UICollectionView not scrolling after custom UIView added to view - swift

I'm trying to add a custom UIView after adding a UICollectionView because I wanna show the custom bar view above the collection view. This is my code:
func loadFilters() {
let categoriesFlowLayout = UICollectionViewFlowLayout()
categoriesFlowLayout.scrollDirection = .vertical
categoriesCollection = UICollectionView(frame: CGRect(x: 10, y: getY(yAxis: searchField) + 10, width: view.frame.size.width - 20, height: (view.frame.size.height * 9 / 10) - getY(yAxis: searchField) - 10), collectionViewLayout: categoriesFlowLayout)
categoriesCollection.register(categoriesCell.self, forCellWithReuseIdentifier: "categoriesCell")
categoriesCollection.delegate = self
categoriesCollection.dataSource = self
categoriesCollection.backgroundColor = UIColor.clear
categoriesCollection.showsVerticalScrollIndicator = false
categoriesCollection.showsHorizontalScrollIndicator = false
view.addSubview(categoriesCollection)
addBar()
categoriesCollection.isUserInteractionEnabled = true
}
The addBar() function is declared in the custom superclass ViewController
if addBar() is called before view.addSubview(categoriesCollection) it looks like the image below but if it is called after then my collection view does not scroll or recognize touches. Is there anyway that will make the collection view scroll and bring the custom bar to front?
I've used sendSubviewToBack() and bringSubviewToFront() functions as well but the result is the same

When you insert a view above another view, the top view gets all touch events. So the UICollectionView does not receive any touch events anymore since another view is above it.
As I see from your post, you just want the bar at the bottom of the screen. So check the size of your custom UIView. It probably fills the entire screen and is completely above the UICollectionView. Just give the UIView some sort of background color and see, how much space it fills.
If this doesn't work, you can use a UIGestureRecognizer on the custom UIView and forward the touch events to the UICollectionView.

Related

Exist way notify when custom UIView will be presented or removeFromSuperview()?

I am create custom UIView using this code:
lazy var temporary: UIView = {
let view = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
view.backgroundColor = .white
return view
}()
Exist way use NotificationCenter notify when this view will be presented and removed from VC if I am use:
self.view.addSubview(temporary)
or
temporary.removeFromSuperview()
I'm not totally sure what you are asking. I think you're asking for a way to tell when your custom view is added as a subview of another view.
The easiest way to do that is to make your view a custom subclass of UIView, and implement didMoveToSuperview() or willMove(toSuperview:). Those methods get called when your view is added as a child view of another view.
If you really want to use the notification center you could have your custom view class broadcast a notification when it gets added to a superview.

swift NSCollectionView layout wrong after window resize

I have a NSCollectionView using sections and flow layout. Initial layout is fine but resizing the window causes the vertical position of the collection view items to move (relative to the top window boundary). The section breaks stay stationary relative to the top window boundary (good). But the items moving up causes them to overlap with the sections and eventually move up out of the window area as I decrease the height of the window.
I think this is related to how the mac uses the bottom as the origin of the coordinates. Resizing the window causes the bottom window boundary to move.
For reference here's where I configure my collection view, including standard flow layout.
fileprivate func configureCollectionView() {
let nib = NSNib(nibNamed: "MonitorViewItem", bundle: nil)
mapCollectionView.register(nib, forItemWithIdentifier: NSUserInterfaceItemIdentifier("MonitorViewItem"))
let flowLayout = NSCollectionViewFlowLayout()
flowLayout.itemSize = NSSize(width: 100.0, height: 40.0)
flowLayout.sectionInset = NSEdgeInsets(top: 25.0, left: 10.0, bottom: 10.0, right: 10.0)
flowLayout.minimumInteritemSpacing = 10.0
flowLayout.minimumLineSpacing = 10.0
mapCollectionView.collectionViewLayout = flowLayout
}
I tried invalidating the layout in my window resizing delegate function. My print statement confirms its being called as the window resizes, but invalidating the layout is not solving the issue.
extension MapWindowController: NSWindowDelegate {
func windowDidResize(_ notification: Notification) {
print("got resize")
mapCollectionView.collectionViewLayout!.invalidateLayout()
}
}
So far I have not attempted to subclass my view and override isFlipped.
Here's my window hierarchy in my .xib:
Window
View
Bordered Scroll View - Collection View
Clip View
Map Collection view
Collection View Flow layout
scroller
scroller
Any suggestions to fix the collection view item vertical positions as the nswindow is resized?

