Ensure all infobars disappear when navigating between pages with infobars.

Previously, when navigating from one page with 3+ infobars to another
page with infobars, the animation would show only one or two infobars
hiding then one or two infobars appearing, even though all the existing
infobars should disappear, then all the new infobars should appear. To
the user, it appeared as if some of the new infobars had been there all
along (peeking up in the back), which is confusing and wrong.

This strange behavior was caused by the logic for deciding when to show
a hiding or appearing animation. This logic didn't associate a
particular infobar with a particular view; it just ensured that the
number of views matched the number of infobars. So, if infobars were
removed and then new infobars were quickly added, there would be fewer
animations than expected.

The new code explicitly associates an infobar with each view, so if all
the infobars are removed and then several new ones added, the animations
will reflect that correctly.

BUG=396223

Review URL: https://codereview.chromium.org/1634083002

Cr-Commit-Position: refs/heads/master@{#371635}

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

@@ -21,7 +21,6 @@ import org.chromium.chrome.R;
 import org.chromium.chrome.browser.infobar.InfoBarContainer.InfoBarAnimationListener;
 
 import java.util.ArrayList;
-import java.util.Collection;
 
 /**
  * Layout that displays infobars in a stack. Handles all the animations when adding or removing
@@ -120,16 +119,6 @@ class InfoBarContainerLayout extends FrameLayout {
         processPendingAnimations();
     }
 
-    /**
-     * Removes multiple infobars simultaneously. This method (as opposed to calling removeInfoBar()
-     * multiple times) ensures that the animations will happen in the optimal order, i.e. back
-     * infobars disappear first.
-     */
-    void removeInfoBars(Collection<Item> items) {
-        mItems.removeAll(items);
-        processPendingAnimations();
-    }
-
     /**
      * Notifies that an infobar's View ({@link Item#getView}) has changed. If the
      * infobar is visible in the front of the stack, the infobar will fade out the old contents,
@@ -243,16 +232,18 @@ class InfoBarContainerLayout extends FrameLayout {
      * content fades in.
      */
     private class FrontInfoBarAppearingAnimation extends InfoBarAnimation {
+        private Item mFrontItem;
         private InfoBarWrapper mFrontWrapper;
         private View mFrontContents;
 
-        FrontInfoBarAppearingAnimation(View frontContents) {
-            mFrontContents = frontContents;
+        FrontInfoBarAppearingAnimation(Item frontItem) {
+            mFrontItem = frontItem;
         }
 
         @Override
         void prepareAnimation() {
-            mFrontWrapper = new InfoBarWrapper(getContext());
+            mFrontContents = mFrontItem.getView();
+            mFrontWrapper = new InfoBarWrapper(getContext(), mFrontItem);
             mFrontWrapper.addView(mFrontContents);
             addWrapper(mFrontWrapper);
         }
@@ -289,9 +280,12 @@ class InfoBarContainerLayout extends FrameLayout {
     private class BackInfoBarAppearingAnimation extends InfoBarAnimation {
         private InfoBarWrapper mAppearingWrapper;
 
+        BackInfoBarAppearingAnimation(Item appearingItem) {
+            mAppearingWrapper = new InfoBarWrapper(getContext(), appearingItem);
+        }
+
         @Override
         void prepareAnimation() {
-            mAppearingWrapper = new InfoBarWrapper(getContext());
             addWrapper(mAppearingWrapper);
         }
 
@@ -318,14 +312,11 @@ class InfoBarContainerLayout extends FrameLayout {
         private InfoBarWrapper mNewFrontWrapper;
         private View mNewFrontContents;
 
-        FrontInfoBarDisappearingAndRevealingAnimation(View newFrontContents) {
-            mNewFrontContents = newFrontContents;
-        }
-
         @Override
         void prepareAnimation() {
             mOldFrontWrapper = mInfoBarWrappers.get(0);
             mNewFrontWrapper = mInfoBarWrappers.get(1);
+            mNewFrontContents = mNewFrontWrapper.getItem().getView();
             mNewFrontWrapper.addView(mNewFrontContents);
         }
 
@@ -366,7 +357,7 @@ class InfoBarContainerLayout extends FrameLayout {
             for (int i = 0; i < mInfoBarWrappers.size(); i++) {
                 mInfoBarWrappers.get(i).setTranslationY(0);
             }
-            announceForAccessibility(mFrontItem.getAccessibilityText());
+            announceForAccessibility(mNewFrontWrapper.getItem().getAccessibilityText());
         }
 
         @Override
@@ -415,14 +406,11 @@ class InfoBarContainerLayout extends FrameLayout {
         private View mOldContents;
         private View mNewContents;
 
-        FrontInfoBarSwapContentsAnimation(View newContents) {
-            mNewContents = newContents;
-        }
-
         @Override
         void prepareAnimation() {
             mFrontWrapper = mInfoBarWrappers.get(0);
             mOldContents = mFrontWrapper.getChildAt(0);
+            mNewContents = mFrontWrapper.getItem().getView();
             mFrontWrapper.addView(mNewContents);
         }
 
@@ -447,8 +435,8 @@ class InfoBarContainerLayout extends FrameLayout {
         void onAnimationEnd() {
             mFrontWrapper.removeViewAt(0);
             InfoBarContainerLayout.this.setTranslationY(0f);
-            mFrontItem.setControlsEnabled(true);
-            announceForAccessibility(mFrontItem.getAccessibilityText());
+            mFrontWrapper.getItem().setControlsEnabled(true);
+            announceForAccessibility(mFrontWrapper.getItem().getAccessibilityText());
         }
 
         @Override
@@ -589,13 +577,7 @@ class InfoBarContainerLayout extends FrameLayout {
     private final ArrayList<Item> mItems = new ArrayList<>();
 
     /**
-     * The Item that is currently shown on the front (i.e. top) of the stack. Like mItems, this
-     * value is not meaningful during animations.
-     */
-    private Item mFrontItem;
-
-    /**
-     * The list of InfoBarWrapper views that are currently visible.
+     * The currently visible InfoBarWrappers, in front to back order.
      */
     private final ArrayList<InfoBarWrapper> mInfoBarWrappers = new ArrayList<>();
 
@@ -618,51 +600,48 @@ class InfoBarContainerLayout extends FrameLayout {
         // removals happen before additions or swaps, and changes are made to back infobars before
         // front infobars.
 
