QuickLook/QuickLook.Plugin/QuickLook.Plugin.MarkdownViewer/Plugin.cs

// Copyright © 2017 Paddy Xu
// 
// This file is part of QuickLook program.
// 
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

using System;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Windows;
using System.Windows.Threading;
using QuickLook.Common.Plugin;
using QuickLook.Plugin.HtmlViewer;
using UtfUnknown;

namespace QuickLook.Plugin.MarkdownViewer
{
    public class Plugin : IViewer
    {
        private WebpagePanel _panel;

        public int Priority => 0;

        public void Init()
        {
        }

        public bool CanHandle(string path)
        {
            return !Directory.Exists(path) && new[] {".md", ".rmd", ".markdown"}.Any(path.ToLower().EndsWith);
        }

        public void Prepare(string path, ContextObject context)
        {
            context.PreferredSize = new Size(1000, 600);
        }

        public void View(string path, ContextObject context)
        {
            _panel = new WebpagePanel();
            context.ViewerContent = _panel;
            context.Title = Path.GetFileName(path);

            _panel.NavigateToHtml(GenerateMarkdownHtml(path));
            _panel.Dispatcher.Invoke(() => { context.IsBusy = false; }, DispatcherPriority.Loaded);
        }

        public void Cleanup()
        {
            GC.SuppressFinalize(this);

            _panel?.Dispose();
            _panel = null;
        }

        private string GenerateMarkdownHtml(string path)
        {
            var bytes = File.ReadAllBytes(path);
            var encoding = CharsetDetector.DetectFromBytes(bytes).Detected?.Encoding ?? Encoding.Default;

            var md = encoding.GetString(bytes);
            md = WebUtility.HtmlEncode(md);

            var html = Resources.md2html.Replace("{{content}}", md);

            return html;
        }
    }
}