When working with multiple screens and mouse location in Cocoa you have to go through converting the point coordinates to the current screen coordinates. For example if you have a second monitor on the left and you want to get the mouse position relative to that screen, [NSEvent mousePosition] will return something like (-1200, 130), which is often not what you want. This class provides three simple methods to simplify conversion of points to the current screen coordinates: /* Returns the screen where the mouse resides */ + (NSScreen *)currentScreenForMouseLocation; /* Allows you to convert a point from global coordinates to the current screen coordinates. */ - (NSPoint)convertPointToScreenCoordinates:(NSPoint)aPoint; /* Allows to flip the point coordinates, so y is 0 at the top instead of the bottom. x remains the same */ - (NSPoint)flipPoint:(NSPoint)aPoint; License: MIT