I created an iOS 7 passcode replica and I have this problem I can't seem to solve. I need the lock screen view to be on top of everything else, so the app is covered in iOS' multitasking view, so I add it directly to the keyWindow. Everything fine so far.
The problem arises if there's an alertView or actionSheet (will only mention alertViews in this post, to keep it simple) open when I have to display the lock screen. It has been answered several times that there are no references to alertViews in iOS 7, which is true, and the window in which they are displayed is _UIModalItemHostingWindow, which has 2 UIViews, indeed with no reference to the alertView.
This _UIModalItemHostingWindow also becomes the new keyWindow, so it's on top of everything else, but it can not be found in [UIApplication sharedApplication].windows meaning if I add the lock screen to my former keyWindow (the default keyWindow, if you will), it will be beneath the alertView and its dimmed background, so the user can't interact with the lock screen before dismissing the alertView. The other option is detailed a bit further below.
The lock screen works like this: on applicationDidEnterBackground it checks if the passcode is enabled; if it is enabled and the passcode duration is 0 (user selected to lock the app immediately), it adds the lock screen now, so it covers the app in the multitasking view. Now, the option I mentioned above is to add the alertView to this _UIModalItemHostingWindow window, but when returning to the app, the lock screen view is displayed with a 1+ second delay (even though I added it before I went to background!) and the app isn't covered by anything in the multitasking view. (Currently it's displayed in the wrong position too, if you go ahead and download it, that is fixed, but I didn't pushed the commit yet).
I tried hiding and removeFromSuperview this _UIModalItemHostingWindow, but when coming back to the app, the alertView animation still runs as if it was just fired. I suspect the delay mentioned above also happens due to how Apple handles alertViews when coming back to foreground.
I also tried creating a new window and to make that the new keyWindow, but same thing happens.
Here's a small discussion about this, covering all the stuff I tried, maybe I missed something in this post.
https://github.com/rolandleth/LTHPasscodeViewController/issues/16
Any ideas? Except creating manual references to every alertView and actionSheet inside my app, because I'm trying to find a fix for the passcode library, not my own apps; I can find dirty workarounds for that, no problem :)
Update: The window is _UIAlertOverlayWindow if an actionSheet is used instead of an alertView, but it behaves the same as far as I can tell.
The simplest solution is to have a lockscreen window instead of a lockscreen view.
Create a new UIWindow, set its frame to UIScreen bounds, put a simple rootViewController there that should handle rotation and display your "lock screen" views and set the windowLevel to UIWindowLevelAlert + 1.
Then set window's hidden to YES. Whenewer you want to show the lockscreen, just set hidden to NO.
I guess that adding a view to keyWindow also doesn't work when a popover/action sheet is displayed and also when a keyboard is displayed (keyboard has its own window on top of the key window).
Related
Chase bank's iOS app is showing blank view hiding apps details when double tap the home button from the app. And when you login inside the app and touchID alert appears the apps view is not hidden by blank view.
So far I can hide app details by showing image loaded on applicationWillResignActive but it makes app hide it's details while touchID alert comes up.
I've checked similar questions on SO like this or this. Also here. But there is no answer to my question. How to replicate Chase bank's app behavior? How not to hide app details with touchID alert, but have them hidden when double tapped the home button?
I know it's an old question but couldn't find a valid answer to this exact question. So here's my solution.
steps:
create a instance variable for blocker view
init blocker view only once when it's necessary (I did it on applicationWillResignActive)
add blocker view as subview to the window at applicationDidEnterBackground
remove blocker view at applicationWillEnterForeground
The app delegate's applicationWillResignActive is the right place where you put a black or whatever view you want to show when the app is being moved to background. You need to add the desired UIView on Window object. Also you need to remove that view when the app becomes active again.
I'm developing an app on iOS 7 with a desired feature is that
When I home button, app enter background, I will add an image to current UIWindow. So when app enter background, if user double home button on iOS 7, os will show a small screenshot of current view of my app, so user can see my added image. :) (I did it)
When user return my app by clicking app icon, I want to remove this image immediately. In this situation, "immediately" means that user can NOT see this image anymore, user just see his/her current view when app enter foreground. I try to place the code remove image on the beginning of applicationWillEnterForeground delegate, but I'm still able to see this image for a short time after it disappears.
I also try to set hidden, alpha property for this imageview first, then removeFromSuperview, but it not works.
Can anyone help me to remove it "immediately" as my desire.
That is done automatically for all applications, you don't need to do anything in you code.
I don't think that you can do it faster, it depends of device performance. Sorry man.
Like other says it is really tricky how iOS handles these events. I've been researching and depends on the memory state of the device to do it faster or not. Indeed, in iPhone 4 and 4S may not show the image that you added on applicationWillEnterForeground method.
If I were you I would solve it by adding a smooth fade out animation of that image when the app becomes active again. With [UIView animateWithDuration: animations:] it could be nicely done! :)
If I find out something else I'll answer here!
When a foreground app gets backgrounded (e.g. Home button gets pressed), how can I change elements on the topmost view controller prior to when iOS takes a snapshot of it and starts the animation to show the next screen?
