// Erase on Shake
public override void MotionBegan(UIEventSubtype eType, UIEvent evt)
{
if (eType == UIEventSubtype.MotionShake)
{
var alert = UIAlertController.Create(
"Erase Canvas?",
"This will clear the shared Realm database and erase the canvas. Are you sure you wish to proceed?",
UIAlertControllerStyle.Alert);
alert.AddAction(UIAlertAction.Create("Erase", UIAlertActionStyle.Destructive, action => _drawer?.ErasePaths()));
alert.AddAction(UIAlertAction.Create("Cancel", UIAlertActionStyle.Cancel, null));
if (alert.PopoverPresentationController != null)
{
alert.PopoverPresentationController.SourceView = View;
}
PresentViewController(alert, animated: true, completionHandler: null);
//// unlike other gesture actions, don't call View.SetNeedsDisplay but let major Realm change prompt redisplay
}
}
// use the back button in preference to trying to detect shake, which is not built in
public override void OnBackPressed()
{
_drawer.ErasePaths();
_canvas.Invalidate();
}
