I have a PageViewController which shows 4 four view Controllers horizontally,
Can I embed all this viewControllers in a UIScrollView? It would be easier to manage some tasks.
Till now I tried doing this in PageViewController, conforming the PageViewController to UIScrollViewDelegate:
for view in self.view.subviews {
if let subView = view as? UIScrollView {
subView.delegate = self
subView.isScrollEnabled = true
subView.bouncesZoom = false
}
}
But it actually recognises the scrolling for the single ViewController and not for the entire stack of four VCs.
I'd like to have the contentSize of the ScrollView equal to the entire width of all viewControllers.
You cannot change a UIPageViewController into a scroll view. It already is a scroll view, but has a lot of built-in functionality for memory-managed paging through view controllers.
If your goal is to put 4 view controllers into a scroll view:
create a new (plain) UIViewController
add a UIScrollView and constrain it to all 4 sides
add a UIStackView (Distribution: Fill Equally) to the scroll view
constrain all 4 sides of the stack view to the scroll view's content layout guide
constrain its height to the scroll view's frame layout guide height
add 4 UIContainerViews to the stack view
embed each of your 4 "page" view controllers into the 4 containers
constrain the width of the first container to width of scroll view frame layout guide
You now have a full-view UIScrollView where you can scroll back and forth through your 4 "page" view controllers.
I have a UICollectionView filled with dates ranging from one date to another. I have implemented the UICollectionView with IGListKit. I would Like to enable paging on each cell so that each cell will land in the middle of the circle when it scrolls past it. (Like below) I have tried a few ways of paging, but these don't centre directly in the middle of the circle (As seen in the second image). What is happening is, the cells are getting paged to the left-hand side, I would like there to be an inset of 20 so that it fits into the circle
To enable the current date to show on the left-hand side in the circle when the view first loads, I have the semantic set to Force Right-to-Left and I also have edgeInsets which are:
left: screenWidth-62, right: 20)
The width of the cell is 42 and the inset at the side is 20, therefore the first cell will sit in the circle with these insets. So when the view first loads, the collection view looks like this:
I basically want each cell to land inside of this circle when it scrolls past (if the scrolling stops)
This is what I have so far:
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
if scrollView == self.collectionView {
var currentCellOffset = self.collectionView.contentOffset
currentCellOffset.x += (self.collectionView.frame.width / 2) + 20
if let indexPath = self.collectionView.indexPathForItem(at: currentCellOffset) {
self.collectionView.scrollToItem(at: indexPath, at: .centeredHorizontally, animated: true)
}
}
}
and this:
collectionView.decelerationRate = UIScrollView.DecelerationRate.fast
Does anyone know how to solve this?
Thank you
i created a custom collection view layout for paging by cell instead of screen
i also outline a few different ways to customize it with examples in the README
check it out here
let me know if you have any questions about it or need more help
Using Xcode 10, iOS 11.4+, Swift 4
I have a series of UIViewControllers that I am navigating through,
each of which is being placed into a ContainerView.
Based on which VC is pushed, I am hiding/showing the Top or Bottom views (shown in gray) in the Main Controller while the ContainerView is always in the middle (light blue).
What I would like to do is set the constraints so that the ContainerView is appropriately sized when the Top or Bottom views are shown/hidden.
For example, when the "Main Menu" is shown, the ContainerView should fill the entire Main Container view (Top and Bottom views will be hidden)
When "Item1" is shown, the Top view will be shown and the Bottom view hidden. Therefore, ContainerView should fill the Main Container view left, right, and bottom, but the ContainerView Top should be constrained to the Top view bottom.
When "Item5" is shown, the Top and Bottom views will also be shown.
Therefore, ContainerView should fill Main Container view left, right, and be constrained to the Top view bottom, and the Bottom view top (as shown in the Main Container)
I've tried using code like this to fill the entire Main view:
NSLayoutConstraint.activate([
ContainerView.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: 0),
ContainerView.rightAnchor.constraint(equalTo: self.view.rightAnchor, constant: 0),
ContainerView.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 0),
ContainerView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: 0)
])
However, the ContainerView never changes, and Xcode gives me a lot of warnings like:
[LayoutConstraints] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one
you don't want.
