MYUtilities: KVUtils.m@3d3dcc3116d5 (annotated)

jens@0	1	//
jens@0	2	// KVUtils.m
jens@0	3	// MYUtilities
jens@0	4	//
jens@0	5	// Created by Jens Alfke on 2/25/08.
jens@0	6	// Copyright 2008 Jens Alfke. All rights reserved.
jens@0	7	//
jens@0	8
jens@0	9	#import "KVUtils.h"
jens@0	10
jens@0	11
jens@0	12	@implementation Observance
jens@0	13
jens@0	14	- (id) initWithTarget: (id)target
jens@0	15	action: (SEL)action
jens@0	16	observed: (id)observed
jens@0	17	keyPath: (NSString*)keyPath
jens@0	18	options: (NSKeyValueObservingOptions)options
jens@0	19	{
jens@0	20	self = [super init];
jens@0	21	if (self != nil) {
jens@0	22	_target = target;
jens@0	23	_action = action;
jens@0	24	_observed = observed;
jens@0	25	_keyPath = [keyPath copy];
jens@0	26	_options = options;
jens@0	27
jens@0	28	options &= ~(MYKeyValueObservingOptionOnce \| MYKeyValueObservingOptionDelayed);
jens@0	29
jens@0	30	[_observed addObserver: self forKeyPath: _keyPath options: options context: _action];
jens@0	31	}
jens@0	32	return self;
jens@0	33	}
jens@0	34
jens@0	35	- (void) dealloc
jens@0	36	{
jens@0	37	[_observed removeObserver: self forKeyPath: _keyPath];
jens@0	38	[_keyPath release];
jens@0	39	[super dealloc];
jens@0	40	}
jens@0	41
jens@0	42
jens@0	43	@synthesize observed=_observed, keyPath=_keyPath;
jens@0	44
jens@0	45
jens@0	46	- (void) stopObserving
jens@0	47	{
jens@0	48	[_observed removeObserver: self forKeyPath: _keyPath];
jens@0	49	_observed = nil;
jens@0	50	_target = nil;
jens@0	51	_action = NULL;
jens@0	52	}
jens@0	53
jens@0	54
jens@0	55	- (void) _callTargetWithChange: (NSDictionary*)change
jens@0	56	{
jens@0	57	@try{
jens@0	58	[_target performSelector: _action withObject: _observed withObject: change];
jens@0	59	}@catch( NSException *x ) {
jens@0	60	Warn(@"Uncaught exception in -[%@<%p> %s] while observing change of key-path %@ in %@<%p>: %@",
jens@0	61	_target,_target, _action, _keyPath, _observed,_observed, x);
jens@0	62	}
jens@0	63	}
jens@0	64
jens@0	65
jens@0	66	- (void)observeValueForKeyPath:(NSString *)keyPath
jens@0	67	ofObject:(id)object
jens@0	68	change:(NSDictionary *)change
jens@0	69	context:(void *)context
jens@0	70	{
jens@0	71	if( object == _observed ) {
jens@0	72	if( _options & MYKeyValueObservingOptionDelayed )
jens@0	73	[self performSelector: @selector(_callTargetWithChange:) withObject: change
jens@0	74	afterDelay: 0.0];
jens@0	75	else
jens@0	76	[self _callTargetWithChange: change];
jens@0	77	if( _options & MYKeyValueObservingOptionOnce )
jens@0	78	[self stopObserving];
jens@0	79	}
jens@0	80	}
jens@0	81
jens@0	82
jens@0	83	@end
jens@0	84
jens@0	85
jens@0	86
jens@0	87
jens@0	88	@implementation Observer
jens@0	89
jens@0	90
jens@0	91	- (id) init
jens@0	92	{
jens@0	93	return [self initWithTarget: self];
jens@0	94	}
jens@0	95
jens@0	96
jens@0	97
jens@0	98	- (id) initWithTarget: (id)target
jens@0	99	{
jens@0	100	Assert(target);
jens@0	101	self = [super init];
jens@0	102	if (self != nil) {
jens@0	103	_target = target;
jens@0	104	_observances = [[NSMutableArray alloc] init];
jens@0	105	}
jens@0	106	return self;
jens@0	107	}
jens@0	108
jens@0	109
jens@0	110	- (void) dealloc
jens@0	111	{
jens@0	112	[self stopObserving];
jens@0	113	[_observances release];
jens@0	114	[super dealloc];
jens@0	115	}
jens@0	116
jens@0	117
jens@0	118	@synthesize target=_target;
jens@0	119
jens@0	120
jens@0	121	- (void) observe: (id)observed
jens@0	122	keyPath: (NSString*)keyPath
jens@0	123	options: (NSKeyValueObservingOptions)options
jens@0	124	action: (SEL)action
jens@0	125	{
jens@0	126	Observance *o = [[Observance alloc] initWithTarget: _target
jens@0	127	action: action
jens@0	128	observed: observed
jens@0	129	keyPath: keyPath
jens@0	130	options: options];
jens@0	131	[_observances addObject: o];
jens@0	132	[o release];
jens@0	133	}
jens@0	134
jens@0	135
jens@0	136	- (void) observe: (id)observed
jens@0	137	keyPath: (NSString*)keyPath
jens@0	138	action: (SEL)action
jens@0	139	{
jens@0	140	[self observe: observed keyPath: keyPath options: 0 action: action];
jens@0	141	}
jens@0	142
jens@0	143
jens@0	144	- (void) stopObserving
jens@0	145	{
jens@0	146	[_observances makeObjectsPerformSelector: @selector(stopObserving)];
jens@0	147	[_observances removeAllObjects];
jens@0	148	}
jens@0	149
jens@0	150
jens@0	151	- (void) stopObserving: (id)observed keyPath: (NSString*)keyPath
jens@0	152	{
jens@0	153	// observed or keyPath may be nil
jens@0	154	for( int i=_observances.count-1; i>=0; i-- ) {
jens@0	155	Observance *o = [_observances objectAtIndex: i];
jens@0	156	if( (observed==nil \|\| observed==o.observed) && (keyPath==nil \|\| [keyPath isEqual: o.keyPath]) ) {
jens@0	157	[o stopObserving];
jens@0	158	[_observances removeObjectAtIndex: i];
jens@0	159	}
jens@0	160	}
jens@0	161	}
jens@0	162
jens@0	163	@end

author	Jens Alfke <jens@mooseyard.com>
	Wed Apr 02 14:45:33 2008 -0700 (2008-04-02)
changeset 2	3d3dcc3116d5
child 3	8fad19466c59
permissions	-rw-r--r--