I have two scenes - DifficultScene and GameScene. In DifficultScene I have three buttons - easy, medium and hard. I use a global variable Bool to keep track of the current difficulty level. When I try easy mode everything works fine, but when I try medium or hard, bool is changing every second, jumping from hard to medium and easy, making game unplayable. My question is - how can I fix it? Here are code were it happens:
GamesScene.m
-(void)update:(CFTimeInterval)currentTime {
/* Called before each frame is rendered */
extern BOOL isEasyMode;
extern BOOL isMediumMode;
extern BOOL isHardMode;
if ((isEasyMode = YES)) {
NSLog(#"easy");
[self computer];
}
if ((isMediumMode = YES)) {
NSLog(#"medium");
[self computerMedium];
}
if ((isHardMode = YES)) {
NSLog(#"hard");
[self computerHard];
}
[self scoreCount];
}
(if more code is needed, i will post it)
I think your update method calls periodically as per timer so it will get called continuously if it so then. Thats why it is happening i think and another major thing is you should use == for comparison. you are using (isEasyMode = YES) that means you are assigning YES to isEasyMode.
So replce all if statement like if ((isEasyMode = YES)) with if (isEasyMode == YES).
Update :
if statement should like,
if (isEasyMode == YES) {
NSLog(#"easy");
[self computer];
}
Hope this will help :)
Related
So I'm plan to create a safe init function for NSDictionary like someone else did, but as I'm a SDK developer:
I want add a switch for it, the user can decide if he want open it or not;
I don't want to use Category to implement it.
So I create a totally new class named "ALDictionarySafeFunction.h", it has two functions, the first one is the switch function, like this:
+(void)enableSafeFunction{
[ALSwizzlingHelper swizzleSelector:#selector(initWithObjects:forKeys:count:)
ofClass:NSClassFromString(#"__NSPlaceholderDictionary")
withSwizzledSelector:#selector(safeInitWithObjects:forKeys:count:)
ofClass:[ALDictionarySafeFunction class]];
}
The ALSwizzlingHelper can help me to swizzle two functions.
The second is the safe init function, like this:
-(instancetype)safeInitWithObjects:(const id _Nonnull __unsafe_unretained *)objects forKeys:(const id _Nonnull __unsafe_unretained *)keys count:(NSUInteger)cnt {
BOOL containNilObject = NO;
for (NSUInteger i = 0; i < cnt; i++) {
if (objects[i] == nil) {
containNilObject = YES;
NSLog(#"There is a nil object(key: %#)", keys[i]);
}
}
if (containNilObject) {
//Do something to make sure that it won't cause a crash even it has some nil value
}
//There is the problem, next line
[self safeInitWithObjects:objects forKeys:keys count:cnt];
}
For the normal situation(Write the swizzled method in the Category), I need to do like I wrote to invoke the original method.
But the problem is I cannot do it here, because that the "self" object is the instance of “__NSPlaceholderDictionary”, and the "__NSPlaceholderDictionary" class doesn't have the instance method "safeInitWithObjects:forKeys:count:".
So what should I do?
Is there a way to make it?
Any advice will be appreciated.
I got into a very noob problem which I can not seem to solve in any way, I am sure I am overlooking something, but cannot figure it out for gods sake!!
Okay, so I have a start/stop button in my app, it should resume the action if the action is paused and pause the action if it is already running. Here is my code:
- (IBAction)pause:(id)sender {
if(paused){
[self.progressBar resumeLayer];
paused = false;
NSLog(#"resume");
}
if(!paused){
[self.progressBar pauseLayer];
paused = true;
NSLog(#"pause");
}
}
The problem is: When i run the app and press on the button to pause, it works fine however after that it won't resume at all. After NSLogging to the console, I found that pause is called right after resume.... Why is this?? First: the button is clicked only once, how can it call two opposite methods? Second: Why isn't my BOOL check working?
