UIImageView display in front of navigation bar? - iphone

Is there any way to display an image infront of the navigation bar?
I know this is a little bit messy - but its just an asthetic thing. The imageview takes up more height than the view and therefore needs to overlap the navigation bar a little bit.
Is this possible at all? It must be. :)
Thank you

sure, just have the image on a view that is on top of the navigation controller view and you can put it wherever you like. It is however probably aesthetically unpleasing, and more likely than not frowned upon by the Apple Human Interface Guidelines.

If your content is big enough that you need the space where the nav bar is, but you still need the nav bar to be present, how about making it transparent? (See, for example, the built-in Photos app.)
But, in general, UIKit views don't clip their contents. So if your view draws outside of its bounds, that will layer on to of whatever views are below it.

Related

Unable to get the correct frame for UIViewControllerAnimatedTransitioning to UIPageViewController

I have been battling this transition animation and I am pretty much out of ideas. I am attempting something similar to going from the collection to the individual photos in the Photos app on iOS.
It all works to my satisfaction with the exception that the frame for the "big" detail view of the image is not correct. It is the right size but it is about 87 points closer to the top of the screen compared to the actual position of the image in the final state. This is pretty much the same height as what is above the "safe area" (iPhone X titles + navItem) and irritatingly close to what is also below the safe area (toolbar and iPhone X home area).
I have Googled (and "SO'd") a bunch of different solutions to similar sounding problems. E.g: UIViewControllerAnimatedTransitioning with Safe Area Insets on iPhone X
I have downloaded and perused example code from Github. E.g: https://github.com/SamStone92/CustomTransitions
It seems to me that I have something in my view (controller) hierarchy which is complicating this more than most. I would love some hints as to what might be causing the problem and how I might go about fixing it.
My hierarchy is:
NavigationController containing the root VC with a UICollectionView.
Tapping a cell transitions to a UIPageViewController for a "detail view" where I can page between items in the collection.
UIPageViewController has a bottom toolbar in addition to the navigation bar.
The content ViewController has a ScrollView with a UIImageView in it to get some zooming.
Seems like the common approach is to add the destination view to the container, force a layout pass and then get the frame. I have tried many variants of this with and without converting the coordinates. (they appear to always remain the same before and after conversion)
My Theory
I am leaning towards the UIPageViewController being the complicating factor. But I have not been able to untangle how to get the correct coordinates.
The destination view (in the animation) is not the content view but the PageVC view which in turn may or may not have added the content view, adapted it to the navigation item or the toolbar.
Seems like viewWillAppear on the content VC does not have the right coordinates. I can tell that the detail content view is getting a call to viewWillLayoutSubviews after that and also after all the animation delegation stuff has had its turn.
This is a color overlay of my main views. Grey is the top and bottom areas outside the safe area. Blue is where the transition animates to before revealing the green, underlying actual position it should have animated to.

How to make tableview's content displayed under a transparent navigation bar?

How to make tableview's content displayed under a transparent navigation bar?
Like this:In "Photos" app, albums displayed under navigation bar.
Special thanks
If you use _rootNavigationController.navigationBar.barStyle = UIBarStyleBlackTranslucent; then set correct tableview frame thats it. If you are in xib dont forget to simulate the translucent navigation bar.
One way I have found to accomplish this is by shifting your tableview's superview up to have the origin at {0, 0}. However after researching more several people have said altering the superview (UIViewControllerWrapperView) is a bad idea. However I also have not found any information on why just changing the frame would create problems. I am shifting the superview right now and haven't found any problems related to it yet.
Might be you can set it like this:
[navigationBar setAlpha:0.5f];
For making the navigation bar transparent alone, you can check this post, How to make a Navigation bar transparent and fade out like in the photo app in the iPhone
Also check this How to set the transparency color for Toolbar and Navigation bar using MonoTouch?
I am not sure whether you can add the table view behind the navigation bar. You might have to add it as a subview of self.parentViewController.view.
Another way to do this is by hiding navigation bar and using a transparent tool bar in place of that. This can be added on top of the current view. The only problem is with the back button. You might have to use custom button for that.

Why is there a 20-pixel-high dark overlay over my app's navigation bar?

