Merge "Gracefully handle focus loops created by app dev." into oc-dr1-dev

am: ae938cee71

Change-Id: I0b0fe6f7cc07362e98f7a5a2b54aa66bbd5ffc7f

1 files changed, 10 insertions, 0 deletions

diff --git a/core/java/android/view/FocusFinder.java b/core/java/android/view/FocusFinder.java
index 48e5ca9a20f4..af26a88e877c 100644
--- a/core/java/android/view/FocusFinder.java
+++ b/core/java/android/view/FocusFinder.java
@@ -193,6 +193,8 @@ public class FocusFinder {
     private View findNextUserSpecifiedFocus(ViewGroup root, View focused, int direction) {
         // check for user specified next focus
         View userSetNextFocus = focused.findUserSetNextFocus(root, direction);
+        View cycleCheck = userSetNextFocus;
+        boolean cycleStep = true; // we want the first toggle to yield false
         while (userSetNextFocus != null) {
             if (userSetNextFocus.isFocusable()
                     && userSetNextFocus.getVisibility() == View.VISIBLE
@@ -201,6 +203,14 @@ public class FocusFinder {
                 return userSetNextFocus;
             }
             userSetNextFocus = userSetNextFocus.findUserSetNextFocus(root, direction);
+            if (cycleStep = !cycleStep) {
+                cycleCheck = cycleCheck.findUserSetNextFocus(root, direction);
+                if (cycleCheck == userSetNextFocus) {
+                    // found a cycle, user-specified focus forms a loop and none of the views
+                    // are currently focusable.
+                    break;
+                }
+            }
         }
         return null;
     }