I have a messaging application, the problem is that the first messages are not visible, when I drag the collection view to see the top messages I can see them but when I release the finger, the collection view jumps back, hiding the first 5 messages that are at the top of the screen
As we can see from the image there is a message (actually are 5 messages at the top), however I have to drag the collection view to peek those messages. I thought that the size of the collection view is actually larger that the screen, however both the collectionView.frame.height and the UIScreen.main.bounds.height have the same height, is that ok? .
Here's the code that I use to setup the collection view:
/// Function that configures the ChatViewController collection view
private func configureCollectionView() {
collectionView?.backgroundColor = Theme.current.chatGeneralBackground
collectionView?.alwaysBounceVertical = true
collectionView?.keyboardDismissMode = .onDrag
// Register the chat cell and the loading cellx`
collectionView?.register(ChatCell.self, forCellWithReuseIdentifier: chatCellIdentifier)
collectionView?.register(LoadingCollectionViewCell.self, forCellWithReuseIdentifier: loadingCellIdentifier)
// Initialize the original height of the collection view
collectionViewOriginalHeight = collectionView.frame.height
}
What am I doing wrong?
As of iOS 7.0, all views automatically go behind navigation bars, toolbars and tab bars to provide what Apple calls "context".
For example, if you don't want a view controller to go behind any bars, use this in viewWillAppear
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(true)
self.edgesForExtendedLayout = []
}
It seems to be the problem with constraints, if you are using custom navigation bar top constraints should be in reference to it. If using default navigation controller, you might need to give the top constraint to 44 from safe area.
However UIScreen.main.bounds.height consists of complete screen including the top navigation bar and 20 px of status bar. For collectionView.frame.height you need to minus these values.
Related
I'm writing an application for iOS with Swift and I'm using the auto layout in all my View Controllers but When the personal Hotspot is activated, the view doesn't resize correctly and The bottom of the view goes below the screen. I found It doesn't happen to my all views, except in the views that I have this line of code:
navigationController?.navigationBar.isHidden = true
How can I handle this situation?
I found a solution. I always have this problem when I add a child view controller and the bottom of the child view goes below the screen. I found when the blue bar appears, the height of my parent view controller will be lower than the device screen's height. So I need to change the child view position in the situation.
if let parentHeight = parent?.view.frame.height, parentHeight < UIScreen.main.bounds.height {
view.frame.origin.y = UIScreen.main.bounds.height-childViewHeight-8
}
I have a Navigation Controller and a Collection View under it inside my app. And there is a problem: I use large title inside my Navigation bar, so everything inside is not static. When I scroll the collection view cells, the title (I created it manually using UILabel() to move it as I want inside the navigation bar) and buttons move up and the navigation bar takes form of iOS 10 navigation bar, I mean its height. You can see it here:
The normal state of my Navigation Bar with "Prefer large titles" On:
It happens when I scroll my Collection View, everything goes up:
So the question is simple: how to make the force constant height for the navigation bar? I want it to become fixed even while scrolling. Are there any ideas? Is it possible?
And the second question, if the first is impossible: Another solution for my problem is to make the Navigation Bar with "Prefer large titles" Off bigger. I tried this code:
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
let height: CGFloat = 50 //whatever height you want to add to the existing height
let bounds = self.navigationController!.navigationBar.bounds
self.navigationController?.navigationBar.frame = CGRect(x: 0, y: 0, width: bounds.width, height: bounds.height + height)
}
but it worked only for large titles. So how can I make the navigation bar bigger?
Yes, you can make it fixed. It will not scroll if the very first view in the view hierarchy is not a CollectionView/TableView (ScrollView).
Using Storyboard/Xib:
Consider the following image where a tableView and button are added in scene. Here the navigation bar will collapse on scroll of tableView because tableView is the very first view in viewController's containerView hierarchy attached to the navigation bar.
Now to make the navigation bar fixed, if we just change the order of tableView and button as below, it will disable the collapsing of navigation bar.
To change the order of the view, you have to click, hold and move up/down.
If you have only CollectionView in this scene then you can add a placeholder view at the top and set its height to zero as below,
Programmatically:
If you are setting up view's programmatically then you just need to add a placeholder view at the top or add tableView/collection after adding other views.
e.g,
self.view.addSubview(UIView(frame: .zero))
self.view.addSubview(tableView) // or collectionView
What I want to to: I want to drag down the whole view of a viewController to dismiss to the parent viewController using a pan gesture recognizer.
The Problem: When I drag the view down, the navigationBar decreases its height and does not look good. When the view returns to its original position, the navigationBar returns to the default size. I want the navigationBar to stay at its size. I also tried to use the new large titles and some other properties of the navigationController/-bar, but that did not solve it.
Note: Everything worked fine already before iOS 11.
