JTTargetActionBlock - Adding blocks support for UIControl target/action mechanism

LICENSE

Copyright (c) 2013 Jamz Tang <[email protected]>
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is furnished
to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

UIControl-JTTargetActionBlock.h

/*
 * This file is part of the http://ioscodesnippet.com
 * (c) Jamz Tang <[email protected]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

// JTTargetActionBlock is built with ARC environment

#import <UIKit/UIKit.h>

typedef void(^UIControlEventHandler)(id sender, UIEvent *event);

@interface UIControl (JTTargetActionBlock)

- (void)addEventHandler:(UIControlEventHandler)handler forControlEvent:(UIControlEvents)controlEvent;
- (void)removeEventHandlersForControlEvent:(UIControlEvents)controlEvent;

@end

UIControl-JTTargetActionBlock.m

/*
 * This file is part of the http://ioscodesnippet.com
 * (c) Jamz Tang <[email protected]>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

#import "UIControl-JTTargetActionBlock.h"
#import <objc/runtime.h>

@interface UIControlEventWrapper : NSObject
@property (nonatomic, assign) UIControlEvents controlEvent;
@property (nonatomic, copy)   UIControlEventHandler handler;
@end

@implementation UIControlEventWrapper
@synthesize controlEvent, handler;
- (void)sender:(id)sender forEvent:(UIEvent *)event {
    if (self.handler) {
        self.handler(sender, event);
    }
}
- (void) dealloc {
    objc_removeAssociatedObjects(self);
}
@end

@implementation UIControl (JTTargetActionBlock)

static char *eventWrapperKey;

- (NSMutableArray *)eventWrappers {
    NSMutableArray *wrappers = objc_getAssociatedObject(self, &eventWrapperKey);
    if ( ! wrappers) {
         wrappers = [NSMutableArray array];
        objc_setAssociatedObject(self, &eventWrapperKey, wrappers, OBJC_ASSOCIATION_RETAIN);
    }
    return wrappers;
}

- (void)addEventHandler:(UIControlEventHandler)handler forControlEvent:(UIControlEvents)controlEvent {
    UIControlEventWrapper *wrapper = [[UIControlEventWrapper alloc] init];
    wrapper.controlEvent = controlEvent;
    wrapper.handler      = handler;
    
    [self addTarget:wrapper action:@selector(sender:forEvent:) forControlEvents:controlEvent];
    [[self eventWrappers] addObject:wrapper];
}

- (void)removeEventHandlersForControlEvent:(UIControlEvents)controlEvent {
    __block __weak UIControl *weakSelf = self;
    [[self eventWrappers] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
        UIControlEventWrapper *wrapper = obj;
        if (wrapper.controlEvent == controlEvent) {
            [weakSelf removeTarget:wrapper action:NULL forControlEvents:controlEvent];
        }
    }];
}

@end

UIControl-JTTargetActionBlock.podspec

Pod::Spec.new do |s|
  s.name         = "UIControl-JTTargetActionBlock"
  s.version      = "0.0.1"
  s.summary      = "Adding blocks support for UIControl target/action mechanism"
  s.homepage     = "https://gist.github.com/jamztang/2205564"
  s.author       = { "Jamz Tang" => "[email protected]" }
  s.platform     = :ios
  s.source       = { :git => "git://gist.github.com/2205564.git", :tag => '0.0.1' }
  s.requires_arc = true
  s.ios.deployment_target = '5.0'
  s.source_files  = '*.{h,m}'
  s.license      = { :type => 'MIT', :file => 'LICENSE' }
end

I think there is a leak of UIControlEventWrappers, removeEventHandlersForControlEvent won't remove the element from eventWrappers.

@mystcolor, Thx, it's great!
As @nrichards mentioned, there is a memory leak. Other than what @nrichards mentioned, the wrappers associated with self should be removed in dealloc method, too. Just like this :

- (void) dealloc {
    objc_removeAssociatedObjects(self);
}

Thanks @nrichards, @qiaoxueshi !