ADD week 5

2025-03-31 16:33:42 +02:00
parent 86f265f22d
commit bf645048e6
4927 changed files with 544053 additions and 0 deletions
--- a/02-Easy5/E5/sources/androidx/recyclerview/widget/SnapHelper.java
+++ b/02-Easy5/E5/sources/androidx/recyclerview/widget/SnapHelper.java
@@ -0,0 +1,142 @@
+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: classes.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 SnapHelper.MILLISECONDS_PER_INCH / displayMetrics.densityDpi;
+                }
+            };
+        }
+        return null;
+    }
+}