commit 0faaa0bd7aa5dadea7c365fbb1f186da6eb097ef
author Dmitry Torokhov <dtor@google.com> Thu Sep 24 13:13:55 2015 -0700
committer Dmitry Torokhov <dtor@google.com> Tue Sep 29 13:27:16 2015 -0700
tree 2dc2ff68804e4cb736dd5348d2a755e5ca8a6b71
parent 115f93eeebf7f33b56ed090de70d6e8c733e5d88

Inputflinger: hook up key event replacement processing

Add handling of "replacement" key events in InputReader and EventHub by
consulting device's character key map (if exists) for presence of
replacement key code for given get code and meta state combination,
before passing it to InputDispatcher.

This enables defining special keys, such as ESC, on keyboards lacking
enough physical keys, via combination of normal keys and modifiers, for
example AltR + 1 => ESC.

Bug: 24504154

Change-Id: I7e36104808bedcf724436c1fbb63d37c35cca8af

services/inputflinger/InputReader.cpp

diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp
index 36095bf..b2cbfe8 100644
--- a/services/inputflinger/InputReader.cpp
+++ b/services/inputflinger/InputReader.cpp
@@ -2177,13 +2177,7 @@
         mCurrentHidUsage = 0;
 
         if (isKeyboardOrGamepadKey(scanCode)) {
-            int32_t keyCode;
-            uint32_t flags;
-            if (getEventHub()->mapKey(getDeviceId(), scanCode, usageCode, &keyCode, &flags)) {
-                keyCode = AKEYCODE_UNKNOWN;
-                flags = 0;
-            }
-            processKey(rawEvent->when, rawEvent->value != 0, keyCode, scanCode, flags);
+            processKey(rawEvent->when, rawEvent->value != 0, scanCode, usageCode);
         }
         break;
     }
@@ -2208,8 +2202,18 @@
         || (scanCode >= BTN_JOYSTICK && scanCode < BTN_DIGI);
 }
 
-void KeyboardInputMapper::processKey(nsecs_t when, bool down, int32_t keyCode,
-        int32_t scanCode, uint32_t policyFlags) {
+void KeyboardInputMapper::processKey(nsecs_t when, bool down, int32_t scanCode,
+        int32_t usageCode) {
+    int32_t keyCode;
+    int32_t keyMetaState;
+    uint32_t policyFlags;
+
+    if (getEventHub()->mapKey(getDeviceId(), scanCode, usageCode, mMetaState,
+                              &keyCode, &keyMetaState, &policyFlags)) {
+        keyCode = AKEYCODE_UNKNOWN;
+        keyMetaState = mMetaState;
+        policyFlags = 0;
+    }
 
     if (down) {
         // Rotate key codes according to orientation if needed.
@@ -2262,6 +2266,12 @@
     if (metaStateChanged) {
         mMetaState = newMetaState;
         updateLedState(false);
+
+        // If global meta state changed send it along with the key.
+        // If it has not changed then we'll use what keymap gave us,
+        // since key replacement logic might temporarily reset a few
+        // meta bits for given key.
+        keyMetaState = newMetaState;
     }
 
     nsecs_t downTime = mDownTime;
@@ -2289,7 +2299,7 @@
 
     NotifyKeyArgs args(when, getDeviceId(), mSource, policyFlags,
             down ? AKEY_EVENT_ACTION_DOWN : AKEY_EVENT_ACTION_UP,
-            AKEY_EVENT_FLAG_FROM_SYSTEM, keyCode, scanCode, newMetaState, downTime);
+            AKEY_EVENT_FLAG_FROM_SYSTEM, keyCode, scanCode, keyMetaState, downTime);
     getListener()->notifyKey(&args);
 }
 
@@ -3543,8 +3553,10 @@
 
         virtualKey.scanCode = virtualKeyDefinition.scanCode;
         int32_t keyCode;
+        int32_t dummyKeyMetaState;
         uint32_t flags;
-        if (getEventHub()->mapKey(getDeviceId(), virtualKey.scanCode, 0, &keyCode, &flags)) {
+        if (getEventHub()->mapKey(getDeviceId(), virtualKey.scanCode, 0, 0,
+                                  &keyCode, &dummyKeyMetaState, &flags)) {
             ALOGW(INDENT "VirtualKey %d: could not obtain key code, ignoring",
                     virtualKey.scanCode);
             mVirtualKeys.pop(); // drop the key