.utils.DirectoryInitialization;
 import org.citra.citra_emu.utils.FileBrowserHelper;
 import org.citra.citra_emu.utils.PermissionsHandler;
@@ -27,9 +32,6 @@ import org.citra.citra_emu.utils.PicassoUtils;
 import org.citra.citra_emu.utils.StartupHandler;
 import org.citra.citra_emu.utils.ThemeUtil;
 
-import java.util.Arrays;
-import java.util.Collections;
-
 /**
  * The main Activity of the Lollipop style UI. Manages several PlatformGamesFragments, which
  * individually display a grid of available games for each Fragment, in a tabbed layout.
@@ -46,8 +48,65 @@ public final class MainActivity extends AppCompatActivity implements MainView {
 
     private static MenuItem mPremiumButton;
 
+    private final CitraDirectoryHelper citraDirectoryHelper = new CitraDirectoryHelper(this, () -> {
+        // If mPlatformGamesFragment is null means game directory have not been set yet.
+        if (mPlatformGamesFragment == null) {
+            mPlatformGamesFragment = new PlatformGamesFragment();
+            getSupportFragmentManager()
+                .beginTransaction()
+                .add(mFrameLayoutId, mPlatformGamesFragment)
+                .commit();
+            showGameInstallDialog();
+        }
+    });
+
+    private final ActivityResultLauncher<Uri> mOpenCitraDirectory =
+        registerForActivityResult(new ActivityResultContracts.OpenDocumentTree(), result -> {
+            if (result == null)
+                return;
+            citraDirectoryHelper.showCitraDirectoryDialog(result);
+        });
+
+    private final ActivityResultLauncher<Uri> mOpenGameListLauncher =
+        registerForActivityResult(new ActivityResultContracts.OpenDocumentTree(), result -> {
+            if (result == null)
+                return;
+            int takeFlags =
+                (Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
+            getContentResolver().takePersistableUriPermission(result, takeFlags);
+            // When a new directory is picked, we currently will reset the existing games
+            // database. This effectively means that only one game directory is supported.
+            // TODO(bunnei): Consider fixing this in the future, or removing code for this.
+            getContentResolver().insert(GameProvider.URI_RESET, null);
+            // Add the new directory
+            mPresenter.onDirectorySelected(result.toString());
+        });
+
+    private final ActivityResultLauncher<Boolean> mOpenFileLauncher =
+        registerForActivityResult(new OpenFileResultContract(), result -> {
+            if (result == null)
+                return;
+            String[] selectedFiles = FileBrowserHelper.getSelectedFiles(
+                result, getApplicationContext(), Collections.singletonList("cia"));
+            if (selectedFiles == null) {
+                Toast
+                    .makeText(getApplicationContext(), R.string.cia_file_not_found,
+                              Toast.LENGTH_LONG)
+                    .show();
+                return;
+            }
+            NativeLibrary.InstallCIAS(selectedFiles);
+            mPresenter.refreshGameList();
+        });
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
+        SplashScreen splashScreen = SplashScreen.installSplashScreen(this);
+        splashScreen.setKeepOnScreenCondition(
+            ()
+                -> (PermissionsHandler.hasWriteAccess(this) &&
+                    !DirectoryInitialization.areCitraDirectoriesReady()));
+
         ThemeUtil.applyTheme(this);
 
         super.onCreate(savedInstanceState);
@@ -61,7 +120,7 @@ public final class MainActivity extends AppCompatActivity implements MainView {
         mPresenter.onCreate();
 
         if (savedInstanceState == null) {
-            StartupHandler.HandleInit(this);
+            StartupHandler.HandleInit(this, mOpenCitraDirectory);
             if (PermissionsHandler.hasWriteAccess(this)) {
                 mPlatformGamesFragment = new PlatformGamesFragment();
                 getSupportFragmentManager().beginTransaction().add(mFrameLayoutId, mPlatformGamesFragment)
@@ -144,7 +203,7 @@ public final class MainActivity extends AppCompatActivity implements MainView {
         if (PermissionsHandler.hasWriteAccess(this)) {
             SettingsActivity.launch(this, menuTag, "");
         } else {
-            PermissionsHandler.checkWritePermission(this);
+            PermissionsHandler.checkWritePermission(this, mOpenCitraDirectory);
         }
     }
 
@@ -152,79 +211,18 @@ public final class MainActivity extends AppCompatActivity implements MainView {
     public void launchFileListActivity(int request) {
         if (PermissionsHandler.hasWriteAccess(this)) {
             switch (request) {
+                case MainPresenter.REQUEST_SELECT_CITRA_DIRECTORY:
+                mOpenCitraDirectory.launch(null);
+                break;
                 case MainPresenter.REQUEST_ADD_DIRECTORY:
-                    FileBrowserHelper.openDirectoryPicker(this,
+                mOpenGameListLauncher.launch(null);
-                                                      MainPresenter.REQUEST_ADD_DIRECTORY,
+                break;
-                                                      R.string.select_game_folder,
-                                                      Arrays.asList("elf", "axf", "cci", "3ds",
-                                                                    "cxi", "app", "3dsx", "cia",
-                                                                    "rar", "zip", "7z", "torrent",
-                                                                    "tar", "gz"));
-                    break;
                 case MainPresenter.REQUEST_INSTALL_CIA:
-                    FileBrowserHelper.openFilePicker(this, MainPresenter.REQUEST_INSTALL_CIA,
+                mOpenFileLauncher.launch(true);
-                                                     R.string.install_cia_title,
+                break;
-                                                     Collections.singletonList("cia"), true);
-                    break;
             }
         } else {
-            PermissionsHandler.checkWritePermission(this);
+            PermissionsHandler.checkWritePermission(this, mOpenCitraDirectory);
-        }
-    }
-
-    /**
-     * @param requestCode An int describing whether the Activity that is returning did so successfully.
-     * @param resultCode  An int describing what Activity is giving us this callback.
-     * @param result      The information the returning Activity is providing us.
-     */
-    @Override
-    protected void onActivityResult(int requestCode, int resultCode, Intent result) {
-        super.onActivityResult(requestCode, resultCode, result);
-        switch (requestCode) {
-            case MainPresenter.REQUEST_ADD_DIRECTORY:
-                // If the user picked a file, as opposed to just backing out.
-                if (resultCode == MainActivity.RESULT_OK) {
-                    // When a new directory is picked, we currently will reset the existing games
-                    // database. This effectively means that only one game directory is supported.
-                    // TODO(bunnei): Consider fixing this in the future, or removing code for this.
-                    getContentResolver().insert(GameProvider.URI_RESET, null);
-                    // Add the new directory
-                    mPresenter.onDirectorySelected(FileBrowserHelper.getSelectedDirectory(result));
-                }
-                break;
-                case MainPresenter.REQUEST_INSTALL_CIA:
-                    // If the user picked a file, as opposed to just backing out.
-                    if (resultCode == MainActivity.RESULT_OK) {
-                        NativeLibrary.InstallCIAS(FileBrowserHelper.getSelectedFiles(result));
-                        mPresenter.refeshGameList();
-                    }
-                    break;
-        }
-    }
-
-    @Override
-    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
-        switch (requestCode) {
-            case PermissionsHandler.REQUEST_CODE_WRITE_PERMISSION:
-                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
-                    DirectoryInitialization.start(this);
-
-                    mPlatformGamesFragment = new PlatformGamesFragment();
-                    getSupportFragmentManager().beginTransaction().add(mFrameLayoutId, mPlatformGamesFragment)
-                            .commit();
-
-                    // Immediately prompt user to select a game directory on first boot
-                    if (mPresenter != null) {
-                        mPresenter.launchFileListActivity(MainPresenter.REQUEST_ADD_DIRECTORY);
-                    }
-                } else {
-                    Toast.makeText(this, R.string.write_permission_needed, Toast.LENGTH_SHORT)
-                            .show();
-                }
-                break;
-            default:
-                super.onRequestPermissionsResult(requestCode, permissions, grantResults);
-                break;
         }
     }
 
@@ -245,6 +243,18 @@ public final class MainActivity extends AppCompatActivity implements MainView {
         }
     }
 
+    private void showGameInstallDialog() {
+        new MaterialAlertDialogBuilder(this)
+            .setIcon(R.mipmap.ic_launcher)
+            .setTitle(R.string.app_name)
+            .setMessage(R.string.app_game_install_description)
+            .setCancelable(false)
+            .setNegativeButton(android.R.string.cancel, null)
+            .setPositiveButton(android.R.string.ok,
+                               (d, v) -> mOpenGameListLauncher.launch(null))
+            .show();
+    }
+
     @Override
     protected void onDestroy() {
         EmulationActivity.tryDismissRunningNotification(this);

src/android/app/src/main/java/org/citra/citra_emu/ui/main/MainPresenter.java

@@ -1,5 +1,6 @@
 package org.citra.citra_emu.ui.main;
 
+import android.content.Context;
 import android.os.SystemClock;
 
 import org.citra.citra_emu.BuildConfig;
@@ -9,10 +10,12 @@ import org.citra.citra_emu.features.settings.model.Settings;
 import org.citra.citra_emu.features.settings.utils.SettingsFile;
 import org.citra.citra_emu.model.GameDatabase;
 import org.citra.citra_emu.utils.AddDirectoryHelper;
+import org.citra.citra_emu.utils.PermissionsHandler;
 
 public final class MainPresenter {
     public static final int REQUEST_ADD_DIRECTORY = 1;
     public static final int REQUEST_INSTALL_CIA = 2;
+    public static final int REQUEST_SELECT_CITRA_DIRECTORY = 3;
 
     private final MainView mView;
     private String mDirToAdd;
@@ -25,7 +28,7 @@ public final class MainPresenter {
     public void onCreate() {
         String versionName = BuildConfig.VERSION_NAME;
         mView.setVersionString(versionName);
-        refeshGameList();
+        refreshGameList();
     }
 
     public void launchFileListActivity(int request) {
@@ -46,6 +49,10 @@ public final class MainPresenter {
                 mView.launchSettingsActivity(SettingsFile.FILE_NAME_CONFIG);
                 return true;
 
+            case R.id.button_select_root:
+                mView.launchFileListActivity(REQUEST_SELECT_CITRA_DIRECTORY);
+                return true;
+
             case R.id.button_add_directory:
                 launchFileListActivity(REQUEST_ADD_DIRECTORY);
                 return true;
@@ -74,9 +81,12 @@ public final class MainPresenter {
         mDirToAdd = dir;
     }
 
-    public void refeshGameList() {
+    public void refreshGameList() {
-        GameDatabase databaseHelper = CitraApplication.databaseHelper;
+        Context context = CitraApplication.getAppContext();
-        databaseHelper.scanLibrary(databaseHelper.getWritableDatabase());
+        if (PermissionsHandler.hasWriteAccess(context)) {
-        mView.refresh();
+            GameDatabase databaseHelper = CitraApplication.databaseHelper;
+            databaseHelper.scanLibrary(databaseHelper.getWritableDatabase());
+            mView.refresh();
+        }
     }
 }

src/android/app/src/main/java/org/citra/citra_emu/utils/CitraDirectoryHelper.java

