A set of flags that indicate how the button highlights when it receives a mouse-down event (that is, when the button is pressed).
- macOS 10.0+
The value of this property is the logical OR of one or more of flags described in the "Constants” section of
NSChange are specified, both are recorded, but the resulting behavior depends on the button cell’s image. If the button has no image, or if the image has no alpha (transparency) data,
NSChange is used; if the image has alpha data,
NSChange is used. This arrangement allows the color swap of the background to show through the image’s transparent pixels.