I have a form in a Mac app that needs to scroll. I have a scrollView embedded in a ViewController. I have the scrollView assigned with an identifier that links it to its own NSScrollView file. The constraints are set to the top, right, and left of the view controller, it also has the hight constraint set to the full height of the ViewController.
Here is my code:
import Cocoa
class ScrollView: NSScrollView {
override func draw(_ dirtyRect: NSRect) {
super.draw(dirtyRect)
// Drawing code here.
NSRect documentView.NSMakeSize(0, 0, 1058.width, 1232.height)
}
override func scrollWheel(with event: NSEvent) {
switch event.phase {
case NSEvent.Phase.began:
Swift.print("Began")
// case NSEvent.Phase.changed:
// Swift.print("Changed")
case NSEvent.Phase.ended:
Swift.print("Ended")
default:
break
}
switch event.momentumPhase {
case NSEvent.Phase.began:
Swift.print("Momentum Began")
// case NSEvent.Phase.changed:
// Swift.print("Momentum Changed")
case NSEvent.Phase.ended:
Swift.print("Momentum Ended")
default:
break
}
super.scrollWheel(with: event)
}
I cant seem to get my app to scroll at all. I think I am not setting the frame correctly. What is the best way to do set the frame correctly? Am I coding the NSScrollView correctly?
I think you are making your life very hard because you are doing things that are not exactly recommended by Apple. First of all, you should not subclass NSScrollView. Rather you should read first Introduction to Scroll View Programming Guide for Cocoa by Apple to understand how you should create the correct hierarchy of views for an NSScrollView to work correctly.
A second recommendation is for you to check this nice article about how you should set up an NSScrollView in a playground, so that you can play with the code you want to implement.
Third, using Autolayout and NSScrollView has caused a lot of grief to a lot of people. You need to set up the AutoLayout just right, so that everything is going to work as expected. I recommend that you check this answer by Ken Thomases, which clearly explains how you need to set up auto layout constraints for an NSScrollView to work properly.
I just got over the "hump" with a NSScrollView inside a NSWindow. In order for scrolling to occur the view inside the NSScrollview needs to be larger than the content window. That's hard to set with dynamic constraints. Statically setting the inner view to a larger width/height than the window "works" but the static sizes usually are not what you want.
Here is my interface builder view hierarchy and constraints, not including the programmatically added boxes
In my app the user is adding "boxes" (custom draggable views) inside the mainView, which is inside a scrollview in a NSwindow.
Here's the functionality I wanted:
If I expanded the NSWindow, I wanted the mainView inside the scrollview to expand to fill the whole window. No scrolling needed in this case if all the boxes are visible.
If I shrank the NSWindow, I wanted the mainView inside the scrollview to shrink just enough to include all my mainView subviews ("boxes"), but not any further (i added a minBorder of 20). This results in scrolling if a box's position is further right/up than the nswindow's width/height.
I found the trick is to calculate the size of the mainView I want based on the max corner of each draggable boxview, or the height/width of the content frame of the nswindow, whichever is larger.
Below is my code, including some debugging prints.
Be careful of which subviews you use to calculate the max size. If you include a subview that's dynamically attached to the right/top of the window, then your window will never shrink. If you add +20 border to that, you might infinite loop. Not a problem in my case.
extension MapWindowController: NSWindowDelegate {
func windowDidEndLiveResize(_ notification: Notification) {
if let frame = window?.frame, let content = window?.contentRect(forFrameRect: frame) {
print("window did resize \(frame)")
var maxX: CGFloat = content.width
var maxY: CGFloat = content.height
for view in mainView?.subviews ?? [] {
let frameMaxX = view.frame.maxX + minBorder
let frameMaxY = view.frame.maxY + minBorder
if frameMaxX > maxX {
maxX = frameMaxX
}
if frameMaxY > maxY {
maxY = frameMaxY
}
}
print("view maxX \(maxX) maxY \(maxY)")
print("window width \(content.width) height \(content.height)")
mainView?.setFrameSize(NSSize(width: maxX, height: maxY))
}
}
}
I'm trying to animate a collectionview by using layout constraints however I cannot get it to work. I have a collectionview that takes up the entire screen and on a button tap I want to essentially move the collectionview up to make room for another view to come in from the bottom - see image below
The incoming UIView animates just fine (the view coming up from the bottom) - The reason I want to move the collectionview is that the incoming UIView obscures the collection view so am just trying to move the collectionview up at the same time as the new view so that all of the content in the collectionview can be displayed without being hidden by the new view - I use a reference view to get the right layout constraints for the final position for the collectionview Image to show what I am trying to achieve Am I going about it the right way?
Nothing happens with the code example below and I am not sure where to go from here - the same approach is used for animating the incoming view and works just fine but doesn't seem to work for the collectionview...
Any help would be kindly appreciated
var colViewBottomToReferenceTop: NSLayoutConstraint?
var colViewBottomToViewBottom: NSLayoutConstraint?
override func viewDidLoad() {
super.viewDidLoad()
colViewBottomToReferenceTop = musicCollectionView.bottomAnchor.constraint(equalTo: referenceView.topAnchor)
colViewBottomToViewBottom = musicCollectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
NSLayoutConstraint.active([colViewBottomToViewBottom!])
NSLayoutConstraint.deactivate([colViewBottomToReferenceTop!])
}
func playerShow() {
NSLayoutConstraint.activate([colViewBottomToReferenceTop!])
UIView.animate(withDuration: 0.5, animations: {
self.view.layoutIfNeeded()
})
}
#IBAction func btnTapped(_ sender: UIButton) {
playerShow()
}
You want to deactivate the other before animation
NSLayoutConstraint.deactivate([colViewBottomToViewBottom!])
NSLayoutConstraint.activate([colViewBottomToReferenceTop!])
Look to this Demo
I have an autolayouted UIView and need to know the width of it. How do I find the width the easiest way in Swift?
You can find the width of any view by
let width = yourView.bounds.width
If you have applied a width constraint to the view and you have an outlet for that constraint then you can find it by.
let width = yourWidthConstraint.constant
The right place to get the UIScreen frame data is in viewDidLayoutSubviews as it is called after the subViews have been laid out in screen also it is called after every time your device changes orientation such as your width will be different when your user goes into landscape mode.This is called after viewWillAppear:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
let viewWidth = self.myView.bounds.width
}
Inside implementation your view you can use
override func layoutSubviews() {
super.layoutSubviews()
// you can get width of view in this function
print(self.frame.size.width)
}
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.
When does the correct frame size of the UIView is calculated when I add my custom UIView by using storyboard?
I can't get correct frame size in UIView's init(frame: CGRect) or init(coder aDecoder: NSCoder) or awakeFromNib(). I get the correct size in override func layoutSubviews() but this time the view is not added to the view controller's view.
Edit:
I want to do this in the UIView subclass because I add a CAGradientLayer layer (which has same size with my view) to my custom UIView. There must be a better way than setting up the view in UIViewControllers viewDidLayoutSubviews method.
There are two vertical constraints (trailing and leading space to superview) that adjust the width of my custom view. But the width is 600 in the mentioned methods, not the screen width.
func viewWillAppear(_ animated: Bool)
This is called on the viewController after the view hierarchy is in place and the geometry is set up.
It is usually the best place to arrange geometry-dependent viewController code, and is called just before transition animations are run.
It is followed by a call to viewDidAppear which is called after transition animations have completed.
update
as you want to set this directly in a custom view (rather than in the viewController) the appropriate UIView function to override is layoutSubviews. Be sure to call super.layoutSubviews() in the override.
override func layoutSubviews() {
super.layoutSubviews()
//self.frame will be correct here
}
This will be called after the viewController's viewWillAppear and before viewDidAppear
update 2: collectionView cells
Collection view cells get their frame data from the collectionview's layout. When a cell needs to know it's geometry, you can override applyLayoutAttributes
func applyLayoutAttributes(_ layoutAttributes: UICollectionViewLayoutAttributes!)
One of the default layoutAttributes is the frame property. See also my comment below on how to extract the frame directly from collectionView.layout.
Since viewDidLayoutSubviews() is getting called multiple times, I'd recommend using the viewDidAppear() delegate.
viewDidLoad() is called before any frame was set.
viewDidLayoutSubviews() is called during frame sizing and will be called multiple times with different frame sizes (usually frameZero before a frame is calculated).
viewDidAppear() All frames are set.
You should have an IBOutlet to your UIView and in the viewDidLayoutSubviews() method, get the size by yourViewOutlet.frame.size.