public override bool DispatchTouchEvent(MotionEvent e)
{
var index = e.ActionIndex;
var action = e.ActionMasked;
var pointerId = e.GetPointerId(index);
switch (action & MotionEventActions.Mask)
{
case MotionEventActions.PointerDown:
MultiTouchGesture?.Invoke(this, EventArgs.Empty);
break;
case MotionEventActions.Up:
if ((DateTime.Now - _downTime).TotalMilliseconds < 200)
{
SingleTapGesture?.Invoke(this, EventArgs.Empty);
}
break;
}
switch (action)
{
case MotionEventActions.Down:
_downTime = DateTime.Now;
if (_velocityTracker == null)
{
_velocityTracker = VelocityTracker.Obtain();
}
else
{
// Reset the velocity tracker back to its initial state.
_velocityTracker.Clear();
}
if (IfVelocityTrackerIsNull())
{
return(true);
}
_velocityTracker.AddMovement(e);
break;
case MotionEventActions.Move:
if (IfVelocityTrackerIsNull())
{
return(true);
}
_velocityTracker.AddMovement(e);
_velocityTracker.ComputeCurrentVelocity(Sensitivity);
TryExportVelocity(_velocityTracker.GetXVelocity(pointerId), _velocityTracker.GetYVelocity(pointerId));
break;
case MotionEventActions.Up:
case MotionEventActions.Cancel:
if (IfVelocityTrackerIsNull())
{
return(true);
}
_velocityTracker.Recycle();
_velocityTracker = null;
break;
}
return(true);
}
public virtual bool OnTouchEvent(Android.Views.MotionEvent ev)
{
switch (ev.Action)
{
case MotionEventActions.Down:
{
mVelocityTracker = VelocityTracker.Obtain();
if (null != mVelocityTracker)
{
mVelocityTracker.AddMovement(ev);
}
else
{
Log.Info(LOG_TAG, "Velocity tracker is null");
}
mLastTouchX = GetActiveX(ev);
mLastTouchY = GetActiveY(ev);
mIsDragging = false;
break;
}
case MotionEventActions.Move: {
float x = GetActiveX(ev);
float y = GetActiveY(ev);
float dx = x - mLastTouchX, dy = y - mLastTouchY;
if (!mIsDragging)
{
// Use Pythagoras to see if drag length is larger than
// touch slop
mIsDragging = FloatMath.Sqrt((dx * dx) + (dy * dy)) >= mTouchSlop;
}
if (mIsDragging)
{
mListener.OnDrag(dx, dy);
mLastTouchX = x;
mLastTouchY = y;
if (null != mVelocityTracker)
{
mVelocityTracker.AddMovement(ev);
}
}
break;
}
case MotionEventActions.Cancel: {
// Recycle Velocity Tracker
if (null != mVelocityTracker)
{
mVelocityTracker.Recycle();
mVelocityTracker = null;
}
break;
}
case MotionEventActions.Up: {
if (mIsDragging)
{
if (null != mVelocityTracker)
{
mLastTouchX = GetActiveX(ev);
mLastTouchY = GetActiveY(ev);
// Compute velocity within the last 1000ms
mVelocityTracker.AddMovement(ev);
mVelocityTracker.ComputeCurrentVelocity(1000);
float vX = mVelocityTracker.GetXVelocity(0), vY = mVelocityTracker
.GetYVelocity(0);
// If the velocity is greater than minVelocity, call
// listener
if (Math.Max(Math.Abs(vX), Math.Abs(vY)) >= mMinimumVelocity)
{
mListener.OnFling(mLastTouchX, mLastTouchY, -vX,
-vY);
}
}
}
// Recycle Velocity Tracker
if (null != mVelocityTracker)
{
mVelocityTracker.Recycle();
mVelocityTracker = null;
}
break;
}
}
return(true);
}
public override bool OnTouchEvent(MotionEvent e)
{
if (mVelocityTracker == null)
{
mVelocityTracker = VelocityTracker.Obtain();
}
mVelocityTracker.AddMovement(e);
MotionEventActions action = e.Action;
if (action == MotionEventActions.Down)
{
x = e.GetX();
if (IsSlided())
{
dispatched = DispatchTouchEventToView(GetChildAt(0), e);
}
else
{
dispatched = DispatchTouchEventToView(GetChildAt(1), e);
}
}
else if (action == MotionEventActions.Move)
{
if (dispatched)
{
if (IsSlided())
{
DispatchTouchEventToView(GetChildAt(0), e);
}
else
{
DispatchTouchEventToView(GetChildAt(1), e);
}
}
else
{
float dx = e.GetX() - x;
View view = this.GetChildAt(1);
int left = (int)(view.Left + dx);
if (left >= 0)
{
view.Layout(left, view.Top, view.Width + left,
view.Top + view.Height);
}
}
x = e.GetX();
}
else if (action == MotionEventActions.Cancel ||
action == MotionEventActions.Up)
{
if (dispatched)
{
if (IsSlided())
{
DispatchTouchEventToView(GetChildAt(0), e);
}
else
{
DispatchTouchEventToView(GetChildAt(1), e);
}
}
else
{
mVelocityTracker.ComputeCurrentVelocity(1000);
int velocityX = (int)mVelocityTracker.GetXVelocity(0);
if (velocityX > VELOCITY_X_SPEED)
{
SetSlided(true);
}
else if (velocityX < -VELOCITY_X_SPEED)
{
SetSlided(false);
}
else
{
View view = GetChildAt(1);
if (view.Left >= view.Width / 2)
{
SetSlided(true);
}
else
{
SetSlided(false);
}
}
if (mVelocityTracker != null)
{
try
{
mVelocityTracker.Recycle();
}
catch
{ }
}
}
}
else if (!IsSlided())
{
DispatchTouchEventToView(GetChildAt(1), e);
}
return(true);
}