Once again, I'm almost entirely sure this is something dumb that I'm doing, but I've been banging my head against this one for hours & am getting nowhere.
I'm trying to restructure the view hierarchy of my app. I need to be able to detect user interface orientation changes globally in order to correctly rotate a "Loading" view displayed when the app is downloading content. (device orientation changes seem to fire at different times, causing the view that needs to respond to these events to rotate sporadically).
The app previously added a UINavigationController's view to the main window. I modified the hierarchy to add the view of a UIViewController subclass to the main window, and added the view of the UINavigationController to the subclass's view. The UIViewController subclass manages the display & rotation of the "Loading" subview, and I was expecting the rest of the app to continue behaving normally, as inserting one extra empty view into the hierarchy didn't feel like I was changing too much.
My initial problem was the positioning of the UINavigationController - it was 20 pixels too low, resulting in a gap between the status bar and the navigation bar, and cutting off the bottom 20 pixels of the tab bar. I was able to adjust this by setting the frame property of the UINavigationController's view to the bounds property of the UIViewController's view, which corrected the position.
However, now I'm stuck with a 20-pixel-high dark "overlay" on top of my navigation bar. If I were to guess, I'd say it was black with 50% opacity. Touch events on this bar don't work (e.g. if I try to tap the "Back" button through the overlay, nothing happens). The fact that the height is equal to that of the status bar hasn't escaped me, but I'm at a total loss as to what could be causing it.
I hate feeling this stupid, so if anyone has any insight into this problem, you'd really make my day. Thanks in advance!
OK, a few things pop out from your post.
My initial problem was the positioning of the
UINavigationController - it was 20
pixels too low
This makes me believe it is related to your new problem.
I was able to adjust this by setting
the frame property of the
UINavigationController's view to the
bounds property of the
UIViewController's view
This sounds like the view it was loaded onto was offset 20 pixels, and when you set it to the bounds, it repositioned it on the windows view space.
Touch events on this bar don't work
(e.g. if I try to tap the "Back"
button through the overlay, nothing
happens)
This is the big thing. If touch events aren't being sent to the view, then what that means is that the OS doesn't see a view where you are pressing (or rather the view you want it to), so that view doesn't get the message to do something.
From what you have said, I believe your problem is with your base view controller that you just added. Try redoing the frame on, making it conform to where you want. Then take out the code you put in to set the navigation controllers frame. The navigation controller should fit to the view you added too, and once you have that main view where it needs to be (20 pixels higher apparently), then everything should work.

Is it possible to change the frame origins of an iPhone screen as is done when a statusBar is shown or hidden?

When a UIStatusBar is hidden in an app, the origin of all views is (0, 0), the upper left hand corner of the screen. However, when a statusBar is shown, the origin is still (0, 0) yet the views will move down as not to cover the statusBar.
How is this working? Is it possible to duplicate this effect in code?
Essentially, my end goal is to hide the statusBar and replace it with a UIView at certain points in the app (like the google app). But I have a LOT of views and don't want to have to resize all of them after the statusBar is hidden.
You could create a container view enclosing all your "normal" views and set autoresizing masks everywhere. That way, shrinking your container view will automatically resize everything else. In fact, this is how UIViewControllers work. But be aware that while standard Apple controllers like UINavigationController know how to deal with the status bar, they don't know anything about what you want to do, so they're going to be confused more often than not.
Alternatively, you can always show your own status bar underneath the real one, hiding the latter when needed. But in this case you will have to fight Apple-provided controllers which will try to expand when you hide the status bar. You can also play with a two-window layout where the top window does not overlap the status bar, but I'm not sure it will be any easier.
Since Apple doesn't support any of the above, expect a lot of things to stop working correctly. Perhaps, the very best approach is to rethink your UI design.

After tabBar setHidden, the controller's view won't stretch full screen

In fact, the screen area where the tab bar was before, now is not accessible. If I add something on to that area, it just got cropped.
I tried setFrame to 320x480 but it won't help
please help
The best I can tell, and I have done considerable research, is that you cannot go full screen when you have a tabBar without playing a lot of tricks with the view hierarchy. Assuming the view hierarchy is dangerous because Apple may change it in a future revision. In my case I wrote my own tabBar replacement.