@@ -0,0 +1,87 @@
+package org.citra.citra_emu.utils;
+
+import android.content.Intent;
+import android.net.Uri;
+import androidx.fragment.app.FragmentActivity;
+import java.util.concurrent.Executors;
+import org.citra.citra_emu.dialogs.CitraDirectoryDialog;
+import org.citra.citra_emu.dialogs.CopyDirProgressDialog;
+
+/**
+ * Citra directory initialization ui flow controller.
+ */
+public class CitraDirectoryHelper {
+    public interface Listener {
+        void onDirectoryInitialized();
+    }
+
+    private final FragmentActivity mFragmentActivity;
+    private final Listener mListener;
+
+    public CitraDirectoryHelper(FragmentActivity mFragmentActivity, Listener mListener) {
+        this.mFragmentActivity = mFragmentActivity;
+        this.mListener = mListener;
+    }
+
+    public void showCitraDirectoryDialog(Uri result) {
+        CitraDirectoryDialog citraDirectoryDialog = CitraDirectoryDialog.newInstance(
+            result.toString(), ((moveData, path) -> {
+                Uri previous = PermissionsHandler.getCitraDirectory();
+                // Do noting if user select the previous path.
+                if (path.equals(previous)) {
+                    return;
+                }
+                int takeFlags = (Intent.FLAG_GRANT_WRITE_URI_PERMISSION |
+                                 Intent.FLAG_GRANT_READ_URI_PERMISSION);
+                mFragmentActivity.getContentResolver().takePersistableUriPermission(path,
+                                                                                    takeFlags);
+                if (!moveData || previous == null) {
+                    initializeCitraDirectory(path);
+                    mListener.onDirectoryInitialized();
+                    return;
+                }
+
+                // If user check move data, show copy progress dialog.
+                showCopyDialog(previous, path);
+            }));
+        citraDirectoryDialog.show(mFragmentActivity.getSupportFragmentManager(),
+                                  CitraDirectoryDialog.TAG);
+    }
+
+    private void showCopyDialog(Uri previous, Uri path) {
+        CopyDirProgressDialog copyDirProgressDialog = new CopyDirProgressDialog();
+        copyDirProgressDialog.showNow(mFragmentActivity.getSupportFragmentManager(),
+                                      CopyDirProgressDialog.TAG);
+
+        // Run copy dir in background
+        Executors.newSingleThreadExecutor().execute(() -> {
+            FileUtil.copyDir(
+                mFragmentActivity, previous.toString(), path.toString(),
+                new FileUtil.CopyDirListener() {
+                    @Override
+                    public void onSearchProgress(String directoryName) {
+                        copyDirProgressDialog.onUpdateSearchProgress(directoryName);
+                    }
+
+                    @Override
+                    public void onCopyProgress(String filename, int progress, int max) {
+                        copyDirProgressDialog.onUpdateCopyProgress(filename, progress, max);
+                    }
+
+                    @Override
+                    public void onComplete() {
+                        initializeCitraDirectory(path);
+                        copyDirProgressDialog.dismissAllowingStateLoss();
+                        mListener.onDirectoryInitialized();
+                    }
+                });
+        });
+    }
+
+    private void initializeCitraDirectory(Uri path) {
+        if (!PermissionsHandler.setCitraDirectory(path.toString()))
+            return;
+        DirectoryInitialization.resetCitraDirectoryState();
+        DirectoryInitialization.start(mFragmentActivity);
+    }
+}

src/android/app/src/main/java/org/citra/citra_emu/utils/DirectoryInitialization.java

@@ -9,19 +9,18 @@ package org.citra.citra_emu.utils;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.net.Uri;
 import android.os.Environment;
 import android.preference.PreferenceManager;
-
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
-
-import org.citra.citra_emu.NativeLibrary;
-
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.concurrent.atomic.AtomicBoolean;
+import org.citra.citra_emu.CitraApplication;
+import org.citra.citra_emu.NativeLibrary;
 
 /**
  * A service that spawns its own thread in order to copy several binary and shader files
@@ -49,6 +48,9 @@ public final class DirectoryInitialization {
             if (PermissionsHandler.hasWriteAccess(context)) {
                 if (setCitraUserDirectory()) {
                     initializeInternalStorage(context);
+                    CitraApplication.documentsTree.setRoot(Uri.parse(userPath));
+                    NativeLibrary.CreateLogFile();
+                    NativeLibrary.LogUserDirectory(userPath);
                     NativeLibrary.CreateConfigFile();
                     directoryState = DirectoryInitializationState.CITRA_DIRECTORIES_INITIALIZED;
                 } else {
@@ -75,6 +77,11 @@ public final class DirectoryInitialization {
         return directoryState == DirectoryInitializationState.CITRA_DIRECTORIES_INITIALIZED;
     }
 
+    public static void resetCitraDirectoryState() {
+        directoryState = null;
+        isCitraDirectoryInitializationRunning.compareAndSet(true, false);
+    }
+
     public static String getUserDirectory() {
         if (directoryState == null) {
             throw new IllegalStateException("DirectoryInitialization has to run at least once!");
@@ -88,15 +95,11 @@ public final class DirectoryInitialization {
     private static native void SetSysDirectory(String path);
 
     private static boolean setCitraUserDirectory() {
-        if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
+        Uri dataPath = PermissionsHandler.getCitraDirectory();
-            File externalPath = Environment.getExternalStorageDirectory();
+        if (dataPath != null) {
-            if (externalPath != null) {
+            userPath = dataPath.toString();
-                userPath = externalPath.getAbsolutePath() + "/citra-emu";
+            Log.debug("[DirectoryInitialization] User Dir: " + userPath);
-                Log.debug("[DirectoryInitialization] User Dir: " + userPath);
+            return true;
-                // NativeLibrary.SetUserDirectory(userPath);
-                return true;
-            }
-
         }
 
         return false;

src/android/app/src/main/java/org/citra/citra_emu/utils/DocumentsTree.java

@@ -0,0 +1,271 @@
+package org.citra.citra_emu.utils;
+
+import android.content.Context;
+import android.net.Uri;
+import android.provider.DocumentsContract;
+
+import androidx.annotation.Nullable;
+import androidx.documentfile.provider.DocumentFile;
+
+import org.citra.citra_emu.CitraApplication;
+import org.citra.citra_emu.model.CheapDocument;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.URLDecoder;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.StringTokenizer;
+
+/**
+ * A cached document tree for citra user directory.
+ * For every filepath which is not startsWith "content://" will need to use this class to traverse.
+ * For example:
+ * C++ citra log file directory will be /log/citra_log.txt.
+ * After DocumentsTree.resolvePath() it will become content URI.
+ */
+public class DocumentsTree {
+    private DocumentsNode root;
+    private final Context context;
+    public static final String DELIMITER = "/";
+
+    public DocumentsTree() {
+        context = CitraApplication.getAppContext();
+    }
+
+    public void setRoot(Uri rootUri) {
+        root = null;
+        root = new DocumentsNode();
+        root.uri = rootUri;
+        root.isDirectory = true;
+    }
+
+    public boolean createFile(String filepath, String name) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null) return false;
+        if (!node.isDirectory) return false;
+        if (!node.loaded) structTree(node);
+        Uri mUri = node.uri;
+        try {
+            String filename = URLDecoder.decode(name, FileUtil.DECODE_METHOD);
+            if (node.children.get(filename) != null) return true;
+            DocumentFile createdFile = FileUtil.createFile(context, mUri.toString(), name);
+            if (createdFile == null) return false;
+            DocumentsNode document = new DocumentsNode(createdFile, false);
+            document.parent = node;
+            node.children.put(document.key, document);
+            return true;
+        } catch (Exception e) {
+            Log.error("[DocumentsTree]: Cannot create file, error: " + e.getMessage());
+        }
+        return false;
+    }
+
+    public boolean createDir(String filepath, String name) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null) return false;
+        if (!node.isDirectory) return false;
+        if (!node.loaded) structTree(node);
+        Uri mUri = node.uri;
+        try {
+            String filename = URLDecoder.decode(name, FileUtil.DECODE_METHOD);
+            if (node.children.get(filename) != null) return true;
+            DocumentFile createdDirectory = FileUtil.createDir(context, mUri.toString(), name);
+            if (createdDirectory == null) return false;
+            DocumentsNode document = new DocumentsNode(createdDirectory, true);
+            document.parent = node;
+            node.children.put(document.key, document);
+            return true;
+        } catch (Exception e) {
+            Log.error("[DocumentsTree]: Cannot create file, error: " + e.getMessage());
+        }
+        return false;
+    }
+
+    public int openContentUri(String filepath, String openmode) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null) {
+            return -1;
+        }
+        return FileUtil.openContentUri(context, node.uri.toString(), openmode);
+    }
+
+    public String getFilename(String filepath) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null) {
+            return "";
+        }
+        return node.name;
+    }
+
+    public String[] getFilesName(String filepath) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null || !node.isDirectory) {
+            return new String[0];
+        }
+        // If this directory have not been iterate struct it.
+        if (!node.loaded) structTree(node);
+        return node.children.keySet().toArray(new String[0]);
+    }
+
+    public long getFileSize(String filepath) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null || node.isDirectory) {
+            return 0;
+        }
+        return FileUtil.getFileSize(context, node.uri.toString());
+    }
+
+    public boolean isDirectory(String filepath) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null) return false;
+        return node.isDirectory;
+    }
+
+    public boolean Exists(String filepath) {
+        return resolvePath(filepath) != null;
+    }
+
+    public boolean copyFile(String sourcePath, String destinationParentPath, String destinationFilename) {
+        DocumentsNode sourceNode = resolvePath(sourcePath);
+        if (sourceNode == null) return false;
+        DocumentsNode destinationNode = resolvePath(destinationParentPath);
+        if (destinationNode == null) return false;
+        try {
+            DocumentFile destinationParent = DocumentFile.fromTreeUri(context, destinationNode.uri);
+            if (destinationParent == null) return false;
+            String filename = URLDecoder.decode(destinationFilename, "UTF-8");
+            DocumentFile destination = destinationParent.createFile("application/octet-stream", filename);
+            if (destination == null) return false;
+            DocumentsNode document = new DocumentsNode();
+            document.uri = destination.getUri();
+            document.parent = destinationNode;
+            document.name = destination.getName();
+            document.isDirectory = destination.isDirectory();
+            document.loaded = true;
+            InputStream input = context.getContentResolver().openInputStream(sourceNode.uri);
+            OutputStream output = context.getContentResolver().openOutputStream(destination.getUri());
+            byte[] buffer = new byte[1024];
+            int len;
+            while ((len = input.read(buffer)) != -1) {
+                output.write(buffer, 0, len);
+            }
+            input.close();
+            output.flush();
+            output.close();
+            destinationNode.children.put(document.key, document);
+            return true;
+        } catch (Exception e) {
+            Log.error("[DocumentsTree]: Cannot copy file, error: " + e.getMessage());
+        }
+        return false;
+    }
+
+    public boolean renameFile(String filepath, String destinationFilename) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null) return false;
+        try {
+            Uri mUri = node.uri;
+            String filename = URLDecoder.decode(destinationFilename, FileUtil.DECODE_METHOD);
+            DocumentsContract.renameDocument(context.getContentResolver(), mUri, filename);
+            node.rename(filename);
+            return true;
+        } catch (Exception e) {
+            Log.error("[DocumentsTree]: Cannot rename file, error: " + e.getMessage());
+        }
+        return false;
+    }
+
+    public boolean deleteDocument(String filepath) {
+        DocumentsNode node = resolvePath(filepath);
+        if (node == null) return false;
+        try {
+            Uri mUri = node.uri;
+            if (!DocumentsContract.deleteDocument(context.getContentResolver(), mUri)) {
+                return false;
+            }
+            if (node.parent != null) {
+                node.parent.children.remove(node.key);
+            }
+            return true;
+        } catch (Exception e) {
+            Log.error("[DocumentsTree]: Cannot rename file, error: " + e.getMessage());
+        }
+        return false;
+    }
+
+    @Nullable
+    private DocumentsNode resolvePath(String filepath) {
+        if (root == null)
+            return null;
+        StringTokenizer tokens = new StringTokenizer(filepath, DELIMITER, false);
+        DocumentsNode iterator = root;
+        while (tokens.hasMoreTokens()) {
+            String token = tokens.nextToken();
+            if (token.isEmpty()) continue;
+            iterator = find(iterator, token);
+            if (iterator == null) return null;
+        }
+        return iterator;
+    }
+
+    @Nullable
+    private DocumentsNode find(DocumentsNode parent, String filename) {
+        if (parent.isDirectory && !parent.loaded) {
+            structTree(parent);
+        }
+        return parent.children.get(filename);
+    }
+
+    /**
+     * Construct current level directory tree
+     *
+     * @param parent parent node of this level
+     */
+    private void structTree(DocumentsNode parent) {
+        CheapDocument[] documents = FileUtil.listFiles(context, parent.uri);
+        for (CheapDocument document : documents) {
+            DocumentsNode node = new DocumentsNode(document);
+            node.parent = parent;
+            parent.children.put(node.key, node);
+        }
+        parent.loaded = true;
+    }
+
+    private static class DocumentsNode {
+        private DocumentsNode parent;
+        private final Map<String, DocumentsNode> children = new HashMap<>();
+        private String key;
+        private String name;
+        private Uri uri;
+        private boolean loaded = false;
+        private boolean isDirectory = false;
+
+        private DocumentsNode() {}
+
+        private DocumentsNode(CheapDocument document) {
+            name = document.getFilename();
+            uri = document.getUri();
+            key = FileUtil.getFilenameWithExtensions(uri);
+            isDirectory = document.isDirectory();
+            loaded = !isDirectory;
+        }
+
+        private DocumentsNode(DocumentFile document, boolean isCreateDir) {
+            name = document.getName();
+            uri = document.getUri();
+            key = FileUtil.getFilenameWithExtensions(uri);
+            isDirectory = isCreateDir;
+            loaded = true;
+        }
+
+        private void rename(String key) {
+            if (parent == null) {
+                return;
+            }
+            parent.children.remove(this.key);
+            this.name = key;
+            parent.children.put(key, this);
+        }
+    }
+}

src/android/app/src/main/java/org/citra/citra_emu/utils/FileBrowserHelper.java

@@ -1,71 +1,48 @@
 package org.citra.citra_emu.utils;
 
