Add support for arbitrary axes in MotionEvents.

This change makes it possible to extend the set of axes that
are reported in MotionEvents by defining new axis constants.

The MotionEvent object is now backed by its C++ counterpart
to avoid having to maintain multiple representations of the
same data.

Change-Id: Ibe93c90d4b390d43c176cce48d558d20869ee608

1 files changed, 291 insertions, 6 deletions

diff --git a/libs/ui/Input.cpp b/libs/ui/Input.cpp
index b8d59e6..90b954e 100644
--- a/libs/ui/Input.cpp
+++ b/libs/ui/Input.cpp
@@ -15,6 +15,16 @@
 
 #include <ui/Input.h>
 
+#include <math.h>
+
+#ifdef HAVE_ANDROID_OS
+#include <binder/Parcel.h>
+
+#include "SkPoint.h"
+#include "SkMatrix.h"
+#include "SkScalar.h"
+#endif
+
 namespace android {
 
 static const char* CONFIGURATION_FILE_DIR[] = {
@@ -237,6 +247,41 @@ void KeyEvent::initialize(const KeyEvent& from) {
     mEventTime = from.mEventTime;
 }
 
+
+// --- PointerCoords ---
+
+#ifdef HAVE_ANDROID_OS
+status_t PointerCoords::readFromParcel(Parcel* parcel) {
+    bits = parcel->readInt32();
+
+    uint32_t count = __builtin_popcount(bits);
+    if (count > MAX_AXES) {
+        return BAD_VALUE;
+    }
+
+    for (uint32_t i = 0; i < count; i++) {
+        values[i] = parcel->readInt32();
+    }
+    return OK;
+}
+
+status_t PointerCoords::writeToParcel(Parcel* parcel) const {
+    parcel->writeInt32(bits);
+
+    uint32_t count = __builtin_popcount(bits);
+    for (uint32_t i = 0; i < count; i++) {
+        parcel->writeInt32(values[i]);
+    }
+    return OK;
+}
+#endif
+
+void PointerCoords::tooManyAxes(int axis) {
+    LOGW("Could not set value for axis %d because the PointerCoords structure is full and "
+            "cannot contain more than %d axis values.", axis, int(MAX_AXES));
+}
+
+
 // --- MotionEvent ---
 
 void MotionEvent::initialize(
@@ -272,6 +317,33 @@ void MotionEvent::initialize(
     addSample(eventTime, pointerCoords);
 }
 
+void MotionEvent::copyFrom(const MotionEvent* other, bool keepHistory) {
+    InputEvent::initialize(other->mDeviceId, other->mSource);
+    mAction = other->mAction;
+    mFlags = other->mFlags;
+    mEdgeFlags = other->mEdgeFlags;
+    mMetaState = other->mMetaState;
+    mXOffset = other->mXOffset;
+    mYOffset = other->mYOffset;
+    mXPrecision = other->mXPrecision;
+    mYPrecision = other->mYPrecision;
+    mDownTime = other->mDownTime;
+    mPointerIds = other->mPointerIds;
+
+    if (keepHistory) {
+        mSampleEventTimes = other->mSampleEventTimes;
+        mSamplePointerCoords = other->mSamplePointerCoords;
+    } else {
+        mSampleEventTimes.clear();
+        mSampleEventTimes.push(other->getEventTime());
+        mSamplePointerCoords.clear();
+        size_t pointerCount = other->getPointerCount();
+        size_t historySize = other->getHistorySize();
+        mSamplePointerCoords.appendArray(other->mSamplePointerCoords.array()
+                + (historySize * pointerCount), pointerCount);
+    }
+}
+
 void MotionEvent::addSample(
         int64_t eventTime,
         const PointerCoords* pointerCoords) {
@@ -279,11 +351,224 @@ void MotionEvent::addSample(
     mSamplePointerCoords.appendArray(pointerCoords, getPointerCount());
 }
 
