SimpleNote/MainWindow.axaml.cs

using System;
using System.ComponentModel;
using Avalonia;
using Avalonia.Controls;
using System.Reactive.Linq;
using Avalonia.Input;
using Avalonia.Interactivity;
using Avalonia.Media;

namespace SimpleNote;

public partial class MainWindow : Window
{
    private ViewModel viewModel;
    private PixelRect? screen;
    public MainWindow()
    {
        screen = Screens.Primary?.WorkingArea;
        if (screen == null)
        {
            Console.WriteLine("No screen available.");
            Environment.Exit(1);
        }
        
        this.Position = new PixelPoint(screen.Value.Width / 2 - 25, 10);
        this.Width = 50;
        // this.MaxWidth = screen.Value.Width - 100;
        
        InitializeComponent();
        viewModel = new ViewModel();
        DataContext = viewModel;

        this.GetObservable(Window.WidthProperty)
            .Subscribe(width =>
            {
                if (DataContext is ViewModel vm)
                {
                    vm.WindowWidth = (double)width;
                }
            });
    }

    /*
    public void init_TextField(string text)
    {
        var textBlock = new TextBlock
        {
            Text = text,
            FontSize = viewModel.FontSize,
            FontFamily = new FontFamily(FontFamily.DefaultFontFamilyName)
        };
        textBlock.Measure(Size.Infinity);
        viewModel.WindowWidth = textBlock.DesiredSize.Width + 50;
        Note.Text = text;
    }
    */

    public static double TextWidth(string text)
    {
        var textBlock = new TextBlock
        {
            Text = text,
            FontSize = ViewModel._fontSize,
            FontFamily = new FontFamily(FontFamily.DefaultFontFamilyName)
        };
        textBlock.Measure(Size.Infinity);
        return textBlock.DesiredSize.Width + 30 < 60 ? 60 : textBlock.DesiredSize.Width + 30;
    }

    private void TextBox_OnTextChanged(object? sender, TextChangedEventArgs e)
    {
        if (sender == null) return;
        ((TextBox)sender).Width = TextWidth(((TextBox)sender).Text);
        double width = 55;
        foreach (var note in viewModel.Notes)
        {
            width += note.Width + 49;
        }

        if (width == 55) width -= 5;
        
        this.Width = width;
        this.Position = new PixelPoint((int)((screen.Value.Width - width) / 2), 10);
    }

    private void InputElement_OnKeyDown(object? sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter)
            this.Focus();
    }
}