Merge "Fix child view ordering for accessibility." into lmp-dev
diff --git a/core/java/android/view/ViewGroup.java b/core/java/android/view/ViewGroup.java
index b586caa..4116b6b 100644
--- a/core/java/android/view/ViewGroup.java
+++ b/core/java/android/view/ViewGroup.java
@@ -7106,7 +7106,7 @@
ViewLocationHolder holder = ViewLocationHolder.obtain(parent, child);
holders.add(holder);
}
- Collections.sort(holders);
+ sort(holders);
for (int i = 0; i < childCount; i++) {
ViewLocationHolder holder = holders.get(i);
children.set(i, holder.mView);
@@ -7116,6 +7116,23 @@
}
}
+ private void sort(ArrayList<ViewLocationHolder> holders) {
+ // This is gross but the least risky solution. The current comparison
+ // strategy breaks transitivity but produces very good results. Coming
+ // up with a new strategy requires time which we do not have, so ...
+ try {
+ ViewLocationHolder.setComparisonStrategy(
+ ViewLocationHolder.COMPARISON_STRATEGY_STRIPE);
+ Collections.sort(holders);
+ } catch (IllegalArgumentException iae) {
+ // Note that in practice this occurs extremely rarely in a couple
+ // of pathological cases.
+ ViewLocationHolder.setComparisonStrategy(
+ ViewLocationHolder.COMPARISON_STRATEGY_LOCATION);
+ Collections.sort(holders);
+ }
+ }
+
private void clear() {
mChildren.clear();
}
@@ -7134,6 +7151,12 @@
private static final SynchronizedPool<ViewLocationHolder> sPool =
new SynchronizedPool<ViewLocationHolder>(MAX_POOL_SIZE);
+ public static final int COMPARISON_STRATEGY_STRIPE = 1;
+
+ public static final int COMPARISON_STRATEGY_LOCATION = 2;
+
+ private static int sComparisonStrategy = COMPARISON_STRATEGY_STRIPE;
+
private final Rect mLocation = new Rect();
public View mView;
@@ -7149,6 +7172,10 @@
return holder;
}
+ public static void setComparisonStrategy(int strategy) {
+ sComparisonStrategy = strategy;
+ }
+
public void recycle() {
clear();
sPool.release(this);
@@ -7160,6 +7187,18 @@
if (another == null) {
return 1;
}
+
+ if (sComparisonStrategy == COMPARISON_STRATEGY_STRIPE) {
+ // First is above second.
+ if (mLocation.bottom - another.mLocation.top <= 0) {
+ return -1;
+ }
+ // First is below second.
+ if (mLocation.top - another.mLocation.bottom >= 0) {
+ return 1;
+ }
+ }
+
// We are ordering left-to-right, top-to-bottom.
if (mLayoutDirection == LAYOUT_DIRECTION_LTR) {
final int leftDifference = mLocation.left - another.mLocation.left;