+import android.content.ClipData;
+import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
-import android.os.Environment;
 
 import androidx.annotation.Nullable;
-import androidx.fragment.app.FragmentActivity;
+import androidx.documentfile.provider.DocumentFile;
 
-import com.nononsenseapps.filepicker.FilePickerActivity;
+import java.util.ArrayList;
-import com.nononsenseapps.filepicker.Utils;
-
-import org.citra.citra_emu.activities.CustomFilePickerActivity;
-
-import java.io.File;
 import java.util.List;
 
 public final class FileBrowserHelper {
-    public static void openDirectoryPicker(FragmentActivity activity, int requestCode, int title, List<String> extensions) {
-        Intent i = new Intent(activity, CustomFilePickerActivity.class);
-
-        i.putExtra(FilePickerActivity.EXTRA_ALLOW_MULTIPLE, false);
-        i.putExtra(FilePickerActivity.EXTRA_ALLOW_CREATE_DIR, false);
-        i.putExtra(FilePickerActivity.EXTRA_MODE, FilePickerActivity.MODE_DIR);
-        i.putExtra(FilePickerActivity.EXTRA_START_PATH,
-                Environment.getExternalStorageDirectory().getPath());
-        i.putExtra(CustomFilePickerActivity.EXTRA_TITLE, title);
-        i.putExtra(CustomFilePickerActivity.EXTRA_EXTENSIONS, String.join(",", extensions));
-
-        activity.startActivityForResult(i, requestCode);
-    }
-
-    public static void openFilePicker(FragmentActivity activity, int requestCode, int title,
-                                      List<String> extensions, boolean allowMultiple) {
-        Intent i = new Intent(activity, CustomFilePickerActivity.class);
-
-        i.putExtra(FilePickerActivity.EXTRA_ALLOW_MULTIPLE, allowMultiple);
-        i.putExtra(FilePickerActivity.EXTRA_ALLOW_CREATE_DIR, false);
-        i.putExtra(FilePickerActivity.EXTRA_MODE, FilePickerActivity.MODE_FILE);
-        i.putExtra(FilePickerActivity.EXTRA_START_PATH,
-                Environment.getExternalStorageDirectory().getPath());
-        i.putExtra(CustomFilePickerActivity.EXTRA_TITLE, title);
-        i.putExtra(CustomFilePickerActivity.EXTRA_EXTENSIONS, String.join(",", extensions));
-
-        activity.startActivityForResult(i, requestCode);
-    }
 
     @Nullable
-    public static String getSelectedDirectory(Intent result) {
+    public static String[] getSelectedFiles(Intent result, Context context, List<String> extension) {
-        // Use the provided utility method to parse the result
+        ClipData clipData = result.getClipData();
-        List<Uri> files = Utils.getSelectedFilesFromResult(result);
+        List<DocumentFile> files = new ArrayList<>();
-        if (!files.isEmpty()) {
+        if (clipData == null) {
-            File file = Utils.getFileForUri(files.get(0));
+            files.add(DocumentFile.fromSingleUri(context, result.getData()));
-            return file.getAbsolutePath();
+        } else {
+            for (int i = 0; i < clipData.getItemCount(); i++) {
+                ClipData.Item item = clipData.getItemAt(i);
+                Uri uri = item.getUri();
+                files.add(DocumentFile.fromSingleUri(context, uri));
+            }
         }
-
-        return null;
-    }
-
-    @Nullable
-    public static String[] getSelectedFiles(Intent result) {
-        // Use the provided utility method to parse the result
-        List<Uri> files = Utils.getSelectedFilesFromResult(result);
         if (!files.isEmpty()) {
-            String[] paths = new String[files.size()];
+            List<String> filePaths = new ArrayList<>();
-            for (int i = 0; i < files.size(); i++)
+            for (int i = 0; i < files.size(); i++) {
-                paths[i] = Utils.getFileForUri(files.get(i)).getAbsolutePath();
+                DocumentFile file = files.get(i);
-            return paths;
+                String filename = file.getName();
+                int extensionStart = filename.lastIndexOf('.');
+                if (extensionStart > 0) {
+                    String fileExtension = filename.substring(extensionStart + 1);
+                    if (extension.contains(fileExtension)) {
+                        filePaths.add(file.getUri().toString());
+                    }
+                }
+            }
+            if (filePaths.isEmpty()) {
+                return null;
+            }
+            return filePaths.toArray(new String[0]);
         }
 
         return null;

src/android/app/src/main/java/org/citra/citra_emu/utils/FileUtil.java

@@ -1,11 +1,385 @@
 package org.citra.citra_emu.utils;
 
+import android.content.ContentResolver;
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.ParcelFileDescriptor;
+import android.provider.DocumentsContract;
+import android.system.Os;
+import android.system.StructStatVfs;
+import android.util.Pair;
+import androidx.annotation.Nullable;
+import androidx.documentfile.provider.DocumentFile;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.URLDecoder;
+import java.util.ArrayList;
+import java.util.List;
+import org.citra.citra_emu.model.CheapDocument;
 
 public class FileUtil {
+    static final String PATH_TREE = "tree";
+    static final String DECODE_METHOD = "UTF-8";
+    static final String APPLICATION_OCTET_STREAM = "application/octet-stream";
+    static final String TEXT_PLAIN = "text/plain";
+
+    public interface CopyDirListener {
+        void onSearchProgress(String directoryName);
+        void onCopyProgress(String filename, int progress, int max);
+
+        void onComplete();
+    }
+
+    /**
+     * Create a file from directory with filename.
+     *
+     * @param context   Application context
+     * @param directory parent path for file.
+     * @param filename  file display name.
+     * @return boolean
+     */
+    @Nullable
+    public static DocumentFile createFile(Context context, String directory, String filename) {
+        try {
+            Uri directoryUri = Uri.parse(directory);
+            DocumentFile parent;
+            parent = DocumentFile.fromTreeUri(context, directoryUri);
+            if (parent == null) return null;
+            filename = URLDecoder.decode(filename, DECODE_METHOD);
+            int extensionPosition = filename.lastIndexOf('.');
+            String extension = "";
+            if (extensionPosition > 0) {
+                extension = filename.substring(extensionPosition);
+            }
+            String mimeType = APPLICATION_OCTET_STREAM;
+            if (extension.equals(".txt")) {
+                mimeType = TEXT_PLAIN;
+            }
+            DocumentFile isExist = parent.findFile(filename);
+            if (isExist != null) return isExist;
+            return parent.createFile(mimeType, filename);
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot create file, error: " + e.getMessage());
+        }
+        return null;
+    }
+
+    /**
+     * Create a directory from directory with filename.
+     *
+     * @param context       Application context
+     * @param directory     parent path for directory.
+     * @param directoryName directory display name.
+     * @return boolean
+     */
+    @Nullable
+    public static DocumentFile createDir(Context context, String directory, String directoryName) {
+        try {
+            Uri directoryUri = Uri.parse(directory);
+            DocumentFile parent;
+            parent = DocumentFile.fromTreeUri(context, directoryUri);
+            if (parent == null) return null;
+            directoryName = URLDecoder.decode(directoryName, DECODE_METHOD);
+            DocumentFile isExist = parent.findFile(directoryName);
+            if (isExist != null) return isExist;
+            return parent.createDirectory(directoryName);
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot create file, error: " + e.getMessage());
+        }
+        return null;
+    }
+
+    /**
+     * Open content uri and return file descriptor to JNI.
+     *
+     * @param context  Application context
+     * @param path     Native content uri path
+     * @param openmode will be one of "r", "r", "rw", "wa", "rwa"
+     * @return file descriptor
+     */
+    public static int openContentUri(Context context, String path, String openmode) {
+        try (ParcelFileDescriptor parcelFileDescriptor =
+                 context.getContentResolver().openFileDescriptor(Uri.parse(path), openmode)) {
+            if (parcelFileDescriptor == null) {
+                Log.error("[FileUtil]: Cannot get the file descriptor from uri: " + path);
+                return -1;
+            }
+            return parcelFileDescriptor.detachFd();
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot open content uri, error: " + e.getMessage());
+        }
+        return -1;
+    }
+
+    /**
+     * Reference:  https://stackoverflow.com/questions/42186820/documentfile-is-very-slow
+     * This function will be faster than DocumentFile.listFiles
+     *
+     * @param context Application context
+     * @param uri     Directory uri.
+     * @return CheapDocument lists.
+     */
+    public static CheapDocument[] listFiles(Context context, Uri uri) {
+        final ContentResolver resolver = context.getContentResolver();
+        final String[] columns = new String[]{
+                DocumentsContract.Document.COLUMN_DOCUMENT_ID,
+                DocumentsContract.Document.COLUMN_DISPLAY_NAME,
+                DocumentsContract.Document.COLUMN_MIME_TYPE,
+        };
+        Cursor c = null;
+        final List<CheapDocument> results = new ArrayList<>();
+        try {
+            String docId;
+            if (isRootTreeUri(uri)) {
+                docId = DocumentsContract.getTreeDocumentId(uri);
+            } else {
+                docId = DocumentsContract.getDocumentId(uri);
+            }
+            final Uri childrenUri = DocumentsContract.buildChildDocumentsUriUsingTree(uri, docId);
+            c = resolver.query(childrenUri, columns, null, null, null);
+            while (c.moveToNext()) {
+                final String documentId = c.getString(0);
+                final String documentName = c.getString(1);
+                final String documentMimeType = c.getString(2);
+                final Uri documentUri = DocumentsContract.buildDocumentUriUsingTree(uri, documentId);
+                CheapDocument document = new CheapDocument(documentName, documentMimeType, documentUri);
+                results.add(document);
+            }
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot list file error: " + e.getMessage());
+        } finally {
+            closeQuietly(c);
+        }
+        return results.toArray(new CheapDocument[0]);
+    }
+
+    /**
+     * Check whether given path exists.
+     *
+     * @param path Native content uri path
+     * @return bool
+     */
+    public static boolean Exists(Context context, String path) {
+        Cursor c = null;
+        try {
+            Uri mUri = Uri.parse(path);
+            final String[] columns = new String[] {DocumentsContract.Document.COLUMN_DOCUMENT_ID};
+            c = context.getContentResolver().query(mUri, columns, null, null, null);
+            return c.getCount() > 0;
+        } catch (Exception e) {
+            Log.info("[FileUtil] Cannot find file from given path, error: " + e.getMessage());
+        } finally {
+            closeQuietly(c);
+        }
+        return false;
+    }
+
+    /**
+     * Check whether given path is a directory
+     *
+     * @param path content uri path
+     * @return bool
+     */
+    public static boolean isDirectory(Context context, String path) {
+        final ContentResolver resolver = context.getContentResolver();
+        final String[] columns = new String[] {DocumentsContract.Document.COLUMN_MIME_TYPE};
+        boolean isDirectory = false;
+        Cursor c = null;
+        try {
+            Uri mUri = Uri.parse(path);
+            c = resolver.query(mUri, columns, null, null, null);
+            c.moveToNext();
+            final String mimeType = c.getString(0);
+            isDirectory = mimeType.equals(DocumentsContract.Document.MIME_TYPE_DIR);
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot list files, error: " + e.getMessage());
+        } finally {
+            closeQuietly(c);
+        }
+        return isDirectory;
+    }
+
+    /**
+     * Get file display name from given path
+     *
+     * @param path content uri path
+     * @return String display name
+     */
+    public static String getFilename(Context context, String path) {
+        final ContentResolver resolver = context.getContentResolver();
+        final String[] columns = new String[] {DocumentsContract.Document.COLUMN_DISPLAY_NAME};
+        String filename = "";
+        Cursor c = null;
+        try {
+            Uri mUri = Uri.parse(path);
+            c = resolver.query(mUri, columns, null, null, null);
+            c.moveToNext();
+            filename = c.getString(0);
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot get file size, error: " + e.getMessage());
+        } finally {
+            closeQuietly(c);
+        }
+        return filename;
+    }
+
+    public static String[] getFilesName(Context context, String path) {
+        Uri uri = Uri.parse(path);
+        List<String> files = new ArrayList<>();
+        for (CheapDocument file : FileUtil.listFiles(context, uri)) {
+            files.add(file.getFilename());
+        }
+        return files.toArray(new String[0]);
+    }
+
+    /**
+     * Get file size from given path.
+     *
+     * @param path content uri path
+     * @return long file size
+     */
+    public static long getFileSize(Context context, String path) {
+        final ContentResolver resolver = context.getContentResolver();
+        final String[] columns = new String[] {DocumentsContract.Document.COLUMN_SIZE};
+        long size = 0;
+        Cursor c = null;
+        try {
+            Uri mUri = Uri.parse(path);
+            c = resolver.query(mUri, columns, null, null, null);
+            c.moveToNext();
+            size = c.getLong(0);
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot get file size, error: " + e.getMessage());
+        } finally {
+            closeQuietly(c);
+        }
+        return size;
+    }
+
+    public static boolean copyFile(Context context, String sourcePath, String destinationParentPath, String destinationFilename) {
+        try {
+            Uri sourceUri = Uri.parse(sourcePath);
+            Uri destinationUri = Uri.parse(destinationParentPath);
+            DocumentFile destinationParent = DocumentFile.fromTreeUri(context, destinationUri);
+            if (destinationParent == null) return false;
+            String filename = URLDecoder.decode(destinationFilename, "UTF-8");
+            DocumentFile destination = destinationParent.findFile(filename);
+            if (destination == null) {
+                destination = destinationParent.createFile("application/octet-stream", filename);
+            }
+            if (destination == null) return false;
+            InputStream input = context.getContentResolver().openInputStream(sourceUri);
+            OutputStream output = context.getContentResolver().openOutputStream(destination.getUri());
+            byte[] buffer = new byte[1024];
+            int len;
+            while ((len = input.read(buffer)) != -1) {
+                output.write(buffer, 0, len);
+            }
+            input.close();
+            output.flush();
+            output.close();
+            return true;
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot copy file, error: " + e.getMessage());
+        }
+        return false;
+    }
+
+    public static void copyDir(Context context, String sourcePath, String destinationPath,
+                               CopyDirListener listener) {
+        try {
+            Uri sourceUri = Uri.parse(sourcePath);
+            Uri destinationUri = Uri.parse(destinationPath);
+            final List<Pair<CheapDocument, DocumentFile>> files = new ArrayList<>();
+            final List<Pair<Uri, Uri>> dirs = new ArrayList<>();
+            dirs.add(new Pair<>(sourceUri, destinationUri));
+            // Searching all files which need to be copied and struct the directory in destination.
+            while (!dirs.isEmpty()) {
+                DocumentFile fromDir = DocumentFile.fromTreeUri(context, dirs.get(0).first);
+                DocumentFile toDir = DocumentFile.fromTreeUri(context, dirs.get(0).second);
+                if (fromDir == null || toDir == null)
+                    continue;
+                Uri fromUri = fromDir.getUri();
+                if (listener != null) {
+                    listener.onSearchProgress(fromUri.getPath());
+                }
+                CheapDocument[] documents = FileUtil.listFiles(context, fromUri);
+                for (CheapDocument document : documents) {
+                    String filename = document.getFilename();
+                    if (document.isDirectory()) {
+                        DocumentFile target = toDir.findFile(filename);
+                        if (target == null || !target.exists()) {
+                            target = toDir.createDirectory(filename);
+                        }
+                        if (target == null)
+                            continue;
+                        dirs.add(new Pair<>(document.getUri(), target.getUri()));
+                    } else {
+                        DocumentFile target = toDir.findFile(filename);
+                        if (target == null || !target.exists()) {
+                            target =
+                                toDir.createFile(document.getMimeType(), document.getFilename());
+                        }
+                        if (target == null)
+                            continue;
+                        files.add(new Pair<>(document, target));
+                    }
+                }
+
+                dirs.remove(0);
+            }
+
+            int total = files.size();
+            int progress = 0;
+            for (Pair<CheapDocument, DocumentFile> file : files) {
+                DocumentFile to = file.second;
+                Uri toUri = to.getUri();
+                String filename = getFilenameWithExtensions(toUri);
+                String toPath = toUri.getPath();
+                DocumentFile toParent = to.getParentFile();
+                if (toParent == null)
+                    continue;
+                FileUtil.copyFile(context, file.first.getUri().toString(),
+                                  toParent.getUri().toString(), filename);
+                progress++;
+                if (listener != null) {
+                    listener.onCopyProgress(toPath, progress, total);
+                }
+            }
+            if (listener != null) {
+                listener.onComplete();
+            }
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot copy directory, error: " + e.getMessage());
+        }
+    }
+
+    public static boolean renameFile(Context context, String path, String destinationFilename) {
+        try {
+            Uri uri = Uri.parse(path);
+            DocumentsContract.renameDocument(context.getContentResolver(), uri, destinationFilename);
+            return true;
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot rename file, error: " + e.getMessage());
+        }
+        return false;
+    }
+
+    public static boolean deleteDocument(Context context, String path) {
+        try {
+            Uri uri = Uri.parse(path);
+            DocumentsContract.deleteDocument(context.getContentResolver(), uri);
+            return true;
+        } catch (Exception e) {
+            Log.error("[FileUtil]: Cannot delete document, error: " + e.getMessage());
+        }
+        return false;
+    }
+
     public static byte[] getBytesFromFile(File file) throws IOException {
         final long length = file.length();
 
