diff options
Diffstat (limited to 'core/java/android/view/VelocityTracker.java')
| -rw-r--r-- | core/java/android/view/VelocityTracker.java | 139 |
1 files changed, 87 insertions, 52 deletions
diff --git a/core/java/android/view/VelocityTracker.java b/core/java/android/view/VelocityTracker.java index 5d89c46..9581080 100644 --- a/core/java/android/view/VelocityTracker.java +++ b/core/java/android/view/VelocityTracker.java @@ -55,12 +55,12 @@ public final class VelocityTracker implements Poolable<VelocityTracker> { } }, 2)); - final float mPastX[] = new float[NUM_PAST]; - final float mPastY[] = new float[NUM_PAST]; - final long mPastTime[] = new long[NUM_PAST]; + final float mPastX[][] = new float[MotionEvent.BASE_AVAIL_POINTERS][NUM_PAST]; + final float mPastY[][] = new float[MotionEvent.BASE_AVAIL_POINTERS][NUM_PAST]; + final long mPastTime[][] = new long[MotionEvent.BASE_AVAIL_POINTERS][NUM_PAST]; - float mYVelocity; - float mXVelocity; + float mYVelocity[] = new float[MotionEvent.BASE_AVAIL_POINTERS]; + float mXVelocity[] = new float[MotionEvent.BASE_AVAIL_POINTERS]; private VelocityTracker mNext; @@ -105,7 +105,9 @@ public final class VelocityTracker implements Poolable<VelocityTracker> { * Reset the velocity tracker back to its initial state. */ public void clear() { - mPastTime[0] = 0; + for (int i = 0; i < MotionEvent.BASE_AVAIL_POINTERS; i++) { + mPastTime[i][0] = 0; + } } /** @@ -120,18 +122,21 @@ public final class VelocityTracker implements Poolable<VelocityTracker> { public void addMovement(MotionEvent ev) { long time = ev.getEventTime(); final int N = ev.getHistorySize(); - for (int i=0; i<N; i++) { - addPoint(ev.getHistoricalX(i), ev.getHistoricalY(i), - ev.getHistoricalEventTime(i)); + final int pointerCount = ev.getPointerCount(); + for (int p = 0; p < pointerCount; p++) { + for (int i=0; i<N; i++) { + addPoint(p, ev.getHistoricalX(p, i), ev.getHistoricalY(p, i), + ev.getHistoricalEventTime(i)); + } + addPoint(p, ev.getX(p), ev.getY(p), time); } - addPoint(ev.getX(), ev.getY(), time); } - private void addPoint(float x, float y, long time) { + private void addPoint(int pos, float x, float y, long time) { int drop = -1; int i; if (localLOGV) Log.v(TAG, "Adding past y=" + y + " time=" + time); - final long[] pastTime = mPastTime; + final long[] pastTime = mPastTime[pos]; for (i=0; i<NUM_PAST; i++) { if (pastTime[i] == 0) { break; @@ -146,8 +151,8 @@ public final class VelocityTracker implements Poolable<VelocityTracker> { drop = 0; } if (drop == i) drop--; - final float[] pastX = mPastX; - final float[] pastY = mPastY; + final float[] pastX = mPastX[pos]; + final float[] pastY = mPastY[pos]; if (drop >= 0) { if (localLOGV) Log.v(TAG, "Dropping up to #" + drop); final int start = drop+1; @@ -190,44 +195,48 @@ public final class VelocityTracker implements Poolable<VelocityTracker> { * must be positive. */ public void computeCurrentVelocity(int units, float maxVelocity) { - final float[] pastX = mPastX; - final float[] pastY = mPastY; - final long[] pastTime = mPastTime; - - // Kind-of stupid. - final float oldestX = pastX[0]; - final float oldestY = pastY[0]; - final long oldestTime = pastTime[0]; - float accumX = 0; - float accumY = 0; - int N=0; - while (N < NUM_PAST) { - if (pastTime[N] == 0) { - break; + for (int pos = 0; pos < MotionEvent.BASE_AVAIL_POINTERS; pos++) { + final float[] pastX = mPastX[pos]; + final float[] pastY = mPastY[pos]; + final long[] pastTime = mPastTime[pos]; + + // Kind-of stupid. + final float oldestX = pastX[0]; + final float oldestY = pastY[0]; + final long oldestTime = pastTime[0]; + float accumX = 0; + float accumY = 0; + int N=0; + while (N < NUM_PAST) { + if (pastTime[N] == 0) { + break; + } + N++; } - N++; - } - // Skip the last received event, since it is probably pretty noisy. - if (N > 3) N--; - - for (int i=1; i < N; i++) { - final int dur = (int)(pastTime[i] - oldestTime); - if (dur == 0) continue; - float dist = pastX[i] - oldestX; - float vel = (dist/dur) * units; // pixels/frame. - if (accumX == 0) accumX = vel; - else accumX = (accumX + vel) * .5f; - - dist = pastY[i] - oldestY; - vel = (dist/dur) * units; // pixels/frame. - if (accumY == 0) accumY = vel; - else accumY = (accumY + vel) * .5f; + // Skip the last received event, since it is probably pretty noisy. + if (N > 3) N--; + + for (int i=1; i < N; i++) { + final int dur = (int)(pastTime[i] - oldestTime); + if (dur == 0) continue; + float dist = pastX[i] - oldestX; + float vel = (dist/dur) * units; // pixels/frame. + if (accumX == 0) accumX = vel; + else accumX = (accumX + vel) * .5f; + + dist = pastY[i] - oldestY; + vel = (dist/dur) * units; // pixels/frame. + if (accumY == 0) accumY = vel; + else accumY = (accumY + vel) * .5f; + } + mXVelocity[pos] = accumX < 0.0f ? Math.max(accumX, -maxVelocity) + : Math.min(accumX, maxVelocity); + mYVelocity[pos] = accumY < 0.0f ? Math.max(accumY, -maxVelocity) + : Math.min(accumY, maxVelocity); + + if (localLOGV) Log.v(TAG, "Y velocity=" + mYVelocity +" X velocity=" + + mXVelocity + " N=" + N); } - mXVelocity = accumX < 0.0f ? Math.max(accumX, -maxVelocity) : Math.min(accumX, maxVelocity); - mYVelocity = accumY < 0.0f ? Math.max(accumY, -maxVelocity) : Math.min(accumY, maxVelocity); - - if (localLOGV) Log.v(TAG, "Y velocity=" + mYVelocity +" X velocity=" - + mXVelocity + " N=" + N); } /** @@ -237,7 +246,7 @@ public final class VelocityTracker implements Poolable<VelocityTracker> { * @return The previously computed X velocity. */ public float getXVelocity() { - return mXVelocity; + return mXVelocity[0]; } /** @@ -247,6 +256,32 @@ public final class VelocityTracker implements Poolable<VelocityTracker> { * @return The previously computed Y velocity. */ public float getYVelocity() { - return mYVelocity; + return mYVelocity[0]; + } + + /** + * Retrieve the last computed X velocity. You must first call + * {@link #computeCurrentVelocity(int)} before calling this function. + * + * @param pos Which pointer's velocity to return. + * @return The previously computed X velocity. + * + * @hide Pending API approval + */ + public float getXVelocity(int pos) { + return mXVelocity[pos]; + } + + /** + * Retrieve the last computed Y velocity. You must first call + * {@link #computeCurrentVelocity(int)} before calling this function. + * + * @param pos Which pointer's velocity to return. + * @return The previously computed Y velocity. + * + * @hide Pending API approval + */ + public float getYVelocity(int pos) { + return mYVelocity[pos]; } } |