I am looking for an effective way to re-position a popover using the new uipopoverpresentationcontroller. I have succesfully presented the popover, and now I want to move it without dismissing and presenting again. I am having trouble using the function:
(void)popoverPresentationController:(UIPopoverPresentationController *)popoverPresentationController
willRepositionPopoverToRect:(inout CGRect *)rect
inView:(inout UIView **)view
I know it's early in the game, but it anyone has an example of how to do this efficiently I would be grateful if you shared it with me. Thanks in advance.
Unfortunately this hacky workaround is the only solution I've found:
[vc.popoverPresentationController setSourceRect:newSourceRect];
[vc setPreferredContentSize:CGRectInset(vc.view.frame, -0.01, 0.0).size];
This temporarily changes the content size of the presented view, causing the popover and arrow to be repositioned. The temporary change in size is not visible.
It seems this is a problem Apple need to fix - changing the sourceView or sourceRect properties of UIPopoverPresentationController does nothing when it's already presenting a popover (without this workaround).
Hope this works for you too!
I had luck using containerView?.setNeedsLayout() and containerView?.layoutIfNeeded() after changing the sourceRect of the popoverPresentationController, like so:
func movePopoverTo(_ newRect: CGRect) {
let popover = self.presentedViewController as? MyPopoverViewController {
popover.popoverPresentationController?.sourceRect = newRect
popover.popoverPresentationController?.containerView?.setNeedsLayout()
popover.popoverPresentationController?.containerView?.layoutIfNeeded()
}
}
And even to have a popover follow a tableView cell without having to change anything:
class MyTableViewController: UITableViewController {
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "MyPopoverSegue" {
guard let controller = segue.destination as? MyPopoverViewController else { fatalError("Expected destination controller to be a 'MyPopoverViewController'!") }
guard let popoverPresentationController = controller.popoverPresentationController else { fatalError("No popoverPresentationController!") }
guard let rowIndexPath = sender as? IndexPath else { fatalError("Expected sender to be an 'IndexPath'!") }
guard myData.count > rowIndexPath.row else { fatalError("Index (\(rowIndexPath.row)) Out Of Bounds for array (count: \(myData.count))!") }
if self.presentedViewController is MyPopoverViewController {
self.presentedViewController?.dismiss(animated: false)
}
popoverPresentationController.sourceView = self.tableView
popoverPresentationController.sourceRect = self.tableView.rectForRow(at: rowIndexPath)
popoverPresentationController.passthroughViews = [self.tableView]
controller.configure(myData[rowIndexPath.row])
}
super.prepare(for: segue, sender: sender)
}
}
// MARK: - UIScrollViewDelegate
extension MyTableViewController {
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
if let popover = self.presentedViewController as? MyPopoverViewController {
popover.popoverPresentationController?.containerView?.setNeedsLayout()
popover.popoverPresentationController?.containerView?.layoutIfNeeded()
}
}
}
I used the same method as mentioned in another answer by #Rowan_Jones, however I didn't want the popover's size to actually change. Even by fractions of a point. I realized that you can set the preferredContentSize multiple times back to back, but visually it's size will only change to match the last value.
[vc.popoverPresentationController setSourceRect:newSourceRect];
CGSize finalDesiredSize = CGSizeMake(320, 480);
CGSize tempSize = CGSizeMake(finalDesiredSize.width, finalDesiredSize.height + 1);
[vc setPreferredContentSize:tempSize];
[vc setPreferredContentSize:finalDesiredSize];
So even if finalDesiredSize is the same as your initial preferredContentSize this will cause the popover to be updated, even though it's size doesn't actually change.
Here is an example for how to recenter the popover:
- (void)popoverPresentationController:(UIPopoverPresentationController *)popoverPresentationController willRepositionPopoverToRect:(inout CGRect *)rect inView:(inout UIView **)view {
*rect = CGRectMake((CGRectGetWidth((*view).bounds)-2)*0.5f,(CGRectGetHeight((*view).bounds)-2)*0.5f, 2, 2);
I have also used this method to ensure that the popover moved to the correct location after moving by setting the *rect and the *view to the original sourceRect and sourceView.
As an additional note, I don't believe that this method is called when the popover's source is set using a bar button item.