UIButton action is not triggered after constraint layouts changed

I have got an UIButton on a storyboard ViewController. When I load data into the form and the layout is significantly changing the button does not recognise the touch action.
I have figured out that when button is visible on the scrollview right after it if filled with data, the touch action works.
If the data too long and the button is not visible at first, just when it is scrolled into the display, the touch action does not work.
I was checking if something is above the button, but nothing. I have tried to change the zPosition of the button, not solved the problem.
What can be the issue?
I have made custom classes from the UIScrollView and the UIButton to check how the touches event triggered. It is showing the same behaviour, which is obvious. If the button is visible right at the beginning, the UIButton's touchesBegan event is triggered. If the button moves down and not visible at the beginning, it is never triggered, but the scrollview's touchesBegan is called instead.
Depending on the size of the data I load into the page sometimes the button is visible at the beginning, but the form can be still scrolled a bit. In this case the button still work, so it seems that this behaviour is not depending on if the scrollview is scrolled before or not, just on the initial visibility of the button.
Is there any layout or display refresh function which should be called to set back the behaviour to the button?
The code portion which ensures that the contentview is resized for the scroll if the filled data requires bigger space.
func fillFormWithData() {
dispDescription.text = jSonData[0]["advdescription"]
dispLongDescription.text = jSonData[0]["advlongdesc"]
priceandcurrency.text = jSonData[0]["advprice"]! + " " + jSonData[0]["advpricecur"]!
validitydate.text = jSonData[0]["advdate"]!
contentview.layoutIfNeeded()
let contentRect = CGRect(x: 0, y: 0, width: scrollview.frame.width, height: uzenetbutton.frame.origin.y+uzenetbutton.frame.height+50)
contentview.frame.size.height = contentRect.size.height
scrollview.contentSize = contentview.bounds.size
}
Ok, so another update. I have coloured the contentview background to blue and the scrollview background to white. When I load the data and resize the layout constraints, the contentview is resizing as expected, however now the scrollview is going to the bottom. After I scroll the view it is resizing to the original size which fits the screen. Now the button is only recognised when I touch the are which is blue behind. With the white background it is not recognised anymore, so it seems that the scrollview is hiding the button.
Let me get this clear the button is added in storyboard and it is a spritekit project?? If you are using zPosition?? Why don’t u connect the UIButton via the assistant editor as an IBAction then the action is always tied to the button.
You can also do it differently
Create an SKLabelNode and put it on the screen where you want to have the button and then set a name to it as myButton
override func touchesBegan(_ touches: Set<UITouch>, with event:
UIEvent?) {
if let touch = touches.first {
let location = touch.location(in: self)
let tappedNodes = nodes(at: location)
for node in tappedNodes {
if node.name == "myButton" {
// call your action here
}
}
}
}
EDIT 1:
You could also try auto resizing your scrollView.content this works also if you are adding any views via the app or programmatically
private func resizeScrollView(){
print("RESIZING THE SCROLLVIEW from \(scrollView.contentSize)")
for view in scrollView.subviews {
contentRect = contentRect.union(view.frame)
}
scrollView.contentSize = CGSize(width: contentRect.size.width, height: contentRect.size.height + 150)
print("THE CONTENT SIZE AFTER RESIZING IS: \(scrollView.contentSize)")
}
EDIT 2: I think I found the issue with your project. You need to move the MessageButton(UzenetButton) above DispDescription label in the object inspector in that way it will always be above your message textView.
At the moment the UzeneButton is at the very far back in your view hierarchy so if your textView is resizing whilst editing it covers the button that is why you cannot click on it.
See #Endre Olah,
To make situation more clear do one more thing, set clipToBound property of contentview to true.
you will notice that after loading of data your button not fully visible, it means it is shifting out of bound of its parentView (ContentView)
And that's why button is not taking your touch. However, if you carefully touch upper part of button it still do its job. Because upper part is still in bound of ContentView
Solution :
After loading of data you have to make sure that you increase height of ContentView such that button should never go out of bound of its parentView(ContentView).
FOR EXAMPLE
#IBOutlet var heightConstraintOfContentView : NSLayoutConstraint!
After loading of data
let contentRect = CGRect(x: 0, y: 0, width: scrollview.frame.width, height: uzenetbutton.frame.origin.y+uzenetbutton.frame.height+50)
heightConstraintOfContentView.constant = contentRect.size.height
contentView.layoutIfNeeded()
I use following steps when I need to use scrollview with dynamic content:
1) Firstly add a scrollView with top, bottom, trailing and leading is 0 to super view.
2) Add a view to scrollView and view's trailing, leading bottom and top space to scrollView can be set to 0 (or you can add margin optionally).
3) Now, you should add UI elements like buttons, labels with appropriate top, bottom, trailing and leading margins to each other.
4) Lastly, add equal height and equal width constraint to view with Safe Area:
and change equal height priority of view to 250:
It should solve your problem with UIScrollView.
Finally, I have found the solution in another chain, once it became clear that the scrollview's contentview is resizing on scroll event to the original size. (Not clear why this is like this, but that is the fact.)
So I had to add a height constraint to the contentview in the storyboard and create an outlet to it and adjust this constraint when the content size is changing, like this:
#IBOutlet weak var ContentViewHeight: NSLayoutConstraint!
func fillFormWithData() {
dispDescription.text = jSonData[0]["advdescription"]
dispLongDescription.text = jSonData[0]["advlongdesc"]
priceandcurrency.text = jSonData[0]["advprice"]! + " " + jSonData[0]["advpricecur"]!
validitydate.text = jSonData[0]["advdate"]!
contentview.layoutIfNeeded()
let contentRect = CGRect(x: 0, y: 0, width: scrollview.frame.width, height: uzenetbutton.frame.origin.y+uzenetbutton.frame.height+50)
contentview.bounds = contentRect
scrollview.contentSize = contentRect.size
----------- This is the key line to the success ----------
ContentViewHeight.constant = contentRect.size.height
----------------------------------------------------------
}
After this is added, it works perfectly.

