private void OnSourceInitialized(object sender, EventArgs e)
{
_complete = new Throttle(TimeSpan.FromMilliseconds(100), Complete);
_source = (HwndSource)PresentationSource.FromVisual(_window);
_source.AddHook(WndProc);
TouchpadHelper.RegisterInput(_source.Handle);
}
private void OnClosed(object sender, EventArgs e)
{
ManipulationDelta = null;
ManipulationCompleted = null;
_source?.RemoveHook(WndProc);
TouchpadHelper.UnregisterInput();
}
public TouchpadTracker(Window window)
{
if (!TouchpadHelper.Exists())
{
return;
}
this._window = window ?? throw new ArgumentNullException(nameof(window));
this._window.SourceInitialized += OnSourceInitialized;
this._window.Closed += OnClosed;
}
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
switch (msg)
{
case TouchpadHelper.WM_INPUT:
var contacts = TouchpadHelper.ParseInput(lParam);
if (contacts?.Length > 1)
{
Check(contacts[0]);
handled = true;
}
break;
}
return(IntPtr.Zero);
}