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

1 files changed, 16 insertions, 3 deletions

diff --git a/core/java/android/view/KeyEvent.java b/core/java/android/view/KeyEvent.java
index 03407a3..43b77e6 100755
--- a/core/java/android/view/KeyEvent.java
+++ b/core/java/android/view/KeyEvent.java
@@ -529,15 +529,17 @@ public class KeyEvent extends InputEvent implements Parcelable {
     /** Key code constant: Blue "programmable" key.
      * On TV remotes, acts as a contextual/programmable key. */
     public static final int KEYCODE_PROG_BLUE       = 186;
+    /** Key code constant: App switch key.
+     * Should bring up the application switcher dialog. */
+    public static final int KEYCODE_APP_SWITCH      = 187;
 
-    private static final int LAST_KEYCODE           = KEYCODE_PROG_BLUE;
+    private static final int LAST_KEYCODE           = KEYCODE_APP_SWITCH;
 
     // NOTE: If you add a new keycode here you must also add it to:
     //  isSystem()
     //  native/include/android/keycodes.h
     //  frameworks/base/include/ui/KeycodeLabels.h
     //  external/webkit/WebKit/android/plugins/ANPKeyCodes.h
-    //  tools/puppet_master/PuppetMaster/nav_keys.py
     //  frameworks/base/core/res/res/values/attrs.xml
     //  emulator?
     //
@@ -737,6 +739,7 @@ public class KeyEvent extends InputEvent implements Parcelable {
         "KEYCODE_PROG_GREEN",
         "KEYCODE_PROG_YELLOW",
         "KEYCODE_PROG_BLUE",
+        "KEYCODE_APP_SWITCH",
     };
 
     // Symbolic names of all metakeys in bit order from least significant to most significant.
@@ -1056,7 +1059,17 @@ public class KeyEvent extends InputEvent implements Parcelable {
      * the tracking to be canceled.
      */
     public static final int FLAG_TRACKING = 0x200;
-    
+
+    /**
+     * Set when a key event has been synthesized to implement default behavior
+     * for an event that the application did not handle.
+     * Fallback key events are generated by unhandled trackball motions
+     * (to emulate a directional keypad) and by certain unhandled key presses
+     * that are declared in the key map (such as special function numeric keypad
+     * keys when numlock is off).
+     */
+    public static final int FLAG_FALLBACK = 0x400;
+
     /**
      * Private control to determine when an app is tracking a key sequence.
      * @hide