Change tab in tab bar controller using finger swipe

I have three tabs in my tabbar controller and I want to switch between these tabs just like tinder switches the tab using finger touch. I have done it using UISwipeGestureRecognizer but its not exactly same as that of Tinder (the dating app ) swiping.
I have added UISwipeGestureRecognizer on one of the Tabbar controller and then added the function to change the tabbar selected index. But the animations is not controlled by finger touch. I want the swiping should be controlled by finger touch.
I think the best way to do it is to put all your tab views in a UIScrollView. You place them next to each other.
Implement the scroll view delegate methods in your tabbarController.
You'll probably need scrollViewDidEndScrollingAnimation and scrollViewDidEndDecelerating to know on which view you are when the user stops scrolling, like this:
let page_width=UIScreen.main.bounds.width
let page=Int(floor((scrollView.contentOffset.x-page_width/2)/page_width)+1)
Here, I assume each of your tab view is the same size as the screen.
I am bit late but I found my ans -
I have created 4 UIviewcontrollers programatically and then
created an array of it.
var views = [CareTeamTableViewController(),VFCChatQViewController(), NewAccountViewController(), ShareViewController()]
Then I added a scrollview in my main UiViewController
private func initMainScroll() {
scrollView = UIScrollView.init()
scrollView?.delegate = self
scrollView?.showsHorizontalScrollIndicator = false
scrollView?.isPagingEnabled = true
self.view.addSubview(scrollView!)
}
and then added the views array like :
func setupScrollView(complete:()->()) {
scrollView?.frame = views.first!.view.frame
scrollView?.contentSize = CGSize(width: CGFloat(views.count) * UIScreen.main.bounds.width, height: 0)
_ = views.map({ addViewToScrollView($0) })
_ = views.map({ $0.view.frame.origin = CGPoint(x: CGFloat(views.index(of: $0)!) * UIScreen.main.bounds.width, y: 0) })
complete()
}
func addViewToScrollView(_ viewController: UIViewController) {
scrollView?.addSubview(viewController.view)
viewController.willMove(toParentViewController: self)
addChildViewController(viewController)
}

