Smooth scrolling with prefersLargeTitles and UITableView - ios

I encountered a problem with the scrolling when using the prefersLargeTitles and added UITableView.
If I set the prefersLargeTitles within a navigation controller and its root is a UITableViewController everything is fine, scrolling of the navigation large title works the same way we can see in the system apps (in iOS 11+).
The problem
However, if I use a UIViewController and add a UITableView in it, scroll seems to act differently. Navigation bar is moving more/faster than I actually scroll. It just hides/shows the large title whenever I scroll into a position that just triggers it, so I end up with the totally different feeling.

Turns out that the layout is causing this problem.
The problem occurs if the UITableView use Align top to: Safe Area constraint (besides the bottom, leading and trailing to Safe Area) and is not extended under the bar.
However if I use the extended layout, align top to the superview, I can still use the UITableView and get the correct behaviour of the large title and its navigation bar.
edgesForExtendedLayout = .top
extendedLayoutIncludesOpaqueBars = true
Or use navigation bar's isTranslucent = true which extends it too.

Related

UICollectionView under Navigation Bar, but not under Tab Bar

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.

Text slightly under navigation bar in autolayout

On some screens the label inside a StackView partially disappears under the navigation bar. Currently I have a constraint stackView.top = Top Layout Guide.bottom, but it does not seem to work as I hoped. How to constrain my StackView, so that everything would be properly visible?
The problem was solved by embedding the view into navigation controller. After that the constraint started working perfectly.

Add a UINavigationBar to a UIView using Autolayout

I have a modal view that I'm presenting over the current view that has a UINavigationBar as a subview. Everything's working great, except that the UINavigationBar doesn't want to behave according to the autolayout constraints. Everything else in the view behaves as desired.
For some reason, the left and right bar button items are cut off on the edges of the view. I inspected the view at runtime to reveal that the total width of the UINavigationBar is the right width, but the bar buttons aren't conforming.
I also checked to make sure I didn't have negative margins or some other anomaly in the constraint definitions.
I have also tried setting the frame of the UINavigationBar manually, but it yielded no improvement.
Problematic View
Constraints
I'd like to keep the UINavigationBar, because it gets styled globally with the rest of my app (as opposed to creating a custom UIView imitation and styling it individually). Does anyone know what handle to jiggle to get the bar button items to conform to the right width?

Table view top space to navigation bar increased after pressing back

When I click one of the cells in the table view, it opens a new view with the following code:
let fullResView : FullResponseViewController = self.storyboard?.instantiateViewControllerWithIdentifier("FullResponseView") as! FullResponseViewController
fullResView.receivedPost = post
self.navigationController?.pushViewController(fullResView, animated: false)
When I press back, it increases the distance between the table view and the Top Layout Guide. Representation:
Hierarchy:
I have a tab bar controller, that is embedded in a navigation controller.
The table view is drag & dropped after creating an normal view. So the table view is inside a View.
Table view does contain an header view. When setting a background color for this, it moves together with it, so it should not be anything with those constraints.
constraints for the table view are:
equal with to superview
Align Center X to superview
top space to Top Layout Guide
bottom space to Bottom Layout Guide
I've tried the following:
set this in viewWillAppear:
self.responsesTableView.contentOffset = CGPointMake(0, 0)
self.automaticallyAdjustsScrollViewInsets = false
This did work when I pressed back, then switch to another view in the tab bar, and then switch back again. Without contentOffset it will stay like this forever.
As i seen the OP images that seems like Navigation translucent property Issue. Because after push a viewcontroller there is same 44px white space. so it means if your Navigation translucent property is true then your UITableview start from 0th Y position. And if your Navigation translucent property is false then UITableview start from 44px Y position.
So i guess in between push and back some where UINavigation's translucent become a true and false. make following one line add in your appdelegate class in DidFinish method:
UINavigationBar.appearance().translucent = false
This is appearance of UINavigationBar for make this false globley in your project. Hope that will be fix your issue.
I'm not sure if this is related to your particular issue, but it's worth checking whether your UITableView is the first control on your screen:
Why is there extra padding at the top of my UITableView
Even in the latest version of Xcode, this is a bug. But it's easy enough to fix, if you know how to get around it.

UISearchBar on UITableView strange offset issue

I have a UITableView which has a UISearchBar subview. This is all on the view of a UIViewController along with a few other subviews (labels, text fields and such).
The search bar and content offset of the table are acting quite strangely, but it seems dependent on the order in which these views are added to the main view in the xib. I created a sample project with just my table/search and a label in order to test, and the result is the same. When the table is added after the label, everything works fine:
Setup:
Correct and Expected Result:
However, if I simply change the order in which my 2 subviews sit on the main view (aka table added before the label) then weird things start happening.
Apparently bad setup:
Weird offset of Search Bar:
I'm not changing anything else whatsoever, so why does Xcode seem to care which order these subviews are added to the main view?? If I scroll up on the "bad" table setup, the search bar disappears immediately at its top edge, but the table's content will continue to scroll up until it reaches the top of the frame that was set in the xib. Scroll back down and the search bar doesn't reappear until the strange lowered location. This is in Xcode 5.1.1, not the new beta. The result is the same with or without Autolayout turned on.
Any idea why this is happening? Is this a bug, or am I missing something? (I didn't post any code because all I'm doing is setting the number of sections, rows, and setting the text on the cell. Not messing with content insets, offset, anything. I load the view from the app delegate as the root of a nav controller)
This happens because a UIViewController's property called automaticallyAdjustsScrollViewInsets
With iOS 7, UIViewControllers have a property called
automaticallyAdjustsScrollViewInsets, and it defaults to YES. If you
have a scroll view that is either the root view of your view
controller (such as with a UITableViewController) or the subview at
index 0, then that property will adjust both the contentInset and the
scrollIndicatorInsets. This will allow your scroll view to start its
content and scroll indicators below the navigation bar (if your view
controller is in a navigation controller).
From Big Nerd Ranch
If you are using storyboards, you can change it by selecting the view controller and in the attributes inspector deselect Adjust scroll view insets.
Here is its description from apple documentation:
Default value is YES, which allows the view controller to adjust its
scroll view insets in response to the screen areas consumed by the
status bar, navigation bar, and toolbar or tab bar. Set to NO if you
want to manage scroll view inset adjustments yourself, such as when
there is more than one scroll view in the view hierarchy.
I have same problem before about position of tableview and searchbar. i tried the following and it works for me.
If you do not write code for that and if it is only problem of xib or storyboard then try all outlet's autosizing and origin setting to fix its position and see the difference. it may be work for you.
Update : automaticallyAdjustsScrollViewInsets has been deprecated in ios 11 and a new field contentInsetAdjustmentBehavior has been introduced.
if #available(iOS 11.0, *) {
tableview.contentInsetAdjustmentBehavior = .never
} else {
automaticallyAdjustsScrollViewInsets = false
}
UITableView header can contains only one UIView, so if you need UISearchBar plus UILabel, you need to wrap they into UIView and add this view as UITableView header.

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