Linux Application.Top renders only after scaling terminal window

Description I’m trying to run my application on Debian, but my Application.Top renders only after i resize my terminal window. This works just fine on Windows. I can write to the terminal with System.Console just fine on Debian before attempting to call Application.Run(). But unlike on Windows, where the Application.Top is rendered immediately after Application.Run() is called, The terminal window stays blank on Debian until the terminal window is resized.

Program entrypoint

    static void Main(string[] args)
    {
        Application.QuitKey = Key.Esc;
        Application.Init();
        _iWnd = new AppWindow("SubTopic",_padding);
        Application.Top.Resized += Top_Resized;
        Application.Top.Add(_iWnd._top);
        Application.Run(Application.Top);
        Application.Shutdown();
    }

The class AppWindow is called just to add padding to the window drawn using a struct. AppWindow class constructor:

        public AppWindow(string title,Padding _pad) {
            Colors.Base.Normal = Application.Driver.MakeAttribute(Color.White, Color.Black);
            _padding = _pad;

            _top = new Toplevel()
            {
                X = 0,
                Y = 0,
                Width = Dim.Fill(),
                Height = Dim.Fill(),
            };

            _window = new Window()
            {
                LayoutStyle = LayoutStyle.Absolute,
                CanFocus = false,
                ColorScheme = Colors.Base,
                Title = title,
                X = _pad.Left,
                Y = _pad.Top,
                Width = Dim.Fill(_pad.Right),
                Height = Dim.Fill(_pad.Bottom),
            };
            //Resize();
            _top.Add(_window);
            _window.Add(_labels);
            Resize();
        }

And the class also includes a function to add labels to the window according to the display size when initialized:

        public void Resize()
        {
            int winHeight;
            _window.GetCurrentHeight(out winHeight);
            if (winHeight == 0) return;
            _labels = new Label[winHeight-1];
            Debug.WriteLine($"  Labels:{_labels.Length}");
            for (int y = 1; y < _labels.Length; y += 4)
            {
                _labels[y] = new Label("┤"+y) { ColorScheme = Colors.Base, X = _padding.Left, Y = y + _padding.Top, };
            }
            _top.Clear();
            _top.Add(_labels);
        }

The Resize mehod is called whenever Application.Top.Resized is invoked.

The same issue persists even with a minimal Window application setup.

Build info Target Framework: .NET7.0 Deployment mode: Self-contained Target Runtime: Linux-x86

Target OS/Shell info OS: Debian GNU/Linux 11 (WSL2) Codename: Bullseye Shell: Tested on : Bash, ZSH, TMUX

[BDisp]

@JesFo , I was playing with this and the problem isn’t TMUX, but with some others Linux terminal. You have to use both events (Resize and Loaded). First of all I have to write this command (export TERM=xterm-256color) on TMUX to have the colors. With the code bellow I could have it always working on load and resizing:

		static void Main(string[] args)
		{
			Application.QuitKey = Key.Esc;
			Application.Init ();
			_iWnd = new AppWindow ("SubTopic", _padding);
			Application.Top.Resized += Top_Resized;
			Application.Top.Loaded += Top_Loaded;
			Application.Top.Add (_iWnd._top);
			Application.Run (Application.Top);
			_iWnd.Dispose ();
			Application.Shutdown ();
		}
		
		private void Top_Loaded ()
		{
			_iWnd.Resize ();
		}

		private void Top_Resized (Size size)
		{
			_iWnd.Resize ();
		}

		public struct Padding {
			public int Left;
			public int Right;
			public int Top;
			public int Bottom;

			public Padding (int len)
			{
				Left = len;
				Right = len;
				Top = len;
				Bottom = len;
			}
		}

		public class AppWindow : Window {
			public Toplevel _top;
			private Window _window;
			private Label [] _labels;

			public AppWindow (string title, Padding _pad)
			{
				Colors.Base.Normal = Application.Driver.MakeAttribute (Color.White, Color.Black);
				_padding = _pad;

				_top = new Toplevel () {
					X = 0,
					Y = 0,
					Width = Dim.Fill (),
					Height = Dim.Fill (),
				};

				_window = new Window () {
					LayoutStyle = LayoutStyle.Absolute,
					CanFocus = false,
					ColorScheme = Colors.Base,
					Title = title,
					X = _pad.Left,
					Y = _pad.Top,
					Width = Dim.Fill (_pad.Right),
					Height = Dim.Fill (_pad.Bottom),
				};
				_top.Add (_window);
				Resize ();
			}

			public void Resize ()
			{
				int winHeight;
				_window.GetCurrentHeight (out winHeight);
				if (_labels != null) {
					foreach (var view in _labels) {
						_top.Remove (view);
						view?.Dispose ();
					}
				}
				if (winHeight == 0) return;
				_labels = new Label [(winHeight / 4) + (winHeight % 4)];
				Debug.WriteLine ($"  Labels:{_labels.Length}");
				int i = 0;
				for (int y = 1; y < winHeight; y += 4) {
					_labels [i] = new Label ("┤" + y) { ColorScheme = Colors.Base, X = _padding.Left, Y = y + _padding.Top, };
					if (y + 4 < winHeight) {
						i++;
					}
				}
				_top.Clear ();
				_top.Add (_labels);
			}
		}

[tig]

Closing as won’t fix: Use Loaded instead.