I noticed you have to use .adjustsImageWhenAncestorFocused to 'pop' the collection view cell's image when focused. This has created a problem for me, without .adjustsImageWhenAncestorFocused the images are fine, but with that method, it crops my images on the top and bottom.
Did anyone run into this and solve it? I tried .clipsToBounds = true but that doesn't solve my problem.
You could make your UICollectionView bigger, or use this method to control the focus animation:
let originalImageSize = CGSizeMake(100, 100)
let focusedImageSize = CGSizeMake(120, 120)
override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
coordinator.addCoordinatedAnimations({ [unowned self] in
if self.focused {
self.imageView.frame.size = focusedImageSize
}
else {
self.imageView.frame.size = originalImageSize
}
}, completion: nil)
}
You need to add this code to your custom UICollectionViewCell class. Hope it helps.
Related
I'm attempting to implement an animation that shows/hides a view in a horizontal arrangement. I'd like this to happen with slide, and with no opacity changes. I'm using auto-layout everywhere.
Critically, the total width of the containing view changes with the window. So, constant-based animations are not possible (or so I believe, but happy to be proved wrong).
|- viewA -|- viewB -|
My first attempt was to use NSStackView, and animate the isHidden property of an arranged subview. Despite seeming like it might do the trick, I was not able to pull off anything close to what I was after.
My second attempt was to apply two constraints, one to force viewB to be zero width, and a second to ensure the widths are equal. On animation I change the priorities of these constraints from defaultHigh <-> defaultLow.
This results in the correct layout in both cases, but the animation is not working out.
With wantsLayer = true on the containing view, no animation occurs whatsoever. The views just jump to their final states. Without wantsLayer, the views do animate. However, when collapsing, viewA does a nice slide, but viewB instantly disappears. As an experiment, I changed the zero width to a fixed 10.0, and with that, the animation works right in both directions. However, I want the view totally hidden.
So, a few questions:
Is it possible to animate layouts like this with layer-backed views?
Are there other techniques possible for achieving the same effect?
Any ideas on how to achieve these nicely with NSStackView?
class LayoutAnimationViewController: NSViewController {
let containerView: NSView
let view1: ColorView
let view2: ColorView
let widthEqualContraint: NSLayoutConstraint
let widthZeroConstraint: NSLayoutConstraint
init() {
self.containerView = NSView()
self.view1 = ColorView(color: NSColor.red)
self.view2 = ColorView(color: NSColor.blue)
self.widthEqualContraint = view2.widthAnchor.constraint(equalTo: view1.widthAnchor)
widthEqualContraint.priority = .defaultLow
self.widthZeroConstraint = view2.widthAnchor.constraint(equalToConstant: 0.0)
widthZeroConstraint.priority = .defaultHigh
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func loadView() {
self.view = containerView
// view.wantsLayer = true
view.addSubview(view1)
view.addSubview(view2)
view.subviewsUseAutoLayout = true
NSLayoutConstraint.activate([
view1.topAnchor.constraint(equalTo: view.topAnchor),
view1.bottomAnchor.constraint(equalTo: view.bottomAnchor),
view1.leadingAnchor.constraint(equalTo: view.leadingAnchor),
// view1.trailingAnchor.constraint(equalTo: view2.leadingAnchor),
view2.topAnchor.constraint(equalTo: view.topAnchor),
view2.bottomAnchor.constraint(equalTo: view.bottomAnchor),
view2.leadingAnchor.constraint(equalTo: view1.trailingAnchor),
view2.trailingAnchor.constraint(equalTo: view.trailingAnchor),
widthEqualContraint,
widthZeroConstraint,
])
}
func runAnimation() {
view.layoutSubtreeIfNeeded()
self.widthEqualContraint.toggleDefaultPriority()
self.widthZeroConstraint.toggleDefaultPriority()
// self.leadingConstraint.toggleDefaultPriority()
NSAnimationContext.runAnimationGroup({ (context) in
context.allowsImplicitAnimation = true
context.duration = 3.0
self.view.layoutSubtreeIfNeeded()
}) {
Swift.print("animation complete")
}
}
}
extension LayoutAnimationViewController {
#IBAction func runTest1(_ sender: Any?) {
self.runAnimation()
}
}
Also, some potentially relevant, but so far unhelpful, related questions:
Animating Auto Layout changes concurrently with NSPopover contentSize change
Animating Auto Layout constraints with NSView.layoutSubtreeIfNeeded() not working on macOS High Sierra
Hide view item of NSStackView with animation
I'm trying to create a tray popover app with table very similar to the one Dropbox has in it's popover view.
There is a table of files and when you hover mouse over a table cell, cell will highlight and show additional controls.
I'm not sure if NSTableView is suitable for this at all?
Does anyone have any advice?
This would be an ideal use of NSTableView. Using a view-based NSTableView, you'll be easily able to create the look of those cells (views). The highlight on mouse-over should be accomplishable if you add an NSTrackingArea to the table view (scroll view might be better) with -[NSView addTrackingArea:], which gives you callbacks for -mouseMoved: events. From that method you can use the locationInWindow property on the NSEvent, and then use NSTableView's -rowAtPoint: call to query which row you should change to display the hover event.
As a possible amendment here, I had to do the following to make this work:
highlightedRow: MyCustomRow?
func viewWillAppear(){
configureTableHighlight()
}
func configureTableHighlight() {
let trackingArea = NSTrackingArea(rect: scrollView.frame, options: [.mouseMoved, .activeInKeyWindow, .inVisibleRect], owner: self, userInfo: nil)
scrollView.addTrackingArea(trackingArea)
}
override func mouseMoved(with event: NSEvent) {
let pointInTableView = tableView.convert(event.locationInWindow, to: nil)
let row = tableView.row(at: pointInTableView)
if row == -1 {
highlightedRow?.highlight = false
highlightedRow = nil
return
}
guard let view = tableView.view(atColumn: 0, row: row, makeIfNecessary: false) as? MyCustomRow else {
return
}
if(highlightedRow == view){
return
}
view.highlight = true;
highlightedRow?.highlight = false
highlightedRow = view;
}
This might depend on where you add the trackingView however.
Additional reference:
mouseover detection in NSTableView's NSCell?
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.
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];
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.