+const PointerCoords* MotionEvent::getRawPointerCoords(size_t pointerIndex) const {
+    return &mSamplePointerCoords[getHistorySize() * getPointerCount() + pointerIndex];
+}
+
+float MotionEvent::getRawAxisValue(int32_t axis, size_t pointerIndex) const {
+    return getRawPointerCoords(pointerIndex)->getAxisValue(axis);
+}
+
+float MotionEvent::getAxisValue(int32_t axis, size_t pointerIndex) const {
+    float value = getRawPointerCoords(pointerIndex)->getAxisValue(axis);
+    switch (axis) {
+    case AINPUT_MOTION_AXIS_X:
+        value += mXOffset;
+        break;
+    case AINPUT_MOTION_AXIS_Y:
+        value += mYOffset;
+        break;
+    }
+    return value;
+}
+
+const PointerCoords* MotionEvent::getHistoricalRawPointerCoords(
+        size_t pointerIndex, size_t historicalIndex) const {
+    return &mSamplePointerCoords[historicalIndex * getPointerCount() + pointerIndex];
+}
+
+float MotionEvent::getHistoricalRawAxisValue(int32_t axis, size_t pointerIndex,
+        size_t historicalIndex) const {
+    return getHistoricalRawPointerCoords(pointerIndex, historicalIndex)->getAxisValue(axis);
+}
+
+float MotionEvent::getHistoricalAxisValue(int32_t axis, size_t pointerIndex,
+        size_t historicalIndex) const {
+    float value = getHistoricalRawPointerCoords(pointerIndex, historicalIndex)->getAxisValue(axis);
+    switch (axis) {
+    case AINPUT_MOTION_AXIS_X:
+        value += mXOffset;
+        break;
+    case AINPUT_MOTION_AXIS_Y:
+        value += mYOffset;
+        break;
+    }
+    return value;
+}
+
 void MotionEvent::offsetLocation(float xOffset, float yOffset) {
     mXOffset += xOffset;
     mYOffset += yOffset;
 }
 
+static inline void scaleAxisValue(PointerCoords& c, int axis, float scaleFactor) {
+    float* value = c.editAxisValue(axis);
+    if (value) {
+        *value *= scaleFactor;
+    }
+}
+
+void MotionEvent::scale(float scaleFactor) {
+    mXOffset *= scaleFactor;
+    mYOffset *= scaleFactor;
+    mXPrecision *= scaleFactor;
+    mYPrecision *= scaleFactor;
+
+    size_t numSamples = mSamplePointerCoords.size();
+    for (size_t i = 0; i < numSamples; i++) {
+        PointerCoords& c = mSamplePointerCoords.editItemAt(i);
+        // No need to scale pressure or size since they are normalized.
+        // No need to scale orientation since it is meaningless to do so.
+        scaleAxisValue(c, AINPUT_MOTION_AXIS_X, scaleFactor);
+        scaleAxisValue(c, AINPUT_MOTION_AXIS_Y, scaleFactor);
+        scaleAxisValue(c, AINPUT_MOTION_AXIS_TOUCH_MAJOR, scaleFactor);
+        scaleAxisValue(c, AINPUT_MOTION_AXIS_TOUCH_MINOR, scaleFactor);
+        scaleAxisValue(c, AINPUT_MOTION_AXIS_TOOL_MAJOR, scaleFactor);
+        scaleAxisValue(c, AINPUT_MOTION_AXIS_TOOL_MINOR, scaleFactor);
+    }
+}
+
+#ifdef HAVE_ANDROID_OS
+static inline float transformAngle(const SkMatrix* matrix, float angleRadians) {
+    // Construct and transform a vector oriented at the specified clockwise angle from vertical.
+    // Coordinate system: down is increasing Y, right is increasing X.
+    SkPoint vector;
+    vector.fX = SkFloatToScalar(sinf(angleRadians));
+    vector.fY = SkFloatToScalar(-cosf(angleRadians));
+    matrix->mapVectors(& vector, 1);
+
+    // Derive the transformed vector's clockwise angle from vertical.
+    float result = atan2f(SkScalarToFloat(vector.fX), SkScalarToFloat(-vector.fY));
+    if (result < - M_PI_2) {
+        result += M_PI;
+    } else if (result > M_PI_2) {
+        result -= M_PI;
+    }
+    return result;
+}
+
+void MotionEvent::transform(const SkMatrix* matrix) {
+    float oldXOffset = mXOffset;
+    float oldYOffset = mYOffset;
+
+    // The tricky part of this implementation is to preserve the value of
+    // rawX and rawY.  So we apply the transformation to the first point
+    // then derive an appropriate new X/Y offset that will preserve rawX and rawY.
+    SkPoint point;
+    float rawX = getRawX(0);
+    float rawY = getRawY(0);
+    matrix->mapXY(SkFloatToScalar(rawX + oldXOffset), SkFloatToScalar(rawY + oldYOffset),
+            & point);
+    float newX = SkScalarToFloat(point.fX);
+    float newY = SkScalarToFloat(point.fY);
+    float newXOffset = newX - rawX;
+    float newYOffset = newY - rawY;
+
+    mXOffset = newXOffset;
+    mYOffset = newYOffset;
+
+    // Apply the transformation to all samples.
+    size_t numSamples = mSamplePointerCoords.size();
+    for (size_t i = 0; i < numSamples; i++) {
+        PointerCoords& c = mSamplePointerCoords.editItemAt(i);
+        float* xPtr = c.editAxisValue(AINPUT_MOTION_AXIS_X);
+        float* yPtr = c.editAxisValue(AINPUT_MOTION_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* orientationPtr = c.editAxisValue(AINPUT_MOTION_AXIS_ORIENTATION);
+        if (orientationPtr) {
+            *orientationPtr = transformAngle(matrix, *orientationPtr);
+        }
+    }
+}
+
+status_t MotionEvent::readFromParcel(Parcel* parcel) {
+    size_t pointerCount = parcel->readInt32();
+    size_t sampleCount = parcel->readInt32();
+    if (pointerCount == 0 || pointerCount > MAX_POINTERS || sampleCount == 0) {
+        return BAD_VALUE;
+    }
+
+    mDeviceId = parcel->readInt32();
+    mSource = parcel->readInt32();
+    mAction = parcel->readInt32();
+    mFlags = parcel->readInt32();
+    mEdgeFlags = parcel->readInt32();
+    mMetaState = parcel->readInt32();
+    mXOffset = parcel->readFloat();
+    mYOffset = parcel->readFloat();
+    mXPrecision = parcel->readFloat();
+    mYPrecision = parcel->readFloat();
+    mDownTime = parcel->readInt64();
+
+    mPointerIds.clear();
+    mPointerIds.setCapacity(pointerCount);
+    mSampleEventTimes.clear();
+    mSampleEventTimes.setCapacity(sampleCount);
+    mSamplePointerCoords.clear();
+    mSamplePointerCoords.setCapacity(sampleCount * pointerCount);
+
+    for (size_t i = 0; i < pointerCount; i++) {
+        mPointerIds.push(parcel->readInt32());
+    }
+
+    while (sampleCount-- > 0) {
+        mSampleEventTimes.push(parcel->readInt64());
+        for (size_t i = 0; i < pointerCount; i++) {
+            mSamplePointerCoords.push();
+            status_t status = mSamplePointerCoords.editTop().readFromParcel(parcel);
+            if (!status) {
+                return status;
+            }
+        }
+    }
+    return OK;
+}
+
+status_t MotionEvent::writeToParcel(Parcel* parcel) const {
+    size_t pointerCount = mPointerIds.size();
+    size_t sampleCount = mSampleEventTimes.size();
+
+    parcel->writeInt32(pointerCount);
+    parcel->writeInt32(sampleCount);
+
+    parcel->writeInt32(mDeviceId);
+    parcel->writeInt32(mSource);
+    parcel->writeInt32(mAction);
+    parcel->writeInt32(mFlags);
+    parcel->writeInt32(mEdgeFlags);
+    parcel->writeInt32(mMetaState);
+    parcel->writeFloat(mXOffset);
+    parcel->writeFloat(mYOffset);
+    parcel->writeFloat(mXPrecision);
+    parcel->writeFloat(mYPrecision);
+    parcel->writeInt64(mDownTime);
+
+    for (size_t i = 0; i < pointerCount; i++) {
+        parcel->writeInt32(mPointerIds.itemAt(i));
+    }
+
+    const PointerCoords* pc = mSamplePointerCoords.array();
+    for (size_t h = 0; h < sampleCount; h++) {
+        parcel->writeInt64(mSampleEventTimes.itemAt(h));
+        for (size_t i = 0; i < pointerCount; i++) {
+            status_t status = (pc++)->writeToParcel(parcel);
+            if (!status) {
+                return status;
+            }
+        }
+    }
+    return OK;
+}
+#endif
+
+
 // --- InputDeviceInfo ---
 
