Added patched recyclerview-selection 1.0.0

app/src/main/java/androidx/recyclerview/selection/DefaultBandHost.java

@@ -0,0 +1,156 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.recyclerview.selection;
+
+import static androidx.core.util.Preconditions.checkArgument;
+
+import android.graphics.Canvas;
+import android.graphics.Point;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.view.View;
+
+import androidx.annotation.DrawableRes;
+import androidx.annotation.NonNull;
+import androidx.recyclerview.selection.SelectionTracker.SelectionPredicate;
+import androidx.recyclerview.widget.GridLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.RecyclerView.ItemDecoration;
+import androidx.recyclerview.widget.RecyclerView.OnScrollListener;
+
+/**
+ * RecyclerView backed {@link BandSelectionHelper.BandHost}.
+ */
+final class DefaultBandHost<K> extends GridModel.GridHost<K> {
+
+    private static final Rect NILL_RECT = new Rect(0, 0, 0, 0);
+
+    private final RecyclerView mRecyclerView;
+    private final Drawable mBand;
+    private final ItemKeyProvider<K> mKeyProvider;
+    private final SelectionPredicate<K> mSelectionPredicate;
+
+    DefaultBandHost(
+            @NonNull RecyclerView recyclerView,
+            @DrawableRes int bandOverlayId,
+            @NonNull ItemKeyProvider<K> keyProvider,
+            @NonNull SelectionPredicate<K> selectionPredicate) {
+
+        checkArgument(recyclerView != null);
+
+        mRecyclerView = recyclerView;
+        mBand = mRecyclerView.getContext().getResources().getDrawable(bandOverlayId);
+
+        checkArgument(mBand != null);
+        checkArgument(keyProvider != null);
+        checkArgument(selectionPredicate != null);
+
+        mKeyProvider = keyProvider;
+        mSelectionPredicate = selectionPredicate;
+
+        mRecyclerView.addItemDecoration(
+                new ItemDecoration() {
+                    @Override
+                    public void onDrawOver(
+                            Canvas canvas,
+                            RecyclerView unusedParent,
+                            RecyclerView.State unusedState) {
+                        DefaultBandHost.this.onDrawBand(canvas);
+                    }
+                });
+    }
+
+    @Override
+    GridModel<K> createGridModel() {
+        return new GridModel<>(this, mKeyProvider, mSelectionPredicate);
+    }
+
+    @Override
+    int getAdapterPositionAt(int index) {
+        return mRecyclerView.getChildAdapterPosition(mRecyclerView.getChildAt(index));
+    }
+
+    @Override
+    void addOnScrollListener(@NonNull OnScrollListener listener) {
+        mRecyclerView.addOnScrollListener(listener);
+    }
+
+    @Override
+    void removeOnScrollListener(@NonNull OnScrollListener listener) {
+        mRecyclerView.removeOnScrollListener(listener);
+    }
+
+    @Override
+    Point createAbsolutePoint(@NonNull Point relativePoint) {
+        return new Point(relativePoint.x + mRecyclerView.computeHorizontalScrollOffset(),
+                relativePoint.y + mRecyclerView.computeVerticalScrollOffset());
+    }
+
+    @Override
+    Rect getAbsoluteRectForChildViewAt(int index) {
+        final View child = mRecyclerView.getChildAt(index);
+        final Rect childRect = new Rect();
+        child.getHitRect(childRect);
+        childRect.left += mRecyclerView.computeHorizontalScrollOffset();
+        childRect.right += mRecyclerView.computeHorizontalScrollOffset();
+        childRect.top += mRecyclerView.computeVerticalScrollOffset();
+        childRect.bottom += mRecyclerView.computeVerticalScrollOffset();
+        return childRect;
+    }
+
+    @Override
+    int getVisibleChildCount() {
+        return mRecyclerView.getChildCount();
+    }
+
+    @Override
+    int getColumnCount() {
+        RecyclerView.LayoutManager layoutManager = mRecyclerView.getLayoutManager();
+        if (layoutManager instanceof GridLayoutManager) {
+            return ((GridLayoutManager) layoutManager).getSpanCount();
+        }
+
+        // Otherwise, it is a list with 1 column.
+        return 1;
+    }
+
+    @Override
+    void showBand(@NonNull Rect rect) {
+        mBand.setBounds(rect);
+        // TODO: mRecyclerView.invalidateItemDecorations() should work, but it isn't currently.
+        // NOTE: That without invalidating rv, the band only gets updated
+        // when the pointer moves off a the item view into "NO_POSITION" territory.
+        mRecyclerView.invalidate();
+    }
+
+    @Override
+    void hideBand() {
+        mBand.setBounds(NILL_RECT);
+        // TODO: mRecyclerView.invalidateItemDecorations() should work, but it isn't currently.
+        mRecyclerView.invalidate();
+    }
+
+    @SuppressWarnings("WeakerAccess") /* synthetic access */
+    void onDrawBand(@NonNull Canvas c) {
+        mBand.draw(c);
+    }
+
+    @Override
+    boolean hasView(int pos) {
+        return mRecyclerView.findViewHolderForAdapterPosition(pos) != null;
+    }
+}