commit 4cea0f5bfc7d34299f5f645d37f94b14ac3dc22a
author Wale Ogunwale <ogunwale@google.com> Fri Dec 25 06:30:31 2015 -0800
committer Wale Ogunwale <ogunwale@google.com> Mon Jan 04 20:37:02 2016 +0000
tree 6f6aab50eb4ba9b488e615de328294294e4b2d92
parent d6f5e6bb91cf2f970a2410940860ed60db70df5e

Don't allow unfocusable activity/stack to gain focus

Prevents them from being resumed since we always want to resumed
activity to be a focusable acitvity.

Bug: 26273032
Change-Id: Ied832e100d9a2d8915762db53c9230774be21d1c

services/core/java/com/android/server/am/ActivityStackSupervisor.java

diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index df1aa52..688243d 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -492,8 +492,8 @@
                 calculateDefaultMinimalSizeOfResizeableTasks(activityDisplay);
             }
 
-            createStackOnDisplay(HOME_STACK_ID, Display.DEFAULT_DISPLAY, true);
-            mHomeStack = mFocusedStack = mLastFocusedStack = getStack(HOME_STACK_ID);
+            mHomeStack = mFocusedStack = mLastFocusedStack =
+                    getStack(HOME_STACK_ID, CREATE_IF_NEEDED, ON_TOP);
 
             mInputManagerInternal = LocalServices.getService(InputManagerInternal.class);
         }
@@ -538,10 +538,15 @@
     }
 
     /** NOTE: Should only be called from {@link ActivityStack#moveToFront} */
-    void setFocusStack(String reason, ActivityStack focusedStack) {
-        if (focusedStack != mFocusedStack) {
+    void setFocusStackUnchecked(String reason, ActivityStack focusCandidate) {
+        if (!focusCandidate.isFocusable()) {
+            // The focus candidate isn't focusable. Move focus to the top stack that is focusable.
+            focusCandidate = focusCandidate.getNextFocusableStackLocked();
+        }
+
+        if (focusCandidate != mFocusedStack) {
             mLastFocusedStack = mFocusedStack;
-            mFocusedStack = focusedStack;
+            mFocusedStack = focusCandidate;
 
             EventLogTags.writeAmFocusedStack(
                     mCurrentUser, mFocusedStack == null ? -1 : mFocusedStack.getStackId(),
@@ -904,7 +909,7 @@
         final ArrayList<ActivityStack> stacks = mHomeStack.mStacks;
         for (int stackNdx = stacks.size() - 1; stackNdx >= 0; --stackNdx) {
             final ActivityStack stack = stacks.get(stackNdx);
-            if (stack != focusedStack && isFrontStack(stack)) {
+            if (stack != focusedStack && isFrontStack(stack) && stack.isFocusable()) {
                 r = stack.topRunningActivityLocked();
                 if (r != null) {
                     return r;