Align control inside NSStackView

Question

I've got NSWindows implementation that is used as modal authorization dialog. The code:

using System;
using AppKit;
using Cairo;

namespace SomeNameSpace
{
  public class DialogWindow : NSWindow
  {
    public DialogWindow() : base()
    {
      var stackView = new NSStackView(){
        AutoresizingMask = NSViewResizingMask.HeightSizable | NSViewResizingMask.WidthSizable,
      };
      stackView.WantsLayer = true;
      stackView.Layer.BackgroundColor = new CoreGraphics.CGColor(255f, 0f, 0f);
      stackView.Alignment = NSLayoutAttribute.Leading;
      stackView.Orientation = NSUserInterfaceLayoutOrientation.Vertical;
      ContentView = stackView; 
      SetFrame(new CoreGraphics.CGRect(Frame.Location, new CoreGraphics.CGSize(300, 210)), true);
      StyleMask |= NSWindowStyle.Closable;
    }

    public void ShowDialog()
    {
      NSApplication.SharedApplication.RunModalForWindow(this);
    }
  }

 public class AuthDialog : DialogWindow
  {
    public AuthDialog() : base()
    {
      var usernameLabel = new NSTextField() {
        StringValue = "Username",
        Editable = false,
        DrawsBackground = false,
        Selectable = false,
        Bezeled = false,
      };
      usernameLabel.SizeToFit();
      var usernameEditor = new NSTextField();
      var passwordLabel = new NSTextField() {
        StringValue = "Password",
        Editable = false,
        DrawsBackground = false,
        Selectable = false,
        Bezeled = false,
      };
      passwordLabel.SizeToFit();
      var passwordEditor = new NSSecureTextField();
      var actionButtonsView = new NSStackView() {
        Orientation = NSUserInterfaceLayoutOrientation.Horizontal,
      };
      actionButtonsView.WantsLayer = true;
      actionButtonsView.Layer.BackgroundColor = new CoreGraphics.CGColor(0f, 255f, 0f);
      var cancelButton = new NSButton() {
        Title = "Cancel",
      };
      var loginButton = new NSButton() {
        Title = "Login",
      };
      actionButtonsView.TranslatesAutoresizingMaskIntoConstraints = false;
      actionButtonsView.AddArrangedSubview(cancelButton);
      actionButtonsView.AddArrangedSubview(loginButton);
      loginButton.SizeToFit();
      var stackView = (NSStackView)ContentView;
      stackView.AddArrangedSubview(usernameLabel);
      stackView.AddArrangedSubview(usernameEditor);
      stackView.AddArrangedSubview(passwordLabel);
      stackView.AddArrangedSubview(passwordEditor);
      stackView.AddArrangedSubview(actionButtonsView);
      ShowsResizeIndicator = false;
    }
  }
}

It simply creates NSStackView based layout. And looks like this:

The question is how can I align last subview (containing buttons) to the right of the parent view (and window)? The programming language doesn't matter. It's easily translated to swift\obj-c and vice-versa.

Answer 1

There is no way to customize the NSStackView itself to achieve this, every view is either leading, trailing, or centered.

However, you can add a constraint to the horizontal stack view that contains the buttons and pin it to the trailing side of the enclosing vertical stack view:

let cancelButton = NSButton(title: "Cancel", target: nil, action: nil)
let loginButton = NSButton(title: "Login", target: nil, action: nil)

// Set content hugging high enough so that the vertical stack view won't
// stretch the buttons in an effort to align them along the leading edge
cancelButton.setContentHuggingPriority(.defaultHigh, for: .horizontal)
loginButton.setContentHuggingPriority(.defaultHigh, for: .horizontal)

// The horizontal stack view's distribution needs to be fill
let horizontalStackView = NSStackView(views: [cancelButton, loginButton])
horizontalStackView.distribution = .fill

stackView.addArrangedSubview(horizontalStackView)

// Pins the buttons to the right (trailing) edge of the vertical stack view
NSLayoutConstraint.activate([
    horizontalStackView.trailingAnchor.constraint(equalTo: stackView.trailingAnchor)
])

Alternatively, you might want to try NSGridView to accomplish layouts like this.