FontManager.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Windows;
using System.Windows.Media;

namespace WpfRichTextBox
{
    /// <summary>
    /// 字体管理器，用于处理 TextEditorControl 的字体设置
    /// </summary>
    public static class FontManager
    {
        /// <summary>
        /// 为 TextEditorControl 设置字体
        /// </summary>
        /// <param name="control">文本编辑器控件</param>
        /// <param name="fontFamilyName">字体族名称</param>
        /// <param name="fontSize">字体大小</param>
        /// <param name="fontWeight">字体粗细</param>
        /// <param name="fontStyle">字体样式</param>
        public static bool SetFont(Editor control, string fontFamilyName, 
            double fontSize = 14, FontWeight? fontWeight = null, FontStyle? fontStyle = null)
        {
            try
            {
                // 设置字体族
                control.FontFamily = new FontFamily(fontFamilyName);
                
                // 设置字体大小
                control.FontSize = fontSize;
                
                // 设置字体粗细
                if (fontWeight.HasValue)
                    control.FontWeight = fontWeight.Value;
                
                // 设置字体样式
                if (fontStyle.HasValue)
                    control.FontStyle = fontStyle.Value;
                
                // 强制重新渲染
                control.InvalidateVisual();
                
                return true;
            }
            catch (Exception ex)
            {
                // 记录错误或显示消息
                System.Diagnostics.Debug.WriteLine($"设置字体失败: {ex.Message}");
                return false;
            }
        }

        /// <summary>
        /// 从文件加载自定义字体
        /// </summary>
        /// <param name="control">文本编辑器控件</param>
        /// <param name="fontFilePath">字体文件路径</param>
        /// <param name="fontSize">字体大小</param>
        public static bool LoadFontFromFile(Editor control, string fontFilePath, double fontSize = 14)
        {
            try
            {
                if (!File.Exists(fontFilePath))
                {
                    throw new FileNotFoundException($"字体文件不存在: {fontFilePath}");
                }

                // 获取字体文件的目录和文件名
                string fontDirectory = Path.GetDirectoryName(fontFilePath);
                string fontFileName = Path.GetFileNameWithoutExtension(fontFilePath);
                
                // 创建字体族 URI
                string fontUri = $"file:///{fontDirectory.Replace('\\', '/')}#{fontFileName}";
                
                // 设置字体
                control.FontFamily = new FontFamily(fontUri);
                control.FontSize = fontSize;
                
                // 强制重新渲染
                control.InvalidateVisual();
                
                return true;
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine($"从文件加载字体失败: {ex.Message}");
                return false;
            }
        }

        /// <summary>
        /// 从资源加载嵌入的字体
        /// </summary>
        /// <param name="control">文本编辑器控件</param>
        /// <param name="resourcePath">资源路径，例如 "./Fonts/#FontName"</param>
        /// <param name="fontSize">字体大小</param>
        public static bool LoadFontFromResource(Editor control, string resourcePath, double fontSize = 14)
        {
            try
            {
                // 创建字体族，使用 pack URI
                control.FontFamily = new FontFamily(new Uri("pack://application:,,,/"), resourcePath);
                control.FontSize = fontSize;
                
                // 强制重新渲染
                control.InvalidateVisual();
                
                return true;
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine($"从资源加载字体失败: {ex.Message}");
                return false;
            }
        }

        /// <summary>
        /// 获取系统可用字体列表
        /// </summary>
        /// <returns>字体名称列表</returns>
        public static List<string> GetSystemFonts()
        {
            return Fonts.SystemFontFamilies
                .Select(f => f.Source)
                .OrderBy(name => name)
                .ToList();
        }

        /// <summary>
        /// 获取等宽字体列表（适合代码编辑器）
        /// </summary>
        /// <returns>等宽字体名称列表</returns>
        public static List<string> GetMonospaceFonts()
        {
            var monospaceFonts = new List<string>
            {
                "Consolas",
                "Courier New", 
                "Lucida Console",
                "Monaco",
                "Menlo",
                "Source Code Pro",
                "Fira Code",
                "JetBrains Mono",
                "Cascadia Code",
                "DejaVu Sans Mono"
            };

            // 过滤出系统中实际存在的字体
            var systemFonts = GetSystemFonts();
            return monospaceFonts.Where(font => systemFonts.Contains(font)).ToList();
        }

        /// <summary>
        /// 检查字体是否可用
        /// </summary>
        /// <param name="fontFamilyName">字体族名称</param>
        /// <returns>字体是否可用</returns>
        public static bool IsFontAvailable(string fontFamilyName)
        {
            try
            {
                var fontFamily = new FontFamily(fontFamilyName);
                var typeface = new Typeface(fontFamily, FontStyles.Normal, FontWeights.Normal, FontStretches.Normal);
                return typeface.TryGetGlyphTypeface(out _);
            }
            catch
            {
                return false;
            }
        }

        /// <summary>
        /// 设置编程字体（推荐的代码编辑器字体设置）
        /// </summary>
        /// <param name="control">文本编辑器控件</param>
        /// <param name="fontSize">字体大小</param>
        public static void SetProgrammingFont(Editor control, double fontSize = 16)
        {
            var preferredFonts = new[]
            {
                "Cascadia Code",
                "JetBrains Mono", 
                "Fira Code",
                "Source Code Pro",
                "Consolas",
                "Courier New"
            };

            foreach (var font in preferredFonts)
            {
                if (IsFontAvailable(font))
                {
                    SetFont(control, font, fontSize, FontWeights.Normal, FontStyles.Normal);
                    return;
                }
            }

            // 如果都不可用，使用系统默认等宽字体
            SetFont(control, "Courier New", fontSize, FontWeights.Normal, FontStyles.Normal);
        }

        /// <summary>
        /// 应用字体设置配置
        /// </summary>
        /// <param name="control">文本编辑器控件</param>
        /// <param name="config">字体配置</param>
        public static bool ApplyFontConfig(Editor control, FontConfig config)
        {
            return SetFont(control, config.FontFamily, config.FontSize, config.FontWeight, config.FontStyle);
        }
    }

    /// <summary>
    /// 字体配置类
    /// </summary>
    public class FontConfig
    {
        public string FontFamily { get; set; } = "Consolas";
        public double FontSize { get; set; } = 14;
        public FontWeight FontWeight { get; set; } = FontWeights.Normal;
        public FontStyle FontStyle { get; set; } = FontStyles.Normal;

        public FontConfig() { }

        public FontConfig(string fontFamily, double fontSize, FontWeight fontWeight = default, FontStyle fontStyle = default)
        {
            FontFamily = fontFamily;
            FontSize = fontSize;
            FontWeight = fontWeight == default ? FontWeights.Normal : fontWeight;
            FontStyle = fontStyle == default ? FontStyles.Normal : fontStyle;
        }
    }
}