EDIT: If I swap out one of the if statements to an else if, it works fine... Why is that?
Thank you!
Please Take Paused variable as BOOL & set with YES & NO
What is "paused"? A global variable? An instance variable? I don't know.
Convention is that instance variables should start with an underscore character, which they will do automatically if you just define a property. That way people have at least some idea what is happening.
Convention for BOOL values is YES or NO. Not true or false.
The real bummer is of course a stupid bug in your code. If paused == YES then the first if is executed, paused is set to NO, and then in the next test you check that paused == NO - which it is at this point.
You would have found that easily by stepping through the code in the debugger, line by line.
- (IBAction)pause:(id)sender {
if(paused){
[self.progressBar resumeLayer];
NSLog(#"resume");
}
if(!paused){
[self.progressBar pauseLayer];
NSLog(#"pause");
}
paused = !paused;
}
You should check for the other state in an else block instead of having two if statements.
The reason why this fails for you now is that, you change the state of paused to false and immediately after the first if statement is done you check for !paused. That will be true as you just changed it to false.
To fix it, you either can use an else if (!paused) statement or just a plain else if the paused variable is a boolean.
Something like this:
- (IBAction)pause:(id)sender {
if(paused){
[self.progressBar resumeLayer];
paused = false;
NSLog(#"resume");
} else {
[self.progressBar pauseLayer];
paused = true;
NSLog(#"pause");
}
}
1) Declare first BOOL variable in #interface ViewController ()
Ex. bool start;
2) Initialize BOOL variable in viewDidLoad method Like this start = YES;
3) now write code in button Action Like this
- (IBAction)btnPause:(UIButton *)btn {
if (start == YES)
{
btn.backgroundColor = [UIColor blackColor];
start = NO;
}
else
{
btn.backgroundColor = [UIColor whiteColor];
start = YES;
}
}
// Its change button background color but you can use your Logic.
I love blocks and it makes me sad when I can't use them. In particular, this happens mostly every time I use delegates (e.g.: with UIKit classes, mostly pre-block functionality).
So I wonder... Is it possible -using the crazy power of ObjC-, to do something like this?
// id _delegate; // Most likely declared as class variable or it will be released
_delegate = [DelegateFactory delegateOfProtocol:#protocol(SomeProtocol)];
_delegate performBlock:^{
// Do something
} onSelector:#selector(someProtocolMethod)]; // would execute the given block when the given selector is called on the dynamic delegate object.
theObject.delegate = (id<SomeProtocol>)_delegate;
// Profit!
performBlock:onSelector:
If YES, how? And is there a reason why we shouldn't be doing this as much as possible?
Edit
Looks like it IS possible. Current answers focus on the first part of the question, which is how. But it'd be nice to have some discussion on the "should we do it" part.
Okay, I finally got around to putting WoolDelegate up on GitHub. Now it should only take me another month to write a proper README (although I guess this is a good start).
The delegate class itself is pretty straightforward. It simply maintains a dictionary mapping SELs to Block. When an instance recieves a message to which it doesn't respond, it ends up in forwardInvocation: and looks in the dictionary for the selector:
- (void)forwardInvocation:(NSInvocation *)anInvocation {
SEL sel = [anInvocation selector];
GenericBlock handler = [self handlerForSelector:sel];
If it's found, the Block's invocation function pointer is pulled out and passed along to the juicy bits:
IMP handlerIMP = BlockIMP(handler);
[anInvocation Wool_invokeUsingIMP:handlerIMP];
}
(The BlockIMP() function, along with other Block-probing code, is thanks to Mike Ash. Actually, a lot of this project is built on stuff I learned from his Friday Q&A's. If you haven't read those essays, you're missing out.)