I'm posting this because I don't have enough points to vote or comment. :)
#turbs's answer worked for me perfectly. It should be the accepted answer.
Setting *rect to the rect you need in the delegate method:
(void)popoverPresentationController:(UIPopoverPresentationController *)popoverPresentationController
willRepositionPopoverToRect:(inout CGRect *)rect
inView:(inout UIView **)view
iOS 12.3
[vc.popoverPresentationController setSourceRect:newSourceRect];
[vc.popoverPresentationController.containerView setNeedsLayout];
Related
I am searching for a way to detect whenever the NSStatusBarButton is right-clicked (using Swift) and call an action.
I am currently setting it up this way:
let statusItem = NSStatusBar.systemStatusBar().statusItemWithLength(-1)
func applicationDidFinishLaunching(aNotification: NSNotification) {
// Insert code here to initialize your application
if let button = statusItem.button {
button.image = NSImage(named: "myImage")
button.alternateImage = NSImage(named: "myImage")
button.action = Selector("myAction")
}
}
I thought of using the button.rightMouseDown(<#theEvent: NSEvent#>) (Because there is no such "alternateAction") but unfortunately I did not manage to come up with something due to the fact that I just started programming Mac apps.
Update:
While searching for a way to do this I saw some threads telling to subclass a NSView but I don't se how this should work (This could be because I am really new to programming and don't even know how to "subclass"). Still I thought there was some easier way to use this since nearly every statusBar App that I know rects on right-clicks.
You can subclass and override the mouseDown method, but since Mac OS X 10.10 (Yosemite), there has been an easier way: NSGestureRecognizer and its subclasses:
func applicationDidFinishLaunching(aNotification: NSNotification) {
// Insert code here to initialize your application
if let button = statusItem.button {
button.image = NSImage(named: "myImage")
button.alternateImage = NSImage(named: "myImage")
button.action = Selector("myAction")
// Add right click functionality
let gesture = NSClickGestureRecognizer()
gesture.buttonMask = 0x2 // right mouse
gesture.target = self
gesture.action = "myRightClickAction:"
button.addGestureRecognizer(gesture)
}
}
func myRightClickAction(sender: NSGestureRecognizer) {
if let button = sender.view as? NSButton {
// Handle your right click event here
}
}
I had the same problem as you with the accepted answer's method: it didn't work for buttonMask 0x2, only buttonMask 0x1. Regular NSButtons (but not NSStatusBarButtons) can handle NSClickGestureRecognizers, so perhaps that's what the answerer was thinking. Another solution I found suggested was to set the NSStatusItem's view to an instance of your own custom subclass of NSView, but as of OS X v10.10, getting or setting view is deprecated, so I didn't want to do that.
I solved this by adding a custom subclass of NSView as a subview of the NSStatusItem's button. My NSView implements -rightMouseUp: to receive the right mouse up event and then just passes that event to a block given to it by my class that wants to handle the right mouse click event.
Here's my custom subclass:
#import <Cocoa/Cocoa.h>
#interface TTRightClickDetector : NSView
#property (copy) void (^onRightMouseClicked)(NSEvent *);
#end
#import "TTRightClickDetector.h"
And the implementation:
#implementation TTRightClickDetector
- (void)rightMouseUp:(NSEvent *)theEvent
{
if(self.onRightMouseClicked)
{
self.onRightMouseClicked(theEvent);
}
}
#end
And here's how I use it:
self.statusItem = [[NSStatusBar systemStatusBar] statusItemWithLength:NSSquareStatusItemLength];
NSStatusBarButton *button = self.statusItem.button;
button.image = [NSImage imageNamed:#"image"];
button.action = #selector(leftMouseClicked:);
TTRightClickDetector *rightClickDetector = [[TTRightClickDetector alloc] initWithFrame:button.frame];
rightClickDetector.onRightMouseClicked = ^(NSEvent *event){
[self rightMouseClicked];
};
[button addSubview:rightClickDetector];
The swift version of commanda's answer (subclassing an NSView and implementing mouseDown).
