Rabbit-R1/switch port/java/sources/androidx/recyclerview/widget/SnapHelper.java
2024-05-21 17:08:36 -04:00

142 lines
6.5 KiB
Java

package androidx.recyclerview.widget;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.animation.DecelerateInterpolator;
import android.widget.Scroller;
import androidx.recyclerview.widget.RecyclerView;
/* loaded from: classes2.dex */
public abstract class SnapHelper extends RecyclerView.OnFlingListener {
static final float MILLISECONDS_PER_INCH = 100.0f;
private Scroller mGravityScroller;
RecyclerView mRecyclerView;
private final RecyclerView.OnScrollListener mScrollListener = new RecyclerView.OnScrollListener() { // from class: androidx.recyclerview.widget.SnapHelper.1
boolean mScrolled = false;
@Override // androidx.recyclerview.widget.RecyclerView.OnScrollListener
public void onScrolled(RecyclerView recyclerView, int i, int i2) {
if (i == 0 && i2 == 0) {
return;
}
this.mScrolled = true;
}
@Override // androidx.recyclerview.widget.RecyclerView.OnScrollListener
public void onScrollStateChanged(RecyclerView recyclerView, int i) {
super.onScrollStateChanged(recyclerView, i);
if (i == 0 && this.mScrolled) {
this.mScrolled = false;
SnapHelper.this.snapToTargetExistingView();
}
}
};
public abstract int[] calculateDistanceToFinalSnap(RecyclerView.LayoutManager layoutManager, View view);
public abstract View findSnapView(RecyclerView.LayoutManager layoutManager);
public abstract int findTargetSnapPosition(RecyclerView.LayoutManager layoutManager, int i, int i2);
@Override // androidx.recyclerview.widget.RecyclerView.OnFlingListener
public boolean onFling(int i, int i2) {
RecyclerView.LayoutManager layoutManager = this.mRecyclerView.getLayoutManager();
if (layoutManager == null || this.mRecyclerView.getAdapter() == null) {
return false;
}
int minFlingVelocity = this.mRecyclerView.getMinFlingVelocity();
return (Math.abs(i2) > minFlingVelocity || Math.abs(i) > minFlingVelocity) && snapFromFling(layoutManager, i, i2);
}
public void attachToRecyclerView(RecyclerView recyclerView) throws IllegalStateException {
RecyclerView recyclerView2 = this.mRecyclerView;
if (recyclerView2 == recyclerView) {
return;
}
if (recyclerView2 != null) {
destroyCallbacks();
}
this.mRecyclerView = recyclerView;
if (recyclerView != null) {
setupCallbacks();
this.mGravityScroller = new Scroller(this.mRecyclerView.getContext(), new DecelerateInterpolator());
snapToTargetExistingView();
}
}
private void setupCallbacks() throws IllegalStateException {
if (this.mRecyclerView.getOnFlingListener() != null) {
throw new IllegalStateException("An instance of OnFlingListener already set.");
}
this.mRecyclerView.addOnScrollListener(this.mScrollListener);
this.mRecyclerView.setOnFlingListener(this);
}
private void destroyCallbacks() {
this.mRecyclerView.removeOnScrollListener(this.mScrollListener);
this.mRecyclerView.setOnFlingListener(null);
}
public int[] calculateScrollDistance(int i, int i2) {
this.mGravityScroller.fling(0, 0, i, i2, Integer.MIN_VALUE, Integer.MAX_VALUE, Integer.MIN_VALUE, Integer.MAX_VALUE);
return new int[]{this.mGravityScroller.getFinalX(), this.mGravityScroller.getFinalY()};
}
private boolean snapFromFling(RecyclerView.LayoutManager layoutManager, int i, int i2) {
RecyclerView.SmoothScroller createScroller;
int findTargetSnapPosition;
if (!(layoutManager instanceof RecyclerView.SmoothScroller.ScrollVectorProvider) || (createScroller = createScroller(layoutManager)) == null || (findTargetSnapPosition = findTargetSnapPosition(layoutManager, i, i2)) == -1) {
return false;
}
createScroller.setTargetPosition(findTargetSnapPosition);
layoutManager.startSmoothScroll(createScroller);
return true;
}
void snapToTargetExistingView() {
RecyclerView.LayoutManager layoutManager;
View findSnapView;
RecyclerView recyclerView = this.mRecyclerView;
if (recyclerView == null || (layoutManager = recyclerView.getLayoutManager()) == null || (findSnapView = findSnapView(layoutManager)) == null) {
return;
}
int[] calculateDistanceToFinalSnap = calculateDistanceToFinalSnap(layoutManager, findSnapView);
int i = calculateDistanceToFinalSnap[0];
if (i == 0 && calculateDistanceToFinalSnap[1] == 0) {
return;
}
this.mRecyclerView.smoothScrollBy(i, calculateDistanceToFinalSnap[1]);
}
protected RecyclerView.SmoothScroller createScroller(RecyclerView.LayoutManager layoutManager) {
return createSnapScroller(layoutManager);
}
@Deprecated
protected LinearSmoothScroller createSnapScroller(RecyclerView.LayoutManager layoutManager) {
if (layoutManager instanceof RecyclerView.SmoothScroller.ScrollVectorProvider) {
return new LinearSmoothScroller(this.mRecyclerView.getContext()) { // from class: androidx.recyclerview.widget.SnapHelper.2
@Override // androidx.recyclerview.widget.LinearSmoothScroller, androidx.recyclerview.widget.RecyclerView.SmoothScroller
protected void onTargetFound(View view, RecyclerView.State state, RecyclerView.SmoothScroller.Action action) {
if (SnapHelper.this.mRecyclerView == null) {
return;
}
SnapHelper snapHelper = SnapHelper.this;
int[] calculateDistanceToFinalSnap = snapHelper.calculateDistanceToFinalSnap(snapHelper.mRecyclerView.getLayoutManager(), view);
int i = calculateDistanceToFinalSnap[0];
int i2 = calculateDistanceToFinalSnap[1];
int calculateTimeForDeceleration = calculateTimeForDeceleration(Math.max(Math.abs(i), Math.abs(i2)));
if (calculateTimeForDeceleration > 0) {
action.update(i, i2, calculateTimeForDeceleration, this.mDecelerateInterpolator);
}
}
@Override // androidx.recyclerview.widget.LinearSmoothScroller
protected float calculateSpeedPerPixel(DisplayMetrics displayMetrics) {
return 100.0f / displayMetrics.densityDpi;
}
};
}
return null;
}
}