When trying to set text of TextView, it does not display in the application

[HoofedEar]

Here is what I'm currently doing:

In the OnLoaded method of my window, I'm setting the text of my TextView (_textArea in this case) and I've verified that the text is indeed set to that value here, but my application just displays a blank TextView. (base.OnLoaded is blocked by the little popup btw)

What would be the proper way for me to set this TextView so that the value will be displayed?
I want the shown method to be called once, just as the Window is displayed/loaded.

Help is appreciated and let me know if I need to provide more details!

[tznind]

Hi @HoofedEar, glad to hear you are making an application with Terminal.Gui. Its hard to diagnose your problem without seeing more code but the approach should work. Here is a minimum repro that shows that the approach works.

Are there any Threads involved in your code? If you are showing a form from another thread or something that could account in the behaviour you are describing? If so you should make sure to use Application.MainLoop.Invoke(() => { /* do UI code here*/ }); to perform the cross thread operations.

Also make sure that the TextView you are setting the text on is the same one you can see on your window. If you created it but didn't add it to your window that could account for this.

using Terminal.Gui;

Application.Init();

var w = new MyWindow();


Application.Run(w);

Application.Shutdown();

class MyWindow :Window
{
    TextView tv = new TextView
    {
        Width = Dim.Fill(),
        Height = Dim.Fill()
    };

    public MyWindow()
    {
        Add(tv);
    }

    public override void OnLoaded()
    {
        base.OnLoaded();

        tv.Text = "hello";
    }
}

[HoofedEar]

Hey thanks for the quick response! Here is my code for the MainWindow:

public sealed class MainWindow : Window
{
    private readonly TextView _textArea = new()
    {
        Y = 1,
        Width = Dim.Fill(),
        Height = Dim.Fill(),
        WordWrap = true
    };
    
    private readonly StatusBar _statusBar;

    public MainWindow()
    {
        Title = "05/02/2023";

        ColorScheme = new ColorScheme
        {
            Normal = Application.Driver.MakeAttribute(Color.White, Color.Black)
        };

        // Example of keyboard shortcuts
        async void SaveFile() => await SaveFileAsync();

        _statusBar = new StatusBar(new StatusItem[]
        {
            new(Key.AltMask | Key.S, "Save (Alt+S)", SaveFile),
            new(Key.AltMask | Key.Q, "Quit", Quit)
        });
        
        void Quit()
        {
            Application.Shutdown();
        }

        Add(_statusBar);
        Add(_textArea);
    }
    
    public override void OnLoaded()
    {
        Title = FileHelpers.CurrentFile;
        if (File.Exists("text.txt"))
        {
            _textArea.Text = CryptoHelpers.DecryptFile("text.txt", "password123");
        }
        base.OnLoaded();
    }

    private async Task SaveFileAsync()
    {
        var actual = Encoding.UTF8.GetString(_textArea.Text.ToByteArray());
        CryptoHelpers.EncryptFile(actual, "text.txt", "password123");
        _statusBar.Items.First(i => i.Title == "Save (Alt+S)").Title = "File saved!";
        _statusBar.Enabled = false;
        await Task.Delay(1000);
        _statusBar.Items.First(i => i.Title == "File saved!").Title = "Save (Alt+S)";
        _statusBar.Enabled = true;
    }
}

And here is my Program.cs file:

using Jern;
using Terminal.Gui;

Application.Init();
FileHelpers.CurrentFile = DateTime.Now.ToShortDateString().Replace("/", "-");
Application.Run<MainWindow>();

[tznind]

That looks like it should work. When I remove the calls to EncryptFile and replace them with static strings it seems to work ok (see below).

One thing I would try is get rid of the async on SaveFileAsync and getting rid of all calls to await. If that fixes the problem and threading (async) is needed you will need to use Application.MainLoop.Invoke as I described above when making updates to UI elements.

using System.Text;
using Terminal.Gui;


Application.Init();
- FileHelpers.CurrentFile = DateTime.Now.ToShortDateString().Replace("/", "-");
Application.Run<MainWindow>();
public sealed class MainWindow : Window
{
    private readonly TextView _textArea = new()
    {
        Y = 1,
        Width = Dim.Fill(),
        Height = Dim.Fill(),
        WordWrap = true
    };

    private readonly StatusBar _statusBar;

    public MainWindow()
    {
        Title = "05/02/2023";

        ColorScheme = new ColorScheme
        {
            Normal = Application.Driver.MakeAttribute(Color.White, Color.Black)
        };

        // Example of keyboard shortcuts
        async void SaveFile() => await SaveFileAsync();

        _statusBar = new StatusBar(new StatusItem[]
        {
            new(Key.AltMask | Key.S, "Save (Alt+S)", SaveFile),
            new(Key.AltMask | Key.Q, "Quit", Quit)
        });

        void Quit()
        {
            Application.Shutdown();
        }

        Add(_statusBar);
        Add(_textArea);
    }

    public override void OnLoaded()
    {
-         FileHelpers.CurrentFile;
+        Title = "blah";
-         if (File.Exists("text.txt"))
+        if (true)
        {
            _textArea.Text = "double blah";
        }
        base.OnLoaded();
    }

    private async Task SaveFileAsync()
    {
        var actual = Encoding.UTF8.GetString(_textArea.Text.ToByteArray());
-       CryptoHelpers.EncryptFile(actual, "text.txt", "password123");
        _statusBar.Items.First(i => i.Title == "Save (Alt+S)").Title = "File saved!";
        _statusBar.Enabled = false;
        await Task.Delay(1000);
        _statusBar.Items.First(i => i.Title == "File saved!").Title = "Save (Alt+S)";
        _statusBar.Enabled = true;
    }
}

[HoofedEar]

Hm interesting okay! I did the same and try to use a static string and it worked fine, so I'll look at my other methods and see whats going on.
Thank you for the help!

[tznind]

No problem, good luck!