Simple mouseover effect on NSButton

Question

I am creating a custom NSButtonCell for a custom rendering.

Now, I want to have different aspect depending if the mouse is over the button or not. How can

Answer 1

Swift 5 version with callback, super easy to use:

final class HoverButton: NSButton {

    private let callback: (HoverButton, Bool) -> Void

    init(callback: @escaping (HoverButton, Bool) -> Void) {
        self.callback = callback
        super.init(frame: .zero)
        let area = NSTrackingArea(rect: bounds, options: [.mouseEnteredAndExited, .activeAlways, .inVisibleRect], owner: self, userInfo: nil)
        addTrackingArea(area)
    }

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func mouseEntered(with event: NSEvent) {
        super.mouseEntered(with: event)
        callback(self, true)
    }

    override func mouseExited(with event: NSEvent) {
        super.mouseExited(with: event)
        callback(self, false)
    }

}

Usage:

let button = HoverButton { button, isHovered in
    button.animator().alphaValue = isHovered ? 1 : 0.5
}