如何使用Swift使用NSPopUpButton访问和排序NSTableView

Question

To keep it simple, I used this URL to create a macOS table in Swift (4.1): https://medium.com/@kicsipixel/very-simple-view-based-nstableview-in-swift-ab6d7bb30fbb

I then used this URL to be able to drag and drop rows in the table: http://bit.boutique/blog/2015/6/8/drag-sorting-nstableview-rows-in-swift/

I able to determine how to double click to edit a cell by using this URL: Double click an NSTableView row in Cocoa?

If the table has multiple columns, to determine what column was being edited, I had to open a problem request with Apple. They provided me with this undocumented piece of code (and suggested I open a documentation bug report, which I did).

func control(_ control: NSControl, textShouldEndEditing fieldEditor: NSText) -> Bool {
    print("textShouldEndEditing text is " + (fieldEditor.string) + " [" +  String(describing:  tableView.row(for: control)) + "][" + String(describing: tableView.column(for: control) ) + "]" )
    return true
} // textShouldEndEditing

I pieced all of that together and I thought I was done. I then attempted to add another column to my table, an NSPopUpButton. When I did that the table displays fine but I can no longer drag and drop the rows.

The functions viewFor, writeRowsWith, and DraggingSession endedAt is called but validateDrop and acceptDrop are not.

// MARK: tableView
func numberOfRows(in tableView: NSTableView) -> Int {

    tableView.doubleAction = #selector(doubleClickOnResultRow)

    initPrefs()

    tableView.tableColumns[0].title = localizedString(forKey: "CityNames_") + ":"
    tableView.tableColumns[1].title = localizedString(forKey: "CityDisplayNames_") + ":"
    tableView.tableColumns[2].title = localizedString(forKey: "weatherSource_") + ":"
    tableView.tableColumns[3].title = localizedString(forKey: "API Key 1:_")
    tableView.tableColumns[4].title = localizedString(forKey: "API Key 2:_")

    return locationInformationArray.count
} // numberOfRows

// Populate table
func tableView(_ tableView: NSTableView,
               viewFor tableColumn: NSTableColumn?,
               row: Int) -> NSView? {
    var cell: NSTableCellView

    //print("viewFor: row=" + String(describing:  row), column=" + String(describing:  column) )

    var column = -1
    if tableColumn == tableView.tableColumns[0] {
        column = 0
    } else  if tableColumn == tableView.tableColumns[1] {
        column = 1
    } else  if tableColumn == tableView.tableColumns[2] {
        column = 2
    } else  if tableColumn == tableView.tableColumns[3] {
        column = 3
    } else {
        column = 4
    }

    if (column != 2) {
        cell = (tableView.makeView(withIdentifier: tableColumn!.identifier, owner: nil) as? NSTableCellView)!
        cell.textField?.stringValue = locationInformationArray[row][column]
    } else { // Column 2/Weather Source
        let result = tableView.makeView(withIdentifier: NSUserInterfaceItemIdentifier(rawValue: "weatherSource"), owner: nil) as! NSPopUpButton
        InitWeatherSourceButton(weatherSourceButton: result)
        result.selectItem(at: Int(locationInformationArray[row][column])!)
        return result
    }

    return cell
} // viewFor (Populate)

// Drag "from"
func tableView(_ tableView: NSTableView,
               writeRowsWith writeRowsWithIndexes: IndexSet,
               to toPasteboard: NSPasteboard) -> Bool {
    print("in writeRowsWith")
    let data = NSKeyedArchiver.archivedData(withRootObject: [writeRowsWithIndexes])
    toPasteboard.declareTypes([NSPasteboard.PasteboardType(rawValue: MyRowType)], owner:self)
    toPasteboard.setData(data, forType:NSPasteboard.PasteboardType(rawValue: MyRowType))

    return true
} // writeRowsWith (From Row)

// Drag "to"
func tableView(_ tableView: NSTableView,
               validateDrop info: NSDraggingInfo,
               proposedRow row: Int,
               proposedDropOperation dropOperation: NSTableView.DropOperation) -> NSDragOperation {

    print("in validateDrop, proposedRow=" + String(describing: row))
    tableView.setDropRow(row, dropOperation: NSTableView.DropOperation.above)
    return NSDragOperation.move
} // validateDrop

// Drag "to"
func tableView(_ tableView: NSTableView,
               acceptDrop info: NSDraggingInfo,
               row: Int,
               dropOperation: NSTableView.DropOperation) -> Bool {
    print("in acceptDrop, row=" + String(describing: row))
    let pasteboard = info.draggingPasteboard()
    let rowData = pasteboard.data(forType: NSPasteboard.PasteboardType(rawValue: MyRowType))

    if(rowData != nil) {
        var dataArray = NSKeyedUnarchiver.unarchiveObject(with: rowData!) as! Array<IndexSet>,
        indexSet = dataArray[0]

        let movingFromIndex = indexSet.first

        //tableView.moveRow(at: movingFromIndex!, to: row) // Can only be done if the Array doesn't need to get re-populated
        _moveItem(from: movingFromIndex!, to: row, array: &locationInformationArray)

        tableView.reloadData()
        return true
    }
    else {
        return false
    }
} // acceptDrop

func tableView(_ tableView: NSTableView,
               draggingSession session: NSDraggingSession,
               endedAt screenPoint: NSPoint,
               operation: NSDragOperation) {
        return
}


// Move row in table array
func _moveItem(from: Int,
               to: Int,
               array: inout [[String]]) {
    //print("in _moveItem")
    let item = array[from]
    array.remove(at: from)

    if(to > array.endIndex) {
        array.append(item)
    }
    else {
        array.insert(item, at: to)
    }
} // _moveItem

And finally, I can't determine which row (and column) is being access by the NSPopUpButton:

@IBAction func popUpSelectionDidChange(_ sender: NSPopUpButton) {
    print("Selected item=" + String(describing: sender.indexOfSelectedItem) + " [" +  String(describing:  tableView.row(for: tableView)) + "][" + String(describing: tableView.column(for: tableView)) + "]" )
}

Both the row and column are always -1.

Any suggestions on how to solve both of my remaining issues (in Swift), drag and drop and which Pop Up button was selected?

Thanks.

Answer 1

You'll save some code if you change the type of MyRowType to NSPasteboard.PasteboardType , eg

fileprivate let MyRowType = NSPasteboard.PasteboardType("com.ed-danley.MyRowType")

The tableView:writeRowsWithIndexes:toPasteboard: and tableView:draggingSession:endedAtPoint: messages are for dragging source support (check NSTableView.h to verify).

The tableView:validateDrop:proposedRow:proposedDropOperation: and tableView:acceptDrop:row:dropOperation: messages are for dragging destination support. My guess is you have not configured the table as a drag destination.

To configure the table view as a drag destination, you must call tableView.registerForDraggedTypes([MyRowType]) . This is actually a method on NSView and it's what tells AppKit that you want this view to be a drag destination. You only need to call this once on the table view, so depending on what kind of controller you're using, viewDidLoad or windowDidLoad may be the appropriate place.