Merge "Fade task items when swiping out" into ub-launcher3-qt-dev

go/quickstep/res/layout/icon_recents_root_view.xml

@@ -18,14 +18,16 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:orientation="vertical">
+    android:orientation="vertical"
+    android:clipChildren="false">
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/recent_task_recycler_view"
         android:layout_width="@dimen/recents_list_width"
         android:layout_height="match_parent"
         android:layout_gravity="center_horizontal"
         android:scrollbars="none"
-        android:clipToPadding="false"/>
+        android:clipToPadding="false"
+        android:clipChildren="false"/>
     <TextView
         android:id="@+id/recent_task_empty_view"
         android:layout_width="match_parent"

go/quickstep/src/com/android/quickstep/TaskSwipeCallback.java

@@ -19,6 +19,8 @@ import static androidx.recyclerview.widget.ItemTouchHelper.RIGHT;
 
 import static com.android.quickstep.TaskAdapter.ITEM_TYPE_CLEAR_ALL;
 
+import android.graphics.Canvas;
+
 import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.ItemTouchHelper;
 import androidx.recyclerview.widget.RecyclerView;
@@ -49,6 +51,18 @@ public final class TaskSwipeCallback extends ItemTouchHelper.SimpleCallback {
         }
     }
 
+    @Override
+    public void onChildDraw(@NonNull Canvas c, @NonNull RecyclerView recyclerView,
+            @NonNull ViewHolder viewHolder, float dX, float dY, int actionState,
+            boolean isCurrentlyActive) {
+        if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) {
+            float alpha = 1.0f - dX / (float) viewHolder.itemView.getWidth();
+            viewHolder.itemView.setAlpha(alpha);
+        }
+        super.onChildDraw(c, recyclerView, viewHolder, dX, dY,
+                    actionState, isCurrentlyActive);
+    }
+
     @Override
     public int getSwipeDirs(@NonNull RecyclerView recyclerView,
             @NonNull ViewHolder viewHolder) {