In the iPad's Photos app, when you tap an album the stack of pictures expands to fill the screen - you're in the same view, it's just rearranged the grid a little. But at the top, a left-arrow-style Back button appears, as if pushViewController had been used - except it fades in neatly, rather than sliding in. When you tap that, it fades out again, rather than sliding out.
Is there a way to replicate this behaviour? I've tried a few options so far, and might just be missing something. What I've tried:
Setting self.navigationItem's leftBarButtonItem works, but gives me a square button rather than an angled Back-style one - there are a few hacks online to make this work, such as using pictures for the button, but I'd rather only use them if there's definitely no "official" way to do this.
Setting self.navigationItem.backBarButtonItem - this is generally used to customise the back button when a view controller is pushed, so it has no effect.
[self.navigationController.navigationBar setItems::] - this works, although it gives me the sliding animation rather than fading. As a result, I use animated:NO to make it just appear. Downside: when tapping Back, you do get the sliding out animation, which looks weird because the rest of the UI stays still.
Has anyone managed to replicate this effect?
Thanks in advance!
Your first approach is probably the best.
It doesn't have to be super-hacky, you can use a normal UIButton and customize it to look like a back-button using backgroundImageForState: and titleForState: (etc.), then set the UIButton object as the customView of your UIBarButtonItem.
Many apps these days customize the look & feel of the buttons anyway, so using a custom background image is quite normal. If you use resizableImageWithCapInsets: (or stretchableImageWithLeftCapWidth:topCapHeight: if you need to support iOS earlier than 5.0) then the button can still stretch to fit whatever text goes inside, and as it's a normal UIButton the text is localizable, etc. I don't consider this approach to be hacky, it is a perfectly sensible way to get around the limited functionality of UIBarButtonItem objects.
Better late than never.
To show a back button without pushing a view controller, use pushNavigationItem:animated: and popNavigationItemAnimated: on UINavigationBar. These result in the standard slide animation and creation of a back button. However, there is no way to ensure your content animation runs for the same time as the bar animation other than making an educated guess at the duration.
Since iOS 7 there is a better API for achieving this effect, where you still push and pop view controllers but you provide a custom transition animation through navigationController:animationControllerForOperation:fromViewController:toViewController: from UINavigationControllerDelegate. This allows the animations between the bar and content to be perfectly coordinated.
Finally, if your content before and after is managed by UICollectionViewController, you can use useLayoutToLayoutNavigationTransitions, which is designed for use-cases like Photos.
Related
Typically, the UIBarButtonItem will be highlighted when we tap it.
However, I intend to show the users that the action is automatically done for them when the view is loaded after 4 sec.
So I want to highlight the Button without tapping it.
How can I achieve that?
For a UIVIew object such as a UIButton, you can either use the following code Glow category on UIView that adds support for making views glow or use this example.
If you are using the first one, you can just call startGlowing and stopGlowing. When you call startGlowing, the view will start to pulse with a soft light, this effect is removed when stopGlowing is called. Check this.
For UIBarButtonItem, you might have to use the solution provided here.
As I observed that UIActionSheet is always appearing from down side in iPhone,
but in some app, as I saw in AlarmClock, then two button became visible, one from upside and second from downside of iPhone,
What is that exactly, I can't understand, as far as I feel, it looks UIActionSheet,
I want such appearance for one of my app....
Help!
Yes just like Ole said, you can't customize UIActionSheet . But since it is just a simple subview you can create your personal "action sheet" by subviewing and animating. So if you want a button to appear on the top and one on the button, then create two UIViews resize them to the right size for your button, add your action sheet style background or any other background, add your button, connect your IBActions to the buttons and your IBOutlets to the views. Then when you want the buttons to appear animate them onto the screen (using sone CGRect, animation time and finally [UIView commitAnimations])
Probably just one or two custom views with a custom animation. UIActionSheet is not customizable so if you want something else than the default behavior you have to write it yourself. It's not that difficult.
I am working on an app which displays user information on the home view. Its a regular tab bar application, which brings up the home view on load. I need to display something like,
Hello Joe,
Your current points are : xxx
I would like this to be in a white curved background box. (The background for the view is blue). Is there something like a UIPanel or something like that. I would really like to avoid having another view or a webView, not sure if thats going to affect the speed of loading the page.
If there were a UIPanel control it would derive from UIView, so I'm not sure why you want to avoid another view. If I'm understanding you, it sounds like you want a custom alert window of some sort. You could just use the UIAlertView control to display your message, but if you are dead set on a custom look, then you will need to use a view.
This shouldn't affect performance noticeably if you are just displaying some text with maybe a button on a custom image. Especially if this is just a tab bar application with nothing too crazy happening in the background (animations, etc.).
I would suggest creating a View either in code (this will be slightly faster, but once again probably not noticeably so) or with Interface Builder that has a black background with an opacity of like .2-.5 and on that view adding a UIImageView set to your custom image (a png of a white curved box with transparent corners). Then put a UILabel with your text and a button to dismiss it.
On load just instantiate the above view and add it to your current view. It will show your message modally. Then capture the button tap event to have it remove itself from it's superview.
There are plenty of examples of how to do exactly this out there and there are even other ways of doing it than what I've suggested. If you need further assistance let me know.
I would like to implement the effect of a view sliding in, much like the animation of a view being brought in by presentModalViewController, but the view only slides in to cover half the screen.
I approached it this way:
1) Right before thew view should appear and slide in, addSubview the child view. Position it in such a way it's out of view in the beginning.
2) Call a method on the view controller of the subview to perform the Core Animation code to bring it in.
Doing the above didn't seem to work (nothing happens - the view just appears at its starting location). Adding the view ahead of time in viewDidLoad won't work either. Ideally, I would like the code to have the same requirement as presentModalViewController - which requires you to instantiate the view controller at the point you need to bring the view in and animate it.
Would appreciate if you can provide pointer or code on animating the view in/out as well.
I would check out the sample project ViewTransitions on the Apple dev site. It is a great resource for understanding the simple things you need to do when setting up transitions. If you wanted to only slide in half-way you could try setting the frame of the "sliding view" to only half the screen... just check out the code and give it a try.
I usually animate modal screen in the parent viewController instead of modal viewController itself.
Maybe you should post the code you use in step number 2.
I did something similar on one of my apps, where the user slides a view from one edge of the screen to the other as if placeing a cover over the screen.
If what you are trying to do is an automatic animation (without user interaction) I believe that you need to: set to the sliding view a frame representing the final position. Do this within an animation block. Play with the duration, animation curve, etc parameters.
I'm trying to create a modal status indicator display for an iPhone app, and would like one similar to this one used in Tweetie:
Specifically, this one "shades out" the entire screen, including the toolbar. I don't believe through any normal UIView manipulation, I can extend past the bounds of my window, can I? I believe I've seen a status indicator like this somewhere else on iPhone, possibly when I added an Exchange e-mail account.
I've tried subclassing UIAlertView and overriding its drawRect method. If I don't call [super drawRect:] it doesn't ever display the normal UIAlertView text box, however my drawing rectangle is in an odd size and position.
Anyone have any advice to accomplish this?
Check out MBProgressHUD.
Take a look at the source code to the WordPress application. They have code which you can basically drag and drop into your application to do this.
http://iphone.wordpress.org/development/
I haven't done this myself, but you could layer a UIView at the top of the view hierarchy, and use setHidden to dynamically show or hide it. Since it's at the top of the stack, it should be able to intercept all touch events.