iOS Overlay view which always sits on top? - iphone

I haven't been able to find anything on this and feel it likely isn't possible in a simple manner.
Can I have a view, such a loading bar for example which constantly sits over every other view controller until I choose to dismiss it but at the same time any underlying view can still be interacted with? Sort of acting like a system view. Be persistent when presenting new view controllers and all.
Thanks.

Add it as a subview of your window. Like this:
UIView *myView = ...
[self.window addSubview:myView];

Rather than adding it to the window, as #JackyBoy suggests, add it to the window's rootViewController's view. That will rotate along with the device. If you just add it to the window, you may have problems with rotation.
UIView *myView = ...
[UIApplication sharedApplication].keyWindow.rootViewController.view addSubview:myView];

Related

Can two UIViewControllers use a single navigation bar?

In my iPhone app I am trying to have the allusion of having a single static navigation bar, so the title and buttons don't ever swipe across when switching views.
I can't think a way of doing it (simply at least), so do you have any suggestions? I need to have a static title and buttons up in the nav bar space (even if I don't use the UINavigationBar, but make something custom) so that when I do something such as push a view controller, when it swipes across my nav bar doesn't move and the buttons change function for the new view.
Edit
Ok, I have thought of a possible method. Each of my views have a secondary view in which gold the view contents, except the nav bar objects. Can I override the pop and push methods to just animate this subview on and off screen?
Just do a push as normal but set it to not animate.
i.e.
[self.navigationController pushViewController:newViewController animated:NO];
Then when you want to go back...
[self.navigationController popViewControllerAnimated:NO];
Then you can have two navigation bars but it will look like it's the same bar as it isn't animating.
EDIT TO ALSO ANIMATE IN THE VIEW AND KEEP THE NAV BAR
I'm not sure of the whole flow of the app but if you want to keep the nav bar and swipe the new UI in then you could create a scroll view (with paging) and put the views of each VC on different frames of the scroll view or something.
Why do you want to keep the nav bar still anyway? There is nothing wrong with animating the nav bar and keeping the same buttons etc on it.
Having said that, if you are using different VCs then the nav bar should change anyway to show the details (i.e. title) of the VC you are currently looking at.
ANOTHER MORE RADICAL APPROACH
OK, thinking laterally now :D
How about, you use the not animated push and pop (as above) but instead of just displaying the UI you can animate it in from the relevant side. (A singleton or a VC subclass which you then subclass for your UI could do this for you across all view controllers).
The next problem is that it will look like the UI has gone instantly blank before animating in the new UI so you need to animate out the old UI. This means both UIs (the old and the new) have to be on the screen at the same time.
You can get round this by converting the entire view of the old UI into an image (not hard to do will find a link) and then passing this image into the new VC. The new VC will then instantly display this image and animate it out of the screen at the same time as animating its own UI onto the screen.
Really not as hard to do as it sounds. Especially if you subclass UIViewController ad give it a function animateUI and a property oldUIImage and direction. Then you can override viewWillAppear in this class to do the animation for you. Then the only thing you have to do is give each VC an image and a direction when you push/pop to it.
This is just giving the illusion of what you're after and means you can still keep a fairly simple object model and flow of the app.
...or something.
Just a riff on #Fogmeister's good idea...
In the presenting view controller, get self.view's image by implementing the suggestion here. Then, when it's time to present...
UIImage *image = [self makeImage]; // what it was called in the other post, consider a better name
MyViewController *newVC = [[MyViewController alloc] initWithNibName:#"MyViewController" bundle:nil];
newVC.presentationImage = image;
[self.navigationController pushViewController:newVC animated:NO];
In MyViewController, give it a UIImage property called presentationImage, then ...
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
UIImageView *imageView = [[UIImageView alloc] initWithImage:self.presentationImage];
imageView.frame = self.view.bounds;
imageView.tag = 128;
[self.view addSubview:imageView];
}
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
UIImageView *imageView = (UIImageView *)[self.view viewWithTag:128];
[UIView animateWithDuration:0.5 animations:^{
imageView.frame = CGRectOffset(imageView.frame, -self.frame.size.width, 0);
}];
}
FYI - I didn't test or even compile this. Just liked the idea and decided to stretch my fingers.
To do this in a "clean" way, you'd need to abandon UINavigationController and write a custom container controller that does not push new navigation items onto it's navigation bar when pushing a new view controller (or allows you to push the navigation item in a non-animated fashion while animating the push of the view controllers views).
However doing this will take some time. If you decide to do this, i recommend the WWDC Session on UIViewController containment.
Another alternative that springs to my mind is to (by subclassing or method swizzling) alter the behaviour of UINavigationController to push the navigation items non-animated while animating the viewcontroller-push.
I have in no way tested this, but overriding push (and pop respectively) in a subclass like this might work:
- (void)pushViewController:(UIViewController *)vc animated:(BOOL)animated {
[super pushViewController:vc animated:animated];
[self.navigationBar setItems:self.navigationBar.items animated:NO];
}
If this method doesn't work, it might be worth inspection what animations are going on inside the nav bar directly after the call to pushViewController:animated:. Maybe you can cancel some animations to go to the final state directly.