@@ -21,8 +395,8 @@ public class FileUtil {
         int numRead;
 
         try (InputStream is = new FileInputStream(file)) {
-            while (offset < bytes.length
+            while (offset < bytes.length &&
-                    && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
+                   (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0) {
                 offset += numRead;
             }
         }
@@ -34,4 +408,53 @@ public class FileUtil {
 
         return bytes;
     }
+
+    public static boolean isRootTreeUri(Uri uri) {
+        final List<String> paths = uri.getPathSegments();
+        return paths.size() == 2 && PATH_TREE.equals(paths.get(0));
+    }
+
+    public static boolean isNativePath(String path) {
+        try {
+            return path.charAt(0) == '/';
+        } catch (StringIndexOutOfBoundsException e) {
+            Log.error("[FileUtil] Cannot determine the string is native path or not.");
+        }
+        return false;
+    }
+
+    public static String getFilenameWithExtensions(Uri uri) {
+        final String path = uri.getPath();
+        final int index = path.lastIndexOf('/');
+        return path.substring(index + 1);
+    }
+
+    public static double getFreeSpace(Context context, Uri uri) {
+        try {
+            Uri docTreeUri = DocumentsContract.buildDocumentUriUsingTree(
+                uri, DocumentsContract.getTreeDocumentId(uri));
+            ParcelFileDescriptor pfd =
+                context.getContentResolver().openFileDescriptor(docTreeUri, "r");
+            assert pfd != null;
+            StructStatVfs stats = Os.fstatvfs(pfd.getFileDescriptor());
+            double spaceInGigaBytes = stats.f_bavail * stats.f_bsize / 1024.0 / 1024 / 1024;
+            pfd.close();
+            return spaceInGigaBytes;
+        } catch (Exception e) {
+            Log.error("[FileUtil] Cannot get storage size.");
+        }
+
+        return 0;
+    }
+
+    public static void closeQuietly(AutoCloseable closeable) {
+        if (closeable != null) {
+            try {
+                closeable.close();
+            } catch (RuntimeException rethrown) {
+                throw rethrown;
+            } catch (Exception ignored) {
+            }
+        }
+    }
 }

src/android/app/src/main/java/org/citra/citra_emu/utils/ForegroundService.java

@@ -27,7 +27,7 @@ public class ForegroundService extends Service {
     private void showRunningNotification() {
         // Intent is used to resume emulation if the notification is clicked
         PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
-                new Intent(this, EmulationActivity.class), PendingIntent.FLAG_UPDATE_CURRENT);
+                new Intent(this, EmulationActivity.class), PendingIntent.FLAG_IMMUTABLE | PendingIntent.FLAG_UPDATE_CURRENT);
 
         NotificationCompat.Builder builder = new NotificationCompat.Builder(this, getString(R.string.app_notification_channel_id))
                 .setSmallIcon(R.drawable.ic_stat_notification_logo)

src/android/app/src/main/java/org/citra/citra_emu/utils/GameIconRequestHandler.java

@@ -13,12 +13,12 @@ import java.nio.IntBuffer;
 public class GameIconRequestHandler extends RequestHandler {
     @Override
     public boolean canHandleRequest(Request data) {
-        return "iso".equals(data.uri.getScheme());
+        return "content".equals(data.uri.getScheme()) || data.uri.getScheme() == null;
     }
 
     @Override
     public Result load(Request request, int networkPolicy) {
-        String url = request.uri.getHost() + request.uri.getPath();
+        String url = request.uri.toString();
         int[] vector = NativeLibrary.GetIcon(url);
         Bitmap bitmap = Bitmap.createBitmap(48, 48, Bitmap.Config.RGB_565);
         bitmap.copyPixelsFromBuffer(IntBuffer.wrap(vector));

src/android/app/src/main/java/org/citra/citra_emu/utils/PermissionsHandler.java

@@ -1,28 +1,32 @@
 package org.citra.citra_emu.utils;
 
-import android.annotation.TargetApi;
 import android.content.Context;
-import android.content.pm.PackageManager;
+import android.content.Intent;
-import android.os.Build;
+import android.content.SharedPreferences;
+import android.net.Uri;
+import android.preference.PreferenceManager;
 
-import androidx.core.content.ContextCompat;
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.annotation.Nullable;
+import androidx.documentfile.provider.DocumentFile;
 import androidx.fragment.app.FragmentActivity;
 
-import static android.Manifest.permission.WRITE_EXTERNAL_STORAGE;
+import org.citra.citra_emu.CitraApplication;
+import org.citra.citra_emu.R;
 
 public class PermissionsHandler {
-    public static final int REQUEST_CODE_WRITE_PERMISSION = 500;
+    public static final String CITRA_DIRECTORY = "CITRA_DIRECTORY";
+    public static final SharedPreferences mPreferences = PreferenceManager.getDefaultSharedPreferences(CitraApplication.getAppContext());
 
     // We use permissions acceptance as an indicator if this is a first boot for the user.
-    public static boolean isFirstBoot(final FragmentActivity activity) {
+    public static boolean isFirstBoot(FragmentActivity activity) {
-        return ContextCompat.checkSelfPermission(activity, WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED;
+        return !hasWriteAccess(activity.getApplicationContext());
     }
 
-    @TargetApi(Build.VERSION_CODES.M)
+    public static boolean checkWritePermission(FragmentActivity activity,
-    public static boolean checkWritePermission(final FragmentActivity activity) {
+                                               ActivityResultLauncher<Uri> launcher) {
         if (isFirstBoot(activity)) {
-            activity.requestPermissions(new String[]{WRITE_EXTERNAL_STORAGE},
+            launcher.launch(null);
-                    REQUEST_CODE_WRITE_PERMISSION);
             return false;
         }
 
@@ -30,6 +34,31 @@ public class PermissionsHandler {
     }
 
     public static boolean hasWriteAccess(Context context) {
-        return ContextCompat.checkSelfPermission(context, WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
+        try {
+            Uri uri = getCitraDirectory();
+            if (uri == null)
+                return false;
+            int takeFlags = (Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
+            context.getContentResolver().takePersistableUriPermission(uri, takeFlags);
+            DocumentFile root = DocumentFile.fromTreeUri(context, uri);
+            if (root != null && root.exists()) return true;
+            context.getContentResolver().releasePersistableUriPermission(uri, takeFlags);
+        } catch (Exception e) {
+            Log.error("[PermissionsHandler]: Cannot check citra data directory permission, error: " + e.getMessage());
+        }
+        return false;
+    }
+
+    @Nullable
+    public static Uri getCitraDirectory() {
+        String directoryString = mPreferences.getString(CITRA_DIRECTORY, "");
+        if (directoryString.isEmpty()) {
+            return null;
+        }
+        return Uri.parse(directoryString);
+    }
+
+    public static boolean setCitraDirectory(String uriString) {
+        return mPreferences.edit().putString(CITRA_DIRECTORY, uriString).commit();
     }
 }

src/android/app/src/main/java/org/citra/citra_emu/utils/PicassoUtils.java

@@ -31,7 +31,7 @@ public class PicassoUtils {
     public static void loadGameIcon(ImageView imageView, String gamePath) {
         Picasso
                 .get()
-                .load(Uri.parse("iso:/" + gamePath))
+                .load(Uri.parse(gamePath))
                 .fit()
                 .centerInside()
                 .config(Bitmap.Config.RGB_565)

src/android/app/src/main/java/org/citra/citra_emu/utils/StartupHandler.java

@@ -1,21 +1,23 @@
 package org.citra.citra_emu.utils;
 
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
 import android.text.TextUtils;
-
+import android.text.method.LinkMovementMethod;
+import android.widget.TextView;
+import androidx.activity.result.ActivityResultLauncher;
 import androidx.appcompat.app.AlertDialog;
 import androidx.fragment.app.FragmentActivity;
-
 import com.google.android.material.dialog.MaterialAlertDialogBuilder;
-
 import org.citra.citra_emu.R;
 import org.citra.citra_emu.activities.EmulationActivity;
 
 public final class StartupHandler {
-    private static void handlePermissionsCheck(FragmentActivity parent) {
+    private static void handlePermissionsCheck(FragmentActivity parent,
+                                               ActivityResultLauncher<Uri> launcher) {
         // Ask the user to grant write permission if it's not already granted
-        PermissionsHandler.checkWritePermission(parent);
+        PermissionsHandler.checkWritePermission(parent, launcher);
 
