Fix bugs in fallback key handling.

If a fallback key is generated using a key plus a modifier,
then it's possible we might get a different fallback key
generated if the modifier has changed.  PhoneWindowManager
needs to remember which fallback is last generated for a
given key code so that it can apply the same fallback action.

When generating cancellation events, it's important to have
preserved the policyFlags of the original event.  Otherwise
we may not dispatch the cancellation properly.  For example,
some actions are not performed if the POLICY_FLAG_TRUSTED
is not specified.

Remember the metaState associated with a key event so we can
include it when canceled.

Tell the policy when a fallback is being cancelled so that it
can clean up its state.

After a SEARCH shortcut is invoked, clear the flag indicating
that a shortcut is pending.  This is to prevent SEARCH from
getting stuck down in the case where we might forget to send
the up.  (Shouldn't happen anymore after the prior fixes.)

Bug: 5616255
Change-Id: I68f0a9679c7af464eaf31c099f2aa50b53fecf1f

1 files changed, 46 insertions, 9 deletions

diff --git a/core/java/android/view/KeyCharacterMap.java b/core/java/android/view/KeyCharacterMap.java
index 5b371ebf31cd..2cb724f31b13 100644
--- a/core/java/android/view/KeyCharacterMap.java
+++ b/core/java/android/view/KeyCharacterMap.java
@@ -386,19 +386,19 @@ public class KeyCharacterMap implements Parcelable {
      *
      * @param keyCode The key code.
      * @param metaState The meta key modifier state.
-     * @param outFallbackAction The fallback action object to populate.
-     * @return True if a fallback action was found, false otherwise.
+     * @return The fallback action, or null if none.  Remember to recycle the fallback action.
      *
      * @hide
      */
-    public boolean getFallbackAction(int keyCode, int metaState,
-            FallbackAction outFallbackAction) {
-        if (outFallbackAction == null) {
-            throw new IllegalArgumentException("fallbackAction must not be null");
-        }
-
+    public FallbackAction getFallbackAction(int keyCode, int metaState) {
+        FallbackAction action = FallbackAction.obtain();
         metaState = KeyEvent.normalizeMetaState(metaState);
-        return nativeGetFallbackAction(mPtr, keyCode, metaState, outFallbackAction);
+        if (nativeGetFallbackAction(mPtr, keyCode, metaState, action)) {
+            action.metaState = KeyEvent.normalizeMetaState(action.metaState);
+            return action;
+        }
+        action.recycle();
+        return null;
     }
 
     /**
@@ -727,7 +727,44 @@ public class KeyCharacterMap implements Parcelable {
      * @hide
      */
     public static final class FallbackAction {
+        private static final int MAX_RECYCLED = 10;
+        private static final Object sRecycleLock = new Object();
+        private static FallbackAction sRecycleBin;
+        private static int sRecycledCount;
+
+        private FallbackAction next;
+
         public int keyCode;
         public int metaState;
+
+        private FallbackAction() {
+        }
+
+        public static FallbackAction obtain() {
+            final FallbackAction target;
+            synchronized (sRecycleLock) {
+                if (sRecycleBin == null) {
+                    target = new FallbackAction();
+                } else {
+                    target = sRecycleBin;
+                    sRecycleBin = target.next;
+                    sRecycledCount--;
+                    target.next = null;
+                }
+            }
+            return target;
+        }
+
+        public void recycle() {
+            synchronized (sRecycleLock) {
+                if (sRecycledCount < MAX_RECYCLED) {
+                    next = sRecycleBin;
+                    sRecycleBin = this;
+                    sRecycledCount += 1;
+                } else {
+                    next = null;
+                }
+            }
+        }
     }
 }