kCGErrorFailure while performing drag and drop in NSView

Question

Hi all,

I have created a simple drag and drop application in which I am sometimes getting this exception msg, displayed in debugger console:

kCGErrorRangeCheck: CGSNewWindowWithOpaqueShape: Cannot create window

kCGErrorFailure: Set a breakpoint @ CGErrorBreakpoint() to catch errors as they are logged.

kCGErrorIllegalArgument: CGSMoveWindow: Invalid window 0x0

kCGErrorIllegalArgument: CGSOrderWindowList

kCGErrorIllegalArgument: CGSOrderWindowList

kCGErrorIllegalArgument: CGSGetWindowBounds: NULL window

kCGErrorIllegalArgument: CGSMoveWindow: Invalid window 0x0

kCGErrorIllegalArgument: CGSOrderWindowList

kCGErrorIllegalArgument: CGSGetWindowBounds: NULL window

Can anyone suggest me why is it occurring and how can I resolve it?

Also can anyone suggest how to set breakpoint for @CGErrorBreakpoint() so that I can debug and trace its cause?

The code in concludeDragOperation is:

NSPoint dropLocation = [sender draggedImageLocation];
id dragSource = [sender draggingSource];
NSPasteboard *pb = [sender draggingPasteboard];
NSData *draggedData = [pb dataForType:IconDragDataType];
id unarchievedObject = [NSKeyedUnarchiver unarchiveObjectWithData:draggedData];
[unarchievedObject setFrameOrigin:dropLocation];

Thanks,

Miraaj

Answer 1

To set a breakpoint in CGErrorBreakpoint open the breakpoints window (command-option-B), double-click on the line that says "Double-Click for Symbol" and enter CGErrorBreakpoint in the text field.