QuickLook/QuickLook/PipeServerManager.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.Diagnostics;
using System.IO;
using System.IO.Pipes;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Threading;

namespace QuickLook
{
    internal static class PipeMessages
    {
        public const string RunAndClose = "QuickLook.App.PipeMessages.RunAndClose";
        public const string Switch = "QuickLook.App.PipeMessages.Switch";
        public const string Invoke = "QuickLook.App.PipeMessages.Invoke";
        public const string Toggle = "QuickLook.App.PipeMessages.Toggle";
        public const string Forget = "QuickLook.App.PipeMessages.Forget";
        public const string Close = "QuickLook.App.PipeMessages.Close";
        public const string Quit = "QuickLook.App.PipeMessages.Quit";
    }

    internal class PipeServerManager : IDisposable
    {
        private const string PipeName = "QuickLook.App.Pipe";
        private static PipeServerManager _instance;

        private NamedPipeServerStream _server;

        public PipeServerManager()
        {
            _server = new NamedPipeServerStream(PipeName, PipeDirection.In);

            new Task(() =>
            {
                using (var reader = new StreamReader(_server))
                {
                    Debug.WriteLine("PipeManager: Ready");

                    while (true)
                    {
                        _server.WaitForConnection();
                        var msg = reader.ReadLine();

                        Debug.WriteLine($"PipeManager: {msg}");

                        // dispatch message
                        if (MessageReceived(msg))
                            return;

                        _server.Disconnect();
                    }
                }
            }).Start();
        }

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

            if (_server != null)
                SendMessage(PipeMessages.Quit);
            _server?.Dispose();
            _server = null;
        }

        public static void SendMessage(string pipeMessage, string path = null)
        {
            if (path == null)
                path = "";

            try
            {
                using (var client = new NamedPipeClientStream(".", PipeName, PipeDirection.Out))
                {
                    client.Connect();

                    using (var writer = new StreamWriter(client))
                    {
                        writer.WriteLine($"{pipeMessage}|{path}");
                        writer.Flush();
                    }
                }
            }
            catch (Exception e)
            {
                Debug.WriteLine(e.ToString());
            }
        }

        private bool MessageReceived(string msg)
        {
            var split = msg.IndexOf('|');
            if (split == -1)
                return false;

            var wParam = msg.Substring(0, split);
            var lParam = msg.Substring(split + 1, msg.Length - split - 1);

            switch (wParam)
            {
                case PipeMessages.RunAndClose:
                    Application.Current.Dispatcher.BeginInvoke(
                        new Action(() => ViewWindowManager.GetInstance().RunAndClosePreview()),
                        DispatcherPriority.ApplicationIdle);
                    return false;
                case PipeMessages.Invoke:
                    Application.Current.Dispatcher.BeginInvoke(
                        new Action(() => ViewWindowManager.GetInstance().InvokePreview(lParam)),
                        DispatcherPriority.ApplicationIdle);
                    return false;
                case PipeMessages.Switch:
                    Application.Current.Dispatcher.BeginInvoke(
                        new Action(() => ViewWindowManager.GetInstance().SwitchPreview(lParam)),
                        DispatcherPriority.ApplicationIdle);
                    return false;
                case PipeMessages.Toggle:
                    Application.Current.Dispatcher.BeginInvoke(
                        new Action(() => ViewWindowManager.GetInstance().TogglePreview(lParam)),
                        DispatcherPriority.ApplicationIdle);
                    return false;
                case PipeMessages.Forget:
                    Application.Current.Dispatcher.BeginInvoke(
                        new Action(() => ViewWindowManager.GetInstance().ForgetCurrentWindow()),
                        DispatcherPriority.ApplicationIdle);
                    return false;
                case PipeMessages.Close:
                    Application.Current.Dispatcher.BeginInvoke(
                        new Action(() => ViewWindowManager.GetInstance().ClosePreview()),
                        DispatcherPriority.ApplicationIdle);
                    return false;
                case PipeMessages.Quit:
                    return true;
                default:
                    return false;
            }
        }

        public static PipeServerManager GetInstance()
        {
            return _instance ?? (_instance = new PipeServerManager());
        }
    }
}