Add view over tableview (UITableViewController)

Situation: I've got a UITableViewController loading some data asynchronously from a service. During this time I would like to place a full screen (except navigation bar) view over the table view showing my custom indicator and text.
Problem: The problem I'm facing is that when my custom view (it has a red background) is placed over the UITableView the lines of the table view are shown trough my custom view (see image below).
What I tried:
I tried to use insertBelow and above, didn't work. I also tried to do: tableview.Hidden = true, but this also hides the custom view for some reason as seen on image 2.
Image1: For some reason I can see the lines threw my view.
Image 2: Tableview + custom view gone when hidden = true used.
My code:
public override void ViewDidLoad ()
{
base.ViewDidLoad ();
UIView view = new UIView (new RectangleF (0, 0, this.TableView.Frame.Width, this.TableView.Frame.Height));
view.BackgroundColor = UIColor.Red;
this.TableView.AddSubview (view);
TableView.Source = new SessionTableViewSource ();
}
You can use self.navigationController.view as view for adding subview.
The issue is that the View of a UITableViewController is a UITableView, so you cannot add subviews to the controller on top of the table.
I'd recommend switching from a UITableViewController to a simple UIViewController that contains a UITableView. This way the controller main view is a plain UIView that contains a table, and you can add subviews to the main UIView and they will be placed on top of the table view.
You can try to add the view to the window instead of nesting it in the table view like this:
UIWindow* mainWindow = [[UIApplication sharedApplication] keyWindow];
[mainWindow addSubview: overlayview];
UIWindow* window = [[UIApplication sharedApplication].delegate.window;
[window addSubview: your-overlayview];
Swift / Storyboard Solution
Note: The code below assumes one has a custom view (ratingView in my case) that is to be presented over a UITableView.
I've read many answers to this and similar questions on SO. The other answers from these sources worked to varying degrees for me (e.g.,view loaded but not shown or not accessible,...). I am using Swift 2.0+ and I am sharing the complete solution for doing this using a UITableViewController.
Create an outlet to the Navigation Bar and the view, which you want to bring over the tableview.
//MARK:Outlets
#IBOutlet weak var navBar:UINavigationBar!
#IBOutlet var ratingView: MNGStarRating!
In my case I also wanted to animate the view over the tableview so I used a class variable to hold a reference to the inflection point and a point above the scene (off-screen).
var centerYInflection:NSLayoutConstraint!
var aPointAboveScene = -(max(UIScreen.mainScreen().bounds.width,UIScreen.mainScreen().bounds.height) * 2.0)
Then in viewDidLoad I called a function (configureRatingViewAutoLayout) which configures and adds the constraints for the new view to be animated over the tableview.
func configureRatingViewAutoLayout() {
//REQUIRED
self.navBar.superview?.addSubview(self.ratingView)
var newConstraints:[NSLayoutConstraint] = []
newConstraints.append(self.ratingView.leadingAnchor.constraintEqualToAnchor(self.view.leadingAnchor,constant: 10))
newConstraints.append(self.ratingView.trailingAnchor.constraintEqualToAnchor(self.view.trailingAnchor,constant: 10))
newConstraints.append(self.ratingView.centerXAnchor.constraintEqualToAnchor(self.view.centerXAnchor))
//hides the rating view above the scene
self.centerYInflection = self.ratingView.centerYAnchor.constraintEqualToAnchor(self.view.centerYAnchor, constant: self.aPointAboveScene)
