iOS开源项目：DYNavigationController

DYNavigationController是一个实现了左右滑动导航的项目。

https://github.com/dyang/DYNavigationController

首先用之前的跟视图初始化DYNavigationController

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

    // Override point for customization after application launch.
    RootViewController *rootViewController = [[[RootViewController alloc] init] autorelease];
    DYNavigationController *navigationController = [[[DYNavigationController alloc]
            initWithRootViewController:rootViewController] autorelease];

    self.window.rootViewController = navigationController;
    [self.window makeKeyAndVisible];
    return YES;
}

这个方法定义了左右滑动的手势操作

- (void)setUpGestureRecognizers:(UIViewController *)viewController {
    // Swipe right: pop the current view and go back one level
    UISwipeGestureRecognizer *rightSwipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(popCurrentViewOut:)];
    rightSwipeGesture.direction = UISwipeGestureRecognizerDirectionRight;
    [viewController.view addGestureRecognizer:rightSwipeGesture];
    [rightSwipeGesture release];

    // Swipe left: push a new view
    UISwipeGestureRecognizer *leftSwipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(pushNewViewIn:)];
    leftSwipeGesture.direction = UISwipeGestureRecognizerDirectionLeft;
    [viewController.view addGestureRecognizer:leftSwipeGesture];
    [leftSwipeGesture release];
}

当向右滑动的时候，当前的视图会被移动的屏幕的左边，并加入到导航的栈里

- (void)pushViewController:(UIViewController *)viewController {
    // Place the new view to the right next to the current view
    viewController.view.frame = CGRectOffset(self.view.bounds, self.view.bounds.size.width, );

    // Add the new view to our view hierarchy so that it displays on screen.
    [self.view addSubview:viewController.view];

    // Start animation
    [UIView animateWithDuration:ANIMATION_DURATION delay:ANIMATION_DELAY options:UIViewAnimationCurveEaseInOut animations:^{
        [self currentViewController].view.frame = CGRectOffset(self.view.bounds, -self.view.bounds.size.width, );
        viewController.view.frame = self.view.bounds;
    }   completion:^(BOOL finished) {
        if (finished) {
            // Connect DYNavigationController to viewController if needed
            [self setNavigatorIfNeeded:viewController];

            // Set up gesture recognizer so that we can respond to swipes
            [self setUpGestureRecognizers:viewController];

            // Add the new controller to our viewControllerStack
            [self.viewControllerStack addObject:viewController];
        }
    }];
}

这里使用了UIView的类方法animateWithDuration实现了跳转的动画。

当向左滑动的时候，当前视图被移除导航栈，左边的视图向右移到屏幕中央。

- (void)popViewController {
    // Sanity check - We only pop when there are at least two viewControllers in the stack,
    // otherwise there is nothing to pop
    if (self.viewControllerStack.count < ) return;

    // Start animation
    [UIView animateWithDuration:ANIMATION_DURATION delay:ANIMATION_DELAY options:UIViewAnimationCurveEaseInOut animations:^{
        [self currentViewController].view.frame = CGRectOffset(self.view.bounds, self.view.bounds.size.width, );
        [self previousViewController].view.frame = self.view.bounds;
    } completion:^(BOOL finished) {
        if (finished) {
            // Tear down gesture recognizers
            [self tearDownGestureRecognizers:[self currentViewController]];

            // Remove current viewController.view from self.
            [[self currentViewController].view removeFromSuperview];

            // Remove current viewController from self.
            [[self currentViewController] removeFromParentViewController];

            // Remove current view controller from viewControllerStack
            [self.viewControllerStack removeLastObject];
        }
    }];
}

导航的具体实现在DYNavigationController中，DYNavigationControllerDelegate持有一个DYNavigationController的property，在RootViewController中进行了synthesize，RootViewController实现了DYNavigationControllerDelegate协议，DetailViewController也实现了DYNavigationControllerDelegate协议，所以DetailViewController中可以直接使用这个DYNavigationController的引用，来实现导航功能。