I'm using UICollectionView with a list style on Mac (looks like NSOutlineView in a sidebar). I have expandable rows. So this is the behavior I'm after: -If the user has a row selected, but decides to collapse the selected row's parent, I want to maintain the current selection. Instead this is what happens by default: -If a row selected and I collapse the parent the collection, the collection view automatically selects another row (in my case the first row at index path 0-0). Just because the user collapses the parent doesn't mean the selection should change. For instance in Xcode's Navigator I can have a file selected in a Group and collapse the group without modifying the current selection.

Looking to get column resizing events for UISplitViewController. I have a UITableView inside on of the columns and when the column is resized I need to invalidate the intrinsic content size of the table view cells to recompute row height. Best place to handle this?

Working on a Mac Catalyst app. I have a UInavigationController. On iOS this is full screen but on Mac Catalyst I'm using it inside a UISplitViewController in the supplementary column. This view controller's root view controller has a navigationItem which configures a UISearchController. The search bar is nowhere to be found unless I set it to UINavigationItemSearchBarPlacementStacked. So is UINavigationItemSearchBarPlacementInline not supported for the supplementary column of a UISplitViewController? If that's the case I'm fine with that actually but there's got to be a way to make UINavigationItemSearchBarPlacementStacked look a little better on Mac? The search bar border is barely visible on a white background.

I can't seem to get rid of the "vibrancy" effect on the titlebar/toolbar area of the window on Mac Catalyst. I have a triple Split View controller. The primary vc style is sidebar in the split vc.. And that has the blur/visual effect and that's all well and good. But the title bar area on the supplementary column has the blur effect too and it looks kind of terrible (the navigation bar in the supplementary view controller has all of its navigationBar appearances configured with opaque content:   UINavigationBarAppearance *opaqueAppearance = [[UINavigationBarAppearance alloc]init];     [opaqueAppearance configureWithOpaqueBackground];     opaqueAppearance.backgroundEffect = nil;     opaqueAppearance.backgroundColor = [UIColor myColor]; //set to all appearances But I still get the blur effect on the navigation bar, which presumably is being mapped to NSToolbar. Is it possible to disable this blur effect for the column? It really doesn't look good in my app.

I'm on Mac Catalyst. I have a UISearchController and I keep getting this crash after I clear the search bar, adjust the search scope segmented control if one of the UITableViewCells is focused (via arrow key press) before Focus item does not provide a parentFocusEnvironment. I can workaround the problem by overriding -parentFocusEnvironment, holding the parent UITableView in a property and returning it: -(id<UIFocusEnvironment>)parentFocusEnvironment { id<UIFocusEnvironment>theFocus = [super parentFocusEnvironment]; if (theFocus == nil) { return self.cachedParentFocus; } else { self.cachedParentFocus = theFocus } return theFocus; } The problem with this is it is likely to create a retain cycle (I did try a weak reference but that can cause the following crasher on deallocation (the focus environment continues to call this method on the table view cell even when its outside of a UIWindow): “Cannot form weak reference to instance (0x13799a000) of class UITableView. It is possible that this object was over-released, or is in the process of deallocation.” Anyone run into this and know of a potential workaround?

So when a row is selected in UITableView and the table view / cells within it have focus, and the window is active.... the rows are selected with the system Accent color (in my case blue). I have a view inside the table view cell that does custom drawing. When the cell is selected I draw text white (when unselected I draw the text using UIColor.labelColor). So when the window is not active but the table view row is selected, the selected background color changes to light gray. In this case I draw the text black (because it looks better against the light gray selection color on an inactive window). However when the row is selected but another view in the window has focus (say the sidebar) the selected row turns back to the light gray color. In this case my text is incorrectly drawing white instead of black on the light gray background. How do I check for this state from UIKit? In AppKit I think I'd be using: NSColor.unemphasizedSelectedTextColor https://developer.apple.com/documentation/appkit/nscolor/2998834-unemphasizedselectedtextcolor?language=objc I have to update text color manually because I'm doing custom drawing in these table view cells (I have a view that overrides drawRect:) I can't just use the dynamic colors like UIColor.labelColor. I have to set the colors on state change manually and call setNeedsDisplay on my view. How do I check for the unemphasized state? I did inspect whether or not my table view cell is in the active focusItem's environment, and if it is not I assume the light gray selected color is being used. This worked most of the time but there still seems to be some states where the unemphasized selection color (light gray)is being used on selected cells when the the table view cell is in the active focus environment and my text incorrectly draws white.

My table view supports multiple selection. When holding down the shift key and clicking to extend the selection on Mac focus doesn't move to the clicked row. This isn't how macOS apps normally behave. I tried working around the problem by catching the last selected index path and forcing a focus update: -(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { self.lastSelectedIndexPath = indexPath; } -(void)tableView:(UITableView*)tableView didDeselectRowAtIndexPath:(NSIndexPath*)indexPath {     if ([indexPath isEqual:self.lastSelectedIndexPath])     {         self.lastSelectedIndexPath = nil;     } } -(void)tableViewDidEndMultipleSelectionInteraction:(UITableView *)tableView {   [tableView setNeedsFocusUpdate];     [tableView updateFocusIfNeeded]; } -(NSIndexPath*)indexPathForPreferredFocusedViewInTableView:(UITableView *)tableView { return self.lastSelectedIndexPath; } But that didn't work. UITableview never calls -indexPathForPreferredFocusedViewInTableView: after my -setNeedsFocusUpdate / -updateFocusIfNeeded calls. I tried subclassing UITableView and overriding -preferredFocusEnvironments but that isn't called. Focus system just ignores updating for shift click. Anyone know of a workaround?

