/**
* Analyzes the given motion event and if applicable triggers the appropriate callbacks on the
* {@link OnGestureListener} supplied.
*
* @param ev The current motion event.
* @return true if the {@link OnGestureListener} consumed the event, else false.
*/
public boolean onTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);
final boolean pointerUp =
(action & MotionEventCompat.ACTION_MASK) == MotionEventCompat.ACTION_POINTER_UP;
final int skipIndex = pointerUp ? MotionEventCompat.getActionIndex(ev) : -1;
// Determine focal point
float sumX = 0, sumY = 0;
final int count = MotionEventCompat.getPointerCount(ev);
for (int i = 0; i < count; i++) {
if (skipIndex == i) continue;
sumX += MotionEventCompat.getX(ev, i);
sumY += MotionEventCompat.getY(ev, i);
}
final int div = pointerUp ? count - 1 : count;
final float focusX = sumX / div;
final float focusY = sumY / div;
boolean handled = false;
switch (action & MotionEventCompat.ACTION_MASK) {
case MotionEventCompat.ACTION_POINTER_DOWN:
mDownFocusX = mLastFocusX = focusX;
mDownFocusY = mLastFocusY = focusY;
// Cancel long press and taps
cancelTaps();
break;
case MotionEventCompat.ACTION_POINTER_UP:
mDownFocusX = mLastFocusX = focusX;
mDownFocusY = mLastFocusY = focusY;
// Check the dot product of current velocities.
// If the pointer that left was opposing another velocity vector, clear.
mVelocityTracker.computeCurrentVelocity(1000, mMaximumFlingVelocity);
final int upIndex = MotionEventCompat.getActionIndex(ev);
final int id1 = MotionEventCompat.getPointerId(ev, upIndex);
final float x1 = VelocityTrackerCompat.getXVelocity(mVelocityTracker, id1);
final float y1 = VelocityTrackerCompat.getYVelocity(mVelocityTracker, id1);
for (int i = 0; i < count; i++) {
if (i == upIndex) continue;
final int id2 = MotionEventCompat.getPointerId(ev, i);
final float x = x1 * VelocityTrackerCompat.getXVelocity(mVelocityTracker, id2);
final float y = y1 * VelocityTrackerCompat.getYVelocity(mVelocityTracker, id2);
final float dot = x + y;
if (dot < 0) {
mVelocityTracker.clear();
break;
}
}
break;
case MotionEvent.ACTION_DOWN:
if (mDoubleTapListener != null) {
boolean hadTapMessage = mHandler.hasMessages(TAP);
if (hadTapMessage) mHandler.removeMessages(TAP);
if ((mCurrentDownEvent != null)
&& (mPreviousUpEvent != null)
&& hadTapMessage
&& isConsideredDoubleTap(mCurrentDownEvent, mPreviousUpEvent, ev)) {
// This is a second tap
mIsDoubleTapping = true;
// Give a callback with the first tap of the double-tap
handled |= mDoubleTapListener.onDoubleTap(mCurrentDownEvent);
// Give a callback with down event of the double-tap
handled |= mDoubleTapListener.onDoubleTapEvent(ev);
} else {
// This is a first tap
mHandler.sendEmptyMessageDelayed(TAP, DOUBLE_TAP_TIMEOUT);
}
}
mDownFocusX = mLastFocusX = focusX;
mDownFocusY = mLastFocusY = focusY;
if (mCurrentDownEvent != null) {
mCurrentDownEvent.recycle();
}
mCurrentDownEvent = MotionEvent.obtain(ev);
mAlwaysInTapRegion = true;
mAlwaysInBiggerTapRegion = true;
mStillDown = true;
mInLongPress = false;
if (mIsLongpressEnabled) {
mHandler.removeMessages(LONG_PRESS);
mHandler.sendEmptyMessageAtTime(
LONG_PRESS, mCurrentDownEvent.getDownTime() + TAP_TIMEOUT + LONGPRESS_TIMEOUT);
}
mHandler.sendEmptyMessageAtTime(
SHOW_PRESS, mCurrentDownEvent.getDownTime() + TAP_TIMEOUT);
handled |= mListener.onDown(ev);
break;
case MotionEvent.ACTION_MOVE:
if (mInLongPress) {
break;
}
final float scrollX = mLastFocusX - focusX;
final float scrollY = mLastFocusY - focusY;
if (mIsDoubleTapping) {
// Give the move events of the double-tap
handled |= mDoubleTapListener.onDoubleTapEvent(ev);
} else if (mAlwaysInTapRegion) {
final int deltaX = (int) (focusX - mDownFocusX);
final int deltaY = (int) (focusY - mDownFocusY);
int distance = (deltaX * deltaX) + (deltaY * deltaY);
if (distance > mTouchSlopSquare) {
handled = mListener.onScroll(mCurrentDownEvent, ev, scrollX, scrollY);
mLastFocusX = focusX;
mLastFocusY = focusY;
mAlwaysInTapRegion = false;
mHandler.removeMessages(TAP);
mHandler.removeMessages(SHOW_PRESS);
mHandler.removeMessages(LONG_PRESS);
}
if (distance > mTouchSlopSquare) {
mAlwaysInBiggerTapRegion = false;
}
} else if ((Math.abs(scrollX) >= 1) || (Math.abs(scrollY) >= 1)) {
handled = mListener.onScroll(mCurrentDownEvent, ev, scrollX, scrollY);
mLastFocusX = focusX;
mLastFocusY = focusY;
}
break;
case MotionEvent.ACTION_UP:
mStillDown = false;
MotionEvent currentUpEvent = MotionEvent.obtain(ev);
if (mIsDoubleTapping) {
// Finally, give the up event of the double-tap
handled |= mDoubleTapListener.onDoubleTapEvent(ev);
} else if (mInLongPress) {
mHandler.removeMessages(TAP);
mInLongPress = false;
} else if (mAlwaysInTapRegion) {
handled = mListener.onSingleTapUp(ev);
} else {
// A fling must travel the minimum tap distance
final VelocityTracker velocityTracker = mVelocityTracker;
final int pointerId = MotionEventCompat.getPointerId(ev, 0);
velocityTracker.computeCurrentVelocity(1000, mMaximumFlingVelocity);
final float velocityY = VelocityTrackerCompat.getYVelocity(velocityTracker, pointerId);
final float velocityX = VelocityTrackerCompat.getXVelocity(velocityTracker, pointerId);
if ((Math.abs(velocityY) > mMinimumFlingVelocity)
|| (Math.abs(velocityX) > mMinimumFlingVelocity)) {
handled = mListener.onFling(mCurrentDownEvent, ev, velocityX, velocityY);
}
}
if (mPreviousUpEvent != null) {
mPreviousUpEvent.recycle();
}
// Hold the event we obtained above - listeners may have changed the original.
mPreviousUpEvent = currentUpEvent;
if (mVelocityTracker != null) {
// This may have been cleared when we called out to the
// application above.
mVelocityTracker.recycle();
mVelocityTracker = null;
}
mIsDoubleTapping = false;
mHandler.removeMessages(SHOW_PRESS);
mHandler.removeMessages(LONG_PRESS);
break;
case MotionEvent.ACTION_CANCEL:
cancel();
break;
}
return handled;
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
return fallback.onSingleTapUp(e);
}