NSView Subclass:
class RightMouseHandlerView: NSView {
var onRightMouseDown: (()->())? = nil
override func rightMouseDown(with event: NSEvent) {
super.rightMouseDown(with: event)
if onRightMouseDown != nil {
onRightMouseDown!()
}
}
}
Then adding it to the status bar button and setting the code block:
statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.squareLength)
if let button = statusItem.button {
let rmhView = RightMouseHandlerView(frame: statusItem.button!.frame)
rmhView.rightMouseDown = {
// Do something when right mouse down on button
}
button.addSubview(rmView)
}
I am working on Xcode 6.1.1 on OSX 10.10. I am trying out storyboards for Mac apps. I have a NSTabViewController using the new NSTabViewControllerTabStyleToolbar tabStyle and it is set as the default view controller for the window controller. How do I make my window resize according to the current selected view controller?
Is it possible to do entirely in Interface Builder?
Here is what my storyboard looks like:
The auto layout answer is half of it. You need to set the preferredContentSize in your ViewController for each tab to the fitting size (if you wanted the tab to size to the smallest size satisfying all constraints).
override func viewWillAppear() {
super.viewWillAppear()
preferredContentSize = view.fittingSize
}
If your constraints are causing an issue below try first with a fixed size, the example below sets this in the tab item's view controller's viewWillAppear function (Swift used here, but the Objective-C version works just as well).
override func viewWillAppear() {
super.viewWillAppear()
preferredContentSize = NSSize(width: 400, height: 280)
}
If that works, fiddle with your constraints to figure out what's going on
This solution for 'toolbar style' tab view controllers does animate and supports the nice crossfade effect. In the storyboard designer, add 'TabViewController' in the custom class name field of the NSTabViewController. Don't forget to assign a title to each viewController, this is used as a key value.
import Cocoa
class TabViewController: NSTabViewController {
private lazy var tabViewSizes: [String : NSSize] = [:]
override func viewDidLoad() {
// Add size of first tab to tabViewSizes
if let viewController = self.tabViewItems.first?.viewController, let title = viewController.title {
tabViewSizes[title] = viewController.view.frame.size
}
super.viewDidLoad()
}
override func transition(from fromViewController: NSViewController, to toViewController: NSViewController, options: NSViewController.TransitionOptions, completionHandler completion: (() -> Void)?) {
NSAnimationContext.runAnimationGroup({ context in
context.duration = 0.5
self.updateWindowFrameAnimated(viewController: toViewController)
super.transition(from: fromViewController, to: toViewController, options: [.crossfade, .allowUserInteraction], completionHandler: completion)
}, completionHandler: nil)
}
func updateWindowFrameAnimated(viewController: NSViewController) {
guard let title = viewController.title, let window = view.window else {
return
}
let contentSize: NSSize
if tabViewSizes.keys.contains(title) {
contentSize = tabViewSizes[title]!
}
else {
contentSize = viewController.view.frame.size
tabViewSizes[title] = contentSize
}
let newWindowSize = window.frameRect(forContentRect: NSRect(origin: NSPoint.zero, size: contentSize)).size
var frame = window.frame
frame.origin.y += frame.height
frame.origin.y -= newWindowSize.height
frame.size = newWindowSize
window.animator().setFrame(frame, display: false)
}
}
The window containing a toolbar style tab view controller does resize without any code if you have auto layout constraints in your storyboard tab views (macOS 11.1, Xcode 12.3). I haven't tried other style tab view controllers.
If you want to resize with animation as in Finder, it is sufficient to add one override in your tab view controller. It will resize the window with system-calculated resize animation time and will hide the tab view during resize animation:
class PreferencesTabViewController: NSTabViewController {
override func transition(from fromViewController: NSViewController, to toViewController: NSViewController, options: NSViewController.TransitionOptions = [], completionHandler completion: (() -> Void)? = nil) {
guard let window = view.window else {
super.transition(from: fromViewController, to: toViewController, options: options, completionHandler: completion)
return
}
let fromSize = window.frame.size
let toSize = window.frameRect(forContentRect: toViewController.view.frame).size
let widthDelta = toSize.width - fromSize.width
let heightDelta = toSize.height - fromSize.height
var toOrigin = window.frame.origin
toOrigin.x += widthDelta / 2
toOrigin.y -= heightDelta
let toFrame = NSRect(origin: toOrigin, size: toSize)
NSAnimationContext.runAnimationGroup { context in
context.duration = window.animationResizeTime(toFrame)
view.isHidden = true
window.animator().setFrame(toFrame, display: false)
super.transition(from: fromViewController, to: toViewController, options: options, completionHandler: completion)
} completionHandler: { [weak self] in
self?.view.isHidden = false
}
}
}
Please adjust closure syntax if you are using Swift versions older than 5.3.
