Cocoa requires you to implement NSDraggingDestination methods on your NSView subclass, but it can be preferable to handle these methods in another class, such as an NSViewController.
The APForwardDraggingDestination category on NSView uses method swizzling to route any NSDraggingDestination methods to the given object.
In an NSViewController subclass, although it can be any class, send ap_forwardDraggingDestinationTo: with the object that should receive NSDraggingDestination methods. In this example the view controller will begin to receive drag destination methods for the label:
- (void)viewDidLoad {
[super viewDidLoad];
[self.label ap_forwardDraggingDestinationTo:self];
[self.label registerForDraggedTypes:@[NSPasteboardTypeString]];
}For a more complete demonstration, see ViewController.m.
No known issues at this time but due to the use of method swizzling it should be thoroughly tested on future and prior versions of OS X.
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Copyright (c) 2014 Adam Preble
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