I should note that this goes through the full method resolution machinery every time a particular message is sent; there's a speed hit there. The alternative is the path that Erik H. and EMKPantry each took, which is creating a new clas for each delegate object that you need, and using class_addMethod(). Since every instance of WoolDelegate has its own dictionary of handlers, we don't need to do that, but on the other hand there's no way to "cache" the lookup or the invocation. A method can only be added to a class, not to an instance.
I did it this way for two reasons: this was an excercise to see if I could work out the part that's coming next -- the hand-off from NSInvocation to Block invocation -- and the creation of a new class for every needed instance simply seemed inelegant to me. Whether it's less elegant than my solution, I will leave to each reader's judgement.
Moving on, the meat of this procedure is actually in the NSInvocation category that's found in the project. This utilizes libffi to call a function that's unknown until runtime -- the Block's invocation -- with arguments that are also unknown until runtime (which are accessible via the NSInvocation). Normally, this is not possible, for the same reason that a va_list cannot be passed on: the compiler has to know how many arguments there are and how big they are. libffi contains assembler for each platform that knows/is based on those platforms' calling conventions.
There's three steps here: libffi needs a list of the types of the arguments to the function that's being called; it needs the argument values themselves put into a particular format; then the function (the Block's invocation pointer) needs to be invoked via libffi and the return value put back into the NSInvocation.
The real work for the first part is handled largely by a function which is again written by Mike Ash, called from Wool_buildFFIArgTypeList. libffi has internal structs that it uses to describe the types of function arguments. When preparing a call to a function, the library needs a list of pointers to these structures. The NSMethodSignature for the NSInvocation allows access of each argument's encoding string; translating from there to the correct ffi_type is handled by a set of if/else lookups:
arg_types[i] = libffi_type_for_objc_encoding([sig getArgumentTypeAtIndex:actual_arg_idx]);
...
if(str[0] == #encode(type)[0]) \
{ \
if(sizeof(type) == 1) \
return &ffi_type_sint8; \
else if(sizeof(type) == 2) \
return &ffi_type_sint16; \
Next, libffi wants pointers to the argument values themselves. This is done in Wool_buildArgValList: get the size of each argument, again from the NSMethodSignature, and allocate a chunk of memory that size, then return the list:
NSUInteger arg_size;
NSGetSizeAndAlignment([sig getArgumentTypeAtIndex:actual_arg_idx],
&arg_size,
NULL);
/* Get a piece of memory that size and put its address in the list. */
arg_list[i] = [self Wool_allocate:arg_size];
/* Put the value into the allocated spot. */
[self getArgument:arg_list[i] atIndex:actual_arg_idx];
(An aside: there's several notes in the code about skipping over the SEL, which is the (hidden) second passed argument to any method invocation. The Block's invocation pointer doesn't have a slot to hold the SEL; it just has itself as the first argument, and the rest are the "normal" arguments. Since the Block, as written in client code, could never access that argument anyways (it doesn't exist at the time), I decided to ignore it.)
libffi now needs to do some "prep"; as long as that succeeds (and space for the return value can be allocated), the invocation function pointer can now be "called", and the return value can be set:
ffi_call(&inv_cif, (genericfunc)theIMP, ret_val, arg_vals);
if( ret_val ){
[self setReturnValue:ret_val];
free(ret_val);
}
There's some demonstrations of the functionality in main.m in the project.
Finally, as for your question of "should this be done?", I think the answer is "yes, as long as it makes you more productive". WoolDelegate is completely generic, and an instance can act like any fully written-out class. My intention for it, though, was to make simple, one-off delegates -- that only need one or two methods, and don't need to live past their delegators -- less work than writing a whole new class, and more legible/maintainable than sticking some delegate methods into a view controller because it's the easiest place to put them. Taking advantage of the runtime and the language's dynamism like this hopefully can increase your code's readability, in the same way, e.g., Block-based NSNotification handlers do.
I just put together a little project that lets you do just this...