Use autolayout. Set explicit size constraints on you views. Or once you have entered the UI into each tab view item's view set up the internal constraints such that they force view to be the size you want.
(Xcode6, iOS8, Swift, iPad)
I am trying to create a classic Web-like modal view, where the outside of the dialog box is "grayed-out." To accomplish this, I've set the alpha value of the backgroundColor of the view for the modal to 0.5, like so:
self.view.backgroundColor = UIColor.blackColor().colorWithAlphaComponent(0.5)
The only problem is that when the modal becomes full-screen, the presenting view is removed. (Ref Transparent Modal View on Navigation Controller).
(A bit irritated at the concept here. Why remove the underlying view? A modal is, by definition, to appear atop other content. Once the underlying view is removed, it's not really a modal anymore. it's somewhere between a modal and a push transition. Wa wa wa... Anyway..)
To prevent this from happening, I've set the modalPresentationStyle to CurrentContext in the viewDidLoad method of the parent controller, and in Storyboard... but no luck.
self.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
self.navigationController.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
How do I prevent the presenting view from being removed when the modal becomes full screen?
tyvm.. more info below.
Also in Storyboard, like so (Presentation: Current Context)
Thx for your help... documentation below:
First, remove all explicit setting of modal presentation style in code and do the following:
In the storyboard set the ModalViewController's modalPresentation style to Over Current context
Check the checkboxes in the Root/Presenting ViewController - Provide Context and Define Context.
They seem to be working even unchecked.
You can try this code for Swift:
let popup : PopupVC = self.storyboard?.instantiateViewControllerWithIdentifier("PopupVC") as! PopupVC
let navigationController = UINavigationController(rootViewController: popup)
navigationController.modalPresentationStyle = UIModalPresentationStyle.OverCurrentContext
self.presentViewController(navigationController, animated: true, completion: nil)
For swift 4 latest syntax using extension:
extension UIViewController {
func presentOnRoot(`with` viewController : UIViewController){
let navigationController = UINavigationController(rootViewController: viewController)
navigationController.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
self.present(navigationController, animated: false, completion: nil)
}
}
How to use:
let popup : PopupVC = self.storyboard?.instantiateViewControllerWithIdentifier("PopupVC") as! PopupVC
self.presentOnRoot(with: popup)
The only problem I can see in your code is that you are using CurrentContext instead of OverCurrentContext.
So, replace this:
self.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
self.navigationController.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
for this:
self.modalPresentationStyle = UIModalPresentationStyle.OverCurrentContext
self.navigationController.modalPresentationStyle = UIModalPresentationStyle.OverCurrentContext
This worked for me in Swift 5.0. Set the Storyboard Id in the identity inspector as "destinationVC".
#IBAction func buttonTapped(_ sender: Any) {
let storyboard: UIStoryboard = UIStoryboard(name: "Main", bundle: Bundle.main)
let destVC = storyboard.instantiateViewController(withIdentifier: "destinationVC") as! MyViewController
destVC.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
destVC.modalTransitionStyle = UIModalTransitionStyle.crossDissolve
self.present(destVC, animated: true, completion: nil)
}
The problem with setting the modalPresentationStyle from code was that you should have set it in the init() method of the presented view controller, not the parent view controller.
From UIKit docs: "Defines the transition style that will be used for this view controller when it is presented modally. Set
this property on the view controller to be presented, not the presenter. Defaults to
UIModalTransitionStyleCoverVertical."
The viewDidLoad method will only be called after you already presented the view controller.
The second problem was that you should use UIModalPresentationStyle.overCurrentContext.
