I've got a view Controller which manages my TV Playout (HDMI Apple AV Adapter). Everything works fine. I call my view Controller using a popover on the iPad.
When I open the popover, the external screen is recognized and I can work with it. But when I close the popover View (which means I send my TV Playout View Controller to the background) the TV screen (logically) turns black.
Is there a possibility to tell my view Controller to hold the picture on the TV screen by quit?
Like "pseudocode"
[TVOutViewController stayActiveInBackground]; //pseudocode
Thanks in advance!
I suspect you've coded your view controller so it explicitly shuts down the external UIScreen/UIWindow pair when it becomes inactive. I suggest you move the external screen code out of your popup's view controller and into an object which has a lifetime independent of what's going on on the internal screen, e.g. your application delegate or an object referenced by it. Then just send that object messages from your popup view controller in response to user events.
There's nothing about the Apple APIs that causes this kind of behaviour - it's purely a consequence of how you've designed your app. As such I don't recommend trying to force the view controller to stick around. Instead, try to find a better structure for the app. A view controller should only be responsible for its view, not application state.
OK guys, By chance, I found a solution (or at least a workaround). Be sure to manage the problem using a UISplitViewController with your TVOutViewController as the masterViewController and the ContentViewController as the detailViewController. Apple already did the work. Thanks anyway! :)
Related
My app consists of two views. The first one is a GMSMapView and the second one is used to connect to a Bluetooth device that sends coordinates.
After the Bluetooth device is connected, I use a delegate to send the information back to the map view and move a marker around. To transition between views I was previously using segues, this didn't stop the Bluetooth view controller and the data made its way like I wished to the map view.
I ran into the problem of my map view being reinitiated so I decided to use a navigation controller. Now I use a push segue to get to my second view, and pop to come back to the same instance of the first one. Great, that worked! The issue I have now is that popping the second view seems to stop it completely from running in the background like it used to. Is there a way to keep it running in the background like it did before?
What I'm currently using to pop the second view is
self.navigationController?.popViewControllerAnimated(true)
Any idea would be appreciated! Thanks!
A popped view controller does not "stop running". It is returned to you, and if you don't retain it, it is completely destroyed.
If you don't want that to happen, retain it when it is returned. You are currently ignoring the returned view controller:
self.navigationController?.popViewControllerAnimated(true)
Instead, keep a reference to it:
self.mySecondViewController =
self.navigationController?.popViewControllerAnimated(true)
Be warned, however, that this is a very unusual architecture. You will not be able to use the storyboard segue to push again, because it will push a different copy. It would be better to abandon your navigation controller architecture entirely, as it is completely unsuited to the idea of a view controller persisting after it is popped. If you want an architecture where two view controllers persist simultaneously, you would be better off using a UITabBarController — or, even better, reorganize your app completely. The notion that you need the view controller to persist after being popped is a "bad smell": it means that you have put the functionality in the wrong place. Put the functionality in a place that does persist, rather than forcing the view controller to persist in some artificial way.
I have been searching all over the web but I can't seem to find the answer to this.
Currently i am using presentViewController to start new ViewControllers, but on certain view controllers i do not dismiss it and call over it. I currently am not using any navigation controllers or anything like that.
I am just worried that if I call the same viewController again via presentViewController, that the same viewController would have 2 running instances.
Is it possible? Or does the iOS framework automatically reuse the idle viewController?
If so, how do i remove the idle view controllers?
Thank you! (I was holding back my question and tried to find it all over the web, so if you can point me in the right direction, it would be very helpful thanks!)
iOS will not reuse your view controller, you can easily check it yourself by printing your view controller in viewDidLoad, you will notice first that viewDidLoad is called every time, and next that all objects have different addresses.
Unless you create thousand of them, or the navigation of your app doesn’t let you come back to an “idle” view controller, I would not say this is an issue though.
I don’t see any clean way to remove a view controller from the memory without calling “dismiss”. You could try to:
- “refresh” your view with new data.