#interface EJHDelegateObject : NSObject
+ (id)delegateObjectForProtocol:(Protocol*) protocol;
#property (nonatomic, strong) Protocol *protocol;
- (void)addImplementation:(id)blockImplementation forSelector:(SEL)selector;
#end
#implementation EJHDelegateObject
static NSInteger counter;
+ (id)delegateObjectForProtocol:(Protocol *)protocol
{
NSString *className = [NSString stringWithFormat:#"%s%#%i",protocol_getName(protocol),#"_EJH_implementation_", counter++];
Class protocolClass = objc_allocateClassPair([EJHDelegateObject class], [className cStringUsingEncoding:NSUTF8StringEncoding], 0);
class_addProtocol(protocolClass, protocol);
objc_registerClassPair(protocolClass);
EJHDelegateObject *object = [[protocolClass alloc] init];
object.protocol = protocol;
return object;
}
- (void)addImplementation:(id)blockImplementation forSelector:(SEL)selector
{
unsigned int outCount;
struct objc_method_description *methodDescriptions = protocol_copyMethodDescriptionList(self.protocol, NO, YES, &outCount);
struct objc_method_description description;
BOOL descriptionFound = NO;
for (int i = 0; i < outCount; i++){
description = methodDescriptions[i];
if (description.name == selector){
descriptionFound = YES;
break;
}
}
if (descriptionFound){
class_addMethod([self class], selector, imp_implementationWithBlock(blockImplementation), description.types);
}
}
#end
And using an EJHDelegateObject:
self.alertViewDelegate = [EJHDelegateObject delegateObjectForProtocol:#protocol(UIAlertViewDelegate)];
[self.alertViewDelegate addImplementation:^(id _self, UIAlertView* alertView, NSInteger buttonIndex){
NSLog(#"%# dismissed with index %i", alertView, buttonIndex);
} forSelector:#selector(alertView:didDismissWithButtonIndex:)];
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Example" message:#"My delegate is an EJHDelegateObject" delegate:self.alertViewDelegate cancelButtonTitle:#"Cancel" otherButtonTitles:#"OK", nil];
[alertView show];
Edit: This is what I've come up after having understood your requirement. This is just a quick hack, an idea to get you started, it's not properly implemented, nor is it tested. It is supposed to work for delegate methods that take the sender as their only argument. It works It is supposed to work with normal and struct-returning delegate methods.
typedef void *(^UBDCallback)(id);
typedef void(^UBDCallbackStret)(void *, id);
void *UBDDelegateMethod(UniversalBlockDelegate *self, SEL _cmd, id sender)
{
UBDCallback cb = [self blockForSelector:_cmd];
return cb(sender);
}
void UBDelegateMethodStret(void *retadrr, UniversalBlockDelegate *self, SEL _cmd, id sender)
{
UBDCallbackStret cb = [self blockForSelector:_cmd];
cb(retaddr, sender);
}
#interface UniversalBlockDelegate: NSObject
- (BOOL)addDelegateSelector:(SEL)sel isStret:(BOOL)stret methodSignature:(const char *)mSig block:(id)block;
#end
#implementation UniversalBlockDelegate {
SEL selectors[128];
id blocks[128];
int count;
}
- (id)blockForSelector:(SEL)sel
{
int idx = -1;
for (int i = 0; i < count; i++) {
if (selectors[i] == sel) {
return blocks[i];
}
}
return nil;
}
- (void)dealloc
{
for (int i = 0; i < count; i++) {
[blocks[i] release];
}
[super dealloc];
}
- (BOOL)addDelegateSelector:(SEL)sel isStret:(BOOL)stret methodSignature:(const char *)mSig block:(id)block
{
if (count >= 128) return NO;
selectors[count] = sel;
blocks[count++] = [block copy];
class_addMethod(self.class, sel, (IMP)(stret ? UBDDelegateMethodStret : UBDDelegateMethod), mSig);
return YES;
}
#end
Usage:
UIWebView *webView = [[UIWebView alloc] initWithFrame:CGRectZero];
UniversalBlockDelegate *d = [[UniversalBlockDelegate alloc] init];
webView.delegate = d;
[d addDelegateSelector:#selector(webViewDidFinishLoading:) isStret:NO methodSignature:"v#:#" block:^(id webView) {
NSLog(#"Web View '%#' finished loading!", webView);
}];
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://google.com"]]];
I am using Xcode 5.0.2. When I run analyze on my project, it gives me dead store messages for the stop argument in NSArray indexOfObjectWithOptions:passingTest: . The message is - Value stored to 'stop' is never read. The sample code is
NSUInteger index = [self.array indexOfObjectWithOptions:NSEnumerationConcurrent passingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop) {
// Do some check. If it passes
stop = YES; // Reports dead store here
return isFound;
}];
I believe I am stopping the enumeration correctly. Is there a another way of setting the stop value so that I can avoid this message.