The only way I able to get this to work was by doing this on the presenting view controller:
func didTapButton() {
self.definesPresentationContext = true
self.modalTransitionStyle = .crossDissolve
let yourVC = self.storyboard?.instantiateViewController(withIdentifier: "YourViewController") as! YourViewController
let navController = UINavigationController(rootViewController: yourVC)
navController.modalPresentationStyle = .overCurrentContext
navController.modalTransitionStyle = .crossDissolve
self.present(navController, animated: true, completion: nil)
}
I am updating a simple solution. First add an id to your segue which presents modal. Than in properties change it's presentation style to "Over Current Context". Than add this code in presenting view controller (The controller which is presenting modal).
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
let Device = UIDevice.currentDevice()
let iosVersion = NSString(string: Device.systemVersion).doubleValue
let iOS8 = iosVersion >= 8
let iOS7 = iosVersion >= 7 && iosVersion < 8
if((segue.identifier == "chatTable")){
if (iOS8){
}
else {
self.navigationController?.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
}
}
}
Make sure you change segue.identifier to your own id ;)
I have created a CollectionView Control and filled it with images. Now I want to scroll to item at a particular index on start. I have tried out scrollToItemAtIndexPath as follows:
[self.myFullScreenCollectionView scrollToItemAtIndexPath:indexPath
atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
However, I am getting following exception. Could anyone guide me on where am I going wrong.
2013-02-20 02:32:45.219 ControlViewCollection1[1727:c07] *** Assertion failure in
-[UICollectionViewData layoutAttributesForItemAtIndexPath:], /SourceCache/UIKit_Sim/UIKit-2380.17
/UICollectionViewData.m:485 2013-02-20 02:32:45.221 ControlViewCollection1[1727:c07] must return a
UICollectionViewLayoutAttributes instance from -layoutAttributesForItemAtIndexPath: for path
<NSIndexPath 0x800abe0> 2 indexes [0, 4]
Whether it's a bug or a feature, UIKit throws this error whenever scrollToItemAtIndexPath:atScrollPosition:Animated is called before UICollectionView has laid out its subviews.
As a workaround, move your scrolling invocation to a place in the view controller lifecycle where you're sure it has already computed its layout, like so:
#implementation CollectionViewControllerSubclass
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
// scrolling here doesn't work (results in your assertion failure)
}
- (void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
NSIndexPath *indexPath = // compute some index path
// scrolling here does work
[self.collectionView scrollToItemAtIndexPath:indexPath
atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally
animated:YES];
}
#end
At the very least, the error message should probably be more helpful. I've opened a rdar://13416281; please dupe.
If you are trying to scroll when the view controller is loading, make sure to call layoutIfNeeded on the UICollectionView before you call scrollToItemAtIndexPath. This is better than putting the scroll logic in viewDidLayoutSubviews because you won't perform the scroll operation every time the parent view's subviews are laid out.
Sometimes collectionView(_:didSelectItemAt:) is either not called on the main thread, or blocks it, causing scrollToItem(at:at:animated:) to not do anything.
Work around this by doing:
DispatchQueue.main.async {
collectionView.scrollToItem(at: indexPath, at: .centeredHorizontally, animated: true)
}
As of iOS 9.3, Xcode 8.2.1, Swift 3:
Calling scrollToItem(at:) from viewWillAppear() is still broken, particularly if you are using Section Headers/Footers, Auto Layout, Section Insets.
Even if you call setNeedsLayout() and layoutIfNeeded() on the collectionView, the behavior is still borked. Putting the scrolling code in to an animation block doesn't work reliably.
As indicated in the other answers, the solution is to only call scrollToItem(at:) once you are sure everything has been laid out. i.e. in viewDidLayoutSubviews().
However, you need to be selective; you don't want to perform scrolling every time viewWillLayoutSubviews() is called. So a solution is to set a flag in viewWillAppear(), and act it on it in viewDidLayoutSubviews().
i.e.
fileprivate var needsDelayedScrolling = false
override func viewWillAppear(_ animated: Bool)
{
super.viewWillAppear(animated)
self.needsDelayedScrolling = true
// ...
