Create view based NSTableView programmatically using Bindings in Swift

问题

I am working through a Cocoa in Swift book and I am stuck in a chapter on Bindings. The book uses nib files but I want to do everything programmatically (since I am joining a team that does not use nibs). The project is to create a view based table with 2 columns and the content of the table is bound to the arrangedObjects of an array controller. The array controller's content is bound to an array of Employee objects (Employee has 2 properties viz. name and salary).

I was able to create the table programmatically like below (one scroll view, one table view, 2 table columns):

let tableWidth = windowWidth! * 0.6
let tableHeight = windowHeight! * 0.8

scrollView = NSScrollView(frame: NSRect(x: windowWidth!*0.05, y: windowHeight!*0.08, width: tableWidth, height: tableHeight))

employeeTable = NSTableView(frame: NSRect(x: 0, y: 0, width: tableWidth, height: tableHeight))
employeeTable?.bind("content", toObject: (self.arrayController)!, withKeyPath: "arrangedObjects", options: nil)

nameColumn = NSTableColumn(identifier: "name column")
nameColumn?.width = tableWidth * 0.4
nameColumn?.headerCell.title = "Name"

raiseColumn = NSTableColumn(identifier: "raise column")
raiseColumn?.width = tableWidth * 0.6
raiseColumn?.headerCell.title = "Raise"

employeeTable?.addTableColumn(nameColumn!)
employeeTable?.addTableColumn(raiseColumn!)
employeeTable?.setDelegate(self)

scrollView?.documentView = employeeTable

As you can see, I have no clue if this table is Cell-based or View-based. How can I tell what my table is based on? Since the chapter is on Bindings, no delegate or data source methods are being used and I would like to do the same.

Next question: Like I said, the book uses NIBs and has ready access to the NSTableView, NSTableCellView and the NSTextField under it. First, the NSTableView's content was bound to the array controller's arrangedObjects. I was able to do this part programmatically since I created the tableView object myself in code. The book then binds the NSTextField's value to the NSTableCellView's objectValue.name (name is one of the Employee object's properties). How do I do this part since I did not create these NSTableCellView and NSTextField objects in my code? Is there a way to access them (assuming my table is even View-based)?

回答1:

I am answering my own question. Note that I am a beginner and do not know if this is the right way to do things. As noted by user stevesilva in the comments of the above question, I had to implement the delegate method tableView:viewForTableColumn:row: to ensure that the table is view based. Within the delegate method I tried to create a NSTableCellView and bind the textField property but this did not work. I had to subclass NSTableCellView, create a new text field property and then bind that property. This is how my delegate eventually looked.

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

    let frameRect = NSRect(x: 0, y: 0, width: tableColumn!.width, height: 20)

    let tableCellView = MyTableCellView(frame: frameRect)

    if tableColumn?.identifier == "name column" {
        tableCellView.aTextField?.bind("value", toObject: tableCellView, withKeyPath: "objectValue.name", options: nil)
    } else if tableColumn?.identifier == "raise column" {
        tableCellView.aTextField?.bind("value", toObject: tableCellView, withKeyPath: "objectValue.raise", options: nil)
    }

    return tableCellView
}

And this is my subclassed NSTableCellView:

class MyTableCellView: NSTableCellView {

    var aTextField: NSTextField?

    override init(frame frameRect: NSRect) {
        super.init(frame: frameRect)
        aTextField = NSTextField(frame: frameRect)
        aTextField?.drawsBackground = false
        aTextField?.bordered = false
        self.addSubview(aTextField!)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

来源：https://stackoverflow.com/questions/34583638/create-view-based-nstableview-programmatically-using-bindings-in-swift

标签

swift

nstableview

cocoa-bindings

nstablecolumn