Change this:
stop = YES;
to:
*stop = YES;
You need to dereference the pointer to set its value.
To be really safe though you should do this (it avoids a crash if the pointer is nil):
if (stop) {
*stop = YES;
}
You are not using that variable stop in any other place in your code, you are just assigning a value to it, but not using that value.
Situation 1:
If you write a code like:
- (BOOL)deadStore
{
BOOL dead = YES; // dead store warning
dead = NO;
return dead;
}
Situation 2:
If you write a code like:
- (int)deadStore
{
BOOL dead = YES; // dead store warning
int notDead = 7
return notDead;
}
I love blocks and it makes me sad when I can't use them. In particular, this happens mostly every time I use delegates (e.g.: with UIKit classes, mostly pre-block functionality).
So I wonder... Is it possible -using the crazy power of ObjC-, to do something like this?
// id _delegate; // Most likely declared as class variable or it will be released
_delegate = [DelegateFactory delegateOfProtocol:#protocol(SomeProtocol)];
_delegate performBlock:^{
// Do something
} onSelector:#selector(someProtocolMethod)]; // would execute the given block when the given selector is called on the dynamic delegate object.
theObject.delegate = (id<SomeProtocol>)_delegate;
// Profit!
performBlock:onSelector:
If YES, how? And is there a reason why we shouldn't be doing this as much as possible?
Edit
Looks like it IS possible. Current answers focus on the first part of the question, which is how. But it'd be nice to have some discussion on the "should we do it" part.
Okay, I finally got around to putting WoolDelegate up on GitHub. Now it should only take me another month to write a proper README (although I guess this is a good start).
The delegate class itself is pretty straightforward. It simply maintains a dictionary mapping SELs to Block. When an instance recieves a message to which it doesn't respond, it ends up in forwardInvocation: and looks in the dictionary for the selector:
- (void)forwardInvocation:(NSInvocation *)anInvocation {
SEL sel = [anInvocation selector];
GenericBlock handler = [self handlerForSelector:sel];
If it's found, the Block's invocation function pointer is pulled out and passed along to the juicy bits:
IMP handlerIMP = BlockIMP(handler);
[anInvocation Wool_invokeUsingIMP:handlerIMP];
}
(The BlockIMP() function, along with other Block-probing code, is thanks to Mike Ash. Actually, a lot of this project is built on stuff I learned from his Friday Q&A's. If you haven't read those essays, you're missing out.)
I should note that this goes through the full method resolution machinery every time a particular message is sent; there's a speed hit there. The alternative is the path that Erik H. and EMKPantry each took, which is creating a new clas for each delegate object that you need, and using class_addMethod(). Since every instance of WoolDelegate has its own dictionary of handlers, we don't need to do that, but on the other hand there's no way to "cache" the lookup or the invocation. A method can only be added to a class, not to an instance.
I did it this way for two reasons: this was an excercise to see if I could work out the part that's coming next -- the hand-off from NSInvocation to Block invocation -- and the creation of a new class for every needed instance simply seemed inelegant to me. Whether it's less elegant than my solution, I will leave to each reader's judgement.