//the priority must be set below 1000 if you intend to change it after it has been added to a view
self.centerYInflection.priority = 750
newConstraints.append(self.centerYInflection)
//constraints must be added to the container view of the two items
self.ratingView.superview?.addConstraints(newConstraints)
}
Nota Bene - On a UITableViewController; the self.view is the
self.tableView. They point to the same thing so I guess one could also
use the self.tableView reference above.
Sometime later... In response to a UIControl event I call this method.
#IBAction func toggleRatingView (sender:AnyObject?){
//REQUIRED
self.ratingView.superview?.layoutIfNeeded()
UIView.animateWithDuration(1.0, delay: 0.0, usingSpringWithDamping: 0.37, initialSpringVelocity: 0.99, options: [.CurveEaseOut], animations: { () -> Void in
if CGRectContainsRect(self.view.frame, self.ratingView.frame) {
//in frame ~ animate away
//I play a sound to alert the user something is happening
self.centerYInflection.constant = self.aPointAboveScene
self.centerYInflection.priority = UILayoutPriority(950)
//I disable portions of the UI
self.disableUIElements(nil)
} else {
//out of frame ~ animate in
//I play a different sound here
self.centerYInflection.constant = 0
self.centerYInflection.priority = UILayoutPriority(950)
//I enable the UI fully
self.enableUIElements(nil)
}
//REQUIRED
self.ratingView.superview?.setNeedsLayout()
self.ratingView.superview?.layoutIfNeeded()
}) { (success) -> Void in
//do something else
}
}
These helper methods can be configured to control access to elements in your scene during the presentation of the view.
func disableUIElements(sender:AnyObject?) {
//UI
}
func enableUIElements(sender:AnyObject?) {
//UI
}
Caveats
My view is a custom view in the Storyboard (sitting outside of the
tableview but connected to the TableView Controller). The view has a
required user runtime attribute defined layer.zPosition with a Number value set to 2 (this ensures that it presents in front of the
UITableView).
One could also try playing around with bringSubviewToFront:
and sendSubviewToBack: methods if you don't want to set the zPosition
(I think zPosition is simpler to use)
Try this to hook a button at bottom of the UITableViewController
declare button as a variable:
var submitButton: UIButton!
and in viewDidLoad:
submitButton = UIButton(frame: CGRect(x: 5, y: UIScreen.main.bounds.size.height - 50, width: UIScreen.main.bounds.size.width - 10, height: 50))
submitButton.backgroundColor = UIColor.init(red: 180/255, green: 40/255, blue: 56/255, alpha: 1.0)
submitButton.setTitle("Submit", for: .normal)
submitButton.titleLabel?.font = UIFont(name: "Arial", size: 15)
submitButton.titleLabel?.textColor = .white
submitButton.addTarget(self, action: #selector(submit), for: .touchUpInside)
submitButton.layer.cornerRadius = 5
self.view.addSubview(submitButton)
and implement this method:
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
submitButton.frame = CGRect.init(x: submitButton.frame.origin.x, y: UIScreen.main.bounds.size.height + scrollView.contentOffset.y - 50, width: submitButton.frame.width, height: submitButton.frame.height)
}
This works for me:
if let myTopView = Bundle.main.loadNibNamed("MyTopView", owner: self, options: nil)?.first as? MyTopView {
if let view = UIApplication.shared.keyWindow{
view.addSubview(myView);
myTopView.translatesAutoresizingMaskIntoConstraints = false
myTopView.topAnchor.constraint(equalTo: view.topAnchor ).isActive = true
myTopView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
myTopView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
myTopView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
}