I have a tableView between a label which is on top (constraints: align center x, align top to 20).
A button is on the bottom (constraints: align center x, align bottom to 50).
And the tableView is aligned between those two objects by top/bottom to 20.
I am trying to read out the height of the tableView, because depending which device I use the height should differ?
But if I use in my code the following, I always get the same height for the tableView.
The print result is always 616.
What am I missing/not understanding correctly?
#IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
print(tableView.frame.size.height)
}
Try this method
override func viewWillLayoutSubviews() {
super.viewDidLayoutSubviews()
print(tableView.frame.size.height)
}
The reason that you see two different values printed is because this method is called right after viewdidload and once again after all the auto layout or auto resizing calculations on the views have been applied. Meaning the method viewDidLayoutSubviews is called every time the view size changes and the view layout has been recalculated.
For more info on this refer to
Apple documentation on viewdidlayoutsubviews
try getting your height in
override func viewWillLayoutSubviews() {
print(tableView.frame.size.height)
}
When your view controller is created from a storyboard, all initial frames are equal to your storyboard selected ones, so they will be correct only to device selected in the storyboard
First time you can access real frames is after first layoutSubviews, so you need this:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
print(tableView.frame.size.height)
}
Check out more about view lifecycle here
p.s. newer forget to call super. method when you're overriding something, you may break something easily. Unless the documentation says so or you're really knowing what you're doing
I'm working with Cocoa and I create my views in code (no IB) and I'm hitting an issue with NSSplitView.
I have a NSSplitView that I configure in the following way in my view controller, in Swift:
override func viewDidLoad() {
super.viewDidLoad()
let splitView = NSSplitView()
splitView.isVertical = true
splitView.addArrangedSubview(self.createLeftPanel())
splitView.addArrangedSubview(self.createRightPanel())
splitView.adjustSubviews()
self.view.addSubview(splitView)
...
}
The resulting view shows the two subviews and the divider for the NSSplitView, and one view is wider than the other. When I drag the diver to change the width, as soon as I release the mouse, the divider goes back to its original position, as if pulled back by a "spring".
I can't resize the two subviews; the right one always keeps a fixed size. However, nowhere in the code I fix the width of that subview, or any of its content, to a constant.
What I would like to achieve instead is that the right view size is not fixed, and that if I drag the divider at halfway through, the subviews will resize accordingly and end up with the same width.
This is a screen recording of the problem:
Edit: here is how I set the constraints. I'm using Carthography, because otherwise setting constraints in code is extremely verbose beyond the most simple cases.
private func createLeftPanel() -> NSView {
let view = NSView()
let table = self.createTable()
view.addSubview(table)
constrain(view, table) { view, table in // Cartography magic.
table.edges == view.edges // this just constraints table.trailing to
// view.trailing, table.top to view.top, etc.
}
return view
}
private func createRightPanel() -> NSView {
let view = NSView()
let label = NSTextField(labelWithString: "Name of item")
view.addSubview(label)
constrain(view, label) { view, label in
label.edges == view.edges
}
return view
}
I wanted a sheet to be attached to the bottom edge of its parent window, so that I could still see the top part of the parent's content. I show it in the usual way in the parent's view controller.
#IBAction func clickShowSheet(_ sender: NSButton) {
mySheet = MySheetController(windowNibName: "MySheet")
view.window!.beginSheet(mySheet.window!,
completionHandler: {response in
print(response == NSModalResponseOK ? "OK" : "Cancel")
self.mySheet = nil
})
}
To attach it to the bottom edge I implement the parent window's delegate method:
func window(_ window: NSWindow, willPositionSheet sheet: NSWindow, using rect: NSRect) -> NSRect {
var rect = rect
rect.origin.y = sheet.frame.size.height + 15
return rect
}
The effect is satisfactory, tho' I'd like the animation to work the other way.
I also want the sheet to be resizable, so have left the checkbox in the nib on. Resizing by dragging a side is great: the sheet stays centred. The top edge can't be dragged, which would make sense if the sheet was at the top of its window, but the bottom edge can be dragged, leaving the sheet somewhere in the middle. I can make it spring back by implementing windowDidEndLiveResize. It looks silly. So what I need to know is, is there a way to enable/disable dragging of a particular edge?
Pass this as a prop if you are using spring bottom sheet.
blocking={false}
I'm completely new to tvos and I'm trying to implement a UISearchController view where, in my SearchResultsViewController, I have two UICollectionViews displayed one above the other:
The problem is that when the user swipes down to select one of the items in the UICollectionView, the keyboard doesn't dismiss. Even swiping back up to select the keyboard doesn't fully scroll up and it's impossible to see what you're typing. The resulting view is this:
Ideally, I'd like to dismiss the keyboard when the user swipes down to focus on anything else in the interface. I looked at Apple's tvos UIKit Catalog and their example shows a UISearchController which dismisses the keyboard when changing focus, but I don't see that they're doing anything differently.
Here is the code I'm using to setup my UISearchController when the user clicks on a button:
#IBAction func onSearchButton(sender: AnyObject) {
guard let resultsController = storyboard?.instantiateViewControllerWithIdentifier(SearchResultsViewController.storyboardID) as? SearchResultsViewController else { fatalError("Unable to instantiate a SearchResultsViewController.") }
// Create and configure a `UISearchController`.
let searchController = UISearchController(searchResultsController: resultsController)
searchController.searchResultsUpdater = resultsController
searchController.hidesNavigationBarDuringPresentation = false
let searchPlaceholderText = NSLocalizedString("Search for a Show or Movie", comment: "")
searchController.searchBar.placeholder = searchPlaceholderText
// Present the search controller from the root view controller.
guard let rootViewController = view.window?.rootViewController else { fatalError("Unable to get root view controller.") }
rootViewController.presentViewController(searchController, animated: true, completion: nil)
}
After quite a bit of trial and error, I was able to figure out the solution.
The keyboard will automatically dismiss itself as long as:
1) The item the user focuses on is inside of a scrollview
2) The scrollview content size is larger than the screen height by at least 1px (1081px).
After quite a lot of trial and error, finally I figured out.
The reason is that you have nested ScrollViews in searchResultsController.
"ScrollViews" of-course includes UICollectionView, UITableView, and UIScrollView.
According to my investigation, UISearchController behaves as follows.
If the first view which gets focused in searchResultsController is subview of the inner scrollView (which is the horizontal UICollectionView, in your case), then you won't get keyboard hidden as expected.
Interestingly, if the first view which gets focused in searchResultsController is subview of outer scrollView, then you will get keyboard hidden completely, animated, just as expected (!).
I think this is sort of UIKit's bug.
I had exactly same layout and wasn't able to achieve this so far. I believe you return false in tableView(tableView: UITableView, canFocusRowAtIndexPath indexPath: NSIndexPath) -> Bool so that each cells in collection view can scroll horizontally with proper focus behavior. I think it's actually causing the issues. If you make the first cell in the tableview focusable the problem goes away but of course focus behavior is not desired. I just found that out today and will try more tomorrow to find out what I can do about this. I sense that I will need a new design that allows me to use a single collectionview or tableview that has its cells focusable in resultsController. Hope this is easily achievable in tvOS 10.
Work Around Solution: Add one dummy cell at indexPath.row == 0 with height as 1 pixel and enable the focus on it.
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.