Receiving double-click event

Question

I've been searching the Apple docs and the only function I could find pertaining to a double click just returned the acceptable time between clicks for it to be considered a double click.

Can someone please show me an example of a double click event?

Plenty

@duskwuff OSX (see tags) – Plenty

@duskwuff: Also, iOS doesn't have clicks. – Hendley

Right, I was wondering if you were looking for a (probably non-existent?) "double tap" event on iOS. – Hominoid

Answer 1

Override the NSResponder method -mouseUp: and check the supplied event's clickCount. If clickCount == 2, then you're looking at a double-click. If it's 1, then a single click. 0, then they waited long enough between mouse down and mouse up that the system decided it's not a click, just distinct down then up events.

- (void)mouseUp:(NSEvent *)event
{
    NSInteger clickCount = [event clickCount];
    if (2 == clickCount) [self handleDoubleClickEvent:event];
}

This assumes the object handling the click is part of the responder chain. If not, you'll have to get your events another way, like subclassing NSApplication or NSWindow and overriding -sendEvent: to intercept the appropriate event before it gets passed along any further.

Fishwife

It should be emphasized that “NSResponder” in this answer refers to the class in Cocoa (which NSView, NSWindow, and NSApplication inherit from), not the other answerer who named himself after it. – Hendley

Answer 2

See NSEvent's -clickCount method.

Grizzled

Answer 3

Note also that some NSControl has setDoubleAction: so that the selector registered via setDoubleAction: is sent to the target. See the official documentations of

• NSTableView ,
• NSStatusItem ,
• NSPathControl ,
• NSBrowser ,
• NSMatrix .

Oculist

The event (NSEvent object) is not passed to the target; an action message is sent to the target, but, as usual for an action message, the single argument is the control (table view or whatever) sending the message. I'm sure you didn't mean the NSEvent object, but I wanted to make sure that's clear. – Hendley

Yes that's what I meant; I'll rephrase it. Thanks. – Oculist

In my case I had to set a target for an NSTableView when running on OS prior to 10.10, but 10.10 worked OK without the target being set (self in my case) – Madelyn