private void track(MotionEvent event) {
mX.saveTouchPos();
mY.saveTouchPos();
for (int i = 0; i < event.getHistorySize(); i++) {
track(
event.getHistoricalX(0, i), event.getHistoricalY(0, i), event.getHistoricalEventTime(i));
}
track(event.getX(0), event.getY(0), event.getEventTime());
if (stopped()) {
if (mState == PanZoomState.PANNING) {
setState(PanZoomState.PANNING_HOLD);
} else if (mState == PanZoomState.PANNING_LOCKED) {
setState(PanZoomState.PANNING_HOLD_LOCKED);
} else {
// should never happen, but handle anyway for robustness
Log.e(LOGTAG, "Impossible case " + mState + " when stopped in track");
setState(PanZoomState.PANNING_HOLD_LOCKED);
}
}
mX.startPan();
mY.startPan();
updatePosition();
}
/**
* Add a user's movement to the tracker. You should call this for the initial {@link
* MotionEvent#ACTION_DOWN}, the following {@link MotionEvent#ACTION_MOVE} events that you
* receive, and the final {@link MotionEvent#ACTION_UP}. You can, however, call this for whichever
* events you desire.
*
* @param ev The MotionEvent you received and would like to track.
*/
public void addMovement(MotionEvent ev) {
final int mN = ev.getHistorySize();
if (++mLastTouch >= NUM_PAST) {
mLastTouch = 0;
}
for (int i = 0; i < mN; ++i) {
mPastX[mLastTouch] = ev.getHistoricalX(i);
mPastY[mLastTouch] = ev.getHistoricalY(i);
mPastTime[mLastTouch] = ev.getHistoricalEventTime(i);
if (++mLastTouch >= NUM_PAST) {
mLastTouch = 0;
}
}
mPastX[mLastTouch] = ev.getX();
mPastY[mLastTouch] = ev.getY();
mPastTime[mLastTouch] = ev.getEventTime();
}
private int detectSwipe(MotionEvent move) {
final int historySize = move.getHistorySize();
final int pointerCount = move.getPointerCount();
for (int p = 0; p < pointerCount; p++) {
final int pointerId = move.getPointerId(p);
final int i = findIndex(pointerId);
if (i != UNTRACKED_POINTER) {
for (int h = 0; h < historySize; h++) {
final long time = move.getHistoricalEventTime(h);
final float x = move.getHistoricalX(p, h);
final float y = move.getHistoricalY(p, h);
final int swipe = detectSwipe(i, time, x, y);
if (swipe != SWIPE_NONE) {
return swipe;
}
}
final int swipe = detectSwipe(i, move.getEventTime(), move.getX(p), move.getY(p));
if (swipe != SWIPE_NONE) {
return swipe;
}
}
}
return SWIPE_NONE;
}