Add clear all view that scales off device height

Add a custom clear all view that scales its height based off the height
of the device in portrait. This view holds and lays out the actual
button.

Bug: 114136250
Test: Task items + clear all scale to fit flush with screen size
Change-Id: I72b175681c104588970d57cde34cebc0f06b55a0
(cherry picked from commit a2b8ca883040a33a60968c83d6ef9c48468ffe32)

4 files changed, 76 insertions, 19 deletions

diff --git a/go/quickstep/res/layout/clear_all_button.xml b/go/quickstep/res/layout/clear_all_button.xml
index eceffec42..003ee860e 100644
--- a/go/quickstep/res/layout/clear_all_button.xml
+++ b/go/quickstep/res/layout/clear_all_button.xml
@@ -14,15 +14,20 @@
      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>
+<com.android.quickstep.views.ClearAllItemView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/clear_all_item_view"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+    <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"/>
+</com.android.quickstep.views.ClearAllItemView>
diff --git a/go/quickstep/src/com/android/quickstep/TaskAdapter.java b/go/quickstep/src/com/android/quickstep/TaskAdapter.java
index be6faca88..8651698f6 100644
--- a/go/quickstep/src/com/android/quickstep/TaskAdapter.java
+++ b/go/quickstep/src/com/android/quickstep/TaskAdapter.java
@@ -16,6 +16,7 @@
 package com.android.quickstep;
 
 import android.view.LayoutInflater;
+import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
 import android.widget.Button;
@@ -84,10 +85,11 @@ public final class TaskAdapter extends Adapter<ViewHolder> {
                 itemView.setOnClickListener(view -> mTaskActionController.launchTask(taskHolder));
                 return taskHolder;
             case ITEM_TYPE_CLEAR_ALL:
-                Button clearView = (Button) LayoutInflater.from(parent.getContext())
+                View clearView = LayoutInflater.from(parent.getContext())
                         .inflate(R.layout.clear_all_button, parent, false);
                 ClearAllHolder clearAllHolder = new ClearAllHolder(clearView);
-                clearView.setOnClickListener(mClearAllListener);
+                Button clearViewButton = clearView.findViewById(R.id.clear_all_button);
+                clearViewButton.setOnClickListener(mClearAllListener);
                 return clearAllHolder;
             default:
                 throw new IllegalArgumentException("No known holder for item type: " + viewType);
diff --git a/go/quickstep/src/com/android/quickstep/views/ClearAllItemView.java b/go/quickstep/src/com/android/quickstep/views/ClearAllItemView.java
new file mode 100644
index 000000000..378dbf4e4
--- /dev/null
+++ b/go/quickstep/src/com/android/quickstep/views/ClearAllItemView.java
@@ -0,0 +1,41 @@
+/*
+ * 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.
+ */
+
+package com.android.quickstep.views;
+
+import static com.android.quickstep.views.TaskLayoutUtils.getClearAllItemHeight;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.widget.FrameLayout;
+
+/**
+ * Recycler view item that lays out the clear all button and measures the space it takes based on
+ * the device height.
+ */
+public final class ClearAllItemView extends FrameLayout {
+
+    public ClearAllItemView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        int buttonHeight = getClearAllItemHeight(getContext());
+        int newHeightSpec = MeasureSpec.makeMeasureSpec(buttonHeight, MeasureSpec.EXACTLY);
+        super.onMeasure(widthMeasureSpec, newHeightSpec);
+    }
+}
diff --git a/go/quickstep/src/com/android/quickstep/views/TaskLayoutUtils.java b/go/quickstep/src/com/android/quickstep/views/TaskLayoutUtils.java
index f7d6495d2..e28a9e04f 100644
--- a/go/quickstep/src/com/android/quickstep/views/TaskLayoutUtils.java
+++ b/go/quickstep/src/com/android/quickstep/views/TaskLayoutUtils.java
@@ -26,6 +26,8 @@ import com.android.launcher3.InvariantDeviceProfile;
  */
 public final class TaskLayoutUtils {
 
+    private static final float CLEAR_ALL_ITEM_TO_HEIGHT_RATIO = 7.0f / 64;
+
     private TaskLayoutUtils() {}
 
     /**
@@ -39,12 +41,19 @@ public final class TaskLayoutUtils {
     public static int getTaskHeight(Context context) {
         final int availableHeight =
                 InvariantDeviceProfile.INSTANCE.get(context).portraitProfile.availableHeightPx;
-        // TODO: Take into account clear all button height for task height
-        return (int) (availableHeight * 1.0f / MAX_TASKS_TO_DISPLAY);
+        final int availableTaskSpace = availableHeight - getClearAllItemHeight(context);
+        return (int) (availableTaskSpace * 1.0f / MAX_TASKS_TO_DISPLAY);
     }
 
-    public static int getClearAllButtonHeight(Context context) {
-        // TODO: Implement this
-        return 0;
+    /**
+     * Calculate clear all item height scaled to available height in portrait mode.
+     *
+     * @param context current context
+     * @return clear all item height
+     */
+    public static int getClearAllItemHeight(Context context) {
+        final int availableHeight =
+                InvariantDeviceProfile.INSTANCE.get(context).portraitProfile.availableHeightPx;
+        return (int) (CLEAR_ALL_ITEM_TO_HEIGHT_RATIO * availableHeight);
     }
 }