ShrlAlgoToolkit/Melskin/Converters/Internal/CreateSlotClipGeometryConverter.cs

using System.Globalization;
using System.Windows.Data;

namespace Melskin.Converters.Internal;

/// <summary>
/// CreateSlotClipGeometryConverter 是一个实现了 IMultiValueConverter 接口的类，用于根据给定的参数创建一个具有圆角的矩形几何图形。
/// 该转换器接受三个输入值：圆角半径、宽度和高度，并可选地接受一个表示边距的字符串参数。
/// 输出为 RectangleGeometry 对象，可用于定义 UI 元素的剪裁区域。
/// </summary>
internal class CreateSlotClipGeometryConverter : IMultiValueConverter
{
    public static readonly CreateSlotClipGeometryConverter Instance = new();

    //public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    //{
    //    if (values == null || values.Length < 4 ||
    //        values[0] is not CornerRadius radius ||
    //        values[1] is not double width ||
    //        values[2] is not double height ||
    //        values[3] is not double paddingValue)
    //        return null;

    //    var padding = new Thickness(paddingValue);
    //    var rectW = Math.Max(0, width - padding.Left - padding.Right);
    //    var rectH = Math.Max(0, height - padding.Top - padding.Bottom);

    //    var tl = Math.Max(0, radius.TopLeft);
    //    var tr = Math.Max(0, radius.TopRight);
    //    var br = Math.Max(0, radius.BottomRight);
    //    var bl = Math.Max(0, radius.BottomLeft);

    //    double left = padding.Left; double top = padding.Top; double right = left + rectW; double bottom = top + rectH;

    //    // 构造路径
    //    var figure = new PathFigure { IsClosed = true, IsFilled = true, StartPoint = new Point(left + tl, top) };
    //    var segments = new PathSegmentCollection
    //    {
    //        // Top line + TopRight arc
    //        new LineSegment(new Point(right - tr, top), true),
    //        new ArcSegment(new Point(right, top + tr), new Size(tr, tr), 0, false, SweepDirection.Clockwise, true),
    //        // Right line + BottomRight arc
    //        new LineSegment(new Point(right, bottom - br), true),
    //        new ArcSegment(new Point(right - br, bottom), new Size(br, br), 0, false, SweepDirection.Clockwise, true),
    //        // Bottom line + BottomLeft arc
    //        new LineSegment(new Point(left + bl, bottom), true),
    //        new ArcSegment(new Point(left, bottom - bl), new Size(bl, bl), 0, false, SweepDirection.Clockwise, true),
    //        // Left line + TopLeft arc
    //        new LineSegment(new Point(left, top + tl), true),
    //        new ArcSegment(new Point(left + tl, top), new Size(tl, tl), 0, false, SweepDirection.Clockwise, true)
    //    };
    //    figure.Segments = segments;

    //    var geometry = new PathGeometry();
    //    geometry.Figures.Add(figure);
    //    return geometry;
    //}
    public object? Convert(object[]? values, Type targetType, object parameter, CultureInfo culture)
    {
        if (values == null || values.Length < 3 ||
            values[0] is not CornerRadius radius ||
            values[1] is not double width ||
            values[2] is not double height)
            return null;

        var paramStr = parameter as string;
        _ = double.TryParse(paramStr, out var margin);

        var rectW = width - (2 * margin);
        var rectH = height - (2 * margin);

        if (rectW < 0) rectW = 0;
        if (rectH < 0) rectH = 0;

        var left = margin;
        var top = margin;
        var right = left + rectW;
        var bottom = top + rectH;

        var tl = Math.Max(0, radius.TopLeft);
        var tr = Math.Max(0, radius.TopRight);
        var br = Math.Max(0, radius.BottomRight);
        var bl = Math.Max(0, radius.BottomLeft);

        var figure = new PathFigure
        {
            IsClosed = true,
            IsFilled = true,
            StartPoint = new Point(left + tl, top)
        };
        var segments = new PathSegmentCollection
        {
            // Top line + TopRight arc
            new LineSegment(new Point(right - tr, top), true),
            new ArcSegment(new Point(right, top + tr), new Size(tr, tr), 0, false, SweepDirection.Clockwise, true),
            // Right line + BottomRight arc
            new LineSegment(new Point(right, bottom - br), true),
            new ArcSegment(new Point(right - br, bottom), new Size(br, br), 0, false, SweepDirection.Clockwise, true),
            // Bottom line + BottomLeft arc
            new LineSegment(new Point(left + bl, bottom), true),
            new ArcSegment(new Point(left, bottom - bl), new Size(bl, bl), 0, false, SweepDirection.Clockwise, true),
            // Left line + TopLeft arc
            new LineSegment(new Point(left, top + tl), true),
            new ArcSegment(new Point(left + tl, top), new Size(tl, tl), 0, false, SweepDirection.Clockwise, true)
        };
        figure.Segments = segments;

        var geometry = new PathGeometry();
        geometry.Figures.Add(figure);
        return geometry;
    }
    //public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    //{
    //    var radius = (CornerRadius)values[0];
    //    var width = (double)values[1];
    //    var height = (double)values[2];

    //    var paramStr = parameter as string;
    //    _ = double.TryParse(paramStr, out var margin);

    //    var rectW = width - (2 * margin);
    //    var rectH = height - (2 * margin);

    //    //防止初始化时候小于0
    //    if (rectW < 0)
    //    {
    //        rectW = 0;
    //    }
    //    if (rectH < 0)
    //    {
    //        rectH = 0;
    //    }

    //    RectangleGeometry rectangleGeometry = new()
    //    {
    //        RadiusX = radius.BottomLeft,
    //        RadiusY = radius.TopRight,
    //        Rect = new Rect(margin, margin, rectW, rectH),
    //    };

    //    return rectangleGeometry;
    //}
    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}