-        int childCount = mInfoBarWrappers.size();
-        int desiredChildCount = Math.min(mItems.size(), MAX_STACK_DEPTH);
-        boolean shouldRemoveFrontView = mFrontItem != null && !mItems.contains(mFrontItem);
-
-        // First, check if we can remove any back infobars.
-        if (childCount > desiredChildCount + 1
-                || (childCount == desiredChildCount + 1 && !shouldRemoveFrontView)) {
-            runAnimation(new InfoBarDisappearingAnimation());
-            return;
-        }
-
-        // Second, check if we should remove the front infobar.
-        if (shouldRemoveFrontView) {
-            // The second to front infobar, if any, will become the new front infobar.
-            if (!mItems.isEmpty() && childCount >= 2) {
-                mFrontItem = mItems.get(0);
-                runAnimation(new FrontInfoBarDisappearingAndRevealingAnimation(
-                        mFrontItem.getView()));
-                return;
-            } else {
-                mFrontItem = null;
-                runAnimation(new InfoBarDisappearingAnimation());
-                return;
+        // First, remove any infobars that are no longer in mItems, if any. Check the back infobars
+        // before the front.
+        for (int i = mInfoBarWrappers.size() - 1; i >= 0; i--) {
+            Item visibleItem = mInfoBarWrappers.get(i).getItem();
+            if (!mItems.contains(visibleItem)) {
+                if (i == 0 && mInfoBarWrappers.size() >= 2) {
+                    // Remove the front infobar and reveal the second-to-front infobar.
+                    runAnimation(new FrontInfoBarDisappearingAndRevealingAnimation());
+                    return;
+
+                } else {
+                    // Move the infobar to the very back if it's not already there.
+                    InfoBarWrapper wrapper = mInfoBarWrappers.get(i);
+                    if (i != mInfoBarWrappers.size() - 1) {
+                        removeWrapper(wrapper);
+                        addWrapper(wrapper);
+                    }
+
+                    // Remove the backmost infobar (which may be the front infobar).
+                    runAnimation(new InfoBarDisappearingAnimation());
+                    return;
+                }
             }
         }
 
-        // Third, run swap animation on front infobar if needed.
-        if (mFrontItem != null && mItems.contains(mFrontItem)) {
+        // Second, run swap animation on front infobar if needed.
+        if (!mInfoBarWrappers.isEmpty()) {
+            Item frontItem = mInfoBarWrappers.get(0).getItem();
             View frontContents = mInfoBarWrappers.get(0).getChildAt(0);
-            if (frontContents != mFrontItem.getView()) {
-                runAnimation(new FrontInfoBarSwapContentsAnimation(mFrontItem.getView()));
+            if (frontContents != frontItem.getView()) {
+                runAnimation(new FrontInfoBarSwapContentsAnimation());
                 return;
             }
         }
 
-        // Fourth, check if we should add any infobars.
-        if (childCount < desiredChildCount) {
-            if (childCount == 0) {
-                mFrontItem = mItems.get(0);
-                runAnimation(new FrontInfoBarAppearingAnimation(mFrontItem.getView()));
-                return;
-            } else {
-                runAnimation(new BackInfoBarAppearingAnimation());
-                return;
-            }
+        // Third, check if we should add any infobars.
+        int desiredChildCount = Math.min(mItems.size(), MAX_STACK_DEPTH);
+        if (mInfoBarWrappers.size() < desiredChildCount) {
+            Item itemToShow = mItems.get(mInfoBarWrappers.size());
+            runAnimation(mInfoBarWrappers.isEmpty()
+                    ? new FrontInfoBarAppearingAnimation(itemToShow)
+                    : new BackInfoBarAppearingAnimation(itemToShow));
         }
     }
 
@@ -722,7 +701,8 @@ class InfoBarContainerLayout extends FrameLayout {
     public boolean onInterceptTouchEvent(MotionEvent ev) {
         // Trap any attempts to fiddle with the infobars while we're animating.
         return super.onInterceptTouchEvent(ev) || mAnimation != null
-                || (mFrontItem != null && !mFrontItem.areControlsEnabled());
+                || (!mInfoBarWrappers.isEmpty()
+                        && !mInfoBarWrappers.get(0).getItem().areControlsEnabled());
     }
 
     @Override

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

@@ -17,11 +17,14 @@ import org.chromium.chrome.R;
  */
 class InfoBarWrapper extends FrameLayout {
 
+    private final InfoBarContainerLayout.Item mItem;
+
     /**
      * Constructor for inflating from Java.
      */
-    InfoBarWrapper(Context context) {
+    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);
@@ -32,6 +35,10 @@ class InfoBarWrapper extends FrameLayout {
         setPadding(0, shadowHeight, 0, 0);
     }
 
+    InfoBarContainerLayout.Item getItem() {
+        return mItem;
+    }
+
     @Override
     public void onViewAdded(View child) {
         child.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT,