I'm working on a project with a fairly complicated layout that I've developed programatically. The main view consists of 7 different sized views placed vertically with 6 spacer views in-between. All of the spacer views are constrained to be equally tall. According to a loop I'm doing with view.hasAmbiguousLayout, none of my views are ambiguous. I've been extra careful in checking all of the constraints, and the view acts as I expect on different device sizes.
The strange bit happens when I add a contained view controller. I've been using a contained view controller to manage a popup view. This subview has some transparency so I can see the main view below it. If this secondary view has any subviews at all, the main view's layout changes ever so slightly. The moment I add it some of the bottom views move slightly upward.
Is there a cause for this that I am missing or could it just be a bug in ios? (The same thing happens when I build the layout in interface builder)
Related
I am quite new in swift programming and I am developing an app which has multiple custom views, hope some one can help me here.
The issue is that I have a scrollView, inside I have a stackView with about 20 Views inside, every view has inferred constraints and every view has a fixed height, maybe not the best practice but most of the views show correctly (had to re-do about 3 times to get here), but one of my views (around the middle of the stack) is showing correctly in my story board, but somehow it's shrinking it's subviews when launching the app, not sure if I am missing something, I have even removed all the content of these subviews and left only the main views with their heights but still I have the same issue.
To be more detailed the section that fails is a view inside the vertical stackView, it contains a view (container) which has the same leading, trailing, top and bottom as the first one. This container view, contains 5 (sub)views which have the same height each (124), and have practically the same content: a label, a texfield and a custom slider (thought the slider was ruining everything because it's custom but after removing all from the design the error still occurs).
Here is an image of how it's shown in the story board:
views in story board
And here is how it's displayed in the emulator:
view in emulator
Does anybody now why can this be happening? I am not doing any layout stuff in the code only a couple of corner rounding in other views that are inside the stack view.
BTW, I also implemented this 5 slider views using a vertical stack and had the same issue, I switched and changed to simple views and separated by 10 each bottom with the next view top.
Thanks
I am building an iOS app with multiple screens but I want avoid duplication of code as well as one large storyboard. Ideally I would like to load the various View Controllers based on a selected storyboard in my content view when needed.
The template of the screen (Master/Root View) shall be composed by 3 Views, namely:
View A that acts as a Navigation View,
View B where the various View Controllers should be loaded based on user actions and,
View C, much like a Tab bar or a 3rd View where I can display some
circumstantial information.
Now, of course I could go with a traditional UINavigationController and UITabBar but I need greater control over those views, notably in terms of size (they have minimum heights that are larger than the ones for NavBar and TabBar).
I also need those Views to resize based on the Traits and Class Size to keep filling the entire screen.
I am trying to use container views to doing so, but I can't get them to resize automatically despite having tried a different set of constraints in auto-layout. Putting the 3 views in a stackview does not do the trick either.
Ultimately I would like to be able to work separately on my various Controller Views that will be loaded in View B, using their own storyboards, calling them programmatically in B and having everything automatically resized.
Thank you all for your kind and valuable input!
Chris
When using addChildViewController(childVC) / addChild(childVC) (Swift 4.1 / 4.2), followed by myContainerView.addSubview(childVC.view) you need to either
add constraints for the added subview
or
set the frame of the subview and .autoResizingMask
After that, your newly added subview will layout and resize correctly.
Recently i was following a tutorial to create frameworks in Swift, Where they create reusable visual effect view just like we see in Xcode build success pop up. I was doing the UI step by step where they created a new xib file and dragged and dropped UIVisualEffectView into it.
In the above image we can see that the UIVisualEffectView doesn't contain any constraints. It only has auto resizing masks in size inspector(as expected).
But the following image from the tutorial suddenly contains all necessary constraints for it's root view.
I'm already aware that we CANNOT, by default set any constraints for the root view. But in the tutorial the author seems to have added constraints for the same. I'm just curious to know if it is possible to do that or am i missing any fundamental idea ?
EDIT:
Constraints for root view.
OK, found one way to do this...
Haven't done any testing, so I'm not sure if the constraints are really set correctly or will be used by auto-layout at run-time, but this will put them there.
Create a new "View" XIB - this is how it looks to start:
Add a Visual Effect view to this view, and give it width and height constraints of 230 / 230:
Now, drag that Visual Effects view *out of the plain view, onto an empty space:
You will see it maintains its constraints. Then delete the original view, and add the other elements:
As you can actually see on your screenshot the width/height constraints belong to the View (first subview of Visual Effect View).
Look at the green line:
I don't know what's going on your tutorial (and I have no intention of watching it), and I have no idea under what circumstances the screen shot was achieved. But I do know the rules for how a view controller's main view gets sized.
Any view controller's main view must expect to be resized as it is placed into the interface. The size in the storyboard is therefore meaningless. That is why you cannot give it a size with auto layout.
If a view in a xib or storyboard is to be used as the main view of a view controller, it is meaningless (and would be wrong) to set constraints on it, because it will be the task of the view controller's parent (or, in the case of the window's rootViewController, of the window) to set the size of the view when it places it into the hierarchy.
If a view controller wants to vote on the size of its view when it is placed into the view hierarchy (for example, as a popover), that is what the content size (preferred explicit size) is for. But even then, the parent is the one who controls what actually happens.
I designed about 40 view controllers using a 5.5 inch storyboard layout. After all of that I tested it on the iPhone 4S...big mistake. everything is jumbled together being for a larger screen size. I was able to fix one view controller up using Size Classes. I am wondering if there is any way I can adjust all 40 at the same time, or at least avoid doing this for every single one. It is really frustrating finding this out now. Thanks!
This is a relatively complicated issue you are attempting to solve, but I have two potential solutions. Both suggestions are based on moving your current interface into containing UIScrollView instances
If you are using storyboards, then for each of your view controller scenes, put a UIScrollView as a descendent of the view controller's view. From there, provided your subviews are contained within other views (like a container view for a set of buttons), you can move those into your scroll view. You will have to setup constraints to define the size of the scroll view's content, but this will allow the size of the device to have a smaller impact on the interface as you will get scrolling as needed.
If you are using nib files (.xib) then it is essentially the same thing, but easier. In this case, move a UIScrollView onto the canvas, but not as a subview of the default view. Once that is out there, move the original view to be a subview of the scroll view and set constraints to be 0 from the subview to the scroll view. Finally, right click drag from the File's Owner icon to the scroll view and set that as the view outlet.
Hopefully one of these will help you.
I am fairly new to UI elements in iOS (all of my apps were Gl games) but I'm trying it out and I found myself in a bit of a pickle...
The view controller for the bulk of my app is a subclass of UITabBarController and I have a few tabs with (currently empty) child view controllers. For the most part I have these working fine, but my problem is with correctly sizing and placing items inside of a tabbed view controller. If, for instance, I try to place something just above the tab bar, then I can't just set the Y position to the height of the the child view controller's view minus the height of the object I'm placing. I also need to account for the tab bar itself.
I can see that part of my problem is that I'm simply creating the view controller and not telling it what size it's view needs to be. Is there a function provided to me to calculate the height the view needs to be? I could just figure out the height of the bar and subtract that from the overall height, but that just feels to flimsy to me.
Any ideas?
EDIT:
I am doing it all programmatically and I don't intend to use Interface Builder. My main concern with the view size is making sure that things like table views fit snugly.
If you are using Interface Builder and auto layout, you can place UIView items on your UIViewController and if you set a size constraint on the view you're placing you can also set position constraints that are relative to screen edge or adjacent views, in your case UITabBar.