Joystick tweaks. (DO NOT MERGE)

Ensure that the joystick can always reach -1.0, 0.0 and 1.0 positions
even when noise filtering is applied.  (Bug: 3514510)

Add support for a few more standard axes.

Add additional mapping modes for axes.
Some axes are inverted from standard interpretation
or are actually intended to be split into two distict axes
such as left/right trigger controls or accelerator/brake.

Add key layout file for a G25 racing wheel and XBox 360 controller
to tweak behavior.  They work fine without them but the axis mappings
are not ideal.

Change-Id: I0fddd90309af4dc14d35f34fe99ed6e521c0b7c7

2 files changed, 37 insertions, 2 deletions

diff --git a/include/ui/KeyLayoutMap.h b/include/ui/KeyLayoutMap.h
index 904c8f3..d82d0c8 100644
--- a/include/ui/KeyLayoutMap.h
+++ b/include/ui/KeyLayoutMap.h
@@ -24,6 +24,36 @@
 
 namespace android {
 
+struct AxisInfo {
+    enum Mode {
+        // Axis value is reported directly.
+        MODE_NORMAL = 0,
+        // Axis value should be inverted before reporting.
+        MODE_INVERT = 1,
+        // Axis value should be split into two axes
+        MODE_SPLIT = 2,
+    };
+
+    // Axis mode.
+    Mode mode;
+
+    // Axis id.
+    // When split, this is the axis used for values smaller than the split position.
+    int32_t axis;
+
+    // When split, this is the axis used for values after higher than the split position.
+    int32_t highAxis;
+
+    // The split value, or 0 if not split.
+    int32_t splitValue;
+
+    // The flat value, or -1 if none.
+    int32_t flatOverride;
+
+    AxisInfo() : mode(MODE_NORMAL), axis(-1), highAxis(-1), splitValue(0), flatOverride(-1) {
+    }
+};
+
 /**
  * Describes a mapping from keyboard scan codes and joystick axes to Android key codes and axes.
  */
@@ -36,7 +66,7 @@ public:
     status_t mapKey(int32_t scanCode, int32_t* keyCode, uint32_t* flags) const;
     status_t findScanCodesForKey(int32_t keyCode, Vector<int32_t>* outScanCodes) const;
 
-    status_t mapAxis(int32_t scanCode, int32_t* axis) const;
+    status_t mapAxis(int32_t scanCode, AxisInfo* outAxisInfo) const;
 
 private:
     struct Key {
@@ -45,7 +75,7 @@ private:
     };
 
     KeyedVector<int32_t, Key> mKeys;
-    KeyedVector<int32_t, int32_t> mAxes;
+    KeyedVector<int32_t, AxisInfo> mAxes;
 
     KeyLayoutMap();
 
diff --git a/include/ui/KeycodeLabels.h b/include/ui/KeycodeLabels.h
index bdfbf7c..b912e9b 100755
--- a/include/ui/KeycodeLabels.h
+++ b/include/ui/KeycodeLabels.h
@@ -270,6 +270,11 @@ static const KeycodeLabel AXES[] = {
     { "HAT_Y", 16 },
     { "LTRIGGER", 17 },
     { "RTRIGGER", 18 },
+    { "THROTTLE", 19 },
+    { "RUDDER", 20 },
+    { "WHEEL", 21 },
+    { "GAS", 22 },
+    { "BRAKE", 23 },
     { "GENERIC_1", 32 },
     { "GENERIC_2", 33 },
     { "GENERIC_3", 34 },