 InputDeviceInfo::InputDeviceInfo() {
@@ -307,8 +592,8 @@ void InputDeviceInfo::initialize(int32_t id, const String8& name) {
     mMotionRanges.clear();
 }
 
-const InputDeviceInfo::MotionRange* InputDeviceInfo::getMotionRange(int32_t rangeType) const {
-    ssize_t index = mMotionRanges.indexOfKey(rangeType);
+const InputDeviceInfo::MotionRange* InputDeviceInfo::getMotionRange(int32_t axis) const {
+    ssize_t index = mMotionRanges.indexOfKey(axis);
     return index >= 0 ? & mMotionRanges.valueAt(index) : NULL;
 }
 
@@ -316,14 +601,14 @@ void InputDeviceInfo::addSource(uint32_t source) {
     mSources |= source;
 }
 
-void InputDeviceInfo::addMotionRange(int32_t rangeType, float min, float max,
+void InputDeviceInfo::addMotionRange(int32_t axis, float min, float max,
         float flat, float fuzz) {
     MotionRange range = { min, max, flat, fuzz };
-    addMotionRange(rangeType, range);
+    addMotionRange(axis, range);
 }
 
-void InputDeviceInfo::addMotionRange(int32_t rangeType, const MotionRange& range) {
-    mMotionRanges.add(rangeType, range);
+void InputDeviceInfo::addMotionRange(int32_t axis, const MotionRange& range) {
+    mMotionRanges.add(axis, range);
 }
 
 } // namespace android