Intercept keydown events to NSWindow given to a plugin - objective-c

Question

I am writing an audio plugin (VST) in Objective-C on OSX. My plugin gets loaded into an application and is given an NSWindow in which to add my own NSView. I need to be able to intercept keyboard events on the NSWindow which I can partly do, but not fully.
Here's what I have tried so far:
Make sure my view is the first response and handle keyDown events. This works for most keyDown events, but not carriage return or special keys like cut/copy/paste.
Use addLocalMonitorForEventsMatchingMask. This doesn't provide anything more useful than keyDown.
The NSWindow I'm given has a menu with some key equivalents for cut/copy/paste. I occasionally need to intercept these if the user has something selected in my NSView. I also occasionally need to intercept carriage return if the user is entering some data.
My UI is rendered using OpenGL so I'm not using standard Cocoa UI components apart from NSView to host my OpenGL surface.
I don't want the user to have to enable anything special to do this, like accessibility.
In my keyDown handler I have something like this:
- (void)keyDown:(NSEvent*)event
{
NSString* s = event.charactersIgnoringModifiers;
unichar modified_key = 0;
if (s && [s length] > 0)
{
modified_key = [s characterAtIndex:0];
}
if (modified_key == NSCarriageReturnCharacter)
{
// carriage return
}
}
This works in a stand alone application, but fails when it's hosted as an audio plugin. The problem I think is that the application hosting the plugin is intercepting events before they reach my event handlers.

Answer 1

You seem to be handling the event in a strange way. Process the NSEvent keyCode directly. You can use modifierFlags to get the modifiers.
This won't work for certain "system" key combinations (like Command + Space) for which you will need accessibility access.
- (void)keyDown:(NSEvent *)event
{
if (event.keyCode == 36)
NSLog(#"you pressed return!");
if (event.modifierFlags & NSEventModifierFlagCommand)
{
if (event.keyCode == 8)
NSLog(#"you pressed command+c!");
}
}