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

4 files changed, 63 insertions, 19 deletions

diff --git a/data/keyboards/Generic.kcm b/data/keyboards/Generic.kcm
index 24b485d..14d7c80 100644
--- a/data/keyboards/Generic.kcm
+++ b/data/keyboards/Generic.kcm
@@ -42,7 +42,9 @@ key C {
     label:                              'C'
     base:                               'c'
     shift, capslock:                    'C'
-    ctrl, alt, meta:                    none
+    alt:                                '\u00e7'
+    shift+alt:                          '\u00c7'
+    ctrl, meta:                         none
 }
 
 key D {
@@ -56,7 +58,8 @@ key E {
     label:                              'E'
     base:                               'e'
     shift, capslock:                    'E'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0301'
+    ctrl, meta:                         none
 }
 
 key F {
@@ -84,7 +87,8 @@ key I {
     label:                              'I'
     base:                               'i'
     shift, capslock:                    'I'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0302'
+    ctrl, meta:                         none
 }
 
 key J {
@@ -119,7 +123,8 @@ key N {
     label:                              'N'
     base:                               'n'
     shift, capslock:                    'N'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0303'
+    ctrl, meta:                         none
 }
 
 key O {
@@ -154,7 +159,8 @@ key S {
     label:                              'S'
     base:                               's'
     shift, capslock:                    'S'
-    ctrl, alt, meta:                    none
+    alt:                                '\u00df'
+    ctrl, meta:                         none
 }
 
 key T {
@@ -168,7 +174,8 @@ key U {
     label:                              'U'
     base:                               'u'
     shift, capslock:                    'U'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0308'
+    ctrl, meta:                         none
 }
 
 key V {
@@ -253,6 +260,7 @@ key 6 {
     base:                               '6'
     shift:                              '^'
     ctrl, alt, meta:                    none
+    alt+shift:                          '\u0302'
 }
 
 key 7 {
@@ -279,7 +287,8 @@ key 9 {
 key SPACE {
     label:                              ' '
     base:                               ' '
-    ctrl, alt, meta:                    none
+    ctrl, alt:                          none
+    meta:                               fallback SEARCH
 }
 
 key ENTER {
@@ -291,7 +300,8 @@ key ENTER {
 key TAB {
     label:                              '\t'
     base:                               '\t'
-    ctrl, alt, meta:                    none
+    ctrl, alt:                          none
+    meta:                               fallback APP_SWITCH
 }
 
 key COMMA {
@@ -319,7 +329,9 @@ key GRAVE {
     label, number:                      '`'
     base:                               '`'
     shift:                              '~'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0300'
+    alt+shift:                          '\u0303'
+    ctrl, meta:                         none
 }
 
 key MINUS {
@@ -525,3 +537,11 @@ key PLUS {
     label, number:                      '+'
     base:                               '+'
 }
+
+### Non-printing keys ###
+
+key ESCAPE {
+    base:                               fallback BACK
+    meta:                               fallback HOME
+    alt:                                fallback MENU
+}
diff --git a/data/keyboards/Vendor_05ac_Product_0239.kl b/data/keyboards/Vendor_05ac_Product_0239.kl
index 5234d58..6bd3753 100644
--- a/data/keyboards/Vendor_05ac_Product_0239.kl
+++ b/data/keyboards/Vendor_05ac_Product_0239.kl
@@ -104,7 +104,7 @@ key 111   FORWARD_DEL
 key 113   VOLUME_MUTE
 key 114   VOLUME_DOWN
 key 115   VOLUME_UP
-# key 120  switch applications
+key 120   APP_SWITCH
 key 125   META_LEFT
 key 126   META_RIGHT
 key 161   MEDIA_EJECT
diff --git a/data/keyboards/Vendor_22b8_Product_093d.kl b/data/keyboards/Vendor_22b8_Product_093d.kl
index 87b3c32..2749c5b 100644
--- a/data/keyboards/Vendor_22b8_Product_093d.kl
+++ b/data/keyboards/Vendor_22b8_Product_093d.kl
@@ -12,6 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+#
+# Motorola Bluetooth Wireless Keyboard.
+#
+
 key 1     BACK
 key 2     1
 key 3     2
diff --git a/data/keyboards/Virtual.kcm b/data/keyboards/Virtual.kcm
index 8d3c7ac..0ce4a68 100644
--- a/data/keyboards/Virtual.kcm
+++ b/data/keyboards/Virtual.kcm
@@ -39,7 +39,9 @@ key C {
     label:                              'C'
     base:                               'c'
     shift, capslock:                    'C'
-    ctrl, alt, meta:                    none
+    alt:                                '\u00e7'
+    shift+alt:                          '\u00c7'
+    ctrl, meta:                         none
 }
 
 key D {
@@ -53,7 +55,8 @@ key E {
     label:                              'E'
     base:                               'e'
     shift, capslock:                    'E'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0301'
+    ctrl, meta:                         none
 }
 
 key F {
@@ -81,7 +84,8 @@ key I {
     label:                              'I'
     base:                               'i'
     shift, capslock:                    'I'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0302'
+    ctrl, meta:                         none
 }
 
 key J {
@@ -116,7 +120,8 @@ key N {
     label:                              'N'
     base:                               'n'
     shift, capslock:                    'N'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0303'
+    ctrl, meta:                         none
 }
 
 key O {
@@ -151,7 +156,8 @@ key S {
     label:                              'S'
     base:                               's'
     shift, capslock:                    'S'
-    ctrl, alt, meta:                    none
+    alt:                                '\u00df'
+    ctrl, meta:                         none
 }
 
 key T {
@@ -165,7 +171,8 @@ key U {
     label:                              'U'
     base:                               'u'
     shift, capslock:                    'U'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0308'
+    ctrl, meta:                         none
 }
 
 key V {
@@ -250,6 +257,7 @@ key 6 {
     base:                               '6'
     shift:                              '^'
     ctrl, alt, meta:                    none
+    alt+shift:                          '\u0302'
 }
 
 key 7 {
@@ -276,7 +284,8 @@ key 9 {
 key SPACE {
     label:                              ' '
     base:                               ' '
-    ctrl, alt, meta:                    none
+    ctrl, alt:                          none
+    meta:                               fallback SEARCH
 }
 
 key ENTER {
@@ -288,7 +297,8 @@ key ENTER {
 key TAB {
     label:                              '\t'
     base:                               '\t'
-    ctrl, alt, meta:                    none
+    ctrl, alt:                          none
+    meta:                               fallback APP_SWITCH
 }
 
 key COMMA {
@@ -316,7 +326,9 @@ key GRAVE {
     label, number:                      '`'
     base:                               '`'
     shift:                              '~'
-    ctrl, alt, meta:                    none
+    alt:                                '\u0300'
+    alt+shift:                          '\u0303'
+    ctrl, meta:                         none
 }
 
 key MINUS {
@@ -522,3 +534,11 @@ key PLUS {
     label, number:                      '+'
     base:                               '+'
 }
+
+### Non-printing keys ###
+
+key ESCAPE {
+    base:                               fallback BACK
+    meta:                               fallback HOME
+    alt:                                fallback MENU
+}