Merge "Detect when pointer has stopped moving." into jb-dev
diff --git a/include/androidfw/VelocityTracker.h b/include/androidfw/VelocityTracker.h
index 6964588..cbb07829 100644
--- a/include/androidfw/VelocityTracker.h
+++ b/include/androidfw/VelocityTracker.h
@@ -37,6 +37,9 @@
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 @@
float confidence;
inline void clear() {
+ time = 0;
degree = 0;
confidence = 0;
for (size_t i = 0; i <= MAX_DEGREE; i++) {
@@ -58,7 +62,6 @@
};
VelocityTracker();
- VelocityTracker(VelocityTrackerStrategy* strategy);
~VelocityTracker();
// Resets the velocity tracker state.
@@ -96,6 +99,7 @@
inline BitSet32 getCurrentPointerIdBits() const { return mCurrentPointerIdBits; }
private:
+ nsecs_t mLastEventTime;
BitSet32 mCurrentPointerIdBits;
int32_t mActivePointerId;
VelocityTrackerStrategy* mStrategy;
diff --git a/libs/androidfw/VelocityTracker.cpp b/libs/androidfw/VelocityTracker.cpp
index a212948..5dbafd8 100644
--- a/libs/androidfw/VelocityTracker.cpp
+++ b/libs/androidfw/VelocityTracker.cpp
@@ -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 @@
// --- 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 @@
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 @@
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 @@
// 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;