cross platform, port engine and viewer to avalonia

Is your feature request related to a problem? Please describe. Make the engine and viewer truely crossplatform for at least windows, mac, and linux and possibly android and ios.

Describe the solution you'd like A clear and concise description of what you want to happen.

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've consideredetoforms, mono, skiasharp for drawing, reviving drawing compat, uno, windows only support

Additional context GPT 4 ideas on how to proceed

Converting a WinForms application that uses System.Drawing to Avalonia involves several steps. Here is a guide to help you through the process:

1. Set Up Avalonia Project

First, create a new Avalonia application.

Install Avalonia Templates:
```
dotnet new -i Avalonia.Templates
```

Create a new Avalonia Application:

dotnet new avalonia.app -o YourAvaloniaApp
cd YourAvaloniaApp

Install Required NuGet Packages: Ensure you have the necessary Avalonia packages:

dotnet add package Avalonia.Controls
dotnet add package Avalonia.Desktop
dotnet add package Avalonia.Themes.Fluent
dotnet add package Avalonia.Diagnostics

2. Translate Forms and Controls

WinForms controls and their properties need to be mapped to their Avalonia counterparts.

Example:

WinForms Button to Avalonia Button:

// WinForms
var button = new System.Windows.Forms.Button();
button.Text = "Click Me";
button.Click += Button_Click;

// Avalonia
var button = new Avalonia.Controls.Button();
button.Content = "Click Me";
button.Click += Button_Click;

3. Convert System.Drawing to Avalonia.Media

For drawing operations, you'll need to translate from System.Drawing to Avalonia.Media.

Example:

System.Drawing Rectangle to Avalonia.Rect:

// System.Drawing
var rect = new System.Drawing.Rectangle(10, 10, 100, 100);

// Avalonia
var rect = new Avalonia.Rect(10, 10, 100, 100);

Drawing with Graphics to Drawing with DrawingContext: In WinForms, you might use Graphics to draw directly on the form. In Avalonia, you typically override the Render method and use DrawingContext.

// WinForms
protected override void OnPaint(PaintEventArgs e)
{
  base.OnPaint(e);
  e.Graphics.DrawLine(Pens.Black, 0, 0, 100, 100);
}

// Avalonia
public override void Render(DrawingContext context)
{
  base.Render(context);
  var pen = new Avalonia.Media.Pen(Avalonia.Media.Brushes.Black);
  context.DrawLine(pen, new Avalonia.Point(0, 0), new Avalonia.Point(100, 100));
}

4. Replace Event Handlers

Event handlers in WinForms will need to be translated to Avalonia's event system.

Example:

WinForms Button Click Event to Avalonia Button Click Event:

// WinForms
button.Click += (sender, e) => MessageBox.Show("Button Clicked");

// Avalonia
button.Click += (sender, e) => MessageBox.AvaloniaMessageBox.Show("Button Clicked");

5. Adjust Layouts

WinForms uses a different layout system than Avalonia. You need to translate the layout logic.

Example:

WinForms using Dock and Anchor:

// WinForms
button.Dock = DockStyle.Fill;

// Avalonia
var stackPanel = new StackPanel();
stackPanel.Children.Add(button);

6. Style and Theme Adjustments

Avalonia uses XAML for defining UI components and their styles, which is different from the procedural code-based approach in WinForms.

WinForms to Avalonia XAML:

<!-- WinForms -->
<Button Text="Click Me" />

<!-- Avalonia -->
<Button Content="Click Me" />

7. Running the Application

Ensure your Program.cs is set up correctly to run an Avalonia application.

class Program
{
    // Initialization code. Don't use any Avalonia, third-party APIs or
    // any SynchronizationContext-reliant code before AppMain is called: things aren't initialized
    // properly until then.
    public static void Main(string[] args) => BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);

    // Avalonia configuration, don't remove; also used by visual designer.
    public static AppBuilder BuildAvaloniaApp()
        => AppBuilder.Configure<App>()
            .UsePlatformDetect()
            .LogToTrace();
}

8. Testing and Debugging

After translating your application, test it thoroughly to ensure that all functionality has been correctly ported and that there are no issues.

Summary

Converting a WinForms application to Avalonia involves translating forms, controls, drawing logic, event handlers, and layout management from WinForms and System.Drawing to their Avalonia equivalents. This process requires a detailed and methodical approach to ensure all aspects of the application are correctly migrated.

majorsilence / My-FyiReporting