TeakKVOHelpers.h

/* Teak -- Copyright (C) 2016 GoCarrot Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef TeakKVOHelpers_h
#define TeakKVOHelpers_h

#define KeyValueObserverSupported NSMutableDictionary* kvoRegDictionaryForClassName(NSString* className) { static NSMutableDictionary* dict; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ dict = [[NSMutableDictionary alloc] init]; }); NSMutableDictionary* dictForClassName = [dict objectForKey:className]; if (dictForClassName == nil) { dictForClassName = [[NSMutableDictionary alloc] init]; [dict setObject:dictForClassName forKey:className]; } return dictForClassName; } - (void)observeValueForKeyPath:(NSString*)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void*)context { NSString* selector = [kvoRegDictionaryForClassName(NSStringFromClass([object class])) objectForKey:keyPath]; if (selector) { SEL sel = NSSelectorFromString(selector); if ([self respondsToSelector:sel]) { [self performSelector:sel withObject:[change objectForKey:NSKeyValueChangeOldKey] withObject:[change objectForKey:NSKeyValueChangeNewKey]]; } } }

#define KeyValueObserverFor(_className, _key) __attribute__ ((constructor)) void _##_className##_##_key##Reg() { [kvoRegDictionaryForClassName(@#_className) setObject:NSStringFromSelector(@selector(_##_className##_##_key##_ChangedFrom:to:)) forKey:NSStringFromSelector(@selector(_key))]; } - (void)_##_className##_##_key##_ChangedFrom:(id)oldValue to:(id)newValue

#define RegisterKeyValueObserverFor(_object, _key) [_object addObserver:self forKeyPath:NSStringFromSelector(@selector(_key)) options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil]

#define UnRegisterKeyValueObserverFor(_object, _key) [_object removeObserver:self forKeyPath:NSStringFromSelector(@selector(_key))]

#endif /* TeakKVOHelpers_h */