Opacity mask

You can use opacity mask to hide part of widget. Mask is a grayscale image, so black areas are hidden, white areas are visible, and shades of gray areas appear in various levels of transparency.

To add opacity mask:

1. Select widget
2. Open Style Inspector
3. Click Mask image in Mask section and select image file
4. Select image fill mode from the list

To remove opacity mask image click — button on the right.