Peek new infobars behind existing ones

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

Index: chrome/android/java/src/org/chromium/chrome/browser/infobar/InfoBarContainerLayout.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/infobar/InfoBarContainerLayout.java b/chrome/android/java/src/org/chromium/chrome/browser/infobar/InfoBarContainerLayout.java
index dac8fbd155857d5f27d1e05f6671668acba72857..babe13a61cd767ce22726b3c6c6344aa471354e4 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/infobar/InfoBarContainerLayout.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/infobar/InfoBarContainerLayout.java
@@ -15,6 +15,8 @@ import android.content.res.Resources;
 import android.view.Gravity;
 import android.view.MotionEvent;
 import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewGroup.LayoutParams;
 import android.widget.FrameLayout;
 
 import org.chromium.base.ObserverList;
@@ -22,6 +24,7 @@ import org.chromium.chrome.R;
 import org.chromium.chrome.browser.infobar.InfoBarContainer.InfoBarAnimationListener;
 
 import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Layout that displays infobars in a stack. Handles all the animations when adding or removing
@@ -112,6 +115,15 @@ public class InfoBarContainerLayout extends FrameLayout {
         Resources res = context.getResources();
         mBackInfobarHeight = res.getDimensionPixelSize(R.dimen.infobar_peeking_height);
         mFloatingBehavior = new FloatingBehavior(this);
+        mBackgroundPeekSize = getResources().getDimensionPixelSize(R.dimen.infobar_compact_size);
+        mInfoBarShadowHeight = getResources().getDimensionPixelSize(R.dimen.infobar_shadow_height);
+    }
+
+    @Override
+    public void onAttachedToWindow() {
+        super.onAttachedToWindow();
+
+        mBottomContainer = (ViewGroup) getRootView().findViewById(R.id.bottom_container);
     }
 
     /**
@@ -175,10 +187,20 @@ public class InfoBarContainerLayout extends FrameLayout {
 
     // Animation durations.
     private static final int DURATION_SLIDE_UP_MS = 250;
+    private static final int DURATION_PEEK_MS = 500;
     private static final int DURATION_SLIDE_DOWN_MS = 250;
     private static final int DURATION_FADE_MS = 100;
     private static final int DURATION_FADE_OUT_MS = 200;
 
+    /** The height that an infobar will peek when being added behind another one. */
+    private final int mBackgroundPeekSize;
+
+    /** The height of the shadow that sits above the infobar. */
+    private final int mInfoBarShadowHeight;
+
+    /** The bottom container that the infobar container sits inside of. */
+    private ViewGroup mBottomContainer;
+
     /**
      * Base class for animations inside the InfoBarContainerLayout.
      *
@@ -215,11 +237,10 @@ public class InfoBarContainerLayout extends FrameLayout {
          * value to endValue and updates the side shadow positions on each frame.
          */
         ValueAnimator createTranslationYAnimator(final InfoBarWrapper wrapper, float endValue) {
-            ValueAnimator animator = ValueAnimator.ofFloat(wrapper.getTranslationY(), endValue);
+            ValueAnimator animator = ObjectAnimator.ofFloat(wrapper, View.TRANSLATION_Y, endValue);
             animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                 @Override
                 public void onAnimationUpdate(ValueAnimator animation) {
-                    wrapper.setTranslationY((float) animation.getAnimatedValue());
                     mFloatingBehavior.updateShadowPosition();
                 }
             });
@@ -407,9 +428,39 @@ public class InfoBarContainerLayout extends FrameLayout {
 
         @Override
         Animator createAnimator() {
+            AnimatorSet set = new AnimatorSet();
+            List<Animator> animators = new ArrayList<>();
+
             mAppearingWrapper.setTranslationY(mAppearingWrapper.getHeight());
-            return createTranslationYAnimator(mAppearingWrapper, 0f)
-                    .setDuration(DURATION_SLIDE_UP_MS);
+            mAppearingWrapper.setRestrictHeightForAnimation(true);
+            mAppearingWrapper.setHeightForAnimation(mInfoBarShadowHeight + mBackgroundPeekSize);
+            mAppearingWrapper.addView(mAppearingWrapper.getItem().getView());
+            ValueAnimator animator = createTranslationYAnimator(
+                    mAppearingWrapper, mBackInfobarHeight - mBackgroundPeekSize);
+            animators.add(animator);
+
+            animators.add(createTranslationYAnimator(mAppearingWrapper, 0));
+
+            // When the infobar container is running this specific animation, do not clip the
+            // children so the infobars can animate outside their container.
+            set.addListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationStart(Animator animation) {
+                    setHierarchyClipsChildren(false);
+                }
+
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mAppearingWrapper.setRestrictHeightForAnimation(false);
+                    mAppearingWrapper.removeView(mAppearingWrapper.getItem().getView());
+                    setHierarchyClipsChildren(true);
+                }
+            });
+
+            set.playSequentially(animators);
+            set.setDuration(DURATION_PEEK_MS);
+
+            return set;
         }
 
         @Override
@@ -419,6 +470,17 @@ public class InfoBarContainerLayout extends FrameLayout {
     }
 
     /**
+     * Used to set the relevant view hierarchy to not clip its children. This is used during
+     * animation so views can draw outside the normal bounds.
+     * @param clip Whether or not to clip child views.
+     */
+    private void setHierarchyClipsChildren(boolean clip) {
+        setClipChildren(clip);
+        ((ViewGroup) getParent()).setClipChildren(clip);
+        mBottomContainer.setClipChildren(clip);
+    }
+
+    /**
      * The animation to hide the front infobar and reveal the second-to-front infobar. The front
      * infobar slides down and off the screen. The back infobar(s) will adjust to the size of the
      * new front infobar, and then the new front infobar's contents will fade in.
@@ -837,7 +899,10 @@ public class InfoBarContainerLayout extends FrameLayout {
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         widthMeasureSpec = mFloatingBehavior.beforeOnMeasure(widthMeasureSpec);
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
-        mFloatingBehavior.afterOnMeasure(getMeasuredHeight());
+
+        // Make sure the shadow is tall enough to compensate for the peek animation of other
+        // infboars.
+        mFloatingBehavior.afterOnMeasure(getMeasuredHeight() + mBackgroundPeekSize);
     }
 
     @Override