Thanks Quincey,
I did implement that method, and the "normal" outline view UI works fine (ie: toggling the disclosure triangles via the cursor). What I ultimately want to do is to have the "sections" not have the discolsure triangle, but have the whole item triggle the expand/collapse, much like the "source list" style. Then within the sections, certain files which represent library collections should have disclosure triangles to expand/collapse their sub-items.
FWIW, here is my DataSource/Delegate implementation:
| extension ProjectViewController: NSOutlineViewDataSource { |
| |
| public func outlineView(_ outlineView: NSOutlineView, numberOfChildrenOfItem item: Any?) -> Int { |
| if let section = item as? Section { |
| return section.files.count |
| } |
| else { |
| return allSections.count |
| } |
| } |
| |
| public func outlineView(_ outlineView: NSOutlineView, child index: Int, ofItem item: Any?) -> Any { |
| if let section = item as? Section { |
| return section.files[index] |
| } |
| else { |
| return allSections[index] |
| } |
| } |
| |
| public func outlineView(_ outlineView: NSOutlineView, isItemExpandable item: Any) -> Bool { |
| if isProjectSection(item: item) { |
| return false |
| } |
| else if item is Section { |
| return true |
| } |
| else { |
| return item is LibraryFile |
| } |
| } |
| } |
| |
| extension ProjectViewController: NSOutlineViewDelegate { |
| |
| public func outlineView(_ outlineView: NSOutlineView, viewFor tableColumn: NSTableColumn?, item: Any) -> NSView? { |
| if let item = item as? Section { |
| let view = outlineView.make(withIdentifier: item.identifier, owner: nil) |
| if isProjectSection(item: item) { |
| (view?.subviews.filter { $0 is NSTextField }.first as? NSTextField)?.stringValue = project?.name ?? "Untitled" |
| } |
| else if let headerBtn = (view?.subviews.filter { $0 is Button })?.first as? Button { |
| headerBtn.target = self |
| headerBtn.action = #selector(toggleSectionHeader(sender:)) |
| headerBtn.associatedObject = item |
| } |
| return view |
| } |
| else if let item = item as? RepresentsAFile { |
| let view = outlineView.make(withIdentifier: "FileItemCell", owner: nil) |
| (view?.subviews.filter { $0 is NSTextField }.first as? NSTextField)?.stringValue = item.name |
| return view |
| } |
| else { |
| return nil |
| } |
| } |
| } |
And this is the method where I'm trying to call expand/collapse:
| extension ProjectViewController { |
| |
| func toggleSectionHeader(sender: AnyObject?) { |
| guard let section = (sender as? Button)?.associatedObject as? Section else { return } |
| |
| if projectItems.isItemExpanded(section) { |
| projectItems.collapseItem(section) |
| } |
| else { |
| projectItems.expandItem(section) |
| } |
| } |
| } |
It's notable that the isItemExpanded() call works correctly, and returns as expected based on the expanded state of the particular section.
