Fixed an issue where children dissappeared the wrong way

Because we were comparing relative to absolute positions,
we need to calculate the next view the right way.

Test: add children in group, remove the last / middle one
Fixes: 35193074
Change-Id: I415a978b84d528ded402b99b872769b98aa49ec0
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
index 6a5f79f..3bbaf99 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/ExpandableNotificationRow.java
@@ -211,6 +211,8 @@
     private boolean mIsColorized;
     private boolean mUseIncreasedCollapsedHeight;
     private boolean mUseIncreasedHeadsUpHeight;
+    private float mTranslationWhenRemoved;
+    private boolean mWasChildInGroupWhenRemoved;
 
     @Override
     public boolean isGroupExpansionChanging() {
@@ -836,10 +838,22 @@
 
     public void setRemoved() {
         mRemoved = true;
-
+        mTranslationWhenRemoved = getTranslationY();
+        mWasChildInGroupWhenRemoved = isChildInGroup();
+        if (isChildInGroup()) {
+            mTranslationWhenRemoved += getNotificationParent().getTranslationY();
+        }
         mPrivateLayout.setRemoved();
     }
 
+    public boolean wasChildInGroupWhenRemoved() {
+        return mWasChildInGroupWhenRemoved;
+    }
+
+    public float getTranslationWhenRemoved() {
+        return mTranslationWhenRemoved;
+    }
+
     public NotificationChildrenContainer getChildrenContainer() {
         return mChildrenContainer;
     }
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
index dd4e876..9057983 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
@@ -88,6 +88,7 @@
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashSet;
+import java.util.List;
 
 /**
  * A layout which handles a dynamic amount of notifications and presents them in a scrollable stack.
@@ -1836,12 +1837,29 @@
      * @return The first child which has visibility unequal to GONE which is currently below the
      *         given translationY or equal to it.
      */
-    private View getFirstChildBelowTranlsationY(float translationY) {
+    private View getFirstChildBelowTranlsationY(float translationY, boolean ignoreChildren) {
         int childCount = getChildCount();
         for (int i = 0; i < childCount; i++) {
             View child = getChildAt(i);
-            if (child.getVisibility() != View.GONE && child.getTranslationY() >= translationY) {
+            if (child.getVisibility() == View.GONE) {
+                continue;
+            }
+            float rowTranslation = child.getTranslationY();
+            if (rowTranslation >= translationY) {
                 return child;
+            } else if (!ignoreChildren && child instanceof ExpandableNotificationRow) {
+                ExpandableNotificationRow row = (ExpandableNotificationRow) child;
+                if (row.isSummaryWithChildren() && row.areChildrenExpanded()) {
+                    List<ExpandableNotificationRow> notificationChildren =
+                            row.getNotificationChildren();
+                    for (int childIndex = 0; childIndex < notificationChildren.size();
+                            childIndex++) {
+                        ExpandableNotificationRow rowChild = notificationChildren.get(childIndex);
+                        if (rowChild.getTranslationY() + rowTranslation >= translationY) {
+                            return rowChild;
+                        }
+                    }
+                }
             }
         }
         return null;
@@ -2500,7 +2518,7 @@
                     View groupParentWhenDismissed = row.getGroupParentWhenDismissed();
                     nextView = getFirstChildBelowTranlsationY(groupParentWhenDismissed != null
                             ? groupParentWhenDismissed.getTranslationY()
-                            : view.getTranslationY());
+                            : view.getTranslationY(), true /* ignoreChildren */);
                 }
                 if (nextView != null) {
                     nextView.requestAccessibilityFocus();
@@ -2940,7 +2958,17 @@
             AnimationEvent event = new AnimationEvent(child, animationType);
 
             // we need to know the view after this one
-            event.viewAfterChangingView = getFirstChildBelowTranlsationY(child.getTranslationY());
+            float removedTranslation = child.getTranslationY();
+            boolean ignoreChildren = true;
+            if (child instanceof ExpandableNotificationRow) {
+                ExpandableNotificationRow row = (ExpandableNotificationRow) child;
+                if (row.isRemoved() && row.wasChildInGroupWhenRemoved()) {
+                    removedTranslation = row.getTranslationWhenRemoved();
+                    ignoreChildren = false;
+                }
+            }
+            event.viewAfterChangingView = getFirstChildBelowTranlsationY(removedTranslation,
+                    ignoreChildren);
             mAnimationEvents.add(event);
             mSwipedOutViews.remove(child);
         }
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/stack/StackStateAnimator.java b/packages/SystemUI/src/com/android/systemui/statusbar/stack/StackStateAnimator.java
index 55085e5..9893434 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/stack/StackStateAnimator.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/stack/StackStateAnimator.java
@@ -389,10 +389,25 @@
                 // upwards by default
                 float translationDirection = -1.0f;
                 if (viewState != null) {
+                    float ownPosition = changingView.getTranslationY();
+                    if (changingView instanceof ExpandableNotificationRow
+                            && event.viewAfterChangingView instanceof ExpandableNotificationRow) {
+                        ExpandableNotificationRow changingRow =
+                                (ExpandableNotificationRow) changingView;
+                        ExpandableNotificationRow nextRow =
+                                (ExpandableNotificationRow) event.viewAfterChangingView;
+                        if (changingRow.isRemoved()
+                                && changingRow.wasChildInGroupWhenRemoved()
+                                && !nextRow.isChildInGroup()) {
+                            // the next row isn't actually a child from a group! Let's
+                            // compare absolute positions!
+                            ownPosition = changingRow.getTranslationWhenRemoved();
+                        }
+                    }
                     // there was a view after this one, Approximate the distance the next child
                     // travelled
                     translationDirection = ((viewState.yTranslation
-                            - (changingView.getTranslationY() + actualHeight / 2.0f)) * 2 /
+                            - (ownPosition + actualHeight / 2.0f)) * 2 /
                             actualHeight);
                     translationDirection = Math.max(Math.min(translationDirection, 1.0f),-1.0f);