         String start_file = "";
         Bundle extras = parent.getIntent().getExtras();
@@ -32,16 +34,23 @@ public final class StartupHandler {
         }
     }
 
-    public static void HandleInit(FragmentActivity parent) {
+    public static void HandleInit(FragmentActivity parent, ActivityResultLauncher<Uri> launcher) {
         if (PermissionsHandler.isFirstBoot(parent)) {
             // Prompt user with standard first boot disclaimer
-            new MaterialAlertDialogBuilder(parent)
+            AlertDialog dialog =
+                new MaterialAlertDialogBuilder(parent)
                     .setTitle(R.string.app_name)
                     .setIcon(R.mipmap.ic_launcher)
-                    .setMessage(parent.getResources().getString(R.string.app_disclaimer))
+                    .setMessage(R.string.app_disclaimer)
                     .setPositiveButton(android.R.string.ok, null)
-                    .setOnDismissListener(dialogInterface -> handlePermissionsCheck(parent))
+                    .setCancelable(false)
+                    .setOnDismissListener(
+                        dialogInterface -> handlePermissionsCheck(parent, launcher))
                     .show();
+            TextView textView = dialog.findViewById(android.R.id.message);
+            if (textView == null)
+                return;
+            textView.setMovementMethod(LinkMovementMethod.getInstance());
         }
     }
 }

src/android/app/src/main/jni/config.cpp

@@ -26,7 +26,11 @@
 Config::Config() {
     // TODO: Don't hardcode the path; let the frontend decide where to put the config files.
     sdl2_config_loc = FileUtil::GetUserPath(FileUtil::UserPath::ConfigDir) + "config.ini";
-    sdl2_config = std::make_unique<INIReader>(sdl2_config_loc);
+    std::string ini_buffer;
+    FileUtil::ReadFileToString(true, sdl2_config_loc, ini_buffer);
+    if (!ini_buffer.empty()) {
+        sdl2_config = std::make_unique<INIReader>(ini_buffer.c_str(), ini_buffer.size());
+    }
 
     Reload();
 }
@@ -35,12 +39,15 @@ Config::~Config() = default;
 
 bool Config::LoadINI(const std::string& default_contents, bool retry) {
     const std::string& location = this->sdl2_config_loc;
-    if (sdl2_config->ParseError() < 0) {
+    if (sdl2_config == nullptr || sdl2_config->ParseError() < 0) {
         if (retry) {
             LOG_WARNING(Config, "Failed to load {}. Creating file from defaults...", location);
             FileUtil::CreateFullPath(location);
             FileUtil::WriteStringToFile(true, location, default_contents);
-            sdl2_config = std::make_unique<INIReader>(location); // Reopen file
+            std::string ini_buffer;
+            FileUtil::ReadFileToString(true, location, ini_buffer);
+            sdl2_config =
+                std::make_unique<INIReader>(ini_buffer.c_str(), ini_buffer.size()); // Reopen file
 
             return LoadINI(default_contents, false);
         }

src/android/app/src/main/jni/id_cache.cpp

@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include "common/android_storage.h"
 #include "common/common_paths.h"
 #include "common/logging/backend.h"
 #include "common/logging/filter.h"
@@ -159,10 +160,6 @@ jint JNI_OnLoad(JavaVM* vm, void* reserved) {
     log_filter.ParseFilterString(Settings::values.log_filter.GetValue());
     Log::SetGlobalFilter(log_filter);
     Log::AddBackend(std::make_unique<Log::LogcatBackend>());
-    FileUtil::CreateFullPath(FileUtil::GetUserPath(FileUtil::UserPath::LogDir));
-    Log::AddBackend(std::make_unique<Log::FileBackend>(
-        FileUtil::GetUserPath(FileUtil::UserPath::LogDir) + LOG_FILE));
-    LOG_INFO(Frontend, "Logging backend initialised");
 
     // Initialize misc classes
     s_savestate_info_class = reinterpret_cast<jclass>(
@@ -230,6 +227,7 @@ jint JNI_OnLoad(JavaVM* vm, void* reserved) {
     MiiSelector::InitJNI(env);
     SoftwareKeyboard::InitJNI(env);
     Camera::StillImage::InitJNI(env);
+    AndroidStorage::InitJNI(env, s_native_library_class);
 
     return JNI_VERSION;
 }
@@ -254,6 +252,7 @@ void JNI_OnUnload(JavaVM* vm, void* reserved) {
     MiiSelector::CleanupJNI(env);
     SoftwareKeyboard::CleanupJNI(env);
     Camera::StillImage::CleanupJNI(env);
+    AndroidStorage::CleanupJNI();
 }
 
 #ifdef __cplusplus

src/android/app/src/main/jni/lodepng_image_interface.cpp

@@ -3,12 +3,19 @@
 // Refer to the license.txt file included.
 
 #include <lodepng.h>
+#include "common/file_util.h"
 #include "common/logging/log.h"
 #include "jni/lodepng_image_interface.h"
 
 bool LodePNGImageInterface::DecodePNG(std::vector<u8>& dst, u32& width, u32& height,
                                       const std::string& path) {
-    u32 lodepng_ret = lodepng::decode(dst, width, height, path);
+    FileUtil::IOFile file(path, "rb");
+    size_t read_size = file.GetSize();
+    std::vector<u8> in(read_size);
+    if (file.ReadBytes(&in[0], read_size) != read_size) {
+        LOG_CRITICAL(Frontend, "Failed to decode {}", path);
+    }
+    u32 lodepng_ret = lodepng::decode(dst, width, height, in);
     if (lodepng_ret) {
         LOG_CRITICAL(Frontend, "Failed to decode {} because {}", path,
                      lodepng_error_text(lodepng_ret));
@@ -19,11 +26,19 @@ bool LodePNGImageInterface::DecodePNG(std::vector<u8>& dst, u32& width, u32& hei
 
 bool LodePNGImageInterface::EncodePNG(const std::string& path, const std::vector<u8>& src,
                                       u32 width, u32 height) {
-    u32 lodepng_ret = lodepng::encode(path, src, width, height);
+    std::vector<u8> out;
+    u32 lodepng_ret = lodepng::encode(out, src, width, height);
     if (lodepng_ret) {
         LOG_CRITICAL(Frontend, "Failed to encode {} because {}", path,
                      lodepng_error_text(lodepng_ret));
         return false;
     }
+
+    FileUtil::IOFile file(path, "wb");
+    if (file.WriteBytes(&out[0], out.size()) != out.size()) {
+        LOG_CRITICAL(Frontend, "Failed to save encode to path={}", path);
+        return false;
+    }
+
     return true;
 }

src/android/app/src/main/jni/native.cpp

@@ -12,7 +12,9 @@
 
 #include "audio_core/dsp_interface.h"
 #include "common/aarch64/cpu_detect.h"
+#include "common/common_paths.h"
 #include "common/file_util.h"
+#include "common/logging/backend.h"
 #include "common/logging/log.h"
 #include "common/microprofile.h"
 #include "common/scm_rev.h"
@@ -319,6 +321,8 @@ jobjectArray Java_org_citra_citra_1emu_NativeLibrary_GetInstalledGamePaths(
                 path += '/';
                 FileUtil::ForeachDirectoryEntry(nullptr, path, ScanDir);
             } else {
+                if (!FileUtil::Exists(path))
+                    return false;
                 auto loader = Loader::GetLoader(path);
                 if (loader) {
                     bool executable{};
@@ -492,6 +496,23 @@ void Java_org_citra_citra_1emu_NativeLibrary_CreateConfigFile(JNIEnv* env,
     Config{};
 }
 
+void Java_org_citra_citra_1emu_NativeLibrary_CreateLogFile(JNIEnv* env,
+                                                           [[maybe_unused]] jclass clazz) {
+    Log::RemoveBackend(Log::FileBackend::Name());
+    FileUtil::CreateFullPath(FileUtil::GetUserPath(FileUtil::UserPath::LogDir));
+    Log::AddBackend(std::make_unique<Log::FileBackend>(
+        FileUtil::GetUserPath(FileUtil::UserPath::LogDir) + LOG_FILE));
+    LOG_INFO(Frontend, "Logging backend initialised");
+}
+
+void Java_org_citra_citra_1emu_NativeLibrary_LogUserDirectory(JNIEnv* env,
+                                                              [[maybe_unused]] jclass clazz,
+                                                              jstring j_path) {
+    std::string_view path = env->GetStringUTFChars(j_path, 0);
+    LOG_INFO(Frontend, "User directory path: {}", path);
+    env->ReleaseStringUTFChars(j_path, path.data());
+}
+
 jint Java_org_citra_citra_1emu_NativeLibrary_DefaultCPUCore(JNIEnv* env,
                                                             [[maybe_unused]] jclass clazz) {
     return 0;

src/android/app/src/main/jni/native.h

@@ -83,6 +83,13 @@ JNIEXPORT void JNICALL Java_org_citra_citra_1emu_NativeLibrary_SetSysDirectory(J
 JNIEXPORT void JNICALL Java_org_citra_citra_1emu_NativeLibrary_CreateConfigFile(JNIEnv* env,
                                                                                 jclass clazz);
 
+JNIEXPORT void JNICALL Java_org_citra_citra_1emu_NativeLibrary_CreateLogFile(JNIEnv* env,
+                                                                             jclass clazz);
+
+JNIEXPORT void JNICALL Java_org_citra_citra_1emu_NativeLibrary_LogUserDirectory(JNIEnv* env,
+                                                                                jclass clazz,
+                                                                                jstring path);
+
 JNIEXPORT jint JNICALL Java_org_citra_citra_1emu_NativeLibrary_DefaultCPUCore(JNIEnv* env,
                                                                               jclass clazz);
 JNIEXPORT void JNICALL Java_org_citra_citra_1emu_NativeLibrary_SetProfiling(JNIEnv* env,

src/android/app/src/main/res/layout/dialog_citra_directory.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:orientation="vertical">
+
+    <TextView
+        android:textSize="@dimen/text_medium"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="@dimen/spacing_medlarge"
+        android:layout_marginLeft="@dimen/spacing_large"
+        android:layout_marginRight="@dimen/spacing_large"
+        android:text="@string/select_citra_user_folder" />
+
+    <TextView
+        android:id="@+id/path"
+        android:textSize="@dimen/text_medium"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="@dimen/spacing_small"
+        android:layout_marginLeft="@dimen/spacing_large"
+        android:layout_marginRight="@dimen/spacing_large"
+        android:text="@string/fatal_error" />
+
+    <TextView
+        android:id="@+id/space"
+        android:textSize="@dimen/text_medium"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="@dimen/spacing_small"
+        android:layout_marginLeft="@dimen/spacing_large"
+        android:layout_marginRight="@dimen/spacing_large"
+        android:text="@string/free_space" />
+
+    <CheckBox
+        android:id="@+id/checkBox"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="@dimen/spacing_small"
+        android:layout_marginLeft="@dimen/spacing_large"
+        android:layout_marginRight="@dimen/spacing_large"
+        android:text="@string/move_data" />
+</LinearLayout>

src/android/app/src/main/res/layout/filepicker_toolbar.xml

@@ -1,32 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<androidx.appcompat.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
-    android:id="@+id/nnf_picker_toolbar"
-    android:layout_width="match_parent"
-    android:layout_height="wrap_content"
-    android:layout_alignParentTop="true"
-    android:background="?attr/colorPrimary"
-    android:minHeight="?attr/actionBarSize"
-    android:theme="?nnf_toolbarTheme">
-
-    <LinearLayout
-        android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:orientation="vertical">
-
-        <TextView
-            android:id="@+id/filepicker_title"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:ellipsize="start"
-            android:singleLine="true"
-            android:textAppearance="@style/TextAppearance.AppCompat.Widget.ActionBar.Title" />
-
-        <TextView
-            android:id="@+id/nnf_current_dir"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:ellipsize="start"
-            android:singleLine="true"
-            android:textAppearance="@style/TextAppearance.AppCompat.Widget.ActionBar.Subtitle" />
-    </LinearLayout>
-</androidx.appcompat.widget.Toolbar>

src/android/app/src/main/res/menu/menu_game_grid.xml

@@ -13,6 +13,11 @@
         android:title="@string/select_game_folder"
         app:showAsAction="ifRoom">
         <menu>
+            <item
+                android:id="@+id/button_select_root"
+                android:icon="@drawable/ic_folder"
+                android:title="@string/select_citra_user_folder"
+                app:showAsAction="ifRoom" />
             <item
                 android:id="@+id/button_add_directory"
                 android:icon="@drawable/ic_folder"

src/android/app/src/main/res/values-de/strings.xml

@@ -98,7 +98,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">Spieleordner auswählen</string>
-    <string name="add_directory_title">Ordner zur Bibliothek hinzufügen</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">Einstellungen</string>

src/android/app/src/main/res/values-es/strings.xml

@@ -102,7 +102,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">Seleccionar Directorio de Juego</string>
-    <string name="add_directory_title">Añadir Carpeta a la Librería de Juegos</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">Configuración</string>

src/android/app/src/main/res/values-fi/strings.xml

@@ -63,7 +63,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">Valitse pelikansio</string>
-    <string name="add_directory_title">Lisää kansio kirjastoosi</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">Asetukset</string>

src/android/app/src/main/res/values-fr/strings.xml

@@ -98,7 +98,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">Choisir un répertoire de jeu</string>
-    <string name="add_directory_title">Ajouter un répertoire à la bibliothèque</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">Paramètres</string>

src/android/app/src/main/res/values-it/strings.xml

@@ -98,7 +98,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">Seleziona Cartella di Gioco</string>
-    <string name="add_directory_title">Aggiungi una Cartella alla Libreria</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">Impostazioni</string>

src/android/app/src/main/res/values-ja/strings.xml

@@ -66,7 +66,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">ゲームフォルダを選択</string>
-    <string name="add_directory_title">ライブラリにフォルダを追加</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">設定</string>

src/android/app/src/main/res/values-ko/strings.xml

@@ -100,7 +100,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">게임 폴더 선택</string>
-    <string name="add_directory_title">폴더를 라이브러리에 추가</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">설정</string>

src/android/app/src/main/res/values-nb/strings.xml

@@ -98,7 +98,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">Velg Spill Mappe</string>
-    <string name="add_directory_title">Lett til Mappe til Bibliotek </string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">Innstillinger </string>

src/android/app/src/main/res/values-night/styles_filepicker.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<resources>
-
-    <style name="FilePickerBaseTheme" parent="NNF_BaseTheme" />
-</resources>

src/android/app/src/main/res/values-pt/strings.xml

@@ -98,7 +98,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">Escolher pasta de jogos</string>
-    <string name="add_directory_title">Adicionar pasta à biblioteca</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">Configurações</string>

src/android/app/src/main/res/values-zh/strings.xml

@@ -98,7 +98,6 @@
 
     <!-- Add Directory Screen-->
     <string name="select_game_folder">选择游戏目录</string>
-    <string name="add_directory_title">添加文件夹到库中</string>
 
     <!-- Preferences Screen -->
     <string name="preferences_settings">设置</string>

src/android/app/src/main/res/values/dimens.xml

@@ -1,6 +1,7 @@
 <resources>
     <!-- Default screen margins, per the Android Design guidelines. -->
     <dimen name="activity_horizontal_margin">16dp</dimen>
+    <dimen name="text_medium">18dp</dimen>
 
     <dimen name="spacing_small">4dp</dimen>
     <dimen name="spacing_medlarge">12dp</dimen>

src/android/app/src/main/res/values/strings.xml

@@ -3,11 +3,12 @@
 
     <!-- General application strings -->
     <string name="app_name" translatable="false">Citra</string>
-    <string name="app_disclaimer">This software will run games for the Nintendo 3DS handheld game console. No game titles are included.\n\nBefore you run, please place your rightfully owned 3DS game files onto your device storage.</string>
+    <string name="app_disclaimer">This software will run games for the Nintendo 3DS handheld game console. No game titles are included.\n\nBefore you can begin with emulating, please select a folder to store Citra\'s user data in.\n\nWhat\'s this:\n<a href='https://github.com/citra-emu/citra/wiki/Citra-Android-user-data-and-storage'>Wiki - Citra Android user data and storage</a></string>
     <string name="app_notification_channel_name" translatable="false">Citra</string>
     <string name="app_notification_channel_id" translatable="false">Citra</string>
     <string name="app_notification_channel_description">Citra 3DS emulator notifications</string>
     <string name="app_notification_running">Citra is running</string>
+    <string name="app_game_install_description">Next, you will need to select a Game Folder. Citra will display all of the 3DS ROMs inside of the selected folder in the app.\n\nCIA ROMs, updates and DLC will need to be installed separately by clicking on the folder icon and selecting Install CIA.</string>
 
     <!-- Input related strings -->
     <string name="controller_circlepad">Circle Pad</string>
@@ -138,6 +139,7 @@
     <string name="grid_menu_core_settings">Settings</string>
 
     <!-- Add Directory Screen-->
+    <string name="select_citra_user_folder">Select Citra User Folder</string>
     <string name="select_game_folder">Select Game Folder</string>
     <string name="install_cia_title">Install CIA</string>
 
@@ -198,6 +200,10 @@
     <string name="empty_gamelist">No files were found or no game directory has been selected yet.</string>
 
     <string name="do_not_show_this_again">Do not show this again</string>
+    <string name="searching_direcotry">Searching directory: %s</string>
+    <string name="move_data">Move Data</string>
+    <string name="copy_file_name">Copy file: %s</string>
+    <string name="free_space">Free space: %.2f GB</string>
     <string name="savestate_warning_title">Savestates</string>
     <string name="savestate_warning_message">Warning: Savestates are NOT a replacement for in-game saves, and are not meant to be reliable.\n\nUse at your own risk!</string>
 
@@ -227,6 +233,7 @@
     <string name="continue_button">Continue</string>
     <string name="system_archive_not_found">System Archive Not Found</string>
     <string name="system_archive_not_found_message">%s is missing. Please dump your system archives.\nContinuing emulation may result in crashes and bugs.</string>
+    <string name="cia_file_not_found">Installation Failed. CIA file not found.</string>
     <string name="system_archive_general">A system archive</string>
     <string name="save_load_error">Save/Load Error</string>
     <string name="fatal_error">Fatal Error</string>

src/android/app/src/main/res/values/styles.xml

@@ -1,12 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 
-    <style name="FilePickerAlertDialogTheme" parent="Theme.AppCompat.DayNight.Dialog.Alert">
-        <item name="colorPrimary">@color/citra_primary</item>
-        <item name="colorPrimaryDark">@color/citra_secondary</item>
-        <item name="colorAccent">@color/citra_primaryContainer</item>
-    </style>
-
     <style name="CitraMaterialDialog" parent="ThemeOverlay.Material3.MaterialAlertDialog">
         <item name="colorPrimary">@color/citra_surface</item>
         <item name="colorSurface">@color/citra_surface</item>

src/android/app/src/main/res/values/styles_filepicker.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<resources>
-
-    <style name="FilePickerBaseTheme" parent="NNF_BaseTheme.Light" />
-</resources>

src/android/app/src/main/res/values/themes.xml

@@ -1,6 +1,13 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
 
+    <style name="Theme.Citra.Splash.Main" parent="Theme.SplashScreen">
+        <item name="windowSplashScreenBackground">@color/citra_surface</item>
+        <item name="windowSplashScreenAnimatedIcon">@drawable/ic_citra</item>
+        <item name="postSplashScreenTheme">@style/Theme.Citra.Main</item>
+    </style>
+
+
     <style name="Theme.Citra.Main" parent="Theme.Material3.DayNight.NoActionBar">
         <!-- Main theme colors -->
         <item name="colorPrimary">@color/citra_primary</item>
@@ -39,17 +46,4 @@
         <item name="sliderStyle">@style/CitraSlider</item>
     </style>
 
-    <!-- Inherit from a base file picker theme that handles day/night -->
-    <style name="FilePickerTheme" parent="FilePickerBaseTheme">
-        <item name="colorPrimary">@color/citra_primary</item>
-        <item name="colorPrimaryDark">@color/citra_primary</item>
-        <item name="colorAccent">@color/citra_primary</item>
-
-        <!-- Need to set this also to style create folder dialog -->
-        <item name="alertDialogTheme">@style/FilePickerAlertDialogTheme</item>
-
-        <item name="nnf_list_item_divider">@drawable/gamelist_divider</item>
-        <item name="nnf_toolbarTheme">@style/ThemeOverlay.AppCompat.DayNight.ActionBar</item>
-    </style>
-
 </resources>

src/common/CMakeLists.txt

@@ -57,6 +57,8 @@ add_library(common STATIC
     aarch64/cpu_detect.cpp
     aarch64/cpu_detect.h
     alignment.h
+    android_storage.h
+    android_storage.cpp
     announce_multiplayer_room.h
     arch.h
     archives.h
@@ -137,7 +139,7 @@ add_library(common STATIC
 
 create_target_directory_groups(common)
 
-target_link_libraries(common PUBLIC fmt::fmt microprofile Boost::boost Boost::serialization)
+target_link_libraries(common PUBLIC fmt::fmt microprofile Boost::boost Boost::serialization Boost::iostreams)
 target_link_libraries(common PRIVATE libzstd_static)
 set_target_properties(common PROPERTIES INTERPROCEDURAL_OPTIMIZATION ${ENABLE_LTO})
 

src/common/android_storage.cpp

@@ -0,0 +1,190 @@
+// Copyright 2023 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#ifdef ANDROID
+#include "common/android_storage.h"
+
+namespace AndroidStorage {
+JNIEnv* GetEnvForThread() {
+    thread_local static struct OwnedEnv {
+        OwnedEnv() {
+            status = g_jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6);
+            if (status == JNI_EDETACHED)
+                g_jvm->AttachCurrentThread(&env, nullptr);
+        }
+
+        ~OwnedEnv() {
+            if (status == JNI_EDETACHED)
+                g_jvm->DetachCurrentThread();
+        }
+
+        int status;
+        JNIEnv* env = nullptr;
+    } owned;
+    return owned.env;
+}
+
+AndroidOpenMode ParseOpenmode(const std::string_view openmode) {
+    AndroidOpenMode android_open_mode = AndroidOpenMode::NEVER;
+    const char* mode = openmode.data();
+    int o = 0;
+    switch (*mode++) {
+    case 'r':
+        android_open_mode = AndroidStorage::AndroidOpenMode::READ;
+        break;
+    case 'w':
+        android_open_mode = AndroidStorage::AndroidOpenMode::WRITE;
+        o = O_TRUNC;
+        break;
+    case 'a':
+        android_open_mode = AndroidStorage::AndroidOpenMode::WRITE;
+        o = O_APPEND;
+        break;
+    }
+
+    // [rwa]\+ or [rwa]b\+ means read and write
+    if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) {
+        android_open_mode = AndroidStorage::AndroidOpenMode::READ_WRITE;
+    }
+
+    return android_open_mode | o;
+}
+
+void InitJNI(JNIEnv* env, jclass clazz) {
+    env->GetJavaVM(&g_jvm);
+    native_library = clazz;
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature)                   \
+    F(JMethodID, JMethodName, Signature)
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature)               \
+    F(JMethodID, JMethodName, Signature)
+#define F(JMethodID, JMethodName, Signature)                                                       \
+    JMethodID = env->GetStaticMethodID(native_library, JMethodName, Signature);
+    ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+    ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+#undef FR
+}
+
+void CleanupJNI() {
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature) F(JMethodID)
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature) F(JMethodID)
+#define F(JMethodID) JMethodID = nullptr;
+    ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+    ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+#undef FR
+}
+
+bool CreateFile(const std::string& directory, const std::string& filename) {
+    if (create_file == nullptr)
+        return false;
+    auto env = GetEnvForThread();
+    jstring j_directory = env->NewStringUTF(directory.c_str());
+    jstring j_filename = env->NewStringUTF(filename.c_str());
+    return env->CallStaticBooleanMethod(native_library, create_file, j_directory, j_filename);
+}
+
+bool CreateDir(const std::string& directory, const std::string& filename) {
+    if (create_dir == nullptr)
+        return false;
+    auto env = GetEnvForThread();
+    jstring j_directory = env->NewStringUTF(directory.c_str());
+    jstring j_directory_name = env->NewStringUTF(filename.c_str());
+    return env->CallStaticBooleanMethod(native_library, create_dir, j_directory, j_directory_name);
+}
+
+int OpenContentUri(const std::string& filepath, AndroidOpenMode openmode) {
+    if (open_content_uri == nullptr)
+        return -1;
+
+    const char* mode = "";
+    switch (openmode) {
+    case AndroidOpenMode::READ:
+        mode = "r";
+        break;
+    case AndroidOpenMode::WRITE:
+        mode = "w";
+        break;
+    case AndroidOpenMode::READ_WRITE:
+        mode = "rw";
+        break;
+    case AndroidOpenMode::WRITE_TRUNCATE:
+        mode = "wt";
+        break;
+    case AndroidOpenMode::WRITE_APPEND:
+        mode = "wa";
+        break;
+    case AndroidOpenMode::READ_WRITE_APPEND:
+        mode = "rwa";
+        break;
+    case AndroidOpenMode::READ_WRITE_TRUNCATE:
+        mode = "rwt";
+        break;
+    case AndroidOpenMode::NEVER:
+        return -1;
+    }
+    auto env = GetEnvForThread();
+    jstring j_filepath = env->NewStringUTF(filepath.c_str());
+    jstring j_mode = env->NewStringUTF(mode);
+    return env->CallStaticIntMethod(native_library, open_content_uri, j_filepath, j_mode);
+}
+
+std::vector<std::string> GetFilesName(const std::string& filepath) {
+    auto vector = std::vector<std::string>();
+    if (get_files_name == nullptr)
+        return vector;
+    auto env = GetEnvForThread();
+    jstring j_filepath = env->NewStringUTF(filepath.c_str());
+    auto j_object =
+        (jobjectArray)env->CallStaticObjectMethod(native_library, get_files_name, j_filepath);
+    jsize j_size = env->GetArrayLength(j_object);
+    for (int i = 0; i < j_size; i++) {
+        auto string = (jstring)(env->GetObjectArrayElement(j_object, i));
+        vector.emplace_back(env->GetStringUTFChars(string, nullptr));
+    }
+    return vector;
+}
+
+bool CopyFile(const std::string& source, const std::string& destination_path,
+              const std::string& destination_filename) {
+    if (copy_file == nullptr)
+        return false;
+    auto env = GetEnvForThread();
+    jstring j_source_path = env->NewStringUTF(source.c_str());
+    jstring j_destination_path = env->NewStringUTF(destination_path.c_str());
+    jstring j_destination_filename = env->NewStringUTF(destination_filename.c_str());
+    return env->CallStaticBooleanMethod(native_library, copy_file, j_source_path,
+                                        j_destination_path, j_destination_filename);
+}
+
+bool RenameFile(const std::string& source, const std::string& filename) {
+    if (rename_file == nullptr)
+        return false;
+    auto env = GetEnvForThread();
+    jstring j_source_path = env->NewStringUTF(source.c_str());
+    jstring j_destination_path = env->NewStringUTF(filename.c_str());
+    return env->CallStaticBooleanMethod(native_library, rename_file, j_source_path,
+                                        j_destination_path);
+}
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature)                   \
+    F(FunctionName, ReturnValue, JMethodID, Caller)
+#define F(FunctionName, ReturnValue, JMethodID, Caller)                                            \
+    ReturnValue FunctionName(const std::string& filepath) {                                        \
+        if (JMethodID == nullptr) {                                                                \
+            return 0;                                                                              \
+        }                                                                                          \
+        auto env = GetEnvForThread();                                                              \
+        jstring j_filepath = env->NewStringUTF(filepath.c_str());                                  \
+        return env->Caller(native_library, JMethodID, j_filepath);                                 \
+    }
+ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+#undef F
+#undef FR
+
+} // namespace AndroidStorage
+#endif