Here's another screenshot from the Storyboard:
Here's a link to download my sample project:
https://gitlab.com/whoit/containerviews
How can I correctly modify the constraints to accomplish this?
As I've mentioned in the comment, you should have used UIStackView for your top / bottom views visibility controlling.
You will need a UIStackView with following attributes:
Axis: Vertical
Alignment: Fill
Distribution: Fill
Spacing: As per your need
The stack view will contain the Top View, Container View and Bottom View respectively as its sub views.
You need to pin all the sides (leading, trailing, top & bottom) of this stack view to its superview (view controller's view). And as you need some height constraints for your top & bottom view, you give them as your need.
So basically your stack view is now capable of resizing its sub views when you hide any of them. You just need to perform:
theSubViewNeedsTobeHidden.isHidden = true
I've made a working demo for you that can be found here.
Issues
1) You're adding new constraints all the time, as this lines create a new constraints, each time they're getting called:
ContainerView.leftAnchor.constraint(equalTo: self.view.leftAnchor, constant: 0)
2) In the beginning, the MainContainerView is not constraint at all
Solution
I would suggest following:
add those four constraints in the storyboard instead
create IBOutlets for the height-constraints of your top and bottom views.
set the constants of those to 0 (when hiding them)
(optional) for sure you can still fade them in/out by setting their alpha as well, and then add the height constant to the completion block.
Note:
Hidden views (alpha = 0 or isHidden = true) are still taken into account for layouting. That means, your constraints are still valid, when the views are hidden. But to make them look like hidden for the layouting as well, you'll then have to set theirs height constants to 0.
Code
#objc func hideControlViews(_ notification: Notification){
let userInfo = notification.userInfo! as! [String : Bool]
//print("Got top view notification: \(String(describing: userInfo["hide"]))")
if (userInfo["hidetop"]!) {
self.topViewHeightConstraint.constant = 0
} else {
self.topViewHeightConstraint.constant = 64
}
if (userInfo["hidebottom"]!) {
self.bottomViewHeightConstraint.constant = 0
} else {
self.bottomViewHeightConstraint.constant = 108
}
self.view.layoutIfNeeded()
}
In one of my controllers I'm using UICollectionView with two-sided cells (there is a button on the face side of the cell, and if user is tapping it cell should show him/her the other side of the cell).
so I have this in my cell class:
firstView = UIView()
...
self.addSubview(firstView)
infoView = UIView()
...
self.insertSubview(infoView, belowSubview: firstView)
Both views have a lot of elements in them, for structuring these elements I'm using mostly Visual Format constraints and anchors.
i.e.
let topFirstViewConstraint = firstView.topAnchor.constraint(equalTo: self.topAnchor, constant: 4)
allConstraints.append(topFirstViewConstraint)
...
let goButtonCenter = goButton.centerXAnchor.constraint(equalTo: firstView.centerXAnchor, constant: 0)
allConstraints.append(goButtonCenter)
For switching between face and rear views I'm using UIView.transition:
UIView.transition(from: firstView, to: infoView, duration: 0.2, options: .transitionFlipFromLeft) { (success) in
}
It works like a charm, I don't have any autoLayout errors at all.
But if I'm trying to switch from firstView to infoView firstView constraints goes wild and vice versa (I still don't have any errors but I know how these views should look, and it's a mess). I've tried to use self.updateConstraints() in transition closure but it doesn't work.
Did anyone experience something like that?
https://developer.apple.com/documentation/uikit/uiview/1622562-transition says:
fromView: The starting view for the transition. By default, this view is removed from its superview as part of the transition.
What happens with constraints when one party of a constraint gets removed from superview? It definitely doesn‘t work anymore.
What you can try
Discussion:
This method provides a simple way to transition from the view in the fromView parameter to the view in the toView parameter. By default, the view in fromView is replaced in the view hierarchy by the view in toView. If both views are already part of your view hierarchy, you can include the showHideTransitionViews option in the options parameter to simply hide or show them.
I need to do this app that has a weird configuration.
