Using a custom view instead of ImageView to avoid relayout when the icon changes

Bug: 78585335
Change-Id: I078aec5b80ec45933ba4974df68cab23ac4a0ca0

quickstep/res/layout/task.xml

@@ -24,7 +24,7 @@
         android:layout_height="match_parent"
         android:layout_marginTop="@dimen/task_thumbnail_top_margin" />
 
-    <ImageView
+    <com.android.quickstep.views.IconView
         android:id="@+id/icon"
         android:layout_width="@dimen/task_thumbnail_icon_size"
         android:layout_height="@dimen/task_thumbnail_icon_size"

quickstep/src/com/android/quickstep/util/TaskViewDrawable.java

@@ -21,7 +21,7 @@ import android.graphics.ColorFilter;
 import android.graphics.PixelFormat;
 import android.graphics.drawable.Drawable;
 import android.util.FloatProperty;
-import android.widget.ImageView;
+import android.view.View;
 
 import com.android.launcher3.Utilities;
 import com.android.quickstep.views.RecentsView;
@@ -47,7 +47,7 @@ public class TaskViewDrawable extends Drawable {
             (t) -> (Math.max(t, 0.3f) - 0.3f) / 0.7f;
 
     private final RecentsView mParent;
-    private final ImageView mIconView;
+    private final View mIconView;
     private final int[] mIconPos;
 
     private final TaskThumbnailView mThumbnailView;

quickstep/src/com/android/quickstep/views/IconView.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2018 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 android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.drawable.Drawable;
+import android.util.AttributeSet;
+import android.view.View;
+
+/**
+ * A view which draws a drawable stretched to fit its size. Unlike ImageView, it avoids relayout
+ * when the drawable changes.
+ */
+public class IconView extends View {
+
+    private Drawable mDrawable;
+
+    public IconView(Context context) {
+        super(context);
+    }
+
+    public IconView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public IconView(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public void setDrawable(Drawable d) {
+        if (mDrawable != null) {
+            mDrawable.setCallback(null);
+        }
+        mDrawable = d;
+        if (mDrawable != null) {
+            mDrawable.setCallback(this);
+            mDrawable.setBounds(0, 0, getWidth(), getHeight());
+        }
+        invalidate();
+    }
+
+    @Override
+    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+        super.onSizeChanged(w, h, oldw, oldh);
+        if (mDrawable != null) {
+            mDrawable.setBounds(0, 0, w, h);
+        }
+    }
+
+    @Override
+    protected boolean verifyDrawable(Drawable who) {
+        return super.verifyDrawable(who) || who == mDrawable;
+    }
+
+    @Override
+    protected void drawableStateChanged() {
+        super.drawableStateChanged();
+
+        final Drawable drawable = mDrawable;
+        if (drawable != null && drawable.isStateful()
+                && drawable.setState(getDrawableState())) {
+            invalidateDrawable(drawable);
+        }
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        if (mDrawable != null) {
+            mDrawable.draw(canvas);
+        }
+    }
+
+    @Override
+    public boolean hasOverlappingRendering() {
+        return false;
+    }
+}

quickstep/src/com/android/quickstep/views/TaskView.java

@@ -80,7 +80,7 @@ public class TaskView extends FrameLayout implements TaskCallbacks, PageCallback
 
     private Task mTask;
     private TaskThumbnailView mSnapshotView;
-    private ImageView mIconView;
+    private IconView mIconView;
     private float mCurveScale;
     private float mCurveDimAlpha;
     private Animator mDimAlphaAnim;
@@ -133,7 +133,7 @@ public class TaskView extends FrameLayout implements TaskCallbacks, PageCallback
         return mSnapshotView;
     }
 
-    public ImageView getIconView() {
+    public IconView getIconView() {
         return mIconView;
     }
 
@@ -163,7 +163,7 @@ public class TaskView extends FrameLayout implements TaskCallbacks, PageCallback
     @Override
     public void onTaskDataLoaded(Task task, ThumbnailData thumbnailData) {
         mSnapshotView.setThumbnail(task, thumbnailData);
-        mIconView.setImageDrawable(task.icon);
+        mIconView.setDrawable(task.icon);
         mIconView.setOnClickListener(icon -> TaskMenuView.showForTask(this));
         mIconView.setOnLongClickListener(icon -> {
             requestDisallowInterceptTouchEvent(true);
@@ -174,7 +174,7 @@ public class TaskView extends FrameLayout implements TaskCallbacks, PageCallback
     @Override
     public void onTaskDataUnloaded() {
         mSnapshotView.setThumbnail(null, null);
-        mIconView.setImageDrawable(null);
+        mIconView.setDrawable(null);
         mIconView.setOnLongClickListener(null);
     }