MyAvaloniaDemo/AuroraDesk.Presentation/Converters/NodeCanvasConverters.cs

using Avalonia.Data.Converters;
using Avalonia.Media;
using Avalonia;
using AuroraDesk.Core.Entities;
using System;
using System.Collections.ObjectModel;
using System.Globalization;
using System.Linq;

namespace AuroraDesk.Presentation.Converters;

/// <summary>
/// 节点画布相关转换器
/// </summary>
public static class NodeCanvasConverters
{
    public static readonly IValueConverter BooleanToBorderBrushConverter = new BooleanToBorderBrushConverter();
    public static readonly IValueConverter BooleanToBorderThicknessConverter = new BooleanToBorderThicknessConverter();
    public static readonly IValueConverter FilterInputPointsConverter = new FilterInputPointsConverter();
    public static readonly IValueConverter FilterOutputPointsConverter = new FilterOutputPointsConverter();
    public static readonly IValueConverter NodeToSelectionTextConverter = new NodeToSelectionTextConverter();
    public static readonly IValueConverter IsNotNullConverter = new IsNotNullConverter();
}

/// <summary>
/// 布尔值到边框颜色转换器（选中时显示蓝色边框）
/// </summary>
public class BooleanToBorderBrushConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is bool isSelected && isSelected)
        {
            // 使用 StaticResource 的颜色，如果无法获取则使用默认蓝色
            try
            {
                var color = Color.Parse("#3498DB"); // PrimaryBlue
                return new SolidColorBrush(color);
            }
            catch
            {
                return new SolidColorBrush(Color.FromRgb(52, 152, 219)); // #3498DB
            }
        }
        return new SolidColorBrush(Colors.Transparent);
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 布尔值到边框厚度转换器（选中时显示边框）
/// </summary>
public class BooleanToBorderThicknessConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is bool isSelected && isSelected)
        {
            return new Thickness(2);
        }
        return new Thickness(0);
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 过滤输入连接点转换器
/// </summary>
public class FilterInputPointsConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is ObservableCollection<ConnectionPoint> points)
        {
            return points.Where(p => p.Type == ConnectionPointType.Input).ToList();
        }
        return Enumerable.Empty<ConnectionPoint>();
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 过滤输出连接点转换器
/// </summary>
public class FilterOutputPointsConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is ObservableCollection<ConnectionPoint> points)
        {
            return points.Where(p => p.Type == ConnectionPointType.Output).ToList();
        }
        return Enumerable.Empty<ConnectionPoint>();
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 节点到选择文本转换器
/// </summary>
public class NodeToSelectionTextConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        if (value is Node node)
        {
            return $"已选中1个对象 (节点)";
        }
        return "未选中对象";
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

/// <summary>
/// 非空转换器（用于控制可见性）
/// </summary>
public class IsNotNullConverter : IValueConverter
{
    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        return value != null;
    }

    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}