Gap above NSMenuItem custom view

Question

I am using the setView: method on an NSMenuItem to set a custom view. In this custom view there is an image which takes the whole of the view. The NSMenuItem with this custom view is the first in the menu but the problem is it doesn't sit flush with the top of the menu, there is a big gap as you can see here:

alt text

Why is this happening and how can I stop it?

EDIT

I am using this code now but I am getting EXC_BAD_ACCESS on the line InstallControlEventHandler.

-(void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    HIViewRef contentView;
    MenuRef menuRef = [statusMenu carbonMenuRef];

    HIMenuGetContentView(menuRef, kThemeMenuTypePullDown, &contentView);

    EventTypeSpec hsEventSpec[1] = {
        { kEventClassMenu, kEventMenuCreateFrameView }
    };

    InstallControlEventHandler(contentView,
                           NewEventHandlerUPP((EventHandlerProcPtr)hsMenuCreationEventHandler),
                           GetEventTypeCount(hsEventSpec),
                           hsEventSpec,
                           NULL,
                           NULL); // Get EXC_BAD_ACCESS here.
}

static OSStatus hsMenuContentEventHandler( EventHandlerCallRef caller, EventRef event, void* refcon )
{
    OSStatus  err;

    check( GetEventClass( event ) == kEventClassControl );
    check( GetEventKind( event ) == kEventControlGetFrameMetrics );

    err = CallNextEventHandler( caller, event );
    if ( err == noErr )
    {
        HIViewFrameMetrics  metrics;

        verify_noerr( GetEventParameter( event, kEventParamControlFrameMetrics, typeControlFrameMetrics, NULL,
                                        sizeof( metrics ), NULL, &metrics ) );

        metrics.top = 0;

        verify_noerr( SetEventParameter( event, kEventParamControlFrameMetrics, typeControlFrameMetrics,
                                        sizeof( metrics ), &metrics ) );
    }

    return err;
}

static OSStatus hsMenuCreationEventHandler( EventHandlerCallRef caller, EventRef event, void* refcon )
{
    OSStatus  err = eventNotHandledErr;

    if ( GetEventKind( event ) == kEventMenuCreateFrameView)
    {
        err = CallNextEventHandler( caller, event );
        if ( err == noErr )
        {
            static const EventTypeSpec  kContentEvents[] =
            {
                { kEventClassControl, kEventControlGetFrameMetrics }
            };

            HIViewRef          frame;
            HIViewRef          content;

            verify_noerr( GetEventParameter( event, kEventParamMenuFrameView, typeControlRef, NULL,
                                            sizeof( frame ), NULL, &frame ) );
            verify_noerr( HIViewFindByID( frame, kHIViewWindowContentID, &content ) );
            InstallControlEventHandler( content, hsMenuContentEventHandler, GetEventTypeCount( kContentEvents ),
                                       kContentEvents, 0, NULL );
        }
    }

    return err;
}

Also note the line metrics.top = 0 this is the line which should remove the gap at the top. However I cannot get it work that far. Does anyone know why I would be recieving an EXC_BAD_ACCESS there. I have already created and allocated statusMenu so surely it should work?

It looks like there is a white spacer at the top and bottom of every menu. I'd also like to know if it's possible to avoid it. — Nick Moore
I assume the black portion is the image, not the gap? There is some padding between the top and the bottom of the menu, in addition to between separator items, for aesthetic reasons. I'm not sure if this is done is NSMenu or NSMenuItem, but you may need to subclass either one or the other to prevent it. — d11wtq
I've done some research and turned up this mail-archive.com/[email protected]/msg26997.html It looks like a custom NSMenu would be needed & some private API tinkering. — Nick Moore
That's interesting but how would you set the top metrics to zero and I wonder what the code would be like as I as I assume it would be Carbon. — Joshua
Joshua : I make the above code working by replacing "InstallControlEventHandler" function call to "HIViewInstallEventHandler". let me know if that help. — AmitSri

skue skue · Accepted Answer · 2011-03-06T23:12:11

Your post is tagged "Objective-C" and "Cocoa", although your sample code is C and Carbon. I assume you'd prefer a Cocoa solution?

It's actually pretty simple in Cocoa. The only trick is learning how to draw outside the lines. :-)

@interface FullMenuItemView : NSView
@end

@implementation FullMenuItemView
- (void) drawRect:(NSRect)dirtyRect
{
    NSRect fullBounds = [self bounds];
    fullBounds.size.height += 4;
    [[NSBezierPath bezierPathWithRect:fullBounds] setClip];

    // Then do your drawing, for example...
    [[NSColor blueColor] set];
    NSRectFill( fullBounds );
}
@end

Use it like this:

CGFloat menuItemHeight = 32;

NSRect viewRect = NSMakeRect(0, 0, /* width autoresizes */ 1, menuItemHeight);
NSView *menuItemView = [[[FullMenuItemView alloc] initWithFrame:viewRect] autorelease];
menuItemView.autoresizingMask = NSViewWidthSizable;

yourMenuItem.view = menuItemView;

Gap above NSMenuItem custom view

1 Answers