- use something like UIPageViewController if the workflow of your app allows this kind of behaviour.
- rework the navigation so you can dismiss the view before calling another one
Good luck
I would like to create a "deep link" into my storyboard while preserving the backstack (back button navigation).
Ex:
Given the storyboard below (entry point being the leftmost Navigation controller)
When my application is opened via a remote notification I would like to open the second tab in by tab controller AND be able to navigate back to the item list via the back button.
Please note that I am not asking about how to open the second tab, or how to create such a storyboard but specifically if there is a way to do this with storyboards or will I have to do it by code.
Thanks!
PS: I come from an Android background where one recreates the parent view controller manually or (better) inserts it into the backstack. As far as my research goes there is no such thing in ios. I'm hoping I'm wrong.
Your UINavigationController has a viewControllers property. You can create as many view controllers as you want in an NSArray and assign it to this property and that will be the back stack with the last VC in the array displayed.
The problem is that when a notification arrives, your app could be in any state at all. It could be running, with some other screen showing. It could be suspended, with some other screen showing. Or it might not be running at all, and will now have to be launched from scratch.
Thus, starting in the App Delegate routine that responds here, you will have to deal manually (in code) with the situation if you want to put your app into an appropriate state.
I have a presentedViewController on top of the root view controller when the app gets dismissed. (e.g. User navigates to another app or goes back to the home screen.)
I would like to nil it out when the user reactivates the app without it being visible to them. Calling -dismissViewControllerAnimated: is not an option because it only works if the view controller is visible, and I'd like to do it sooner and specifically only in application:openURL:sourceApplication:annotation: and otherwise let the user continue their workflow in the modal view.
Are there any tricks I can use?
According to your comment, the only actual issue is what happens when the app receives application:openURL:sourceApplication:annotation: and is thus brought to the front.
In that case, simply adjust your interface in application:openURL:sourceApplication:annotation: - that is part of its purpose, to allow you to do that. You will be given some time before the "snapshot" is torn away, so if the adjustment involved is to dismiss an existing modal view, dismiss it without animation and there you are.
The user will still see the modal view for a moment, but not really - what the user is seeing is not your interface but the "snapshot" that was created by the system when the app when into the background. The "snapshot" is removed to reveal the actual interface (with a nice crossfade effect in iOS 7).
If the "snapshot" itself is problematic there are ways of preventing it from being taken, but it doesn't sound to me like this is that kind of situation.
(By the way, this raises the question of how the presented view is to know that it must be dismissed. The initial main action is in your app delegate, which is probably some conceptual distance away from the presented view. This would be an appropriate situation in which to use an NSNotification to communicate across this distance.)
I'm working on an iPad app that uses a UISplitView. Inspired by http://blog.blackwhale.at/2010/04/your-first-ipad-split-view-application/, I display a button in my detail view when in portrait mode that shows the popover controller. This works great. However, the appropriate UISplitViewControllerDelegate message is only sent when the device rotates. So, when the app first loads (in portrait mode), my navigation button is not visible.
Is it possible to somehow convince the UISplitViewController to send that message on load or something, or do I need to re-implement my own popover logic to get things working?
Thanks,
-Patrick
We had the exact same issue and it turned out that this thread had the right clues. When comparing our app with the SplitView template, we noticed that the split template does exactly what was mentioned here: set the UISplitViewController as the root view controller in application:didFInishLaunchingWithOptions.
Out previous solution linked the split view controller in the XIB directly to the window. While this works it seems the split view has difficulties getting the startup orientation and the missing button occurs. When we removed the link in the XIB and created it in code in the app delegate, everything ran fine.
That's weird. Maybe you missed something. Take a look at the template based on a splitController. It works fine form very startup no matter in what mode the app was loaded.
did you make sure that your UISplitViewController's view is the only subview of your UIWindow, and that you added it inside the application:didFinishLaunchingWithOptions: method of your app delegate