}
override func viewDidLayoutSubviews()
{
super.viewDidLayoutSubviews()
if self.needsDelayedScrolling {
self.needsDelayedScrolling = false
self.collectionView!.scrollToItem(at: someIndexPath,
at: .centeredVertically,
animated: false)
}
}
}
U can do this and on viewDidLoad method
just make call preformBatchUpdates
[self performBatchUpdates:^{
if ([self.segmentedDelegate respondsToSelector:#selector(segmentedBar:selectedIndex:)]){
[self.segmentedDelegate segmentedBar:self selectedIndex:_selectedPage];
}
} completion:^(BOOL finished) {
if (finished){
[self scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:_selectedPage inSection:0] atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
}
}];
In my case my subclass CollectionView has a property selectedPage, and on a setter of this property i call
- (void)setSelectedPage:(NSInteger)selectedPage {
_selectedPage = selectedPage;
[self performBatchUpdates:^{
if ([self.segmentedDelegate respondsToSelector:#selector(segmentedBar:selectedIndex:)]){
[self.segmentedDelegate segmentedBar:self selectedIndex:_selectedPage];
}
} completion:^(BOOL finished) {
if (finished){
[self scrollToItemAtIndexPath:[NSIndexPath indexPathForItem:_selectedPage inSection:0] atScrollPosition:UICollectionViewScrollPositionCenteredHorizontally animated:YES];
}
}];
}
In view controller i calling this by code
- (void)viewDidLoad {
[super viewDidLoad];
self.navigationBar.segmentedPages.selectedPage = 1;
}
Also remember that you need to use proper UICollectionviewScrollPosition value. Please see code below for clarification:
typedef NS_OPTIONS(NSUInteger, UICollectionViewScrollPosition) {
UICollectionViewScrollPositionNone = 0,
/* For a view with vertical scrolling */
// The vertical positions are mutually exclusive to each other, but are bitwise or-able with the horizontal scroll positions.
// Combining positions from the same grouping (horizontal or vertical) will result in an NSInvalidArgumentException.
UICollectionViewScrollPositionTop = 1 << 0,
UICollectionViewScrollPositionCenteredVertically = 1 << 1,
UICollectionViewScrollPositionBottom = 1 << 2,
/* For a view with horizontal scrolling */
// Likewise, the horizontal positions are mutually exclusive to each other.
UICollectionViewScrollPositionLeft = 1 << 3,
UICollectionViewScrollPositionCenteredHorizontally = 1 << 4,
UICollectionViewScrollPositionRight = 1 << 5
};
Adding the scrolling logic to viewDidAppear worked for me:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
self.collectionView?.scrollToItemAtIndexPath(
someIndexPath,
atScrollPosition: UICollectionViewScrollPosition.None,
animated: animated)
}
Adding it to viewDidLoad doesn't work: it gets ignored.
Adding it to viewDidLayoutSubviews doesn't work unless you want to scroll logic calling any time anything changes. In my case, it prevented the user from manually scrolling the item
Swift 3
UIView.animate(withDuration: 0.4, animations: {
myCollectionview.scrollToItem(at: myIndexPath, at: .centeredHorizontally, animated: false)
}, completion: {
(value: Bool) in
// put your completion stuff here
})
This is based on #Womble's answer, all credit goes to them:
The method viewDidLayoutSubviews() gets called repeatedly. For me (iOS 11.2) the first time it gets called the collectionView.contentSize is {0,0}. The second time, the contentSize is correct. Therefore, I had to add a check for this:
var needsDelayedScrolling = false
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.needsDelayedScrolling = true
// ...
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if self.needsDelayedScrolling && collectionView.contentSize.width > 0 {
self.needsDelayedScrolling = false
self.collectionView!.scrollToItem(at: someIndexPath,
at: .centeredVertically,
animated: false)
}
}
}
After adding that extra && collectionView.contentSize.width > 0 it works beautifully.
My app consists of an NSScrollView whose document view contains a number of vertically stacked NSTextViews — each of which resizes in the vertical direction as text is added.
Currently, this is all managed in code. The NSTextViews resize automatically, but I observe their resizing with an NSViewFrameDidChangeNotification, recalc all their origins so that they don't overlap, and resize their superview (the scroll view's document view) so that they all fit and can be scrolled to.
This seems as though it would be the perfect candidate for autolayout! I set NSLayoutConstraints between the first text view and its container, the last text view and its container, and each text view between each other. Then, if any text view grows, it automatically "pushes down" the origins of the text views below it to satisfy contraints, ultimately growing the size of the document view, and everyone's happy!
