I have a UITableViewController in a Storyboard that I'm adding as a subview to a lone UIView in a UIViewController, my end goal is to get the UITableView flush up against the status bar so that scrolling goes underneath the status bar (not through it with clashes).
I have configured the lone UIView to have constraints of 0 on both verticals and horizontals but as demonstrated in the image I believe autolayout is then adding the 20px y offset that I am including in the layout. If I remove the 20px y offset (and size the UIView to the whole layout) I end up with the clashing.
I suggest you to set up your view controller as follows. Create a UIViewController in IB and add a simple UITableView as a subview of its main view. I almost never use the UITableViewController because it has almost no added value but it restricts you in adding subviews to your table view. Now, you position your table view's origin to (0, 20) and set up the top layout constraint of the table view to the top layout guide instead of the superview. Maybe you should open the drop down menu close to the constraint constant value in IB:
This way your table view will start right under the status bar.
Note however that iOS 7 design guidelines suggest that you would in fact extend the content under the top bars (nav bar and status bar). You should create a 20 points high semi-transparent background png, position it under the status bar, and leave the table view to scroll under the status bar. In this case you should also not forget to check in the "Adjust scroll views inset" option of your view controller.
Related
I have a UICollectionView that I want to go under the navigation bar. Basically I want it to ignore the entire top safe area, yet still want it to respect the bottom safe area, as there's a tabbar there. This is how it currently looks:
But I want the first cell to start directly the very top of the screen, under the (translucent) navigation bar and the status bar.
If I set collectionView.contentInsetAdjustmentBehavior = .never, then the top part works great, but then the bottom part of the collection view content is hidden by the tabbar - you can't scroll all the way to the bottom so to speak. So I have to manually add a bottom inset again? How do I get the height of the tabbar, including any bottom safe area on devices that have the home bar? Or is there a better way to tell the collectionview to ignore only the top area for its content inset adjustment?
You just need to set the bottom content inset of the collection view manually, after setting the adjustment behavior to .never.
The correct inset (including the tab bar and any home bar) can be found in safeAreaInsets.
collectionView.contentInsetAdjustmentBehavior = .never
collectionView.contentInset.bottom = collectionView.safeAreaInsets.bottom
You'll need to do this at a point when the safeAreaInsets have been set, such as viewDidLayoutSubviews.
As far as I remember, it used to be possible by simply adjusting the edgesForExtendedLayout property of the containing view controller, but that was phased out when safe areas were introduced in iOS 11 I believe.
My ViewController is embedded in a UINavigationController, and it has a view that should be aligned with the top of root view. The root view has dark gray background, and occupies full screen. But this is what it looks like now:
As you can see, the root view is displayed below the status bar, which is expected. But the subview (black) is displayed below a white strip. I guess this is the top layout guide, and my subview has a constraint with its top equal to the bottom of the top layout guide. After I remove this constraint, I cannot add a constraint from my subview to the root view by Ctrl-dragging, Xcode always set up the constraint with top layout guide.
My question is:
How can I add a constraint top of subview == top of root view?
Why does the top layout guide occupy the white region?
self.automaticallyAdjustsScrollViewInsets = true
The default value of this property is true, which lets container view controllers know that they should adjust the scroll view insets of this view controller’s view to account for screen areas consumed by a status bar, search bar, navigation bar, toolbar, or tab bar. Set this property to false if your view controller implementation manages its own scroll view inset adjustments.
You can also set this property from Interface Builder
I have a UITabBarController with one UINavigationController holding a UIViewController as root view controller.
when tapping one of the button in the UIViewController, I push a regular chat window UIViewController (with TableView + Input View) end hiding the bottom tab bar. (using the "Hide bottom bar when pushed" flag)
In storyboard I added a regular UIView subclass to VC that look like a bottom bar, and I use Auto Layout to pin it to the bottom of the VC view.
The problem
when I push VC it takes a second for this view to pin to the bottom, it looks like auto layout pin it to the bottom as if the tab bar is not hidden and after a sec it recognise that the tab bar is hidden and moves it to the real bottom of the view.
