Question

I have an NSEvent and want to detect when a rect is clicked so this is the code I have:

- (void)mouseDown:(NSEvent *)event;
{
    NSPoint clickedPoint = [event locationInWindow];
    //perform code for clickedPoint    
}

Instead of using locationInWindow how can I convert a rect or view to a NSPoint so that it will check if I clicked the rect? thanks!

Answer 1

First off, consider whether you really want to override mouseDown: or whether overriding mouseUp: might be a better option. If this click is similar to something like clicking a button, it’s generally a better idea to override mouseUp: rather than mouseDown:, as mouseUp: would allow the user to “change their mind” by dragging the mouse out of the button’s rect before letting go of the mouse.

NSEvent’s locationInWindow gives the location of the event in the base window’s coordinates. To convert that location to the view’s local coordinate system, you can use NSView‘s convertPoint:fromView: like in the following:

- (void)mouseDown:(NSEvent *)event {
  NSPoint eventLocation = [event locationInWindow];
  NSPoint location = [self convertPoint:eventLocation fromView:nil];
  // handle the logic of what to do given the point
}

See Cocoa Event-Handling Guide: Getting the Location of an Event for more information.