How to show context menu from NSButton in macOS

Issue #435

Use NSMenu and popUp

func showQuitMenu() {
    let menu = NSMenu()
    let aboutItem = NSMenuItem(
        title: "About",
        action: #selector(onAboutTouched(_:)),
        keyEquivalent: ""
    )

    let quitItem = NSMenuItem(
        title: "Quit Hacker Pad",
        action: #selector(onQuitTouched(_:)),
        keyEquivalent: ""
    )

    aboutItem.target = self
    quitItem.target = self

    menu.addItem(aboutItem)
    menu.addItem(quitItem)

    menu.popUp(
        positioning: aboutItem,
        at: bottomView.quitButton.frame.origin,
        in: bottomView
    )
}

Use Omnia

let menuHandler = MenuHandler()
menuHandler.add(title: "About", action: {
    NSWorkspace.shared.open(URL(string: "https://onmyway133.github.io/")!)
})

menuHandler.add(title: "Quit Hacker Pad", action: {
    NSApp.terminate(nil)
})

menuHandler.show(from: self.bottomView.gearButton, in: self.bottomView)