Merge "Detect when pointer has stopped moving." into jb-dev (e4db99cf) · Commits · e / os / android_frameworks_base

include/androidfw/VelocityTracker.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -37,6 +37,9 @@ public:
		struct Estimator {
		static const size_t MAX_DEGREE = 2;

		// Estimator time base.
		nsecs_t time;

		// Polynomial coefficients describing motion in X and Y.
		float xCoeff[MAX_DEGREE + 1], yCoeff[MAX_DEGREE + 1];

		@@ -48,6 +51,7 @@ public:
		float confidence;

		inline void clear() {
		time = 0;
		degree = 0;
		confidence = 0;
		for (size_t i = 0; i <= MAX_DEGREE; i++) {
		@@ -58,7 +62,6 @@ public:
		};

		VelocityTracker();
		VelocityTracker(VelocityTrackerStrategy* strategy);
		~VelocityTracker();

		// Resets the velocity tracker state.
		@@ -96,6 +99,7 @@ public:
		inline BitSet32 getCurrentPointerIdBits() const { return mCurrentPointerIdBits; }

		private:
		nsecs_t mLastEventTime;
		BitSet32 mCurrentPointerIdBits;
		int32_t mActivePointerId;
		VelocityTrackerStrategy* mStrategy;

libs/androidfw/VelocityTracker.cpp

+25 −6

Original line number	Diff line number	Diff line
		@@ -33,6 +33,16 @@

		namespace android {

		// Nanoseconds per milliseconds.
		static const nsecs_t NANOS_PER_MS = 1000000;

		// Threshold for determining that a pointer has stopped moving.
		// Some input devices do not send ACTION_MOVE events in the case where a pointer has
		// stopped. We need to detect this case so that we can accurately predict the
		// velocity after the pointer starts moving again.
		static const nsecs_t ASSUME_POINTER_STOPPED_TIME = 40 * NANOS_PER_MS;


		static float vectorDot(const float* a, const float* b, uint32_t m) {
		float r = 0;
		while (m--) {
		@@ -89,15 +99,10 @@ static String8 matrixToString(const float* a, uint32_t m, uint32_t n, bool rowMa
		// --- VelocityTracker ---

		VelocityTracker::VelocityTracker() :
		mCurrentPointerIdBits(0), mActivePointerId(-1),
		mLastEventTime(0), mCurrentPointerIdBits(0), mActivePointerId(-1),
		mStrategy(new LeastSquaresVelocityTrackerStrategy()) {
		}

		VelocityTracker::VelocityTracker(VelocityTrackerStrategy* strategy) :
		mCurrentPointerIdBits(0), mActivePointerId(-1),
		mStrategy(strategy) {
		}

		VelocityTracker::~VelocityTracker() {
		delete mStrategy;
		}
		@@ -125,6 +130,18 @@ void VelocityTracker::addMovement(nsecs_t eventTime, BitSet32 idBits, const Posi
		idBits.clearLastMarkedBit();
		}

		if ((mCurrentPointerIdBits.value & idBits.value)
		&& eventTime >= mLastEventTime + ASSUME_POINTER_STOPPED_TIME) {
		#if DEBUG_VELOCITY
		ALOGD("VelocityTracker: stopped for %0.3f ms, clearing state.",
		(eventTime - mLastEventTime) * 0.000001f);
		#endif
		// We have not received any movements for too long. Assume that all pointers
		// have stopped.
		mStrategy->clear();
		}
		mLastEventTime = eventTime;

		mCurrentPointerIdBits = idBits;
		if (mActivePointerId < 0 \|\| !idBits.hasBit(mActivePointerId)) {
		mActivePointerId = idBits.isEmpty() ? -1 : idBits.firstMarkedBit();
		@@ -467,6 +484,7 @@ bool LeastSquaresVelocityTrackerStrategy::getEstimator(uint32_t id,
		uint32_t n = degree + 1;
		if (solveLeastSquares(time, x, m, n, outEstimator->xCoeff, &xdet)
		&& solveLeastSquares(time, y, m, n, outEstimator->yCoeff, &ydet)) {
		outEstimator->time = newestMovement.eventTime;
		outEstimator->degree = degree;
		outEstimator->confidence = xdet * ydet;
		#if DEBUG_LEAST_SQUARES
		@@ -483,6 +501,7 @@ bool LeastSquaresVelocityTrackerStrategy::getEstimator(uint32_t id,
		// No velocity data available for this pointer, but we do have its current position.
		outEstimator->xCoeff[0] = x[0];
		outEstimator->yCoeff[0] = y[0];
		outEstimator->time = newestMovement.eventTime;
		outEstimator->degree = 0;
		outEstimator->confidence = 1;
		return true;