I am using the same background on different views in my app and remarked something strange with the only view where I use a UIScrollView: the background is lighter than expected.
Uninstalling the scroll view gives it its color back. I am 100% positive this comes from the scroll view only and not it's subviews because uninstalling anything (and everything) else inside the scroll view has no effect.
No scroll view:
Scroll view :
Is there any solution to fix that?
Related
I have a child View Controller within a Container View that hosts a vertically-scrolling UITableView. Tapping a Button expands a separate View that covers the UITableView in the child View Controller. This new View contains a vertically-scrolling Scroll View. No matter what UITableView settings I change, I am unable to scroll the Scroll View unless I remove the UITableView entirely.
I am currently porting my fully-developed Android application to IOS, and my experience with Android Studio leads me to believe that this is an issue with the UITableView stealing focus from the Scroll View.
In short, how may I temporarily remove focus from the background UITableView to allow the overlaid Scroll View to scroll?
With Scroll Views up until this point, I have been setting the bottom -> Superview constraint to priority: 249 since I was having issues setting the contentSize. For some reason, having a Table View in the background disables this effect. My guess is that this happens because the Table View is forcing the Superview to anchor based on its own constraints, and therefore the Scroll View can no longer adjust based on low-priority constraints. Changing the Equal Height parameter of the Scroll View -> Superview to a proportional relation (x2) has temporarily addressed the problem.
I'm experiencing a weird glitch with the transparent navigation controller. When presenting a view controller with a UIImage at the top of the navigation controller: at first presents half of its background blur with a dark section, and half with a clear one; and after a very short moment it changes for a full dark background. As shown in the gif:
The UIImage displayed is mostly white, the borders are very close to pure white. So the grey color does not make much sense (less sense makes the rapid change).
I did disable extend edges under top bar in the Storyboard for the presented view controller. So the image is not hidden behind the Navigation Controller. With this option enabled the glitch does not appear, but I don't want to hide part of the image.
Disabling the transparency, solves my problem, but I'd like to be able to keep the transparency effect.
Edit: I did notice the "grey effect" also makes the navigation controller opaque. But only for that view, when going back, is transparent again.
Xcode 11, Swift 5, iOS 13.2, iPhone XS.
Thank you very much for your help.
I finally found the problem.
I didn't want the UIScrollView to bounce on top so I used this code:
extension ProblematicViewController: UIScrollViewDelegate {
/// Prevent bounce at top
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.contentOffset.y < 0 {
scrollView.contentOffset.y = 0
}
}
}
Which meant the ViewController's Adjust Scroll View Insets were overwrite (I think). So my scroll view did lay under the UINavigationController, to prevent this from happening, I did disable Extend Edges: Under Top Bars, so the root UIView containing the UIScrollView was not covered by the UINavigationController. So the transparency effect could never happen because the view was never under the top bar. More about Adjust Scroll View Insets on this post (helped me to find the problem).
Removing those lines and enabling Adjust Scroll View Insets and Extend Edges: Under Top Bars, solves the glitch problem, but the UIViewController does not have the "prevent bounce on top" behaviour that I wanted.
This kinda explains the weird behaviour of the UINavigationController because the SO has to calculate a transparency over nothing, but is sill strange, the transparency effect is calculated when the ProblematicViewController is fully presented, and not on viewDidLoad() or another view's life cycle before is shown to the user, so the transition is smooth, even when nothing lays behind the effect.
I'm making a simple app and I love using blue effects throughout the UI. Normally if I use a tableView I pin the 4 edges all the way out to the edge of the viewController, and everything scrolls correctly "behind" the blurred navigation bar and tab bar.
However, for one scene I want one view "Original Post VisualFX View" to be "pinned" at the top while the answer fields scroll behind that view and the nav/bottom bars.
Here's the view hierarchy:
Even after I turned off "clip to bounds" on the tableview as well as every view in the hierarchy above it, I can only get the tableView to scroll a BIT behind the Original Post VisualFX View and the bottom tab bar before they disappear. I assume it's because tableViews don't draw things that aren't visible at all within its bounds.
I'm trying to do everything in the Storyboard in IB with as little code as possible. I feel like this shouldn't be that hard, right?
So after tinkering for a while, I found a workaround: use a TableViewController for the whole scene, and just use a custom TableViewCell as the header, which pins it at the top when you scroll. By using ClearColor for the background and putting a UIVisualEffectView with blur in the background, I'm able to get everything to work beautifully.
I have a bunch of things in a scrollview but I cannot get the scrollview to scroll.
In iOS it is simple, we just need to put a view in the scrollview and then size the view to the dimensions we want to scroll. But in OS X, it isn't working. It is bouncing and resizing, but it is not scrolling. What am I missing?
I have a scroll view and within in that a clip view and within in that an NSview with a lot of elements. It just does not scroll. What do I need to set in storyboard to get it to scroll? Right now, I don't think I have set a height for the view to scroll. How do I do that? It does not let me set the height for the clip view. When I set the height for the NSView, it still does not scroll. It could also be an issue with the size of my window or how I setup the VC view controller. What are the best practices for sizing the window or the view controller? Any help would be really helpful. Or if you know any tutorials or places where I can get more info on this.
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.