NSTableView grouping

Question

I am trying to add groups to my NSTableView. I found this function:

func tableView(tableView: NSTableView, isGroupRow row: Int) -> Bool
{
    if (row == 5)
    {
        return true;
    }

    return false;
}

Which works great. Row 5 is a group after that. But I am not sure how to add a title to that?

I am using a custom view:

func tableView(tableView: NSTableView, viewForTableColumn tableColumn: NSTableColumn?, row: Int) -> NSView?
{
    if (row == 5)
    {
        ??????
    }

    let result : CellViewCustom = tableView.makeViewWithIdentifier(tableColumn!.identifier, owner: self) as! CellViewCustom

    ...

    return result
}

But in row 5 it says tableColumn == nil

How do I add text to the group header?

Answer 1

Unlike in iOS, the group cells of NSTableView are "inline" in the (non-nested) data source array.

Simple example

• A custom struct Item with property name , title and isGroup . All instances whose title is not empty are group rows

   struct Item { let name, title : String let isGroup : Bool init(name : String, title : String = "") { self.name = name self.title = title self.isGroup = !title.isEmpty } } 

• Create a data source array and assign 2 group and 3 normal rows

   var items = [Item]() ... items = [Item(name:"", title:"Group 1"), Item(name:"bar"), Item(name:"baz"), Item(name:"", title:"Group 2"), Item(name:"zab")] 

• In isGroupRow just return the value of the property

   func tableView(tableView: NSTableView, isGroupRow row: Int) -> Bool { return items[row].isGroup } 

• In viewForTableColumn create two different views for group and table row

   func tableView(tableView: NSTableView, viewForTableColumn tableColumn: NSTableColumn?, row: Int) -> NSView? { let item = items[row] if item.isGroup { let groupCell = tableView.makeViewWithIdentifier("GroupCell", owner:self) as! NSTableCellView groupCell.textField!.stringValue = item.title return cell } else { let cell = tableView.makeViewWithIdentifier(tableColumn!.identifier, owner: self) as! CellViewCustom ... return cell } }