NSStatusBarButton keep highlighted

Question

As of OS X 10.10 most of NSStatusItem has been deprecated in favour of the button property, which consists of an NSStatusBarButton. It should work like a norma

Answer 1

Struggling with this issue myself, I discovered that overwriting mouseDown: in a category on NSStatusBarButton works:

#import "MUTargetClass.h"

@implementation NSStatusBarButton (Additions)

- (void)mouseDown:(NSEvent *)theEvent
{
    // Relay CTRL+Click to perform a right click action
    if(theEvent.modifierFlags & NSControlKeyMask)
    {
        [self rightMouseDown:theEvent];
        return;
    }

    // Handle highlighting
    [self setHighlighted:YES];

    // Perform action on target
    [(MUTargetClass *)self.target actionSelector:self];
}

@end

MUTargetClass could then for example implement:

#import "NSStatusBarButton+Additions.h"

@implementation MUTargetClass

[…]
    self.statusItem = [[NSStatusBar systemStatusBar] statusItemWithLength:NSVariableStatusItemLength];
    NSStatusBarButton *button = [self.statusItem button];
    [button setTarget:self];
[…]

- (void)actionSelector:(id)sender
{
    // Whatever behavior a click on the button should invoke
}

[…]
    // Reset button's highlighting status when done
    [[self.statusItem button] setHighlighted:NO];
[…]

@end

Note that the functionality of CTRL+clicking the button is getting lost in the mouseDown: -override. As shown above, it can be restored by relaying the event to rightMouseDown:.

A simpler way of having the action called would be something along the lines of [self.target performSelector:self.action] in the category and [self.statusItem setAction:@selector(actionSelector:)] in the target class, however this may cause a leak in ARC projects.

Edit: This works on El Capitan, too.

Answer 2

Anton's solution is perfect. Here it is in Swift 3:

NSEvent.addLocalMonitorForEvents(matching: .leftMouseDown) { [weak self] event in
    if event.window == self?.statusItem.button?.window {
        // Your action:
        self?.togglePopover(self?.statusItem.button)
        return nil
    }

    return event
}

I added an observer for NSApplicationWillResignActive to close the popover and set the button's isHighlighted to false.

Answer 3

I added a subview to the status item, and inside that view I added event handlers for mouseDown etc. which called [[statusItem button] highlight:true]. As it turns out setHighlighted: doesn't do the same thing as highlight:.

NSArray *array = [NSArray arrayWithObjects:[statusItem button], [self statusItemView], nil];
[[[statusItem button] superview] setSubviews:array];
//Highlight like so:
[[statusItem button] highlight:true];

EDIT: As of El Capitan this method no longer works, and neither does statusItem.button.highlight = true either