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 f80439e8f7a28d8b1490f9dd96599eed6d6c8846..937b4865a284ec5646d49166cfc4841120907e9f 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
@@ -21,6 +21,7 @@ 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
@@ -105,6 +106,9 @@ 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.min_touch_target_size);
+
+        setClipChildren(false);
     }
 
     /**
@@ -161,10 +165,14 @@ 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;
+
     /**
      * Base class for animations inside the InfoBarContainerLayout.
      *
@@ -201,11 +209,10 @@ 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();
                 }
             });
@@ -384,6 +391,7 @@ class InfoBarContainerLayout extends FrameLayout {
 
         BackInfoBarAppearingAnimation(Item appearingItem) {
             mAppearingWrapper = new InfoBarWrapper(getContext(), appearingItem);
+            mAppearingWrapper.addView(appearingItem.getView());
         }
 
         @Override
@@ -393,9 +401,28 @@ 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);
+            ValueAnimator animator =
+                    createTranslationYAnimator(mAppearingWrapper, -mBackgroundPeekSize);
+            animator.setDuration(DURATION_PEEK_MS);

[Ted C, 2017/05/17 17:55:54]

We should be able to set the duration on the set since it is the same.

Hmm...or maybe playSequentially doesn't play nicely with that

[mdjones, 2017/05/17 21:05:19]

Setting duration on the set ends up working just fine. Done.

+            animators.add(animator);
+
+            animators.add(
+                    createTranslationYAnimator(mAppearingWrapper, 0).setDuration(DURATION_PEEK_MS));
+
+            set.addListener(new AnimatorListenerAdapter() {

[Ted C, 2017/05/17 17:55:54]

Do you want the view to be removed even if the set were cancelled?  It is
probably ok in this case.

[mdjones, 2017/05/17 21:05:19]

When cancel is called on the animator set, cancel is called on each of its
constituent animations. Canceling an animation will call onAnimationEnd, so this
is run in any case.

+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mAppearingWrapper.removeView(mAppearingWrapper.getItem().getView());
+                }
+            });
+
+            set.playSequentially(animators);
+
+            return set;
         }
 
         @Override
@@ -815,7 +842,10 @@ 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