Enable/disable mouse event on certain area viewport

Hello,

I have a widget in my viewport and a 2D Scene Capture where I render a full screen ArcGIS map into a smaller view. I used an image for this view. This view then shows a blueprint with a car, where the user can rotate around the car using click + mouse movement. Everything works fine, but now the rotation around the car can be done within the entire viewport. What I need is that the user that only rotate around the car with click + mouse movement inside the smaller view (the image in this case).
There is no On Mouse Enter/Leave event with the image, so I tried using a border on top of the image (transparent) with On Mouse Click Down/Up and then using a boolean variable for the mouse movements. This works with mouse down, but with mouse up the user that still rotate around the car in the entire viewport (so the bolean starts False, then goes to True and does not get back to False).

Are there any other options to do this? Maybe I missed something with the mouse up? Or is there something with On Mouse Enter/Leave that I can use?