iOS Dark Mode Toggle

darkmode.m

/*
    During Dark Mode migration for macOS, I found it helpful to have a global hotkey
    which toggled between Light/Dark Mode.
  
    This hack attempts to do something similar for iOS.
  
    1) Add your main window in -applicationDidFinishLaunching:
    2) Triple tap the window (I tend to do this near the title bar) to flip between light and dark.
*/

#if DEBUG

@interface UIApplication ()
+ (void) _setDebugUserInterfaceStyleOverride:(NSInteger)override;
@end


@implementation UIApplication (IccirDebugUserInterfaceStyleOverride)

- (void) iccirToggleDebugUserInterfaceStyleOverride
{
    static NSInteger sOverride = 0;
    sOverride = sOverride == 1 ? 2 : 1;
    [UIApplication _setDebugUserInterfaceStyleOverride:sOverride];
}

@end

void AddInterfaceStyleToggle(UIWindow *window)
{
    UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] init];
     
    [recognizer setNumberOfTapsRequired:3];
    [recognizer addTarget:[UIApplication sharedApplication] action:@selector(iccirToggleDebugUserInterfaceStyleOverride)];

    [window addGestureRecognizer:recognizer];
}

#else

void AddInterfaceStyleToggle(UIWindow *window) { }

#endif

Xcode has a nice Environment Overrides pop-up, but I find this to be way more convenient.