Cocoa: change cursor when it's over an NSButton

You should subclass NSButton first, then add the code below.

- (void)resetCursorRects
{
    if (self.cursor) {
        [self addCursorRect:[self bounds] cursor: self.cursor];
    } else {
        [super resetCursorRects];
    }
}

Now you can set cursor as you like.

[self.button setCursor:[NSCursor pointingHandCursor]];

---

Note: add cursor as a property of your subclass, like this:

@property (strong) NSCursor *cursor;  

[yourButton addCursorRect:[yourButton bounds] cursor:[theCursorYouWant]];

Following the already given example, creating a subclass of NSButton in Swift 5:

import AppKit

class Button: NSButton {
    override func resetCursorRects() {
        addCursorRect(bounds, cursor: .pointingHand)
    }
}