From 8f6d41ee53a2b2bf9122cab52333933fdb3b5ae2 Mon Sep 17 00:00:00 2001
From: Kevin <kevhan@google.com>
Date: Tue, 30 Apr 2019 09:13:24 -0700
Subject: [PATCH] Fade task items when swiping out

As we have a fixed width for the task list now, we have to ensure that
we do not clip the task items when we swipe them out. In addition, we
should fade them out by the end of the swipe as the swipe end location
may still be on a visible part of the screen.

Bug: 131686863
Test: Go to landscape mode, swipe out tasks
Change-Id: If86136a9f9d47098a6dd5d355d3a99d540165c77
---
 go/quickstep/res/layout/icon_recents_root_view.xml |  6 ++++--
 .../com/android/quickstep/TaskSwipeCallback.java   | 14 ++++++++++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/go/quickstep/res/layout/icon_recents_root_view.xml b/go/quickstep/res/layout/icon_recents_root_view.xml
index b64b7fdad6..595a380bd8 100644
--- a/go/quickstep/res/layout/icon_recents_root_view.xml
+++ b/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"
diff --git a/go/quickstep/src/com/android/quickstep/TaskSwipeCallback.java b/go/quickstep/src/com/android/quickstep/TaskSwipeCallback.java
index 19951bb378..76865435a3 100644
--- a/go/quickstep/src/com/android/quickstep/TaskSwipeCallback.java
+++ b/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) {