As shown in the next image, the main view is a UIScrollView. Then inside it should have a UIPageView, and each page of the PageView should have a UITableView.
I've done all this so far. But my problem is that I want the scrolling to behave naturally.
The next is what I mean naturally. Currently when I scroll on one of the UITableViews, it scrolls the tableview (not the scrollview). But I want it to scroll the ScrollView unless the scrollview cannot scroll cause it got to its top or bottom (In that case I'd like it to scroll the tableview).
For example, let's say my scrollview is currently scrolled to the top. Then I put my finger over the tableview (of the current page being shown) and start scrolling down. I this case, I want the scrollview to scroll (no the tableview). If I keep scrolling down my scrollview and it reaches the bottom, if I remove my finger from the display and put it back over the tebleview and scroll down again, I want my tableview to scroll down now because the scrollview reached its bottom and it's not able to keep scrolling.
Do you guys have any idea about how to implement this scrolling?
I'm REALLY lost with this. Any help will be greatly appreciate it :(
Thanks!
The solution to simultaneously handling the scroll view and the table view revolves around the UIScrollViewDelegate. Therefore, have your view controller conform to that protocol:
class ViewController: UIViewController, UIScrollViewDelegate {
I’ll represent the scroll view and table view as outlets:
#IBOutlet weak var scrollView: UIScrollView!
#IBOutlet weak var tableView: UITableView!
We’ll also need to track the height of the scroll view content as well as the screen height. You’ll see why later.
let screenHeight = UIScreen.mainScreen().bounds.height
let scrollViewContentHeight = 1200 as CGFloat
A little configuration is needed in viewDidLoad::
override func viewDidLoad() {
super.viewDidLoad()
scrollView.contentSize = CGSizeMake(scrollViewContentWidth, scrollViewContentHeight)
scrollView.delegate = self
tableView.delegate = self
scrollView.bounces = false
tableView.bounces = false
tableView.scrollEnabled = false
}
where I’ve turned off bouncing to keep things simple. The key settings are the delegates for the scroll view and the table view and having the table view scrolling being turned off at first.
These are necessary so that the scrollViewDidScroll: delegate method can handle reaching the bottom of the scroll view and reaching the top of the table view. Here is that method:
func scrollViewDidScroll(scrollView: UIScrollView) {
let yOffset = scrollView.contentOffset.y
if scrollView == self.scrollView {
if yOffset >= scrollViewContentHeight - screenHeight {
scrollView.scrollEnabled = false
tableView.scrollEnabled = true
}
}
if scrollView == self.tableView {
if yOffset <= 0 {
self.scrollView.scrollEnabled = true
self.tableView.scrollEnabled = false
}
}
}
What the delegate method is doing is detecting when the scroll view has reached its bottom. When that has happened the table view can be scrolled. It is also detecting when the table view reaches the top where the scroll view is re-enabled.
I created a GIF to demonstrate the results:
Modified Daniel's answer to make it more efficient and bug free.
#IBOutlet weak var scrollView: UIScrollView!
#IBOutlet weak var tableView: UITableView!
#IBOutlet weak var tableHeight: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
//Set table height to cover entire view
//if navigation bar is not translucent, reduce navigation bar height from view height
tableHeight.constant = self.view.frame.height-64
self.tableView.isScrollEnabled = false
//no need to write following if checked in storyboard
self.scrollView.bounces = false
self.tableView.bounces = true
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 20
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let label = UILabel(frame: CGRect(x: 0, y: 0, width: tableView.frame.width, height: 30))
label.text = "Section 1"
label.textAlignment = .center
label.backgroundColor = .yellow
return label
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = "Row: \(indexPath.row+1)"
return cell
}
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView == self.scrollView {
tableView.isScrollEnabled = (self.scrollView.contentOffset.y >= 200)
}
if scrollView == self.tableView {
self.tableView.isScrollEnabled = (tableView.contentOffset.y > 0)
}
}
Complete project can be seen here:
https://gitlab.com/vineetks/TableScroll.git
After many trials and errors, this is what worked best for me. The solution has to solve two needs 1) determine who's scrolling property should be used; tableView or scrollView? 2) make sure that the tableView doesn't give authority to the scrollView until it has reached the top of it's table/content.
