管理CCLayer们的Touch

当CCLayer中含有CCMenu时, 仅仅设置self.isTouchEnable是不够的,这时通常需要这样开关CCLayer的触控

- (void)openTouch {
    for (id child in [self children]) {
        if ([child isKindOfClass:[CCMenu class]]) {
            for (CCMenuItem *item in [child children]) {
                [item setIsEnabled:YES];
            }
        }
    }
    self.isTouchEnabled = YES;
}

- (void)closeTouch {
    for (id child in [self children]) {
        if ([child isKindOfClass:[CCMenu class]]) {
            for (CCMenuItem *item in [child children]) {
                [item setIsEnabled:NO];
            }
        }
    }
    self.isTouchEnabled = NO;
}