What Cocoa/Core Foundation helper functions do you wish you knew about 2 years ago?

Question

I just discovered the NSRect helper functions in NSGeometry.h (i.e. NSMidX, NSMaxX, etc...)

These would have made some repetitive coding much easier. I knew about NSMak

Answer 1

Helper function to draw three part images with left cap, fill and right cap. Ideal for custom buttons

void NSDrawThreePartImage(NSRect frame,
    NSImage *startCap,
    NSImage *centerFill,
    NSImage *endCap,
    BOOL vertical,
    NSCompositingOperation op,
    CGFloat alphaFraction,
    BOOL flipped
);

Also look for NSDrawNinePartImage