src/common/android_storage.h

@@ -0,0 +1,84 @@
+// Copyright 2023 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#ifdef ANDROID
+#include <string>
+#include <vector>
+#include <fcntl.h>
+#include <jni.h>
+
+#define ANDROID_STORAGE_FUNCTIONS(V)                                                               \
+    V(CreateFile, bool, (const std::string& directory, const std::string& filename), create_file,  \
+      "createFile", "(Ljava/lang/String;Ljava/lang/String;)Z")                                     \
+    V(CreateDir, bool, (const std::string& directory, const std::string& filename), create_dir,    \
+      "createDir", "(Ljava/lang/String;Ljava/lang/String;)Z")                                      \
+    V(OpenContentUri, int, (const std::string& filepath, AndroidOpenMode openmode),                \
+      open_content_uri, "openContentUri", "(Ljava/lang/String;Ljava/lang/String;)I")               \
+    V(GetFilesName, std::vector<std::string>, (const std::string& filepath), get_files_name,       \
+      "getFilesName", "(Ljava/lang/String;)[Ljava/lang/String;")                                   \
+    V(CopyFile, bool,                                                                              \
+      (const std::string& source, const std::string& destination_path,                             \
+       const std::string& destination_filename),                                                   \
+      copy_file, "copyFile", "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Z")          \
+    V(RenameFile, bool, (const std::string& source, const std::string& filename), rename_file,     \
+      "renameFile", "(Ljava/lang/String;Ljava/lang/String;)Z")
+#define ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(V)                                                 \
+    V(IsDirectory, bool, is_directory, CallStaticBooleanMethod, "isDirectory",                     \
+      "(Ljava/lang/String;)Z")                                                                     \
+    V(FileExists, bool, file_exists, CallStaticBooleanMethod, "fileExists",                        \
+      "(Ljava/lang/String;)Z")                                                                     \
+    V(GetSize, std::uint64_t, get_size, CallStaticLongMethod, "getSize", "(Ljava/lang/String;)J")  \
+    V(DeleteDocument, bool, delete_document, CallStaticBooleanMethod, "deleteDocument",            \
+      "(Ljava/lang/String;)Z")
+namespace AndroidStorage {
+static JavaVM* g_jvm = nullptr;
+static jclass native_library = nullptr;
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature) F(JMethodID)
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature) F(JMethodID)
+#define F(JMethodID) static jmethodID JMethodID = nullptr;
+ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+#undef FR
+// Reference:
+// https://developer.android.com/reference/android/os/ParcelFileDescriptor#parseMode(java.lang.String)
+enum class AndroidOpenMode {
+    READ = O_RDONLY,                        // "r"
+    WRITE = O_WRONLY,                       // "w"
+    READ_WRITE = O_RDWR,                    // "rw"
+    WRITE_APPEND = O_WRONLY | O_APPEND,     // "wa"
+    WRITE_TRUNCATE = O_WRONLY | O_TRUNC,    // "wt
+    READ_WRITE_APPEND = O_RDWR | O_APPEND,  // "rwa"
+    READ_WRITE_TRUNCATE = O_RDWR | O_TRUNC, // "rwt"
+    NEVER = EINVAL,
+};
+
+inline AndroidOpenMode operator|(AndroidOpenMode a, int b) {
+    return static_cast<AndroidOpenMode>(static_cast<int>(a) | b);
+}
+
+AndroidOpenMode ParseOpenmode(const std::string_view openmode);
+
+void InitJNI(JNIEnv* env, jclass clazz);
+
+void CleanupJNI();
+
+#define FS(FunctionName, ReturnValue, Parameters, JMethodID, JMethodName, Signature)               \
+    F(FunctionName, Parameters, ReturnValue)
+#define F(FunctionName, Parameters, ReturnValue) ReturnValue FunctionName Parameters;
+ANDROID_STORAGE_FUNCTIONS(FS)
+#undef F
+#undef FS
+
+#define FR(FunctionName, ReturnValue, JMethodID, Caller, JMethodName, Signature)                   \
+    F(FunctionName, ReturnValue)
+#define F(FunctionName, ReturnValue) ReturnValue FunctionName(const std::string& filepath);
+ANDROID_SINGLE_PATH_DETERMINE_FUNCTIONS(FR)
+#undef F
+#undef FR
+} // namespace AndroidStorage
+#endif

src/common/common_paths.h

@@ -24,10 +24,6 @@
 #define MACOS_EMU_DATA_DIR "Library" DIR_SEP "Application Support" DIR_SEP "Citra"
 // For compatibility with XDG paths.
 #define EMU_DATA_DIR "citra-emu"
-#elif ANDROID
-// On Android internal storage is mounted as "/sdcard"
-#define SDCARD_DIR "sdcard"
-#define EMU_DATA_DIR "citra-emu"
 #else
 #define EMU_DATA_DIR "citra-emu"
 #endif

src/common/file_util.cpp

@@ -7,6 +7,8 @@
 #include <memory>
 #include <sstream>
 #include <unordered_map>
+#include <boost/iostreams/device/file_descriptor.hpp>
+#include <boost/iostreams/stream.hpp>
 #include "common/assert.h"
 #include "common/common_funcs.h"
 #include "common/common_paths.h"
@@ -66,6 +68,11 @@
 
 #endif
 
+#ifdef ANDROID
+#include "common/android_storage.h"
+#include "common/string_util.h"
+#endif
+
 #include <algorithm>
 #include <sys/stat.h>
 
@@ -104,6 +111,8 @@ bool Exists(const std::string& filename) {
         copy += DIR_SEP_CHR;
 
     int result = _wstat64(Common::UTF8ToUTF16W(copy).c_str(), &file_info);
+#elif ANDROID
+    int result = AndroidStorage::FileExists(filename) ? 0 : -1;
 #else
     int result = stat(copy.c_str(), &file_info);
 #endif
@@ -112,6 +121,10 @@ bool Exists(const std::string& filename) {
 }
 
 bool IsDirectory(const std::string& filename) {
+#ifdef ANDROID
+    return AndroidStorage::IsDirectory(filename);
+#endif
+
     struct stat file_info;
 
     std::string copy(filename);
@@ -156,6 +169,11 @@ bool Delete(const std::string& filename) {
         LOG_ERROR(Common_Filesystem, "DeleteFile failed on {}: {}", filename, GetLastErrorMsg());
         return false;
     }
+#elif ANDROID
+    if (!AndroidStorage::DeleteDocument(filename)) {
+        LOG_ERROR(Common_Filesystem, "unlink failed on {}", filename);
+        return false;
+    }
 #else
     if (unlink(filename.c_str()) == -1) {
         LOG_ERROR(Common_Filesystem, "unlink failed on {}: {}", filename, GetLastErrorMsg());
@@ -178,6 +196,24 @@ bool CreateDir(const std::string& path) {
     }
     LOG_ERROR(Common_Filesystem, "CreateDirectory failed on {}: {}", path, error);
     return false;
+#elif ANDROID
+    std::string directory = path;
+    std::string filename = path;
+    if (Common::EndsWith(path, "/")) {
+        directory = GetParentPath(path);
+        filename = GetParentPath(path);
+    }
+    directory = GetParentPath(directory);
+    filename = GetFilename(filename);
+    // If directory path is empty, set it to root.
+    if (directory.empty()) {
+        directory = "/";
+    }
+    if (!AndroidStorage::CreateDir(directory, filename)) {
+        LOG_ERROR(Common_Filesystem, "mkdir failed on {}", path);
+        return false;
+    };
+    return true;
 #else
     if (mkdir(path.c_str(), 0755) == 0)
         return true;
@@ -241,6 +277,9 @@ bool DeleteDir(const std::string& filename) {
 #ifdef _WIN32
     if (::RemoveDirectoryW(Common::UTF8ToUTF16W(filename).c_str()))
         return true;
+#elif ANDROID
+    if (AndroidStorage::DeleteDocument(filename))
+        return true;
 #else
     if (rmdir(filename.c_str()) == 0)
         return true;
@@ -256,6 +295,9 @@ bool Rename(const std::string& srcFilename, const std::string& destFilename) {
     if (_wrename(Common::UTF8ToUTF16W(srcFilename).c_str(),
                  Common::UTF8ToUTF16W(destFilename).c_str()) == 0)
         return true;
+#elif ANDROID
+    if (AndroidStorage::RenameFile(srcFilename, std::string(GetFilename(destFilename))))
+        return true;
 #else
     if (rename(srcFilename.c_str(), destFilename.c_str()) == 0)
         return true;
@@ -275,6 +317,9 @@ bool Copy(const std::string& srcFilename, const std::string& destFilename) {
     LOG_ERROR(Common_Filesystem, "failed {} --> {}: {}", srcFilename, destFilename,
               GetLastErrorMsg());
     return false;
+#elif ANDROID
+    return AndroidStorage::CopyFile(srcFilename, std::string(GetParentPath(destFilename)),
+                                    std::string(GetFilename(destFilename)));
 #else
     using CFilePointer = std::unique_ptr<FILE, decltype(&std::fclose)>;
 
@@ -334,6 +379,10 @@ u64 GetSize(const std::string& filename) {
     struct stat buf;
 #ifdef _WIN32
     if (_wstat64(Common::UTF8ToUTF16W(filename).c_str(), &buf) == 0)
+#elif ANDROID
+    u64 result = AndroidStorage::GetSize(filename);
+    LOG_TRACE(Common_Filesystem, "{}: {}", filename, result);
+    return result;
 #else
     if (stat(filename.c_str(), &buf) == 0)
 #endif
@@ -403,6 +452,10 @@ bool ForeachDirectoryEntry(u64* num_entries_out, const std::string& directory,
     // windows loop
     do {
         const std::string virtual_name(Common::UTF16ToUTF8(ffd.cFileName));
+#elif ANDROID
+    // android loop
+    auto result = AndroidStorage::GetFilesName(directory);
+    for (auto virtual_name : result) {
 #else
     DIR* dirp = opendir(directory.c_str());
     if (!dirp)
@@ -426,6 +479,8 @@ bool ForeachDirectoryEntry(u64* num_entries_out, const std::string& directory,
 #ifdef _WIN32
     } while (FindNextFileW(handle_find, &ffd) != 0);
     FindClose(handle_find);
+#elif ANDROID
+    }
 #else
     }
     closedir(dirp);
@@ -514,12 +569,18 @@ void CopyDir(const std::string& source_path, const std::string& dest_path) {
     if (!FileUtil::Exists(dest_path))
         FileUtil::CreateFullPath(dest_path);
 
