Avoid dividing 0 by 0 in StackScrollAlgorithm.
This is very likely the cause of b/233692725 (which is essentially an
error saying that translationZ is set to Float.NaN). Looked through all
the codepaths modifying translationZ, and this was the only one I could
find that could generate NaN.
Test: Not quite sure how to test it though, since I can't reproduce.
Will add some logging in a follow-up commit.
Bug: 233692725
Change-Id: Ie5db92ee714b2265ceacc366144bdadad00aaf51
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java
index eeed070..32591ce 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java
@@ -884,6 +884,9 @@
childViewState.zTranslation = baseZ;
} else {
float factor = (notificationEnd - shelfStart) / shelfHeight;
+ if (Float.isNaN(factor)) { // Avoid problems when the above is 0/0.
+ factor = 1.0f;
+ }
factor = Math.min(factor, 1.0f);
childViewState.zTranslation = baseZ + factor * zDistanceBetweenElements;
}