In order to see if the scrollview should be used for scrolling vs the tableview, i checked to see if the UIView right above my tableview was within frame. If the UIView is within frame, it's safe to say the scrollView should have authority to scroll. If the UIView is not within frame, that means that the tableView is taking up the entire window, and therefor should have authority to scroll.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.bounds.intersects(UIView.frame) == true {
//the UIView is within frame, use the UIScrollView's scrolling.
if tableView.contentOffset.y == 0 {
//tableViews content is at the top of the tableView.
tableView.isUserInteractionEnabled = false
tableView.resignFirstResponder()
print("using scrollView scroll")
} else {
//UIView is in frame, but the tableView still has more content to scroll before resigning its scrolling over to ScrollView.
tableView.isUserInteractionEnabled = true
scrollView.resignFirstResponder()
print("using tableView scroll")
}
} else {
//UIView is not in frame. Use tableViews scroll.
tableView.isUserInteractionEnabled = true
scrollView.resignFirstResponder()
print("using tableView scroll")
}
}
hope this helps someone!
None of the answers here worked perfectly for me. Each one had it's owned nuanced problem (needing to do a repeated swipe when one scrollview hit it's bottom, or the scroll indicator not looking correct, etc), so figured I'd throw in another answer.
Ole Begemann has a great write up on doing this exactly https://oleb.net/blog/2014/05/scrollviews-inside-scrollviews/
Despite being an old post, the concepts still apply to the current APIs. Additionally, there is a maintained (Xcode 9 compatible) Objective-C implementation of his approach https://github.com/eyeem/OLEContainerScrollView
If you are facing problem with the nested scrolling issue , here tis the simplest solution for it .
go to your design screen
select your scroll view and then disable bounce on scroll
if your view uses table view inside scroll view then disable bounce on scroll of the table view as well
run and check it is solved
check how to disable bounce on scroll of a scroll view
check how to disable bounce on scroll of a tableview view
I was struggling with this problem, too. There is a very simple solution.
In interface builder:
create simple ViewController
add a simple View, it will be our header, and constrain it to superview
it's the red view on the example below
I have added 12px from top, left and right, and set fixed height to 128px
embed a PageViewController, making sure it is constrained to the superview, and not the header
Now, here comes the fun part: for each page you add, make sure its tableView has an offset from top. Thats it. You can do if with this code, for example (assuming you use UITableViewController as a page):
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
let tables = viewControllers.compactMap { $0 as? UITableViewController }
tables.forEach {
$0.tableView.contentInset = UIEdgeInsets(top: headerView.bounds.height, left: 0, bottom: 0, right: 0)
$0.tableView.contentOffset = CGPoint(x: 0, y: -headerView.bounds.height)
}
}
No messy scroll inside scroll inside table view, no mangling with delegates, no duplicated scrolls, perfectly natural behavior. If you can't see the header, it is probably because of the tableView background color. You have to set it to clear, for the header to be visible from under the tableView.
I think there are two options.
Since you know the size of the scroll view and the main view, you are unable to tell whether the scroll view hit the bottom or not.
if (scrollView.contentOffset.y >= (scrollView.contentSize.height - scrollView.frame.size.height)) {
// reach bottom
}
So when it hit; you basically set
[contentScrollView setScrollEnabled:NO];
and other way around for your tableView.
The other thing, which is more precise I think, is to add Gesture to your views.
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(respondToTapGesture:)];
// Specify that the gesture must be a single tap
tapRecognizer.numberOfTapsRequired = 1;
// Add the tap gesture recognizer to the view
[self.view addGestureRecognizer:tapRecognizer];
// Do any additional setup after loading the view, typically from a nib
So when you add Gesture, you can simply control the active view by changing setScrollEnabled in the respondToTapGesture.
I found an awesome library
MXParallaxHeader
In Storyboard just set UIScrollView class to MXScrollView then magic happens.
I used this class to handle my UIScrollView when I embed a UIPageViewController container view. even you can insert a parallax header view for more detail.
