Calling SetGestureConfig method affects onmousemove override of control

Question

To handle touch gestures like pinching, I am calling the SetGestureConfig method in WndProc override method available in control.

I would like to use this method only for pinching gesture instead of GC_ALLGESTURES.

Here is the code

            switch (m.Msg)
            {
                case WM_GESTURENOTIFY:
                    {
                    GESTURECONFIG gc = new GESTURECONFIG();
                    gc.dwID = 0;
                    gc.dwWant = GC_ALLGESTURES;
                    gc.dwBlock = 0;

                    bool result = SetGestureConfig(
                        handle,
                        0,
                        1,
                        ref gc,
                        _gestureConfigSize
                    );

                    if (!result)
                    {
                        throw new Exception("Error in execution of SetGestureConfig");
                    }
                }
                break;
                //... other codes if any
            }

Before using this code, when I touch and move fingers on the control, OnMouseMove override method of the control will be called. But after using this code, it is not the case.

I am handling gesture related functionalities like pinching, panning, etc separately and it is working fine.

Panning should happen only after pinching gesture. If pinching gesture is performed on the control, then panning should be performed on touch move. If pinching gesture is not performed on the control, then I am expecting the default mouse move event to trigger during touch move

But calling the SetGestureConfig method, does not trigger the default mouse move event.

Should I manually call OnMouseMove during pan gesture that occurs without pinching ? Or is there any modification should be made in call to the SetGestureConfig method to avoid blocking the OnMouseMove during pan gesture.

Answer 1

It looks like we can control the gesture we want to listen. Referred remarks section of https://learn.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-setgestureconfig

In the above code, I just need to make the following change to listen only to the pinching gesture and panning(only after pinching is performed). Changes are explained through comments

            switch (m.Msg)
            {
                case WM_GESTURENOTIFY:
                    {
                    GESTURECONFIG gc = new GESTURECONFIG();

                    //Listen to required gestures here
                    //If 0, all gestures like pinching, panning, etc will be listened
                    //If GID_ZOOM, only pinching gesture will be listened
                    gc.dwID = IsPinchingPerformed ? 0 : GID_ZOOM;


                    gc.dwWant = GC_ALLGESTURES;
                    gc.dwBlock = 0;

                    bool result = SetGestureConfig(
                        handle,
                        0,
                        1,
                        ref gc,
                        _gestureConfigSize
                    );

                }
                break;

                //... other codes if any
}