For clear info check this screen shot
Now I will let you the know the constraints of the table view..
Now I am showing the constraints of the InputView
I am also adding my View hierarchy...
I had a similar issue in my project. I solved it by selecting the view I wanted anchored to the bottom (in your case, the input view), held Command, and selected its superview (both views should be highlighted now).
Then I selected the align button at the bottom of IB:
And added a Bottom Edges constraint.
What I had done initially is used the pin menu to pin the view to its superview, but it appears that will pin it to the bottom layout by default, which causes that weird movement during the transition.
EDIT:
After seeing the latest screenshot, the problem could lie in one of the superviews. I'm assuming that chatWindow is a UIView, and your Scroll View is horizontal only. Here's what your should check:
chatWindow is pinned to the scrollView's bottom similar to what I've outlined above.
scrollView is pinned to its superview as I've outlined above.
Moving the inputView outside of the scrollView to the root superview. Then one by one move it down the hierarchy towards its current location.
Using storyboard and Swift, I have a view controller which has two elements on it. A UITextField, and a UIView, which I use merely to give a colored border to the UITextField. The UITextField is a child of the UIView. See:
The problem I am having is that despite having set the top bar and bottom bar simulated metrics attributes to Opaque Navigation Bar and Opaque Tab Bar respectively, See:
When the app builds and runs the top of the UIView is always underneath the nav bar. My over all feeling is that this is somehow a constraints issue but I have not been able to find the solution to it. How do I set the constraints so that the UIView is always immediately underneath the nav bar, and the bottom of the view is always just on top of the tab bar?
Select your UIView in storyboard and assign constraints to the top margins and to bottom margins. There is a 'Pin' button you use to do this that looks something like a Tie-Fighter ship in Star Wars, it is located at the bottom right of your storyboard view.
This will set margins to stretch to top and bottom always.
That is what the layout guides are for. Pin the top to the Top Layout Guide and the bottom to the Bottom Layout Guide. The guides will always move to adjust for any top and bottom bars.
I have a container controller that displays a bar of data right below the lop layout guide.
I want the child controller of the this container controller to be able to scroll behind this bar as well as any navigation bar and status bar. However it seems that when UIKit automatically adjusts the scroll view insets of a controller it only takes into account the length of the top layout guide.
Is there any way to be say that the scroll view insets should be the top layout guide + the height of my bar? I know people are going to suggest I set automaticallyAdjustsScrollViewInsets = NO but I have already tried this. The problem is that I cannot seem to replicate exactly when UIKit sets the content insets and so I get all sorts of weird edge cases that break the insets. The most prominent example being UITableViewController where, because I set the content insets manually, the refresh control is sometimes not in the correct position and when I end refreshing the insets of the scroll view get set to { 0, 0 } so content is hidden behind my bar and the navigation bar.
UPDATE: All the magic seems to be inside the methods _setNavigationControllerContentInsetAdjustment on UIViewController and _computeAndApplyScrollContentInsetDeltaForViewController on UINavigationController.
It appears that only the navigation controller attempts to adjust the scroll view insets and it calculates the insets based on the top and bottom layout guides. It passes these insets onto the view controller which then adds/subtracts the insets from the scroll view and takes into consideration what navigation content insets have been set previously. This ensures that if anyone else modified the content insets between now and when the navigation controller last modified the insets they will not override the intermediary changes.
My solution was to set automaticallyAdjustsScrollViewInsets = NO and handle the setting of the content insets myself.
I created a category on UIViewController that tracked any existing insets that were set so whenever I adjusted the insets to have the scroll view appear below my custom UIView I would not be losing any information, such as the content inset for the UITableViewController with a active refresh control inside it.
After that the last challenge was figuring out where to set the custom insets and after much experimenting I found that - (void)viewDidLayoutSubviews was the best place to do it.
FDScrollingTabBarController is the container controller that I implemented this solution in.