Also, this library provides Cocoapods and Carthage
I attached an image below which represent UIViewHierarchy.
MXScrollView Hierarchy
SWIFT 5
I had some trouble using Vineet's answer for when I could not guarantee the scrollView content offset (Y) due to various different screen sizes. To resolve this, I changed the first trigger event of when the tableView's scroll gets enabled.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.bounds.contains(button.frame) {
tableView.isScrollEnabled = true
}
if scrollView == tableView {
self.tableView.isScrollEnabled = (tableView.contentOffset.y > 0)
}
}
The scrollView.bounds.contains will check if a given element's frame is FULLY within the scrollView's visible content. I set this to a button that I have below the tableView. You could set this to your tableVIew's frame instead if your only condition is that your tableView is fully visible.
I left the original implementation of when to disable the tableView's scroll and it works very well.
I tried the solution marked as the correct answer, but it was not working properly. The user need to click two times on the table view for scroll and after that I was not able to scroll the entire screen again. So I just applied the following code in viewDidLoad():
tableView.addGestureRecognizer(UISwipeGestureRecognizer(target: self, action: #selector(tableViewSwiped)))
scrollView.addGestureRecognizer(UISwipeGestureRecognizer(target: self, action: #selector(scrollViewSwiped)))
And the code below is the implementation of the actions:
func tableViewSwiped(){
scrollView.isScrollEnabled = false
tableView.isScrollEnabled = true
}
func scrollViewSwiped(){
scrollView.isScrollEnabled = true
tableView.isScrollEnabled = false
}
One easy trick, if you want to achieve it is replacing parent scrollview with normal container view.
Adding a pan gesture on container view, you can play with top constraint of first view to assign negative values. You can keep a check of page View's origin if it achieves to top you can start assigning that value on content offset of the pageView's child view. Until user achieves the table view in a state of top most view in container view, you can keep page tableView's scrolling disabled and allow scrolling manually by setting content offset.
So initially the page view height will be collapsed (or say out of screen) or less at bottom. Later on scrolling down it will expand to take more space.
Gesture will automatically stop responding if out of frames say on nav bar or other view outside container view.
Gestures are a key to user interactive transitions used in many apps. You can mimic scroll for a certain time with it.
In my case I'm using constraint for height like that:
self.heightTableViewConstraint.constant = self.tableView.contentSize.height
self.scrollView.contentInset.bottom = self.tableView.contentSize.height
Below code works great for me
As I wanted to show some header after some scroll and table view supposed to scroll
And in ViewDidLoad add
override func viewDidLoad() {
super.viewDidLoad()
mainScrollView.delegate = self
}
Change 265 to whatever number you want to stop upper scroll
extension AccountViewController: UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
print(notebookTableView.contentOffset.y)
if notebookTableView.contentOffset.y < 265 {
if notebookTableView.contentOffset.y > 0 {
mainScrollView.setContentOffset(notebookTableView.contentOffset, animated: false)
} else {
mainScrollView.setContentOffset(CGPoint(x: 0.0, y: 0.0), animated: false)
}
} else {
mainScrollView.setContentOffset(CGPoint(x: 0.0, y: 265), animated: false)
}
}
}
CGFloat tableHeight = 0.0f;
YourArray =[response valueForKey:#"result"];
tableHeight = 0.0f;
for (int i = 0; i < [YourArray count]; i ++) {
tableHeight += [self tableView:self.aTableviewDoc heightForRowAtIndexPath:[NSIndexPath indexPathForRow:i inSection:0]];
}
self.aTableviewDoc.frame = CGRectMake(self.aTableviewDoc.frame.origin.x, self.aTableviewDoc.frame.origin.y, self.aTableviewDoc.frame.size.width, tableHeight);
Maybe brute-force, but working perfectly if cell heights are the same: by the way, I use auto layout.
for the tableView (or collectionView or whatever), set an arbitrary height in storyboard, and make an outlet to class. Wherever appropriate, (viewDidLoad() or...) set the tableView's height big enough so that tableView doesn't need to scroll. (need to know the number of rows in advance) Then only the outer scrollView will scroll nicely.