I have the following layout:
UIImageView
UIView (with UILabel)
UITableView
As the tableView is scrolled up, the height of the imageView is decreased before actually scrolling the tableView. The following code is used for that:
let headerImageViewMaxHeight: CGFloat = 200
let headerImageViewMinHeight: CGFloat = UIApplication.shared.statusBarFrame.height
#IBOutlet var headerImageViewHeightConstraint: NSLayoutConstraint!
#IBOutlet var headerImageView: UIImageView!
#IBOutlet var subtitleView: UIView!
#IBOutlet var subtitleLabel: TextLabel!
private var contentOffsetDictionary: NSMutableDictionary!
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.isKind(of: UICollectionView.self) {
let horizontalOffset: CGFloat = scrollView.contentOffset.x
let collectionView: UICollectionView = scrollView as! UICollectionView
contentOffsetDictionary.setValue(horizontalOffset, forKey: collectionView.tag.description)
} else if scrollView == tableView {
let y: CGFloat = scrollView.contentOffset.y
let newHeaderImageViewHeight: CGFloat = headerImageViewHeightConstraint.constant - y
if newHeaderImageViewHeight > headerImageViewMaxHeight {
headerImageViewHeightConstraint.constant = headerImageViewMaxHeight
} else if newHeaderImageViewHeight < headerImageViewMinHeight {
headerImageViewHeightConstraint.constant = headerImageViewMinHeight
} else {
headerImageViewHeightConstraint.constant = newHeaderImageViewHeight
scrollView.contentOffset.y = 0
}
}
}
The following two images shown the current states of scrolled down or up:
Scrolled down (initial state).
Scrolled up.
As you can see, initially the grey bar saying To Table -> Table 1 is scrolled down and is about 60 high.
When it's scrolled up, it scrolles until the safeArea. What I want to achieve is that once it reaches the safe area, it continues scrolling up into the safeArea (top notch), while keeping the text in exactly the same place (topSpace to safeArea of the text should stay the same). So, basically growing the UIView to go into the safeArea.
This image shows the ViewController layout.
Header View can be ignored, as that is aligned to the top of the viewController, but no constraints to anything else than superView.
TopSpace of the view in question, is 0 to the UIImageView.
Changing headerImageViewMinHeight to 0, makes it scroll up to the actual top of the screen, without expanding it. So this seems like a good start, but needs some extra logic or constraints.
As the UIView doesn't have a specific height constraint, changing its UILabel's top space from = 16 to => 16, there's the warning of missing Y constraint or height.
Otherwise that, together with UILabel's top space to the viewController's safeArea of => 8 sounds like it could work.
Any ideas are welcome.
EDIT: The following picture basically shows what I want, except that here the UILabel's top is not aligned to the safe area.
What this picture shows is achieved by changing headerImageViewMinHeight to 0.
Add constriant
Uncheck constraint to margin
double click on Align bottom/ Align top
click on last baseline (for bottom)/ first baseline (for top constrraint)
DONE
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.
Numerous tutorials on animating AutoLayout constraints suggest to update constant property of a constraint and then call layoutIfNeeded() in animation block.
My situation is a bit tricky.
I have a view that houses 3 subviews. The height of this superview is not fixed - it is calculated as a sum of heights of its subviews.
On some event, I ask one of those 3 subviews to toggle its height (it changes between 0 and 30, i.e. I want to smoothly hide and show it).
The code is similar to this:
// In superview
subview1.isVisibleInContext = !subview1.isVisibleInContext
// In subview
class MySubview: UIView {
#IBOutlet var heightConstraint: NSLayoutConstraint!
var isVisibleInContext = false {
didSet {
updateHeight()
}
}
func toggleHeight() {
let newHeight = isVisibleInContext ? 30 : 0
layoutIfNeeded()
heightConstraint.constant = newHeight
UIView.animate(withDuration: 0.8) {
self.layoutIfNeeded()
}
}
}
Unfortunately, this does not work as I expect.
I can see the smooth change of the height of my subview, but the height of my superview is recalculated immediately after I set the new value for my subview height constraint.
I want to see the height of the superview gradually increasing/decreasing as on of its subviews grows or decreases.
Please someone point me in the right direction. Any help is appreciated.
Thanks a lot!
The animation block should be in the UIView that contains the 3 MySubviews. Inside the MySubview class you only update the height constraint's constant:
In Subview
func toggleHeight() {
let newHeight = isVisibleInContext ? 30 : 0
heightConstraint.constant = newHeight
}
Then in the UIView that contains the 3 MySubviews you animate the change:
In Superview
func toggleHeight(with subview: MySubview) {
subview.toggleHeight()
UIView.animate(withDuration: 0.8) {
self.view.layoutIfNeeded()
}
}
The first thing, that was incorrect in my approach was executing self.layoutIfNeeded(). Having investigated the issue I learned out that I had to execute it on the superivew, like this:
self.superview?.layoutIfNeeded()
That also didn't work out for a reason. The main issue in this case was that the view, which had 3 subviews inside was itself a subview of view. So to make it work I had to use the following code:
self.superview?.superview?.layoutIfNeeded()
Definitely not good that subview has to know the hierarchy of views, however it works.
I have a viewcontroller with 3 UIViews that are stacked on top of each other. By stacked I mean at the bottom of one view, the next view begins. I have placed vertical constraints between each view with constant = 0. When the application begins, in viewDidLoad, I'm adding 500 to the vertical constraint between the two top views, so the bottom two views are pushed down below by doing:
billViewBottomConstraint.constant = 500
I then call the following function to animate the two bottom views moving back up, ending right below the top view:
func animate()
{
self.billViewBottomConstraint.constant = 0
UIView.animate(withDuration: 2.0) {
self.view.layoutIfNeeded()
}
}
The views certainly animate to the right position, but not the way I want. It looks like before the views animate, they are expanded outwards and when the animation is called they contract up and inwards towards the right position.
Inside viewDidLoad, the layout is not ready to be animated. You should wait at least until viewDidLayoutSubviews to properly animate constraints. Check with a boolean to make sure it runs only for the first time.
fileprivate var firstLayoutSubviewsTime = true
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if firstLayoutSubviewsTime {
firstLayoutSubviewsTime = false
animate()
}
}
You should call view.layoutIfNeeded() before the animation block to make sure all views are loaded properly.
You should also modify the constant inside the animation block, not before it.
func animate() {
self.view.layoutIfNeeded()
UIView.animate(withDuration: 2.0) {
self.billViewBottomConstraint.constant = 0
self.view.layoutIfNeeded()
}
}
I have two subViews in ViewController that located one after another (bottom of first connected to the top of second)
First view is changing its height animated (example below), so I expected that second view will descend with animation too, but its not..
How to make it all animated?
Animation block for first view
func animate(){
layoutIfNeeded()
UIView.animateWithDuration(1){
self.labelHeight.constant = 70 // this is constraint
self.layoutIfNeeded()
}
}
Constraints between sibling views are added to their shared super view so you should call layoutIfNeeded() on it. For example:
func animate(){
self.superview?.layoutIfNeeded()
UIView.animateWithDuration(1){
self.labelHeight.constant = 70 // this is constraint
self.superview?.layoutIfNeeded()
}
}