Peek new infobars behind existing ones

chrome/android/java/src/org/chromium/chrome/browser/infobar/InfoBarWrapper.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.infobar;
 
 import android.content.Context;
 import android.content.res.Resources;
 import android.view.Gravity;
 import android.view.View;
 import android.widget.FrameLayout;
 
 import org.chromium.chrome.R;
 
 /**
  * Layout that holds an infobar's contents and provides a background color and a top shadow.
  */
 class InfoBarWrapper extends FrameLayout {
 
     private final InfoBarContainerLayout.Item mItem;
 
+    /** Whether or not the height of the layout should be restricted for animations. */
+    private boolean mRestrictHeightForAnimation;
+
+    /**
+     * The height in px that this view will be restricted to if
+     * {@link #mRestrictHeightForAnimation} is set.
+     */
+    private int mHeightForAnimationPx;
+
     /**
      * Constructor for inflating from Java.
      */
     InfoBarWrapper(Context context, InfoBarContainerLayout.Item item) {
         super(context);
         mItem = item;
         Resources res = context.getResources();
         int peekingHeight = res.getDimensionPixelSize(R.dimen.infobar_peeking_height);
         int shadowHeight = res.getDimensionPixelSize(R.dimen.infobar_shadow_height);
         setMinimumHeight(peekingHeight + shadowHeight);
 
         // setBackgroundResource() changes the padding, so call setPadding() second.
         setBackgroundResource(R.drawable.infobar_wrapper_bg);
         setPadding(0, shadowHeight, 0, 0);
+        setClipChildren(true);
+    }
+
+    /**
+     * @param restrict Whether or not the height of this view should be restricted for animations.
+     */
+    public void setRestrictHeightForAnimation(boolean restrict) {
+        mRestrictHeightForAnimation = restrict;
+    }
+
+    /**
+     * @param heightPx The restricted height in px that will be used if
+     *                 {@link #mRestrictHeightForAnimation} is set.
+     */
+    public void setHeightForAnimation(int heightPx) {
+        mHeightForAnimationPx = heightPx;
     }
 
     InfoBarContainerLayout.Item getItem() {
         return mItem;
     }
 
     @Override
+    public void onMeasure(int widthSpec, int heightSpec) {
+        if (mRestrictHeightForAnimation) {
+            int heightPx = Math.min(mHeightForAnimationPx, MeasureSpec.getSize(heightSpec));
+            heightSpec = MeasureSpec.makeMeasureSpec(heightPx, MeasureSpec.getMode(heightSpec));
+        }
+
+        super.onMeasure(widthSpec, heightSpec);
+    }
+
+    @Override
     public void onViewAdded(View child) {
         child.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT,
                 Gravity.TOP));
     }
 }