Toggle colour inversion on global hotkey

When the registered global hotkey is pressed, toggle screen colour
inversion.

Move the colour inversion code to the `Invert` class.

1 files changed, 4 insertions, 1 deletions

diff --git a/Invert.h b/Invert.h
index c84685e..91a9f69 100644
--- a/Invert.h
+++ b/Invert.h
@@ -1,6 +1,9 @@
 #import <Cocoa/Cocoa.h>
+#import <CoreGraphics/CoreGraphics.h>
 
-@interface Invert : NSObject
+@interface Invert : NSObject {
+    BOOL _inverted;
+}
 
 - (void)toggleInvertColors:(NSEvent *)event;