+#ifdef ANDROID
+    auto result = AndroidStorage::GetFilesName(source_path);
+    for (auto virtualName : result) {
+#else
     DIR* dirp = opendir(source_path.c_str());
     if (!dirp)
         return;
 
     while (struct dirent* result = readdir(dirp)) {
         const std::string virtualName(result->d_name);
+#endif // ANDROID
+
         // check for "." and ".."
         if (((virtualName[0] == '.') && (virtualName[1] == '\0')) ||
             ((virtualName[0] == '.') && (virtualName[1] == '.') && (virtualName[2] == '\0')))
@@ -537,8 +598,11 @@ void CopyDir(const std::string& source_path, const std::string& dest_path) {
         } else if (!FileUtil::Exists(dest))
             FileUtil::Copy(source, dest);
     }
+
+#ifndef ANDROID
     closedir(dirp);
-#endif
+#endif // ANDROID
+#endif // _WIN32
 }
 
 std::optional<std::string> GetCurrentDir() {
@@ -698,11 +762,9 @@ void SetUserPath(const std::string& path) {
         g_paths.emplace(UserPath::ConfigDir, user_path + CONFIG_DIR DIR_SEP);
         g_paths.emplace(UserPath::CacheDir, user_path + CACHE_DIR DIR_SEP);
 #elif ANDROID
-        if (FileUtil::Exists(DIR_SEP SDCARD_DIR)) {
+        user_path = "/";
-            user_path = DIR_SEP SDCARD_DIR DIR_SEP EMU_DATA_DIR DIR_SEP;
+        g_paths.emplace(UserPath::ConfigDir, user_path + CONFIG_DIR DIR_SEP);
-            g_paths.emplace(UserPath::ConfigDir, user_path + CONFIG_DIR DIR_SEP);
+        g_paths.emplace(UserPath::CacheDir, user_path + CACHE_DIR DIR_SEP);
-            g_paths.emplace(UserPath::CacheDir, user_path + CACHE_DIR DIR_SEP);
-        }
 #else
         if (FileUtil::Exists(ROOT_DIR DIR_SEP USERDATA_DIR)) {
             user_path = ROOT_DIR DIR_SEP USERDATA_DIR DIR_SEP;
@@ -929,6 +991,9 @@ std::string_view RemoveTrailingSlash(std::string_view path) {
 
 std::string SanitizePath(std::string_view path_, DirectorySeparator directory_separator) {
     std::string path(path_);
+#ifdef ANDROID
+    return std::string(RemoveTrailingSlash(path));
+#endif
     char type1 = directory_separator == DirectorySeparator::BackwardSlash ? '/' : '\\';
     char type2 = directory_separator == DirectorySeparator::BackwardSlash ? '\\' : '/';
 
@@ -975,6 +1040,7 @@ IOFile& IOFile::operator=(IOFile&& other) noexcept {
 
 void IOFile::Swap(IOFile& other) noexcept {
     std::swap(m_file, other.m_file);
+    std::swap(m_fd, other.m_fd);
     std::swap(m_good, other.m_good);
     std::swap(filename, other.filename);
     std::swap(openmode, other.openmode);
@@ -993,6 +1059,36 @@ bool IOFile::Open() {
         m_good = _wfopen_s(&m_file, Common::UTF8ToUTF16W(filename).c_str(),
                            Common::UTF8ToUTF16W(openmode).c_str()) == 0;
     }
+#elif ANDROID
+    // Check whether filepath is startsWith content
+    AndroidStorage::AndroidOpenMode android_open_mode = AndroidStorage::ParseOpenmode(openmode);
+    if (android_open_mode == AndroidStorage::AndroidOpenMode::WRITE ||
+        android_open_mode == AndroidStorage::AndroidOpenMode::READ_WRITE ||
+        android_open_mode == AndroidStorage::AndroidOpenMode::WRITE_APPEND ||
+        android_open_mode == AndroidStorage::AndroidOpenMode::WRITE_TRUNCATE ||
+        android_open_mode == AndroidStorage::AndroidOpenMode::READ_WRITE_TRUNCATE ||
+        android_open_mode == AndroidStorage::AndroidOpenMode::READ_WRITE_APPEND) {
+        if (!FileUtil::Exists(filename)) {
+            std::string directory(GetParentPath(filename));
+            std::string display_name(GetFilename(filename));
+            if (!AndroidStorage::CreateFile(directory, display_name)) {
+                m_good = m_file != nullptr;
+                return m_good;
+            }
+        }
+    }
+    m_fd = AndroidStorage::OpenContentUri(filename, android_open_mode);
+    if (m_fd != -1) {
+        int error_num = 0;
+        m_file = fdopen(m_fd, openmode.c_str());
+        error_num = errno;
+        if (error_num != 0 && m_file == nullptr) {
+            LOG_ERROR(Common_Filesystem, "Error on file: {}, error: {}", filename,
+                      strerror(error_num));
+        }
+    }
+
+    m_good = m_file != nullptr;
 #else
     m_file = std::fopen(filename.c_str(), openmode.c_str());
     m_good = m_file != nullptr;
@@ -1083,4 +1179,30 @@ bool IOFile::Resize(u64 size) {
     return m_good;
 }
 
+template <typename T>
+using boost_iostreams = boost::iostreams::stream<T>;
+
+template <>
+void OpenFStream<std::ios_base::in>(
+    boost_iostreams<boost::iostreams::file_descriptor_source>& fstream,
+    const std::string& filename) {
+    IOFile file(filename, "r");
+    int fd = dup(file.GetFd());
+    if (fd == -1)
+        return;
+    boost::iostreams::file_descriptor_source file_descriptor_source(fd,
+                                                                    boost::iostreams::close_handle);
+    fstream.open(file_descriptor_source);
+}
+
+template <>
+void OpenFStream<std::ios_base::out>(
+    boost_iostreams<boost::iostreams::file_descriptor_sink>& fstream, const std::string& filename) {
+    IOFile file(filename, "w");
+    int fd = dup(file.GetFd());
+    if (fd == -1)
+        return;
+    boost::iostreams::file_descriptor_sink file_descriptor_sink(fd, boost::iostreams::close_handle);
+    fstream.open(file_descriptor_sink);
+}
 } // namespace FileUtil

src/common/file_util.h

@@ -336,6 +336,15 @@ public:
     [[nodiscard]] bool IsGood() const {
         return m_good;
     }
+    [[nodiscard]] int GetFd() const {
+#ifdef ANDROID
+        return m_fd;
+#else
+        if (m_file == nullptr)
+            return -1;
+        return fileno(m_file);
+#endif
+    }
     [[nodiscard]] explicit operator bool() const {
         return IsGood();
     }
@@ -359,6 +368,7 @@ private:
     bool Open();
 
     std::FILE* m_file = nullptr;
+    int m_fd = -1;
     bool m_good = true;
 
     std::string filename;
@@ -383,6 +393,8 @@ private:
     friend class boost::serialization::access;
 };
 
+template <std::ios_base::openmode o, typename T>
+void OpenFStream(T& fstream, const std::string& filename);
 } // namespace FileUtil
 
 // To deal with Windows being dumb at unicode:

src/common/string_util.cpp

@@ -123,6 +123,12 @@ std::string TabsToSpaces(int tab_size, std::string in) {
     return in;
 }
 
+bool EndsWith(const std::string& value, const std::string& ending) {
+    if (ending.size() > value.size())
+        return false;
+    return std::equal(ending.rbegin(), ending.rend(), value.rbegin());
+}
+
 std::string ReplaceAll(std::string result, const std::string& src, const std::string& dest) {
     std::size_t pos = 0;
 

src/common/string_util.h

@@ -27,6 +27,8 @@ namespace Common {
 
 [[nodiscard]] std::string TabsToSpaces(int tab_size, std::string in);
 
+[[nodiscard]] bool EndsWith(const std::string& value, const std::string& ending);
+
 void SplitString(const std::string& str, char delim, std::vector<std::string>& output);
 
 // "C:/Windows/winhelp.exe" to "C:/Windows/", "winhelp", ".exe"

src/core/CMakeLists.txt

@@ -477,7 +477,7 @@ endif()
 create_target_directory_groups(core)
 
 target_link_libraries(core PUBLIC common PRIVATE audio_core network video_core)
-target_link_libraries(core PUBLIC Boost::boost PRIVATE cryptopp fmt::fmt open_source_archives Boost::serialization)
+target_link_libraries(core PUBLIC Boost::boost PRIVATE cryptopp fmt::fmt open_source_archives Boost::serialization Boost::iostreams)
 set_target_properties(core PROPERTIES INTERPROCEDURAL_OPTIMIZATION ${ENABLE_LTO})
 
 if (ENABLE_WEB_SERVICE)

src/core/cheats/cheats.cpp

@@ -71,16 +71,12 @@ void CheatEngine::SaveCheatFile() const {
     if (!FileUtil::IsDirectory(cheat_dir)) {
         FileUtil::CreateDir(cheat_dir);
     }
-
+    FileUtil::IOFile file(filepath, "w");
-    std::ofstream file;
-    OpenFStream(file, filepath, std::ios_base::out);
 
     auto cheats = GetCheats();
     for (const auto& cheat : cheats) {
-        file << cheat->ToString();
+        file.WriteString(cheat->ToString());
     }
-
-    file.flush();
 }
 
 void CheatEngine::LoadCheatFile() {

src/core/cheats/gateway_cheat.cpp

@@ -8,6 +8,8 @@
 #include <functional>
 #include <string>
 #include <vector>
+#include <boost/iostreams/device/file_descriptor.hpp>
+#include <boost/iostreams/stream.hpp>
 #include "common/file_util.h"
 #include "common/logging/log.h"
 #include "common/string_util.h"
@@ -473,9 +475,9 @@ std::string GatewayCheat::ToString() const {
 std::vector<std::unique_ptr<CheatBase>> GatewayCheat::LoadFile(const std::string& filepath) {
     std::vector<std::unique_ptr<CheatBase>> cheats;
 
-    std::ifstream file;
+    boost::iostreams::stream<boost::iostreams::file_descriptor_source> file;
-    OpenFStream(file, filepath, std::ios_base::in);
+    FileUtil::OpenFStream<std::ios_base::in>(file, filepath);
-    if (!file) {
+    if (!file.is_open()) {
         return cheats;
     }
 

src/core/hw/aes/key.cpp

@@ -6,6 +6,8 @@
 #include <exception>
 #include <optional>
 #include <sstream>
+#include <boost/iostreams/device/file_descriptor.hpp>
+#include <boost/iostreams/stream.hpp>
 #include <cryptopp/aes.h>
 #include <cryptopp/modes.h>
 #include <cryptopp/sha.h>
@@ -428,9 +430,10 @@ void LoadNativeFirmKeysNew3DS() {
 void LoadPresetKeys() {
     const std::string filepath = FileUtil::GetUserPath(FileUtil::UserPath::SysDataDir) + AES_KEYS;
     FileUtil::CreateFullPath(filepath); // Create path if not already created
-    std::ifstream file;
+
-    OpenFStream(file, filepath, std::ios_base::in);
+    boost::iostreams::stream<boost::iostreams::file_descriptor_source> file;
-    if (!file) {
+    FileUtil::OpenFStream<std::ios_base::in>(file, filepath);
+    if (!file.is_open()) {
         return;
     }
 

src/video_core/renderer_opengl/post_processing_opengl.cpp

@@ -10,6 +10,9 @@
 #include "common/string_util.h"
 #include "video_core/renderer_opengl/post_processing_opengl.h"
 
+#include <boost/iostreams/device/file_descriptor.hpp>
+#include <boost/iostreams/stream.hpp>
+
 namespace OpenGL {
 
 // The Dolphin shader header is added here for drop-in compatibility with most
@@ -193,9 +196,9 @@ std::string GetPostProcessingShaderCode(bool anaglyph, std::string_view shader)
         return "";
     }
 
-    std::ifstream file;
+    boost::iostreams::stream<boost::iostreams::file_descriptor_source> file;
-    OpenFStream(file, shader_path, std::ios_base::in);
+    FileUtil::OpenFStream<std::ios_base::in>(file, shader_path);
-    if (!file) {
+    if (!file.is_open()) {
         return "";
     }