dotnet-with-claudecode: Skill for Claude Code

Control Base Classes

Basic Control Structure

public class MyButton : Control
{
    private bool _isPressed;

    // Property with invalidation
    public string Text
    {
        get;
        set
        {
            if (field != value)
            {
                field = value;
                InvalidateMeasure();
            }
        }
    } = "";

    // Enable focus by overriding (not setting property)
    public override bool Focusable => true;

    // Measure: calculate desired size
    protected override Size MeasureContent(Size availableSize)
    {
        var factory = GetGraphicsFactory();
        using var ctx = factory.CreateMeasurementContext(GetDpi());
        var textSize = ctx.MeasureText(Text, GetFont());
        return new Size(textSize.Width + Padding.Horizontal, textSize.Height + Padding.Vertical);
    }

    // Render: draw the control
    protected override void OnRender(IGraphicsContext context)
    {
        var bounds = new Rect(0, 0, Bounds.Width, Bounds.Height);

        var bgColor = _isPressed ? Theme.Palette.ButtonPressedBackground
            : IsMouseOver ? Theme.Palette.ButtonHoverBackground
            : Theme.Palette.ButtonFace;

        context.FillRoundedRectangle(bounds, 4, 4, bgColor);
        context.DrawRoundedRectangle(bounds, 4, 4, Theme.Palette.BorderColor, 1);
        context.DrawText(Text, bounds, GetFont(), Foreground,
            TextAlignment.Center, TextAlignment.Center, TextWrapping.NoWrap);
    }
}

Input Handling

// Mouse - note: MouseEventArgs, not MouseButtonEventArgs
protected override void OnMouseDown(MouseEventArgs e)
{
    if (e.LeftButton)
    {
        _isPressed = true;
        // Capture via Window
        var root = FindVisualRoot();
        if (root is Window window)
            window.CaptureMouse(this);
        InvalidateVisual();
        e.Handled = true;
    }
}

protected override void OnMouseUp(MouseEventArgs e)
{
    if (_isPressed)
    {
        _isPressed = false;
        var root = FindVisualRoot();
        if (root is Window window)
            window.ReleaseMouseCapture();
        if (IsMouseOver) Click?.Invoke(this, EventArgs.Empty);
        InvalidateVisual();
    }
}

// Keyboard
protected override void OnKeyDown(KeyEventArgs e)
{
    if (e.Key == Key.Space || e.Key == Key.Enter)
    {
        Click?.Invoke(this, EventArgs.Empty);
        e.Handled = true;
    }
}