OSX drag and drop function

Question

This is a bit complicated, but I hope someone can help me. I am trying to create a drag and drop function for my OSX application.

This is how he looks at the moment. Thus, there is only one text field that the user can drag around the view. It's simple enough with one text field, but if there are several text fields, it gets complicated, and I don't know how to approach. This is what I have now:

@IBOutlet weak var test: NSTextField! @IBAction override func mouseDragged(theEvent: NSEvent) { NSCursor.closedHandCursor().set() var event_location = theEvent.locationInWindow test.frame.origin.x = event_location.x - 192 test.frame.origin.y = event_location.y } 

Test is the name of my NSTextField. I know his name, so it’s easy to move. But if the user adds more text fields (see on the left panel), then I don’t know how to handle this text field because I don’t have a name (for example, “test” for the first input).

I add text fields through this code:

  let input = NSTextField(frame: CGRectMake(width, height, 100, 22)) self.MainView.addSubview(input) 

How to determine which text field (if there are several in the view) was selected, and then move the corresponding value using drag and drop?

Drag and Drop works for this single static text field

Answer 1

I prepared an example application, so consider the following:

https://github.com/melifaro-/DraggableNSTextFieldSample

The idea is to introduce a SelectableTextField that inherits from NSTextField . SelectableTextField provides the ability to subscribe to an invited listener for a text field selection event. It has a didSelectCallback block variable where you need to set the processing code. Something like that:

 textField.didSelectCallback = { (textField) in //this peace of code will be performed once mouse down event //was detected on the text field self.currentTextField = textField } 

Using the specified callback mechanism, after selecting a text field, we can save it in the currentTextField variable. Thus, when the mouseDragged function is ViewController , we know currentTextField , and we can handle it accordingly. In the case of the sample application, we need to adjust the start of currentTextField to shift the shift event. Hope it got better now.

PS NSTextField opens for inheritance, so you can freely use our SelectableTextField wherever you use NSTextField, including Interface Builder.

EDIT

I checked your sample. Unfortunately, I cannot commit / create a transfer request to your repository, so find my suggestion here:

 override func viewDidLoad() { super.viewDidLoad() didButtonSelectCallback = { (button) in if let currentButton = self.currentButton { currentButton.highlighted = !currentButton.highlighted if currentButton == button { self.currentButton = nil } else { self.currentButton = button } } else { self.currentButton = button } button.highlighted = !button.highlighted } addButtonAtRandomePlace() addButtonAtRandomePlace() didButtonSelectCallback(button: addButtonAtRandomePlace()) } override func mouseDragged(theEvent: NSEvent) { guard let button = currentButton else { return } NSCursor.closedHandCursor().set() button.frame.origin.x += theEvent.deltaX button.frame.origin.y -= theEvent.deltaY } private func addButtonAtRandomePlace() -> SelectableButton { let viewWidth = self.view.bounds.size.width let viewHeight = self.view.bounds.size.height let x = CGFloat(rand() % Int32((viewWidth - ButtonWidth))) let y = CGFloat(rand() % Int32((viewHeight - ButtonHeight))) let button = SelectableButton(frame: CGRectMake(x, y, ButtonWidth, ButtonHeight)) button.setButtonType(NSButtonType.ToggleButton) button.alignment = NSCenterTextAlignment button.bezelStyle = NSBezelStyle.RoundedBezelStyle button.didSelectCallback = didButtonSelectCallback self.view.addSubview(button) return button }