Add support for fallback keycodes.

This change enables the framework to synthesize key events to implement
default behavior when an application does not handle a key.
For example, this change enables numeric keypad keys to perform
their associated special function when numlock is off.

The application is informed that it is processing a fallback keypress
so it can choose to ignore it.

Added a new keycode for switching applications.

Added ALT key deadkeys.

New default key mappings:
- ESC -> BACK
- Meta+ESC -> HOME
- Alt+ESC -> MENU
- Meta+Space -> SEARCH
- Meta+Tab -> APP_SWITCH

Fixed some comments.
Fixed some tests.

Change-Id: Id7f3b6645f3a350275e624547822f72652f3defe

5 files changed, 30 insertions, 5 deletions

diff --git a/include/ui/InputDispatcher.h b/include/ui/InputDispatcher.h
index b621680..7305601 100644
--- a/include/ui/InputDispatcher.h
+++ b/include/ui/InputDispatcher.h
@@ -306,9 +306,10 @@ public:
     virtual bool interceptKeyBeforeDispatching(const sp<InputChannel>& inputChannel,
             const KeyEvent* keyEvent, uint32_t policyFlags) = 0;
 
-    /* Allows the policy a chance to perform default processing for an unhandled key. */
+    /* Allows the policy a chance to perform default processing for an unhandled key.
+     * Returns an alternate keycode to redispatch as a fallback, or 0 to give up. */
     virtual bool dispatchUnhandledKey(const sp<InputChannel>& inputChannel,
-            const KeyEvent* keyEvent, uint32_t policyFlags) = 0;
+            const KeyEvent* keyEvent, uint32_t policyFlags, KeyEvent* outFallbackKeyEvent) = 0;
 
     /* Notifies the policy about switch events.
      */
@@ -735,6 +736,7 @@ private:
             CANCEL_ALL_EVENTS = 0,
             CANCEL_POINTER_EVENTS = 1,
             CANCEL_NON_POINTER_EVENTS = 2,
+            CANCEL_FALLBACK_EVENTS = 3,
         };
 
         InputState();
@@ -771,6 +773,7 @@ private:
             int32_t source;
             int32_t keyCode;
             int32_t scanCode;
+            int32_t flags;
             nsecs_t downTime;
         };
 
@@ -790,7 +793,10 @@ private:
         Vector<KeyMemento> mKeyMementos;
         Vector<MotionMemento> mMotionMementos;
 
-        static bool shouldCancelEvent(int32_t eventSource, CancelationOptions options);
+        static bool shouldCancelKey(const KeyMemento& memento,
+                CancelationOptions options);
+        static bool shouldCancelMotion(const MotionMemento& memento,
+                CancelationOptions options);
     };
 
     /* Manages the dispatch state associated with a single input channel. */
diff --git a/include/ui/InputReader.h b/include/ui/InputReader.h
index 8ec5421..b466ff1 100644
--- a/include/ui/InputReader.h
+++ b/include/ui/InputReader.h
@@ -402,7 +402,6 @@ private:
     } mLocked;
 
     void initializeLocked();
-    void initializeLedStateLocked(LockedState::LedState& ledState, int32_t led);
 
     void configureParameters();
     void dumpParameters(String8& dump);
@@ -414,6 +413,8 @@ private:
 
     ssize_t findKeyDownLocked(int32_t scanCode);
 
+    void resetLedStateLocked();
+    void initializeLedStateLocked(LockedState::LedState& ledState, int32_t led);
     void updateLedStateLocked(bool reset);
     void updateLedStateForModifierLocked(LockedState::LedState& ledState, int32_t led,
             int32_t modifier, bool reset);
diff --git a/include/ui/InputTransport.h b/include/ui/InputTransport.h
index 7efb6cc..119db81 100644
--- a/include/ui/InputTransport.h
+++ b/include/ui/InputTransport.h
@@ -256,7 +256,7 @@ public:
      * Returns WOULD_BLOCK if there is no signal present.
      * Other errors probably indicate that the channel is broken.
      */
-    status_t receiveFinishedSignal(bool& outHandled);
+    status_t receiveFinishedSignal(bool* outHandled);
 
 private:
     sp<InputChannel> mChannel;
diff --git a/include/ui/KeyCharacterMap.h b/include/ui/KeyCharacterMap.h
index a1ccb37..10a3810 100644
--- a/include/ui/KeyCharacterMap.h
+++ b/include/ui/KeyCharacterMap.h
@@ -44,6 +44,12 @@ public:
         KEYBOARD_TYPE_SPECIAL_FUNCTION = 5,
     };
 
+    // Substitute key code and meta state for fallback action.
+    struct FallbackAction {
+        int32_t keyCode;
+        int32_t metaState;
+    };
+
     ~KeyCharacterMap();
 
     static status_t load(const String8& filename, KeyCharacterMap** outMap);
@@ -67,6 +73,13 @@ public:
      */
     char16_t getCharacter(int32_t keyCode, int32_t metaState) const;
 
+    /* Gets the fallback action to use by default if the application does not
+     * handle the specified key.
+     * Returns true if an action was available, false if none.
+     */
+    bool getFallbackAction(int32_t keyCode, int32_t metaState,
+            FallbackAction* outFallbackAction) const;
+
     /* Gets the first matching Unicode character that can be generated by the key,
      * preferring the one with the specified meta key modifiers.
      * Returns 0 if no matching character is generated.
@@ -155,6 +168,10 @@ private:
 
     KeyCharacterMap();
 
+    bool getKey(int32_t keyCode, const Key** outKey) const;
+    bool getKeyBehavior(int32_t keyCode, int32_t metaState,
+            const Key** outKey, const Behavior** outBehavior) const;
+
     bool findKey(char16_t ch, int32_t* outKeyCode, int32_t* outMetaState) const;
 
     static void addKey(Vector<KeyEvent>& outEvents,
diff --git a/include/ui/KeycodeLabels.h b/include/ui/KeycodeLabels.h
index be7db1f..9b1a897 100755
--- a/include/ui/KeycodeLabels.h
+++ b/include/ui/KeycodeLabels.h
@@ -211,6 +211,7 @@ static const KeycodeLabel KEYCODES[] = {
     { "PROG_GREEN", 184 },
     { "PROG_YELLOW", 185 },
     { "PROG_BLUE", 186 },
+    { "APP_SWITCH", 187 },
 
     // NOTE: If you add a new keycode here you must also add it to several other files.
     //       Refer to frameworks/base/core/java/android/view/KeyEvent.java for the full list.