core-animation

Lingering white box using Core Animation where NSScroller used to be

I have a window that features one large image, stretched to fit the window (but retaining its proportions). On top of that image is a control panel. When the user moves the cursor away from the control panel, it fades out. When they move it back over it, it fades in. I messed around with NSViewAnimation to do this but had some troubles,...