Except, it seems there's no way to make an NSTextView automatically grow as text is added in a constraints-based layout? Using the exact same NSTextView that automatically expanded as text was entered before, if I don't specify a constraint for its height, it defautls to 0 and isn't shown. If I do specify a constraint, even an inequality such as >=20, it stays stuck at that size and doesn't grow as text is added.
I suspect this has to do with NSTextView's implementation of -intrinsicContentSize, which by default returns (NSViewNoInstrinsicMetric, NSViewNoInstrinsicMetric).
So my questions: if I subclasses NSTextView to return a more meaningful intrinsicContentSize based on the layout of my text, would my autolayout then work as expected?
Any pointers on implementing intrinsicContentSize for a vertically resizing NSTextView?
I am working on a very similar setup — a vertical stack of views containing text views that expand to fit their text contents and use autolayout.
So far I have had to subclass NSTextView, which is does not feel clean, but works superbly in practice:
- (NSSize) intrinsicContentSize {
NSTextContainer* textContainer = [self textContainer];
NSLayoutManager* layoutManager = [self layoutManager];
[layoutManager ensureLayoutForTextContainer: textContainer];
return [layoutManager usedRectForTextContainer: textContainer].size;
}
- (void) didChangeText {
[super didChangeText];
[self invalidateIntrinsicContentSize];
}
The initial size of the text view when added with addSubview is, curiously, not the intrinsic size; I have not yet figured out how to issue the first invalidation (hooking viewDidMoveToSuperview does not help), but I'm sure I will figure it out eventually.
I had a similar problem with an NSTextField, and it turned out that it was due to the view wanting to hug its text content tightly along the vertical orientation. So if you set the content hugging priority to something lower than the priorities of your other constraints, it may work. E.g.:
[textView setContentHuggingPriority:NSLayoutPriorityFittingSizeCompression-1.0 forOrientation:NSLayoutConstraintOrientationVertical];
And in Swift, this would be:
setContentHuggingPriority(NSLayoutConstraint.Priority.fittingSizeCompression, for:NSLayoutConstraint.Orientation.vertical)
Here is how to make an expanding NSTextView using Auto Layout, in Swift 3
I used Anchors for Auto Layout
Use textDidChange from NSTextDelegate. NSTextViewDelegate conforms to NSTextDelegate
The idea is that textView has edges constraints, which means whenever its intrinsicContentSize changes, it will expand its parent, which is scrollView
import Cocoa
import Anchors
class TextView: NSTextView {
override var intrinsicContentSize: NSSize {
guard let manager = textContainer?.layoutManager else {
return .zero
}
manager.ensureLayout(for: textContainer!)
return manager.usedRect(for: textContainer!).size
}
}
class ViewController: NSViewController, NSTextViewDelegate {
#IBOutlet var textView: NSTextView!
#IBOutlet weak var scrollView: NSScrollView!
override func viewDidLoad() {
super.viewDidLoad()
textView.delegate = self
activate(
scrollView.anchor.top.constant(100),
scrollView.anchor.paddingHorizontally(30)
)
activate(
textView.anchor.edges
)
}
// MARK: - NSTextDelegate
func textDidChange(_ notification: Notification) {
guard let textView = notification.object as? NSTextView else { return }
print(textView.intrinsicContentSize)
textView.invalidateIntrinsicContentSize()
}
}
Class ready for copying and pasting. Swift 4.2, macOS 10.14
class HuggingTextView: NSTextView, NSTextViewDelegate {
//MARK: - Initialization
override init(frame: NSRect) {
super.init(frame: frame)
delegate = self
}
override init(frame frameRect: NSRect, textContainer container: NSTextContainer?) {
super.init(frame: frameRect, textContainer: container)
delegate = self
}
required init?(coder: NSCoder) {
super.init(coder: coder)
delegate = self
}
//MARK: - Overriden
override var intrinsicContentSize: NSSize {
guard let container = textContainer, let manager = container.layoutManager else {
return super.intrinsicContentSize
}
manager.ensureLayout(for: container)
return manager.usedRect(for: container).size
}
//MARK: - NSTextViewDelegate
func textDidChange(_ notification: Notification) {
invalidateIntrinsicContentSize()
}
}