CODEWITHSUNDEEP
cocoansdocumentnswindowcontrollernseventnsresponder
ATV
ATV

Reputation: 4496

Best place to intercept Cmd-Key in NSDocument based app

What would be the most appropriate place to intercept CmdAnyKey key events in an NSDocument based application?

Intention is to switch to some component in the active window - kind of like Firefox allows you to switch the tabs - without having a matching shortcut on a menu command to perform that task.

I.e. ideally the framework should do it's normal processing including handling menu commands and just after all other responders fail to respond to that particular shortcut it should be routed to the custom method.

I've searched NSDocument, NSAppDelegate, NSWindowController but couldn't locate any appropriate mechanism to hook into in order to receive these commands on window level.

So lacking any existing customization mechanism does override keyDown: in a custom NSWindowController look like the most appropriate way to achieve the desired effect?

Upvotes: 1

Views: 259

Answers (1)

pointum
pointum

Reputation: 3177

Yes, subclassing NSWindow is the way to do this if you need to get the keyboard event after everything up the responder chain refused to handle it.

Here's how I did it in one of my projects:

- (void)keyDown:(NSEvent*)event
{
    SEL keyDownBool = @selector(keyDownBool:);

    if ([[self delegate] respondsToSelector:keyDownBool]
    && [[self delegate] performSelector:keyDownBool withObject:event])
    {
        return;
    }

    [super keyDown:event];
}

My custom keyDownBool: delegate method returned YES if it handled particular key event. Otherwise this method passes key event down to super.

Now I'm using + (id)addLocalMonitorForEventsMatchingMask:(NSEventMask)mask handler:(NSEvent* (^)(NSEvent*))block instead of subclassing. The difference is that it handles (and optionally discards) events before they are dispatched.

Upvotes: 2

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