Refactor input reader to add stylus support.

Bug: 5064702

Introduced the concept of an InputListener to further decouple
the InputReader from the InputDispatcher.  The InputListener
exposes just the minimum interface that the InputReader needs
to communicate with the outside world.  The InputReader
passes arguments to the InputListener by reference, which makes
it easy to queue them up.

Consolidated all of the InputReader locks into one simple global
Mutex.  The reason this wasn't done before was due to potential
re-entrance in outbound calls to the InputDispatcher.  To fix this,
the InputReader now queues up all of the events it wants to send
using a QueuedInputListener, then flushes them outside of the
critical section after all of the event processing is finished.
Removing all of the InputMapper locks greatly simplifies the
implementation.

Added tests for new stylus features such as buttons, tool types,
and hovering.

Added some helpers to BitSet32 to handle common code patterns
like finding the first marked bit and clearing it.

Fixed a bug in VelocityTracker where the wrong pointer trace
could get cleared when handling ACTION_POINTER_DOWN.  Oops.

Changed PointerCoords so it no longer stores useless zero
axis values.  Removed editAxisValue because it is not very
useful when all zero value axes are absent and therefore
cannot be edited in place.

Added dispatch of stylus hover events.

Added support for distance and tool types.

Change-Id: I4cf14d134fcb1db7d10be5f2af7b37deef8f8468

1 files changed, 15 insertions, 31 deletions

diff --git a/libs/ui/Input.cpp b/libs/ui/Input.cpp
index 0af7f8043c35..688b99892bf9 100644
--- a/libs/ui/Input.cpp
+++ b/libs/ui/Input.cpp
@@ -280,6 +280,9 @@ status_t PointerCoords::setAxisValue(int32_t axis, float value) {
     uint64_t axisBit = 1LL << axis;
     uint32_t index = __builtin_popcountll(bits & (axisBit - 1LL));
     if (!(bits & axisBit)) {
+        if (value == 0) {
+            return OK; // axes with value 0 do not need to be stored
+        }
         uint32_t count = __builtin_popcountll(bits);
         if (count >= MAX_AXES) {
             tooManyAxes(axis);
@@ -294,23 +297,10 @@ status_t PointerCoords::setAxisValue(int32_t axis, float value) {
     return OK;
 }
 
-float* PointerCoords::editAxisValue(int32_t axis) {
-    if (axis < 0 || axis > 63) {
-        return NULL;
-    }
-
-    uint64_t axisBit = 1LL << axis;
-    if (!(bits & axisBit)) {
-        return NULL;
-    }
-    uint32_t index = __builtin_popcountll(bits & (axisBit - 1LL));
-    return &values[index];
-}
-
 static inline void scaleAxisValue(PointerCoords& c, int axis, float scaleFactor) {
-    float* value = c.editAxisValue(axis);
-    if (value) {
-        *value *= scaleFactor;
+    float value = c.getAxisValue(axis);
+    if (value != 0) {
+        c.setAxisValue(axis, value * scaleFactor);
     }
 }
 
@@ -574,20 +564,14 @@ void MotionEvent::transform(const SkMatrix* matrix) {
     size_t numSamples = mSamplePointerCoords.size();
     for (size_t i = 0; i < numSamples; i++) {
         PointerCoords& c = mSamplePointerCoords.editItemAt(i);
-        float* xPtr = c.editAxisValue(AMOTION_EVENT_AXIS_X);
-        float* yPtr = c.editAxisValue(AMOTION_EVENT_AXIS_Y);
-        if (xPtr && yPtr) {
-            float x = *xPtr + oldXOffset;
-            float y = *yPtr + oldYOffset;
-            matrix->mapXY(SkFloatToScalar(x), SkFloatToScalar(y), & point);
-            *xPtr = SkScalarToFloat(point.fX) - newXOffset;
-            *yPtr = SkScalarToFloat(point.fY) - newYOffset;
-        }
+        float x = c.getAxisValue(AMOTION_EVENT_AXIS_X) + oldXOffset;
+        float y = c.getAxisValue(AMOTION_EVENT_AXIS_Y) + oldYOffset;
+        matrix->mapXY(SkFloatToScalar(x), SkFloatToScalar(y), &point);
+        c.setAxisValue(AMOTION_EVENT_AXIS_X, SkScalarToFloat(point.fX) - newXOffset);
+        c.setAxisValue(AMOTION_EVENT_AXIS_Y, SkScalarToFloat(point.fY) - newYOffset);
 
-        float* orientationPtr = c.editAxisValue(AMOTION_EVENT_AXIS_ORIENTATION);
-        if (orientationPtr) {
-            *orientationPtr = transformAngle(matrix, *orientationPtr);
-        }
+        float orientation = c.getAxisValue(AMOTION_EVENT_AXIS_ORIENTATION);
+        c.setAxisValue(AMOTION_EVENT_AXIS_ORIENTATION, transformAngle(matrix, orientation));
     }
 }
 
@@ -727,7 +711,7 @@ void VelocityTracker::addMovement(nsecs_t eventTime, BitSet32 idBits, const Posi
     }
 
     while (idBits.count() > MAX_POINTERS) {
-        idBits.clearBit(idBits.lastMarkedBit());
+        idBits.clearLastMarkedBit();
     }
 
     Movement& movement = mMovements[mIndex];
@@ -776,7 +760,7 @@ void VelocityTracker::addMovement(const MotionEvent* event) {
         // We do this on down instead of on up because the client may want to query the
         // final velocity for a pointer that just went up.
         BitSet32 downIdBits;
-        downIdBits.markBit(event->getActionIndex());
+        downIdBits.markBit(event->getPointerId(event->getActionIndex()));
         clearPointers(downIdBits);
         break;
     }