Let's say I have a 800x600 window/screen and I'm rendering on layers and on the last layer I render a small rectangle image middle of the screen, we could think about it as a modal dialog. If I render the UI inside this image by calling ui.Draw(image) where the image is just a copy of this small rectangle then this small rectangle is drawn to the screen.

When buttons are hovered nothing happens but if you but the cursor in the place where the buttons will get rendered over the whole screen I do see the buttons changing colors.

Have done some debugging and cursor x, y position are indeed inside the Rect {x, y, widht, height} of the buttons/widgets, what I have tried was to set the ui.container Rect value to be the size of this, small rectangle image, even calling relayout after this but the children rects does not change their values.

At the end it would be nice, I'm not sure if this is already available but have an offset.x offset.y of the entire screen on where Container child Rects will use to detect these events.