Add keycodes and meta-key modifiers to support external keyboards.

Added new key maps for external keyboards.  These maps are intended to
be shared across devices by inheriting the "keyboards.mk" product
makefile as part of the device's product definition.

One of the trickier changes here was to unwind some code in
MetaKeyKeyListener that assumed that only the low 8 bits of the meta key
state were actually used.  The new code abandons bitshifts in favor
of simple conditionals that are probably easier to read anyways.
The special meta key state constants used by MetaKeyKeyListener
are now (@hide) defined in KeyEvent now so as to make it clearer that they
share the same code space even if those codes are not valid for KeyEvents.

The EventHub now takes care of detecting the appropriate key layout
map and key character map when the device is added and sets system
properties accordingly.  This avoids having duplicate code in
KeyCharacterMap to probe for the appropriate key character map
although the current probing mechanism has been preserved for legacy
reasons just in case.

Added support for tracking caps lock, num lock and scroll lock and
turning their corresponding LEDs on and off as needed.

The key character map format will need to be updated to correctly support
PC style external keyboard semantics related to modifier keys.
That will come in a later change so caps lock doesn't actually do
anything right now except turn the shiny LEDs on and off...

Added a list of symbolic key names to KeyEvent and improved the toString()
output for debug diagnosis.  Having this list in a central place in the
framework also allows us to remove it from Monkey so there is one less
thing to maintain when we add new keycodes.

Bug: 2912307
Change-Id: If8c25e8d50a7c29bbf5d663c94284f5f86de5da4

1 files changed, 13 insertions, 0 deletions

diff --git a/include/ui/InputReader.h b/include/ui/InputReader.h
index c15e382..a1b59e6 100644
--- a/include/ui/InputReader.h
+++ b/include/ui/InputReader.h
@@ -419,9 +419,18 @@ private:
         Vector<KeyDown> keyDowns; // keys that are down
         int32_t metaState;
         nsecs_t downTime; // time of most recent key down
+
+        struct LedState {
+            bool avail; // led is available
+            bool on;    // we think the led is currently on
+        };
+        LedState capsLockLedState;
+        LedState numLockLedState;
+        LedState scrollLockLedState;
     } mLocked;
 
     void initializeLocked();
+    void initializeLedStateLocked(LockedState::LedState& ledState, int32_t led);
 
     bool isKeyboardOrGamepadKey(int32_t scanCode);
 
@@ -429,6 +438,10 @@ private:
             uint32_t policyFlags);
 
     ssize_t findKeyDownLocked(int32_t scanCode);
+
+    void updateLedStateLocked(bool reset);
+    void updateLedStateForModifierLocked(LockedState::LedState& ledState, int32_t led,
+            int32_t modifier, bool reset);
 };