My code:
override func viewDidLoad() {
super.viewDidLoad()
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(dragViewDown(_:)))
navigationController!.view.addGestureRecognizer(panGesture)
}
#IBAction func dragViewDown(_ gesture: UIPanGestureRecognizer) {
if let dragView = gesture.view {
let translation = gesture.translation(in: dragView)
dragView.center.y = (dragView.center.y + translation.y)
gesture.setTranslation(CGPoint.zero, in: dragView)
}
}
This test project only has one viewController and does not provide the dismissal, but the problem is the same as in my working project.
I also uploaded the project to GitHub: https://github.com/maddinK7/navitationBar-pull-down-problem
Does anyone have an idea how to solve this? Thanks in advance.
I want the navigationBar to stay at its size
It is staying at its size. If you check the navigation bar's bounds size height before, during, and after the drag, you will see that it remains the same (probably 44) at all times. What's changing is the drawing extension that causes the drawing of the nav bar to extend up behind the status bar. It can't do that when you pull the whole thing away from the top of the screen, because it is not at the top next to the status bar any more. iOS 11 is more strict about the way it performs this drawing extension, probably because it has to do it in a special way on the iPhone X.
So, let's make sure you're doing this correctly:
Make sure that the navigation bar has a top constraint pinned to the safe area layout guide's top, with a constant of zero.
Make sure that the navigation bar has a delegate that returns .topAttached from position(forBar:).
If you are doing both those things and it doesn't help, you'll have to implement this in some other way entirely. Making the view directly draggable like this, without a custom parent view controller, was always dubious.
When UINavigationController attached top, system will add safe area top margin in the navigation background.
(NOTICE: Background margin will not changed when offset value is between 1 and 0)
So you have to handle attached/detached top event by handle gesture offset to change the right offset and content insets.
You can try the solution in my lib example. ;)
My example include UITableViewController in the UINavigationController, so it will relatively complex.
https://github.com/showang/OverlayModalViewController
Since I updated my app to iOS 7 new GUI I have a problem that I can't solve.
My app consists in a scrollable TableView. Trouble is that TableView scrolls underlying top bar, means that table doesn't consider top bar and extends till the top and it's ugly to see.
I tried removing check on "Extend edges under Top Bars" but it's the same.
How can I solve this?
One solution is: set the table view's contentInset and scrollIndicatorInsets to have a top inset of 20. The table view will still underlap the status bar, but it will be completely visible when scrolled all the way.
If you don't like that solution, and you want a permanent empty area behind the status bar, you will have to change the way you pin/position the top of the table view, to allow for the status bar. How you do this depends on whether you are using auto layout. If you are, just pin to the top layout guide. If you are not, you will have to use the "delta" field provided in the nib editor.
If you are using a UITableViewController, however, you are not in charge of the top of the table view; it is a full-screen view and it is the view controller's main view. This is quite a troublesome situation, actually. I have resorted to two solutions:
Put the whole thing into a UINavigationController in order to get the nav bar to "run interference" for me.
Or, embed the table view controller in a custom parent view controller just so that I can position the top of the table view.
In UINavigationController I created an UIView, which goes under status bar but in front of embed controller (the Table), so table disappear behind this view and status bar is always on top.
var patch: UIView!
override func viewDidLoad() {
super.viewDidLoad()
patch = UIView(frame: CGRectMake(0, 0, view.bounds.width, 20))
patch.backgroundColor = UIColor.redColor()
self.view.addSubview(patch)
}
Then I make it disappear when screen goes in Landscape (in iOS9, status bar automatically disappear in Landscape) and make it reappear when screen goes in Portrait.
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
if UIDevice.currentDevice().orientation.isLandscape.boolValue {
patch.hidden = true
} else {
patch.hidden = false
}
}
I created a UINavigationController and a UIViewController. With this setup the view looks like this:
This is what I want. The content "Test Text" does not appear behind the status bar.
Now I created my own UINavigationBar in the UIViewControllers:
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.setNavigationBarHidden(true, animated: false)
let newNavBar:UINavigationBar = UINavigationBar(frame: CGRectMake(0, 0, CGRectGetWidth(self.view.bounds), 64))
newNavBar.tintColor = UIColor.whiteColor()
newNavBar.translucent = true
self.view.addSubview(newNavBar)
}
The result is the following:
The content is behind the new navigation bar.
How can I prevent the content from being behind the new navigation bar?
When you add Navigation Bar in view controller then NavigationBar will take 64pixel ( 20 pixel status bar and 44 pixel navigation bar ) so you need to start your layout after 64pixel from top.
If your content is a UIScrollView, use the contentInsets property to adjust where your content starts, this makes the scrollview be able to scroll the specified amount of pixels "too far", and thus show your content immediately below your custom UINavigationBar.
If your content is not a UIScrollview, then just offset the content with a constraint (you could link it to an IBOutlet, so you can change it if you dynamically change from the old to the new UINavigationBar).