Full screen UIImage view

I have an application with a navigation bar and a tab bar. A user can navigate to a view which displays images in a scroll view. I'd like to have the same behavior as the iPhone photo app: Nav bar at the top, tool bar at the bottom, which will hide or show based upon a tap.
I'm moving my view to the window object in order to achieve full screen mode. This works fine:
myView = [self.view retain];
self.view = nil;
[window addSubview:myView];
But when I want to redisplay the Nav & tool bar, I run into a problem. The bars show fine, but the view is empty, and I can't seem to add any content to the view:
[myView removeFromSuperview];
self.view = myView;
I got a lot of good info from this post
but can't quite get the right combination.
By simply setting the controller's view, you aren't adding it as a subview to anything else, so it will never appear.
Moving views around like this can get a little tricky. I recommend that you not move the view from one to the other, but instead have two UIViews. Add second UIView to the window's subview and set it to hidden=YES initially. When you want to show it, set the image for the UIImageView, and then set the hidden property to NO.
what's wrong with just using setNavigationBarHidden: animated: and setToolbarHidden:animated:?

Present a UIView over a view

How can I make a custom view in iOS which appears above the existing view,but smaller? It should be like UIAlertView, but taken from a .xib file. After user taps a certain button, the small view vanishes and the normal view appears.
If this is posiible, how can I do it? And.. if it's not hard for you, please, include code.
Thanks in advance!
I think what you're looking for is a modal view. Modal views make it easy to have a view take over the screen for a little while, then when they get dismissed have the background view resume where it left off without having to worry about who's on top or handling events in partially-obscured views.
Here is Apple's article describing it.
They key is to have the controller class for your view call [self presentModalViewController:popupController animated:YES]; where "popupController" is the view controller for the view you want to show up. When you're ready to make it go away, call [self dismissModalViewControllerAnimated: YES];
You can just use the addSubview: method on your UIWindow or your visible UIViewController's view to show the UIView, and you can hide/remove it later by calling removeFromSuperview on the presented UIView.

Displaying UIImagePickerController within another UIView

I've been working pretty extensively the last couple months with UIImagePickerController, particularly with the new capabilities in OS3.1 and newer to overlay views on-top of the camera view. This has worked just fine.
However, I am currently working on a project where I'd like to be able to display the camera view of the UIImagePickerController within an existing view. Essentially, the exact opposite of what I've currently been doing.
An example would be a View Controller with navigation components (Think top and bottom horizontal bars with gradients), and upon tapping a button on one of these bars, then content area displays the camera view. The shutter animation would should up, and the top and bottom navigation bars would remain always on-top.
I've had success adding the UIImagePickerController to the window view, as well as presenting it modally, but haven't had any luck adding it as a subView.
ex:
[window addSubview:camera.view];
[self presentModalViewController:camera animated:YES];
All you need to do is call viewWillAppear and viewDidAppear.
Here is an example where _pickerController is an instance of UIImagePickerController:
[self.view addSubview:_pickerController.view];
[_pickerController viewWillAppear:YES];
[_pickerController viewDidAppear:YES];
Call viewWillAppear:YES on the image picker controller after adding its view to your view. Skip the modal view controller business.
I don't think the API provides direct access to the actual view of the UIImagePickerController. The class is actually a subclass of UINavigationController so I don't think it has an actual view itself but rather manages the calling of its subcontrollers and their views.
When you call the UIImagePickerController modally, its doesn't add the views it controls as subviews to the window (or any other view). That is what a modal view means. It presents the view off to the "side" of the view hierarchy.
Even if you could hack this together, I think Apple would reject it as not being part of the API and for violating the HIG.

Multiple Views in one Window

I'm writing a view based app, but I'm a bit confused about loading my views. I'd like to have four different views loaded at the same time in the same window. I can't seem to figure out how to do this. I'd prefer to do everything programatically rather than with the interface builder if possible.
My 4 views are: a UIView, a UIWebView, a UITableView and another UIView with buttons.
Thanks in advance for the help.
Views in an iPhone app are arranged hierarchically - that is, each view has a "parent" view (excepting the root view). The interesting bit here is that UIWindow is itself a subclass of UIView, so you can add all four views to your window directly. (This may not be the best approach, but it's perhaps the simplest.)
All you really have to do is initialize each of your four views programmatically with the location and dimensions you want them to have in the UIWindow. You do this by giving each view a frame parameter, either in the init method or afterwards (depending on the type of view). So, for example, in your app delegate you could add this code:
CGRect frame = CGRectMake(0.0, 0.0, 100.0, 100.0);
UIView *view = [[[UIView alloc] initWithFrame:frame] autorelease];
[window addSubview:view];
This will create a 100x100-pixel view and add it to the upper left corner of the window. You can do similar things for each of the other three views.
Note that developers usually don't initialize views directly in the app delegate - a better approach might be to have a fifth view take the place as the root view for the other four, then add that root view to the window. You can use a view controller for the fifth view to make this task easier - move the view initialization code into that view controller's implementation, then from the app delegate you can just instantiate the view controller and let it take over from there.
You can use [self parentViewController] to get access to the parent UIView