Moving on, the meat of this procedure is actually in the NSInvocation category that's found in the project. This utilizes libffi to call a function that's unknown until runtime -- the Block's invocation -- with arguments that are also unknown until runtime (which are accessible via the NSInvocation). Normally, this is not possible, for the same reason that a va_list cannot be passed on: the compiler has to know how many arguments there are and how big they are. libffi contains assembler for each platform that knows/is based on those platforms' calling conventions.
There's three steps here: libffi needs a list of the types of the arguments to the function that's being called; it needs the argument values themselves put into a particular format; then the function (the Block's invocation pointer) needs to be invoked via libffi and the return value put back into the NSInvocation.
The real work for the first part is handled largely by a function which is again written by Mike Ash, called from Wool_buildFFIArgTypeList. libffi has internal structs that it uses to describe the types of function arguments. When preparing a call to a function, the library needs a list of pointers to these structures. The NSMethodSignature for the NSInvocation allows access of each argument's encoding string; translating from there to the correct ffi_type is handled by a set of if/else lookups:
arg_types[i] = libffi_type_for_objc_encoding([sig getArgumentTypeAtIndex:actual_arg_idx]);
...
if(str[0] == #encode(type)[0]) \
{ \
if(sizeof(type) == 1) \
return &ffi_type_sint8; \
else if(sizeof(type) == 2) \
return &ffi_type_sint16; \
Next, libffi wants pointers to the argument values themselves. This is done in Wool_buildArgValList: get the size of each argument, again from the NSMethodSignature, and allocate a chunk of memory that size, then return the list:
NSUInteger arg_size;
NSGetSizeAndAlignment([sig getArgumentTypeAtIndex:actual_arg_idx],
&arg_size,
NULL);
/* Get a piece of memory that size and put its address in the list. */
arg_list[i] = [self Wool_allocate:arg_size];
/* Put the value into the allocated spot. */
[self getArgument:arg_list[i] atIndex:actual_arg_idx];
(An aside: there's several notes in the code about skipping over the SEL, which is the (hidden) second passed argument to any method invocation. The Block's invocation pointer doesn't have a slot to hold the SEL; it just has itself as the first argument, and the rest are the "normal" arguments. Since the Block, as written in client code, could never access that argument anyways (it doesn't exist at the time), I decided to ignore it.)
libffi now needs to do some "prep"; as long as that succeeds (and space for the return value can be allocated), the invocation function pointer can now be "called", and the return value can be set:
ffi_call(&inv_cif, (genericfunc)theIMP, ret_val, arg_vals);
if( ret_val ){
[self setReturnValue:ret_val];
free(ret_val);
}
There's some demonstrations of the functionality in main.m in the project.
Finally, as for your question of "should this be done?", I think the answer is "yes, as long as it makes you more productive". WoolDelegate is completely generic, and an instance can act like any fully written-out class. My intention for it, though, was to make simple, one-off delegates -- that only need one or two methods, and don't need to live past their delegators -- less work than writing a whole new class, and more legible/maintainable than sticking some delegate methods into a view controller because it's the easiest place to put them. Taking advantage of the runtime and the language's dynamism like this hopefully can increase your code's readability, in the same way, e.g., Block-based NSNotification handlers do.
I just put together a little project that lets you do just this...
