private void OnTouch(object sender, View.TouchEventArgs touchEventArgs)
{
if (_drawer == null)
{
return; // in case managed to trigger before focus event finished setup
}
float fx = touchEventArgs.Event.GetX();
float fy = touchEventArgs.Event.GetY();
var needsRefresh = false;
switch (touchEventArgs.Event.Action & MotionEventActions.Mask)
{
case MotionEventActions.Down:
_drawer.StartDrawing(fx, fy);
needsRefresh = true;
break;
case MotionEventActions.Move:
_drawer.AddPoint(fx, fy);
needsRefresh = true;
break;
case MotionEventActions.Up:
_drawer.StopDrawing(fx, fy);
needsRefresh = true;
break;
}
if (needsRefresh)
{
_canvas.Invalidate();
}
}
public override void TouchesBegan(NSSet touches, UIEvent evt)
{
base.TouchesBegan(touches, evt);
var touch = touches.AnyObject as UITouch;
if (touch != null)
{
var point = touch.LocationInView(View);
_drawer?.StartDrawing((float)point.X * _devicePixelMul, (float)point.Y * _devicePixelMul);
View.SetNeedsDisplay(); // probably after touching Pencils
}
}