I ask because I'm writing an app requiring HIPAA compliance, and I am concerned that the snapshot that the OS takes in order to do this animation sometimes contains sensitive data which should not be visible even for a split second when the app gets foregrounded later.
I'm aware that view controllers have lifecycle methods such as viewWillDisappear which might be usable, but I have a lot of controllers and I'd rather just have something in my App Delegate to handle this (e.g. by adding an opaque full-screen UIImageView overlay) rather than having to write custom code for this in every last controller.
I tried putting overlay-generating code in applicationWillResignActive, and I've been digging with Apple's docs and Google, but it's not working. I suspect the screenshot gets taken before the app has a chance to update the screen.
Thanks!
Not sure about HIPAA's requirements about backgrounding and possibly leaving the user logged in for someone else to resume, but the safest sounds like it would be to add a key UIApplicationExitsOnSuspend with a boolean value of YES to info.plist.
That will prevent the app from backgrounding entirely, and restarts it (possibly triggering a login procedure) every time you go back to it.
Most (if not all) mobile banking applications I've tested do this for safety reasons.
I believe the answer is to not concern oneself with changing what's on the screen before the backgrounding animation begins, but to simply modify what's displayed on the screen once the app enters the background (i.e. inside of applicationDidEnterBackground: in your App Delegate.) This solved my problem.
My UIImageView overlay idea worked here, although I decided just to pop to the root view controller instead. Simpler that way. My root view doesn't have any sensitive info.
Here's what it looks like:
-(void)applicationDidEnterBackground:(UIApplication *)application {
UINavigationController *navigationController =
(UINavigationController *)self.window.rootViewController;
[navigationController popToRootViewControllerAnimated:NO];
...
}
During an active VOIP call, my app is put into the background when an incoming cellular call is received and answered. If, while on the cellular call, I bring my app back to the foreground the app view appears but is unresponsive. The "Touch to return to call" banner appears at the top of the view in green but the app view appears as if there is a darker transparent window overlaid on top of it preventing the view from receiving input. If I put my app into the background, bring another app to the foreground and then bring my app back to the foreground everything works as expected so the problem seems to be specific to active cell calls and/or the green banner only? In Settings->Notifications->Phone I tried turning Notification Center OFF and Alert Style NONE in the hopes of removing the banner to see if the problem still exists but these settings do not effect that banner. In addtion to the App window appearing to have a transparent window overlaid on it, if I touch the window I'm able to drag the entire app window (or view) in all directions (up down side to side) and it has a bounce effect (like tableview vertical scroll) when I release it.
If I dont know the problem I cannot fix it (:
Thanks..
Are you sure there's no view being added on top your view which might be intercepting all your events? My second guess would've been that your app received a memory warning and unloaded a bunch of views. However, that's not very likely since you still see all the views.
I don't know what you really mean to "bring your app back to the foreground",but I can tell you for sure that you cannot call in the same thread the UI and the incoming call, so for situations like this when you want to render some view during a call you can try something like this:
public void InvokeGUIThread(Action action)
{
Dispatcher.Invoke(action);
}
For example if you want to set a text in a textblock do something like this:
InvokeGUIThread(() =>
{
textBlockSome.Text = e.Item.ToString();
});
I'm using simple MPMoviePlayerController. In portrait mode it is emmbedded into my layout. When I rotate my device I want it to go full screen. In full screen mode there is a done button but only thing it does is pausing the video. I want to dismiss modal view controller when the done button is tapped. How can I do this?
I've tried:
Putting a [UIColor clearColor] on a background of a button and place a button over Done button thus intercept touch event into my own selector. It failed because my custom button isn't displayed when MPMoviePlayerController is in fullscreen mode.
Going to notification center and trying to catch "willExitFullscreen" but it won't occur (pressing done button when in landscape fullscreen mode isn't goint out from the fullscreen mode).
Finding done button in the MPMoviePlayerController... but I was unable to find it.
Using MPMoviePlayerViewController isn't an option as I want to be able to use embedded player in my controller when i Portrait mode, and be able to rotate movie without loading it from scratch (so pushing new controller when user changes device orientation isn't right solution for me).
I've read a few topics on this issue and question can be the same or similar but anserws require either things I've checked (i.e. notifications) or things I can't use (MPMoviePlayerViewController).
ANSWER (as I am unable to post it in 7h)
Heh ok..
The culprit of this whole mess was this line of code
[self.mpPlayer setControlStyle:MPMovieControlStyleFullscreen];
So it seems that setting Fullscreen control style when going into fullscreen mode will break done button....
Makes no sense to me. But when I commented out this line I am able to recive willExitFullscreen notification and I can work with that.
The culprit of this whole mess was this line of code
[self.mpPlayer setControlStyle:MPMovieControlStyleFullscreen];
So it seems that setting Fullscreen control style when going into fullscreen mode will break done button....
Makes no sense to me. But when I commented out this line I am able to recive willExitFullscreen notification and I can work with that.