#interface EJHDelegateObject : NSObject
+ (id)delegateObjectForProtocol:(Protocol*) protocol;
#property (nonatomic, strong) Protocol *protocol;
- (void)addImplementation:(id)blockImplementation forSelector:(SEL)selector;
#end
#implementation EJHDelegateObject
static NSInteger counter;
+ (id)delegateObjectForProtocol:(Protocol *)protocol
{
NSString *className = [NSString stringWithFormat:#"%s%#%i",protocol_getName(protocol),#"_EJH_implementation_", counter++];
Class protocolClass = objc_allocateClassPair([EJHDelegateObject class], [className cStringUsingEncoding:NSUTF8StringEncoding], 0);
class_addProtocol(protocolClass, protocol);
objc_registerClassPair(protocolClass);
EJHDelegateObject *object = [[protocolClass alloc] init];
object.protocol = protocol;
return object;
}
- (void)addImplementation:(id)blockImplementation forSelector:(SEL)selector
{
unsigned int outCount;
struct objc_method_description *methodDescriptions = protocol_copyMethodDescriptionList(self.protocol, NO, YES, &outCount);
struct objc_method_description description;
BOOL descriptionFound = NO;
for (int i = 0; i < outCount; i++){
description = methodDescriptions[i];
if (description.name == selector){
descriptionFound = YES;
break;
}
}
if (descriptionFound){
class_addMethod([self class], selector, imp_implementationWithBlock(blockImplementation), description.types);
}
}
#end
And using an EJHDelegateObject:
self.alertViewDelegate = [EJHDelegateObject delegateObjectForProtocol:#protocol(UIAlertViewDelegate)];
[self.alertViewDelegate addImplementation:^(id _self, UIAlertView* alertView, NSInteger buttonIndex){
NSLog(#"%# dismissed with index %i", alertView, buttonIndex);
} forSelector:#selector(alertView:didDismissWithButtonIndex:)];
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:#"Example" message:#"My delegate is an EJHDelegateObject" delegate:self.alertViewDelegate cancelButtonTitle:#"Cancel" otherButtonTitles:#"OK", nil];
[alertView show];
Edit: This is what I've come up after having understood your requirement. This is just a quick hack, an idea to get you started, it's not properly implemented, nor is it tested. It is supposed to work for delegate methods that take the sender as their only argument. It works It is supposed to work with normal and struct-returning delegate methods.
typedef void *(^UBDCallback)(id);
typedef void(^UBDCallbackStret)(void *, id);
void *UBDDelegateMethod(UniversalBlockDelegate *self, SEL _cmd, id sender)
{
UBDCallback cb = [self blockForSelector:_cmd];
return cb(sender);
}
void UBDelegateMethodStret(void *retadrr, UniversalBlockDelegate *self, SEL _cmd, id sender)
{
UBDCallbackStret cb = [self blockForSelector:_cmd];
cb(retaddr, sender);
}
#interface UniversalBlockDelegate: NSObject
- (BOOL)addDelegateSelector:(SEL)sel isStret:(BOOL)stret methodSignature:(const char *)mSig block:(id)block;
#end
#implementation UniversalBlockDelegate {
SEL selectors[128];
id blocks[128];
int count;
}
- (id)blockForSelector:(SEL)sel
{
int idx = -1;
for (int i = 0; i < count; i++) {
if (selectors[i] == sel) {
return blocks[i];
}
}
return nil;
}
- (void)dealloc
{
for (int i = 0; i < count; i++) {
[blocks[i] release];
}
[super dealloc];
}
- (BOOL)addDelegateSelector:(SEL)sel isStret:(BOOL)stret methodSignature:(const char *)mSig block:(id)block
{
if (count >= 128) return NO;
selectors[count] = sel;
blocks[count++] = [block copy];
class_addMethod(self.class, sel, (IMP)(stret ? UBDDelegateMethodStret : UBDDelegateMethod), mSig);
return YES;
}
#end
Usage:
UIWebView *webView = [[UIWebView alloc] initWithFrame:CGRectZero];
UniversalBlockDelegate *d = [[UniversalBlockDelegate alloc] init];
webView.delegate = d;
[d addDelegateSelector:#selector(webViewDidFinishLoading:) isStret:NO methodSignature:"v#:#" block:^(id webView) {
NSLog(#"Web View '%#' finished loading!", webView);
}];
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:#"http://google.com"]]];