NSButton.ButtonType.momentaryChange
A button that displays its alternate content when clicked and returns to its normal content when the user releases it.
Declaration
case momentaryChangeDiscussion
When the value of isHighlighted is true, the button displays its alternate content (for example, its alternateImage or alternateTitle). If the button has no alternate content to display, it may instead draw its normal content using an illuminated effect. When isHighlighted is false, the button displays its normal content (for example, its image or title).
This option corresponds to the Momentary Change type in Interface Builder’s Attributes inspector.