game state singleton cocos2d, initWithEncoder always returns null
- by taber
Hi, I'm trying to write a basic test "game state" singleton in cocos2d, but for some reason upon loading the app, initWithCoder is never called. Any help would be much appreciated, thanks.
Here's my singleton GameState.h:
#import "cocos2d.h"
@interface GameState : NSObject <NSCoding>
{
NSInteger level, score;
Boolean seenInstructions;
}
@property (readwrite) NSInteger level;
@property (readwrite) NSInteger score;
@property (readwrite) Boolean seenInstructions;
+(GameState *) sharedState;
+(void) loadState;
+(void) saveState;
@end
... and GameState.m:
#import "GameState.h"
#import "Constants.h"
@implementation GameState
static GameState *sharedState = nil;
@synthesize level, score, seenInstructions;
-(void)dealloc {
[super dealloc];
}
-(id)init {
if(!(self = [super init]))
return nil;
level = 1;
score = 0;
seenInstructions = NO;
return self;
}
+(void)loadState {
@synchronized([GameState class]) {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *saveFile = [documentsDirectory stringByAppendingPathComponent:kSaveFileName];
Boolean saveFileExists = [[NSFileManager defaultManager] fileExistsAtPath:saveFile];
if(!sharedState) {
sharedState = [GameState sharedState];
}
if(saveFileExists == YES) {
[sharedState release];
sharedState = [[NSKeyedUnarchiver unarchiveObjectWithFile:saveFile] retain];
}
// at this point, sharedState is null, saveFileExists is 1
if(sharedState == nil) {
// this always occurs
CCLOG(@"Couldn't load game state, so initialized with defaults");
sharedState = [self sharedState];
}
}
}
+(void)saveState {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *saveFile = [documentsDirectory stringByAppendingPathComponent:kSaveFileName];
[NSKeyedArchiver archiveRootObject:[GameState sharedState] toFile:saveFile];
}
+(GameState *)sharedState {
@synchronized([GameState class]) {
if(!sharedState) {
[[GameState alloc] init];
}
return sharedState;
}
return nil;
}
+(id)alloc {
@synchronized([GameState class]) {
NSAssert(sharedState == nil, @"Attempted to allocate a second instance of a singleton.");
sharedState = [super alloc];
return sharedState;
}
return nil;
}
+(id)allocWithZone:(NSZone *)zone
{
@synchronized([GameState class]) {
if(!sharedState) {
sharedState = [super allocWithZone:zone];
return sharedState;
}
}
return nil;
}
...
-(void)encodeWithCoder:(NSCoder *)coder {
[coder encodeInt:level forKey:@"level"];
[coder encodeInt:score forKey:@"score"];
[coder encodeBool:seenInstructions forKey:@"seenInstructions"];
}
-(id)initWithCoder:(NSCoder *)coder {
CCLOG(@"initWithCoder called");
self = [super init];
if(self != nil) {
CCLOG(@"initWithCoder self exists");
level = [coder decodeIntForKey:@"level"];
score = [coder decodeIntForKey:@"score"];
seenInstructions = [coder decodeBoolForKey:@"seenInstructions"];
}
return self;
}
@end
... I'm saving the state on app exit, like this:
- (void)applicationWillTerminate:(UIApplication *)application {
[GameState saveState];
[[CCDirector sharedDirector] end];
}
... and loading the state when the app finishes loading, like this:
- (BOOL) application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
...
[GameState loadState];
...
}
I've tried moving around where I call loadState too, for example in my main CCScene, but that didn't seem to work either.
Thanks again in advance.
