Growing NSTableView Row Height

4
votes

I have a view-based NSTableView in a MacOSX app that structures data nicely. I would like to implement the NSTableView to have row heights which grow with the content of the data entered into one of the NSTextViews. I've subclassed an NSTextView to "grow" with the user text but the issue is that having the field embedded in the TableView causes the field to be clipped.

Does anyone have any suggestions as to how to go about implementing a growing row size?

2
macoscocoanstableviewnstextview

2 Answers

7
votes

You need to implement -tableView:heightOfRow: in your table view delegate and return the appropriate height for the row. Furthermore, you need to monitor the text views for changes in their height and call -noteHeightOfRowsWithIndexesChanged: on the table view when any of them changes. To monitor the height of the text views, it should suffice to observe the NSViewFrameDidChangeNotification that they will post.

(If you're using auto layout generally in your UI, I think you will have to leave the text views with translatesAutoresizingMaskIntoConstraints on, place them manually, and set their autoresizing masks as appropriate. Then, you would avoid setting any other constraints on them. This is because you need the frame to be set by the text layout manager but not by auto layout.)

2
votes

I've managed to implement this in Swift 3 (with the help of this great tip and this and this SO answer):

enter image description here

Make sure the table view cell in the NSTableView has a delegate connection to your subclass/view controller which adopts the NSTextFieldDelegate protocol.

Also give it these constraints to make sure it resizes according to the height of the row:

enter image description here

In the delegate use this code:

var editedString: String? = nil
var textCellForHeight: NSTextFieldCell = NSTextFieldCell.init()

func control(_ control: NSControl, textShouldBeginEditing fieldEditor: NSText) -> Bool {
    editedString = fieldEditor.string ?? ""
    return true
}

func control(_ control: NSControl, textShouldEndEditing fieldEditor: NSText) -> Bool {
    editedString = nil
    return true
}   

 func control(_ control: NSControl, textView: NSTextView, doCommandBy commandSelector: Selector) -> Bool {
    if commandSelector == #selector(insertNewline(_:)) {
         textView.insertNewlineIgnoringFieldEditor(self)
         editedString = textView.string ?? ""
         //The NSAnimationContext lines get rid of the animation that normally happens when the height changes
         NSAnimationContext.beginGrouping()
         NSAnimationContext.current().duration = 0
         myTableView.noteHeightOfRows(withIndexesChanged: IndexSet.init(integer: selected))
         NSAnimationContext.endGrouping()
         myTable.needsDisplay = true
         return true
    }
    return false
}

func tableView(_ tableView: NSTableView, heightOfRow row: Int) -> CGFloat {
    if let temp = editedString { //we know it’s currently being edited if it’s not nil
        textCellForHeight.stringValue = temp
        //in my case, there was a specific table column that I knew would be edited
        //you might need to decide on the column width another way.
        let column = myTable.tableColumns[myTable.column(withIdentifier: “TheColumnThatsBeingEdited”)]
        let frame: NSRect = NSMakeRect(0, 0, column.width, CGFloat.greatestFiniteMagnitude)
        return textCellForHeight.cellSize(forBounds: frame).height
    }
  return yourStandardHeightCGFloat
}