I'm using UIMenuBuilder API to add a menu item to the menu bar on Mac Catalyst (adding a UIKeyCommand object). So depending on the current selection the title of the menu item should change. As an example in Finder if a single file is selected and you go to the "Edit" menu in the menu bar there is an item that says "Copy Filename" Now select two files in Finder and go to Edit menu in the menu bar and now it says "Copy 2 Items" Updating a NSMenuItem in Appkit is pretty easy. I figured I'd be able to do this in -canPerformAction:withSender: but the system doesn't pass my UIKeyCommand as the sender but instead an instance of a private class _UIMenuBarItem. I assume there must be a way to dynamically update the title of a menu bar item in a Catalyst app?

My UISplitViewController is configured like this: A list (collection view) is used in the primary view controller (sidebar style). When a selection is made in the primary view controller a table view displays data in the supplementary column. When a selection is made in the supplementary view controller, a view controller with scrollable content is shown in the secondary view controller. This is like the Mail app on Mac. So when I run the app I hit the tab key once and the list (collection view) in the primary column gets focus. I can navigate the list with the keyboard. This works as expected. So now with a selection in the list, a table view is showing in the supplementary column. I hit the tab key again and the table view gets focus. This works as expected as I can navigate the table view from the keyboard with the arrow keys. Now with a selection made in the table view, the scrollable view controller is showing in the secondary view controller column. I hit the tab key again and focus goes back to the list in the primary column. This is not the expected behavior. I'd expect hitting tab would move focus to the scroll view in the secondary column instead of jumping back to the primary column (as I should be able to scroll the scroll view in the secondary column with the up and down arrow keys). The user is then required to click on the secondary view controller in order to scroll it with the arrow keys. This breaks full keyboard navigation. The behavior I'm after is actually the default behavior in the Mail app but I can't figure out how to get it to work in Mac Catalyst?

I'm looking to achieve the AppKit equivalent of -acceptsFirstMouse: from the Mac Catalyst environment: https://developer.apple.com/documentation/appkit/nsview/1483410-acceptsfirstmouse?language=objc "Overridden by subclasses to return YES if the view should be sent a mouseDown: message for an initial mouse-down event, NO if not." Is this possible?

So I just noticed that my calls to -setActionName: on NSUndoManager are not properly updating the Undo/Redo menu item titles in the menu bar on Mac Catalyst. At first I thought maybe my actionName string was too long, so I just created a really simple sample project and ...yeah...my calls to -setActionName are ignored. The menu bar items just say "Undo" and "Redo.." Sample: -(IBAction)changeBackgroundColorAction:(UIButton*)sender {     UIColor *currentBGColor = self.view.backgroundColor;     self.view.backgroundColor = UIColor.yellowColor;     NSUndoManager *undoManager = self.undoManager;     [undoManager registerUndoWithTarget:self selector:@selector(setBackgroundColorWithColor:) object:currentBGColor];     [undoManager setActionName:@"Change BG Color"]; } I'm really starting to regret not using AppKit...

Is it possible to create a popover in Mac Catalyst that allows you to detach it into a new window like NSPopover? https://developer.apple.com/documentation/appkit/nspopoverdelegate/1534822-detachablewindowforpopover?language=objc Thanks in advance

I have a triple UISplitViewController. A UINavigationController is in the secondary column. When the selection changes in the supplementary column I call -setViewControllers:animated: and pass the navigation controller the new vc. I noticed sometimes the navigation view controller isn't updating and this logs out: setViewControllers:animated: called on while an existing transition or presentation is occurring; the navigation stack will not be updated. So this happens when the Split View controller itself is presenting another view controller modally (say a view controller with a UIActivityIndicatorView in it to show loading progress). But there is no transition/presentation occurring on the UINavigationController contained in the secondary view controller column itself. The presentation occurring on the UISplitViewController is completely separate and unrelated to the UINavigationController's navigation stack that's in the secondary column and therefore I should not be prevented from modifying the navigation stack.

I use UNUserNotificationCenterDelegate. I'm in the process of adding new scene configurations for windows for the Mac environment. Some of these windows are auxiliary windows. So I was just wondering what happens with UNNotificationResponse targetScene property. In -userNotificationCenter:didReceiveNotificationResponse:withCompletionHandler: is it possible for one of the auxiliary window scenes to be the targetScene or does UNNotificationResponse always choose the configuration at index 0 in the info.plist?

On macOS it is typical for apps to have a "Done" button showing at the bottom of a window sheet. Usually the button is blue (or whatever your system accent color is set to) and this button can be invoked by pressing the return key. On NSButton all you do is assign the return key as the key equivalent. So in the Mac Catalyst environment how do I achieve this behavior? I'm able to get the button to look exactly how I want configuring UIButton like this: UIButton *doneButton = [UIButton buttonWithType:UIButtonTypeSystem]; [doneButton setTitle:@"Done" forState:UIControlStateNormal]; doneButton.role = UIButtonRolePrimary; Is there a quick way to get its action to be invoked when the return key is pressed or do I have to manually implement UIKeyCommand? Thanks in advance to anyone who answers.