Select Item in NSCollectionView on mouseDown, not mouseUp? - macos

I'd like to make it so my NSCollectionView's selection behavior matches the icon-view in Finder. Finder will select and highlight elements when the mouse button is clicked down, but NSCollectionView's built in behavior appears to use mouse up to trigger a selection.
Is there a way to make NSCollectionView act like Finder in this regard?

Per pfandtrade's comment above, it looks like the highlight state of an NSCollectionViewItem will be changed before that item is selected.
mouseDown = NSCollectionViewItem's highlightState is set to forSelection
mouseUp = NSCOllectionViewItem's highlightState is set to none, but isSelected property is then set to true.
I added the following to my NSCollectionViewItem subclass:
override var highlightState: NSCollectionViewItemHighlightState{
didSet{
if self.highlightState == .forSelection{
self.showSelectedHighlight() //my stylization function
}
}
}

Related

NSTableView selected row flickering while scrolling with arrow keys

I have a view based NSTableView and can't figure out how to work around a visual glitch where the currently selected row flickers while scrolling up or down with the arrow keys.
The selected row should appear 'glued' to either the top or bottom of the view, depending on scroll direction. The Finder shows this correct behavior in list view but a regular table view seems to not behave this way out of the box. I'm confused as to why that is and see no obvious way to circumvent it. Can anybody point me to possible causes / solutions?
Edit No. 1
A cell based NSTableView behaves in the desired way by default, so this is presumably a bug specific to the view based implementation. I don't want to use a cell based table for unrelated reasons though.
Edit No. 2
I've tried making the table view's parent view layer backed, as well as intercepting the up / down arrow keystrokes to do my own scrolling, but so far I haven't been able to eliminate the flickering.
Edit No. 3
I've created a small sample project that reproduces the issue.
It looks like the selection changes and the old and new selected rows are redrawn. Next the selected row is animated up/down. Disabling scroll animation fixes the issue. Scroll animation can be disabled by subclassing NSClipView and overriding scroll(to:).
override func scroll(to newOrigin: NSPoint) {
setBoundsOrigin(newOrigin)
}
It might have some side effects.
Edit
Copied from zrzka's solution, with some adjustments. Scroll animation is temporarily disabled when using the up arrow or down arrow key.
class TableView: NSTableView {
override func keyDown(with event: NSEvent) {
if let clipView = enclosingScrollView?.contentView as? ClipView,
(125...126).contains(event.keyCode) && // down arrow and up arrow
event.modifierFlags.intersection([.option, .shift]).isEmpty {
clipView.isScrollAnimationEnabled = false
super.keyDown(with: event)
clipView.isScrollAnimationEnabled = true
}
else {
super.keyDown(with: event)
}
}
}
class ClipView: NSClipView {
var isScrollAnimationEnabled: Bool = true
override func scroll(to newOrigin: NSPoint) {
if isScrollAnimationEnabled {
super.scroll(to: newOrigin)
} else {
setBoundsOrigin(newOrigin)
documentView?.enclosingScrollView?.flashScrollers()
}
}
}
Did you try change the view ?
scrollView.wantsLayer = true
If you used Interface Builder:
Select the scroll view
Open the View Effects Inspector (or press Cmd-Opt-8)
In the table, find the row for your scroll view and check the box.

How to align a toolbar (or its items) with the leading edge of a split view controller's child?

