How to use CIFilter on NSWindow in OSX 10.9 (Mavericks)?

Question

The old trick that involved using the private API CGSAddWindowFilter() seems to no longer work in Mavericks for some reason. I tried some code described in How does on-screen color inversion work in OS X? and the code below results in the following window.

#import "AppDelegate.h"

//Declarations to avoid compiler warnings (because of private APIs):
typedef void * CGSConnection;
typedef void * CGSWindowID;
extern OSStatus CGSNewConnection(const void **attributes, CGSConnection * id);
typedef void *CGSWindowFilterRef;
extern CGError CGSNewCIFilterByName(CGSConnection cid, CFStringRef filterName, CGSWindowFilterRef *outFilter);
extern CGError CGSAddWindowFilter(CGSConnection cid, CGSWindowID wid, CGSWindowFilterRef filter, int flags);
extern CGError CGSSetCIFilterValuesFromDictionary(CGSConnection cid, CGSWindowFilterRef filter, CFDictionaryRef filterValues);

@implementation AppDelegate

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    [self.window setOpaque:NO];
    [self.window setAlphaValue:1.0];
    [self.window setBackgroundColor:[NSColor colorWithCalibratedWhite:0.0 alpha:0.1]];
    self.window.level = NSDockWindowLevel;

    CGSConnection thisConnection;
    CGSWindowFilterRef compositingFilter;
    int compositingType = 1; // under the window

    /* Make a new connection to CoreGraphics */
    CGSNewConnection(NULL, &thisConnection);

    /* Create a CoreImage filter and set it up */
    CGSNewCIFilterByName(thisConnection, CFSTR("CIColorInvert"), &compositingFilter);
    NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithFloat:3.0] forKey:@"inputRadius"];
    CGSSetCIFilterValuesFromDictionary(thisConnection, compositingFilter, (__bridge CFDictionaryRef)options);

    /* Now apply the filter to the window */
    CGSAddWindowFilter(thisConnection, (CGSWindowID)[self.window windowNumber], compositingFilter, compositingType);
}

@end

Anyone know a trick to make it apply the filter to the background too as it did in OSX 10.8?

I need this to be able to make MenuBarFilter work again in Mavericks.

Answer 1

There you go:

typedef void * CGSConnection;
extern OSStatus CGSSetWindowBackgroundBlurRadius(CGSConnection connection, NSInteger   windowNumber, int radius);
extern CGSConnection CGSDefaultConnectionForThread();

- (void)enableBlurForWindow:(NSWindow *)window
{
    [window setOpaque:NO];
    window.backgroundColor = [NSColor colorWithCalibratedWhite:1.0 alpha:0.5];

    CGSConnection connection = CGSDefaultConnectionForThread();
    CGSSetWindowBackgroundBlurRadius(connection, [window windowNumber], 20);
}