/// <summary>
/// Analyzes the given motion event and if applicable triggers the
/// appropriate callbacks on the
/// <see cref="OnGestureListener">OnGestureListener</see>
/// supplied.
/// </summary>
/// <param name="ev">The current motion event.</param>
/// <returns>
/// true if the
/// <see cref="OnGestureListener">OnGestureListener</see>
/// consumed the event,
/// else false.
/// </returns>
public virtual bool onTouchEvent(android.view.MotionEvent ev)
{
if (mInputEventConsistencyVerifier != null)
{
mInputEventConsistencyVerifier.onTouchEvent(ev, 0);
}
int action = ev.getAction();
float y = ev.getY();
float x = ev.getX();
if (mVelocityTracker == null)
{
mVelocityTracker = android.view.VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);
bool handled = false;
switch (action & android.view.MotionEvent.ACTION_MASK)
{
case android.view.MotionEvent.ACTION_POINTER_DOWN:
{
if (mIgnoreMultitouch)
{
// Multitouch event - abort.
cancel();
}
break;
}
case android.view.MotionEvent.ACTION_POINTER_UP:
{
// Ending a multitouch gesture and going back to 1 finger
if (mIgnoreMultitouch && ev.getPointerCount() == 2)
{
int index = (((action & android.view.MotionEvent.ACTION_POINTER_INDEX_MASK) >> android.view.MotionEvent
.ACTION_POINTER_INDEX_SHIFT) == 0) ? 1 : 0;
mLastMotionX = ev.getX(index);
mLastMotionY = ev.getY(index);
mVelocityTracker.recycle();
mVelocityTracker = android.view.VelocityTracker.obtain();
}
break;
}
case android.view.MotionEvent.ACTION_DOWN:
{
if (mDoubleTapListener != null)
{
bool 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);
}
}
mLastMotionX = x;
mLastMotionY = y;
if (mCurrentDownEvent != null)
{
mCurrentDownEvent.recycle();
}
mCurrentDownEvent = android.view.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 android.view.MotionEvent.ACTION_MOVE:
{
if (mInLongPress || (mIgnoreMultitouch && ev.getPointerCount() > 1))
{
break;
}
float scrollX = mLastMotionX - x;
float scrollY = mLastMotionY - y;
if (mIsDoubleTapping)
{
// Give the move events of the double-tap
handled |= mDoubleTapListener.onDoubleTapEvent(ev);
}
else
{
if (mAlwaysInTapRegion)
{
int deltaX = (int)(x - mCurrentDownEvent.getX());
int deltaY = (int)(y - mCurrentDownEvent.getY());
int distance = (deltaX * deltaX) + (deltaY * deltaY);
if (distance > mTouchSlopSquare)
{
handled = mListener.onScroll(mCurrentDownEvent, ev, scrollX, scrollY);
mLastMotionX = x;
mLastMotionY = y;
mAlwaysInTapRegion = false;
mHandler.removeMessages(TAP);
mHandler.removeMessages(SHOW_PRESS);
mHandler.removeMessages(LONG_PRESS);
}
if (distance > mBiggerTouchSlopSquare)
{
mAlwaysInBiggerTapRegion = false;
}
}
else
{
if ((System.Math.Abs(scrollX) >= 1) || (System.Math.Abs(scrollY) >= 1))
{
handled = mListener.onScroll(mCurrentDownEvent, ev, scrollX, scrollY);
mLastMotionX = x;
mLastMotionY = y;
}
}
}
break;
}
case android.view.MotionEvent.ACTION_UP:
{
mStillDown = false;
android.view.MotionEvent currentUpEvent = android.view.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
android.view.VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumFlingVelocity);
float velocityY = velocityTracker.getYVelocity();
float velocityX = velocityTracker.getXVelocity();
if ((System.Math.Abs(velocityY) > mMinimumFlingVelocity) || (System.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;
mVelocityTracker.recycle();
mVelocityTracker = null;
mIsDoubleTapping = false;
mHandler.removeMessages(SHOW_PRESS);
mHandler.removeMessages(LONG_PRESS);
break;
}
case android.view.MotionEvent.ACTION_CANCEL:
{
cancel();
break;
}
}
if (!handled && mInputEventConsistencyVerifier != null)
{
mInputEventConsistencyVerifier.onUnhandledEvent(ev, 0);
}
return(handled);
}
