gistfile1.txt

//
//  Created by Tony Arnold on 4/03/2014.
//  Copyright (c) 2014 The CocoaBots. All rights reserved.
//

#import <Cocoa/Cocoa.h>

@interface NSView (TCBAdditions)

- (void)tcb_setDraggingDestinationDelegate:(id<NSDraggingDestination>)delegate;
- (id<NSDraggingDestination>)tcb_draggingDestinationDelegate;

@end

NSView+TCBAdditions.m

//
//  Created by Tony Arnold on 4/03/2014.
//  Copyright (c) 2014 The CocoaBots. All rights reserved.
//

#import "NSView+TCBAdditions.h"
#import <objc/runtime.h>

@implementation NSView (TCBAdditions)

- (void)tcb_setDraggingDestinationDelegate:(id<NSDraggingDestination>)delegate
{
    objc_setAssociatedObject(self, @selector(tcb_draggingDestinationDelegate), delegate, OBJC_ASSOCIATION_ASSIGN);
}

- (id<NSDraggingDestination>)tcb_draggingDestinationDelegate
{
    return objc_getAssociatedObject(self, @selector(tcb_draggingDestinationDelegate));
}

#pragma mark - NSDraggingDestination

- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        return [delegate draggingEntered:sender];
    }

    return NSDragOperationNone;
}

- (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        return [delegate draggingUpdated:sender];
    }

    return NSDragOperationNone;
}

- (void)draggingExited:(id<NSDraggingInfo>)sender
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        [delegate draggingExited:sender];
    }
}

- (BOOL)prepareForDragOperation:(id<NSDraggingInfo>)sender
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        return [delegate prepareForDragOperation:sender];
    }

    return NO;
}

- (BOOL)performDragOperation:(id<NSDraggingInfo>)sender
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        return [delegate performDragOperation:sender];
    }

    return NO;
}

- (void)concludeDragOperation:(id<NSDraggingInfo>)sender
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        [delegate concludeDragOperation:sender];
    }
}

- (void)draggingEnded:(id<NSDraggingInfo>)sender
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        [delegate draggingEnded:sender];
    }
}

- (BOOL)wantsPeriodicDraggingUpdates
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        return [delegate wantsPeriodicDraggingUpdates];
    }

    return NO;
}

- (void)updateDraggingItemsForDrag:(id<NSDraggingInfo>)sender
{
    id<NSDraggingDestination> delegate = [self tcb_draggingDestinationDelegate];

    if ([delegate respondsToSelector:_cmd]) {
        [delegate updateDraggingItemsForDrag:sender];
    }
}

@end