Custom shaped NSButton

Question

I am trying to create eight custom buttons (NSButton) in Xcode 4.6.3. Those are the segments of a circle. I used a standard rectangular button for each of them, adding a custom image for each segment. However, when I put the pieces together in one circle, there is no way to click some of these buttons, as the rectangular areas around each of them overlap, and prevent from reaching the other half of the buttons.

I was wondering if there is any way to make the button shape at least triangular, such that I can click on all of these buttons?

Answer 1

From the documentation "View Programming Guide":

Note: For performance reasons, Cocoa does not enforce clipping among sibling views or guarantee correct invalidation and drawing behavior when sibling views overlap. If you want a view to be drawn in front of another view, you should make the front view a subview (or descendant) of the rear view.

In other words, you can't expect overlapping views to process mouse events properly. There's no way of getting around the fact that views occupy rectangular frames. You have to make a single view which performs the work of all of your circle segments (including drawing and event handling, and optionally mouse moved events). YOu will have to use trigonometry to calculate which segment a mouse click occurs in, and respond appropriately as though a button were pressed, by re-drawing the segment and invoking the desired action.