How to get selected item of NSOutlineView without using NSTreeController?

Question

How do I get the selected item of an NSOutlineView with using my own data source. I see I can get selectedRow but it returns a row ID relative to the state of the outline. The only way to do it is to track the expanded collapsed state of the items, but that seems ridiculous.

I was hoping for something like:

array = [outlineViewOutlet selectedItems];

I looked at the other similar questions, they dont seem to answer the question.

Mccaffrey

In case anyone stumbles on this and is trying to find an answer for swift, this is a port of the below code. println(MainOutlineList.itemAtRow(MainOutlineList.selectedRow)) – Bienne

Answer 1

NSOutlineView inherits from NSTableView, so you get nice methods such as selectedRow:

id selectedItem = [outlineView itemAtRow:[outlineView selectedRow]];

Wolfie

Thank you SO much that works just as intended. I wish it was easier to find it in the Apple docs... – Mccaffrey

Great ! and so simple ! – Whithersoever

It returns -1 for selected row, can you guide im missing something? – Weakminded

@Weakminded that would mean nothing is selected (-1 is NSNotFound). – Wolfie

Answer 2

Swift 5

NSOutlineView has a delegate method outlineViewSelectionDidChange

 func outlineViewSelectionDidChange(_ notification: Notification) {

    // Get the outline view from notification object
    guard let outlineView = notification.object as? NSOutlineView else {return}

    // Here you can get your selected item using selectedRow
    if let item = outlineView.item(atRow: outlineView.selectedRow) {
      
    }
}

Bonus Tip: You can also get the parent item of the selected item like this:

func outlineViewSelectionDidChange(_ notification: Notification) {

// Get the outline view from notification object
guard let outlineView = notification.object as? NSOutlineView else {return}

// Here you can get your selected item using selectedRow
if let item = outlineView.item(atRow: outlineView.selectedRow) {
  
     // Get the parent item
      if let parentItem = outlineView.parent(forItem: item){
            
      }  
   } 
}

Tallie

Perfect answer. – Ticket

Answer 3

@Dave De Long: excellent answer, here is the translation to Swift 3.0

@objc private func onItemClicked() {
    if let item = outlineView.item(atRow: outlineView.clickedRow) as? FileSystemItem {
        print("selected item url: \(item.fileURL)")
    }
}

Shown is a case where item is from class FileSystemItem with a property fileURL.

Ml