How to simulate a continuous key press

Question

I need to simulate a continuous key press. For example hold down the 'c' key for 5 seconds. To simulate a key press event I tried to use CGEventCreateKeyboardEvent:

let event:CGEventRef! = CGEventCreateKeyboardEvent(nil, 8, true)
CGEventPost(CGEventTapLocation.CGSessionEventTap, event)

But it acts like if the button is tapped and then released immediately. I need to create an event that keeps holding the button (key down) and then release it (key up).

Answer 1

I'm not sure what you are trying to achieve, but it appears that the system will continue to hold the button down. This simple experiment shows it.

func applicationDidFinishLaunching(aNotification: NSNotification) {
    print("waiting 4 seconds, use this time to position your cursor in a text field")
    let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(4 * Double(NSEC_PER_SEC)))
    dispatch_after(delayTime, dispatch_get_main_queue(), {
        self.insertLetterZ()
    })
}

func insertLetterZ() {
    print("pressing shift")
    self.tapButton(56)

    print("holding button for 2 seconds")
    let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(2 * Double(NSEC_PER_SEC)))
    dispatch_after(delayTime, dispatch_get_main_queue(), {
        print("tapping z, but Z will be selected (since shift is still being pressed)")
        self.tapButton(6)

        print("untapping z and shift")
        self.untapButton(6)
        self.untapButton(56)
    })
}

func tapButton(button: CGKeyCode) {
    let event = CGEventCreateKeyboardEvent(nil, button, true)
    CGEventPost(CGEventTapLocation.CGSessionEventTap, event)
}

func untapButton(button: CGKeyCode) {
    let event = CGEventCreateKeyboardEvent(nil, button, false)
    CGEventPost(CGEventTapLocation.CGSessionEventTap, event)
}

This code however does not capitalize a letter if a user taps the keyboard when shift is programmatically pressed. I have also noticed that if the cursor location is changed between shift and z being tapped "z" will be inserted instead of "Z"