In iOS, a toolbar can be added to any view. In macOS however, it seems only possible to add a toolbar to a window.
I'm working on an app with a split view controller with a toolbar but the toolbar's items only have a meaning with respect to the right view controller's context.
E.g. let's say I have a text editor of some sort, where the left pane shows all documents (like in the Notes app) and the right pane shows the actual text which can be edited. The formatting buttons only affect the text in the right pane. Thus, it seems very intuitive to place the toolbar within that right pane instead of stretching it over the full width of the window.
Is there some way to achieve this?
(Or is there a good UX reason why this would be a bad practice?)
I've noticed how Apple solved this problem in terms of UX in their Notes app: They still use a full-width toolbar but align the button items that are only related to the right pane with the leading edge of that pane.
So in case, there is no way to place a toolbar in a view controller, how can I align the toolbar items with the leading edge of the right view controller as seen in the screenshot above?
Edit:
According to TimTwoToes' answer and the posts linked by Willeke in the comments, it seems to be possible to use Auto Layout for constraining a toolbar item with the split view's child view. This solution would work if there was a fixed toolbar layout. However, Apple encourages (for a good reason) to let users customize your app's toolbar.
Thus, I cannot add constraints to a fixed item in the toolbar. Instead, a viable solution seems to be to use a leading flexible space and adjust its size accordingly.
Initial Notes
It turns out this is tricky because there are many things that need to be considered:
Auto Layout doesn't seem to work properly with toolbar items. (I've read a few posts mentioning that Apple has classified this as a bug.)
Normally, the user can customize your app's toolbar (add and remove items). We should not deprive the user of that option.
Thus, simply constraining a particular toolbar item with the split view or a layout guide is not an option (because the item might be at a different position than expected or not there at all).
After hours of "hacking", I've finally found a reliable way to achieve the desired behavior that doesn't use any internal / undocumented methods. Here's how it looks:
How To
Instead of a standard NSToolbarFlexibleSpaceItem create an NSToolbarItem with a custom view. This will serve as your flexible, resizing space. You can do that in code or in Interface Builder:
Create outlets/properties for your toolbar and your flexible space (inside the respective NSWindowController):
#IBOutlet weak var toolbar: NSToolbar!
#IBOutlet weak var tabSpace: NSToolbarItem!
Create a method inside the same window controller that adjusts the space width:
private func adjustTabSpaceWidth() {
for item in toolbar.items {
if item == tabSpace {
guard
let origin = item.view?.frame.origin,
let originInWindowCoordinates = item.view?.convert(origin, to: nil),
let leftPane = splitViewController?.splitViewItems.first?.viewController.view
else {
return
}
let leftPaneWidth = leftPane.frame.size.width
let tabWidth = max(leftPaneWidth - originInWindowCoordinates.x, MainWindowController.minTabSpaceWidth)
item.set(width: tabWidth)
}
}
}
Define the set(width:) method in an extension on NSToolbarItem as follows:
private extension NSToolbarItem {
func set(width: CGFloat) {
minSize = .init(width: width, height: minSize.height)
maxSize = .init(width: width, height: maxSize.height)
}
}
Make your window controller conform to NSSplitViewDelegate and assign it to your split view's delegate property.1 Implement the following NSSplitViewDelegate protocol method in your window controller:
override func splitViewDidResizeSubviews(_ notification: Notification) {
adjustTabSpaceWidth()
}
This will yield the desired resizing behavior. (The user will still be able to remove the space completely or reposition it, but he can always add it back to the front.)
1 Note:
If you're using an NSSplitViewController, the system automatically assigns that controller to its split view's delegate property and you cannot change that. As a consequence, you need to subclass NSSplitViewController, override its splitViewDidResizeSubviews() method and notify the window controller from there. Your can achieve that with the following code:
protocol SplitViewControllerDelegate: class {
func splitViewControllerDidResize(_ splitViewController: SplitViewController)
}
class SplitViewController: NSSplitViewController {
weak var delegate: SplitViewControllerDelegate?
override func splitViewDidResizeSubviews(_ notification: Notification) {
delegate?.splitViewControllerDidResize(self)
}
}
Don't forget to assign your window controller as the split view controller's delegate:
override func windowDidLoad() {
super.windowDidLoad()
splitViewController?.delegate = self
}
and to implement the respective delegate method:
extension MainWindowController: SplitViewControllerDelegate {
func splitViewControllerDidResize(_ splitViewController: SplitViewController) {
adjustTabSpaceWidth()
}
}
There is no native way to achieve a "local" toolbar. You would have to create the control yourself, but I believe it would be simpel to make.
Aligning the toolbar items using autolayout is described here. Align with custom toolbar item described by Mischa.
The macOS way is to use the Toolbar solution and make them context sensitive. In this instance the text attribute buttons would enable when the right pane has the focus and disable when it looses the focus.

