Move clear all to recycler view (1/2)

First part of moving clear all button to recycler view.  This CL adds
support in the recycler view adapter for a clear all holder type and
hooks it up to the previous clear all animation.

Adding this breaks several assumptions made externally on the type of
the item and index which will be addressed in the second part.

Bug: 114136250
Test: Builds, testing pending 2nd part
Change-Id: Ib16790028d4e9f520945a987b3dace40d19f2468
(cherry pick from 8573ff04b4148c47222abd1a89d99eda734290c3)

2 files changed, 31 insertions, 21 deletions

diff --git a/go/quickstep/res/layout/clear_all_button.xml b/go/quickstep/res/layout/clear_all_button.xml
new file mode 100644
index 000000000..eceffec42
--- /dev/null
+++ b/go/quickstep/res/layout/clear_all_button.xml
@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2019 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.
+-->
+<Button xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/clear_all_button"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:layout_gravity="center_horizontal"
+    android:background="@drawable/clear_all_button"
+    android:gravity="center"
+    android:text="@string/recents_clear_all"
+    android:textAllCaps="false"
+    android:textColor="@color/clear_all_button_text"
+    android:textSize="14sp">
+</Button>
diff --git a/go/quickstep/res/layout/icon_recents_root_view.xml b/go/quickstep/res/layout/icon_recents_root_view.xml
index 6dc293f74..6fb7e19d1 100644
--- a/go/quickstep/res/layout/icon_recents_root_view.xml
+++ b/go/quickstep/res/layout/icon_recents_root_view.xml
@@ -19,29 +19,11 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical">
-    <LinearLayout
-        android:id="@+id/recent_task_content_view"
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/recent_task_recycler_view"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:orientation="vertical"
-        android:visibility="gone">
-        <androidx.recyclerview.widget.RecyclerView
-            android:id="@+id/recent_task_recycler_view"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
-            android:scrollbars="none"/>
-        <Button
-            android:id="@+id/clear_all_button"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:layout_gravity="center_horizontal"
-            android:background="@drawable/clear_all_button"
-            android:gravity="center"
-            android:text="@string/recents_clear_all"
-            android:textAllCaps="false"
-            android:textColor="@color/clear_all_button_text"
-            android:textSize="14sp"/>
-    </LinearLayout>
+        android:scrollbars="none"/>
     <TextView
         android:id="@+id/recent_task_empty_view"
         android:layout_width="match_parent"