NSMenuItem custom view drawRect not always called

I'm using a custom view for NSMenu items so I can control the background colour via isHighlighted.
The issue is, if you use a combination of mouse and keyboard to navigate the menu, it's possible to have two items selected at once. This is because drawRect isn't being called on some items to dehighlight them
Has anyone else run into this?
NSMenuItems should be created using:
NSMenuItem *menuItem = [[NSMenuItem alloc] initWithTitle:#"" action:#selector(menuItemSelected:) keyEquivalent:#""];
where the selector menuItemSelected: is a valid method. isHighlighted won't be toggled if a valid action selector is not provided
Conform NSMenuDelegate and implement following function like this:
func menu(_ menu: NSMenu, willHighlight item: NSMenuItem?) {
for item in menu.items.compactMap({ return $0.isHighlighted ? $0 : nil }) {
item.view?.needsDisplay = true
}
}

Remove 'Layout Orientation' from NSTextView context menu

I have a NSTextView which has a ruler attached showing line numbers. If the user uses the 'Layout Orientation' -> 'Vertical' context menu, things go wonky. The applications intended purpose does not support a Vertical orientation anyway, so I would like to remove this context menu.
So far I have subclassed an NSTextView and overwrote the defaultMenu action:
+ (NSMenu *) defaultMenu
{
// Get our default menu
NSMenu * contextMenu =
[NSTextView defaultMenu];
for(NSInteger menuItemIndex = contextMenu.itemArray.count - 1;
menuItemIndex != -1;
--menuItemIndex)
{
NSMenuItem * menuItem =
[contextMenu itemAtIndex: menuItemIndex];
NSLog(#"%ld %#, %#",
menuItemIndex,
NSStringFromSelector(menuItem.action),
menuItem.title);
} // End of menuItem loop
return contextMenu;
} // End of defaultMenu
My original thought was that I could remove the menu item with a specific selector, but unfortunately the 'Layout Orientation' is a submenu, so it has the submenuAction: selector.
I could still remove the menu by comparing the title, but that seems like a poor way to do this and would probably break in a localized environment.
Any suggestions as to PROPERLY go about removing menu items from the NSTextView context menu? (Removing by index also seems hacky, as that could possible break on different versions of the OS).
Each submenu menuitem has a menu. Scan the submenus for action changeLayoutOrientation:.
You can disable the layout orientation menu items by implementing validateUserInterfaceItem:.
- (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)anItem {
if ([anItem action] == #selector(changeLayoutOrientation:))
return NO;
return [super validateUserInterfaceItem:anItem];
}

NSButton in NSTableCellView: How to find desired objectValue?

I have a view-based NSTableView that is populated through bindings. My textFields & imageViews are bound to the NSTableCellView's objectValue's properties.
If I want to have an edit/info button in my NSTableCellView:
Who should be the target of the button's action?
How would the target get the objectValue that is associated with the cell that the button is in?
I'd ultimately like to show a popover/sheet based on the objectValue.
I found an additional answer: The Answer above seems to assume you're using bindings on your table view. Since I'm kind of a noob I found a way to get the button inside the table view cell.
- (IBAction)getCellButton:(id)sender {
int row = [xmlTable rowForView:sender];
}
This way when you click on the button inside the row, you don't have to have the row selected. It will return the int value of the row to match up with a datasource in an array without bindings.
Your controller class can be the target. To get the object value:
- (IBAction)showPopover:(id)sender {
NSButton *button = (NSButton *)sender;
id representedObject = [(NSTableCellView *)[button superview] objectValue];
}
Or, use a subclass of NSTableCellView, make the cell view the target of the button's action, and call [self objectValue] to get the object.

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