Communicating from the Browser to a Desktop Application

// BrowserSpeak
//
// by Mark Gladding
// Copyright 2009 Tumbywood Software
// http://www.text2go.com
//
// You are free to reuse this code in any commercial or non-commercial work.
//

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Speech.Synthesis;

using BrowserSpeak.Speech;
using HttpServer;

namespace BrowserSpeak
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
            Icon = Properties.Resources.BrowserSpeak;

            mShowHttpRequestDelegate = ShowHttpRequest;
            mUpdateTextBoxDelegate = UpdateTextBoxContents;
            SpeechController.Instance.StateChanged += new EventHandler<StateChangedEventArgs>(SpeechStateChanged);
            TextBuffer.Instance.TextBufferChanged += new EventHandler(OnTextBufferChanged);
            UpdateButtonStates();
            StartHttpCommandDispatcher();
        }

        private void StartHttpCommandDispatcher()
        {
            mCmdDispatcher.AddResourceLocator(new ImageLocator(Properties.Resources.ResourceManager));
            mCmdDispatcher.AddCommand(new SpeakTextCommand());
            mCmdDispatcher.AddCommand(new StopSpeakingCommand());
            mCmdDispatcher.AddCommand(new BufferTextCommand());
            mCmdDispatcher.AddCommand(new PauseSpeakingCommand());
            mCmdDispatcher.AddCommand(new ResumeSpeakingCommand());

            mCmdDispatcher.RequestReceived += new HttpCommandDispatcher.RequestReceivedHandler(OnHttpRequestReceived);
            mCmdDispatcher.Start("http://localhost:60024/");
        }

        private void SpeechStateChanged(object sender, StateChangedEventArgs e)
        {
            UpdateButtonStates();
        }

        private void UpdateButtonStates()
        {
            SynthesizerState state = SpeechController.Instance.State;
            mButtonStop.Enabled = state != SynthesizerState.Ready;
            mButtonPauseResume.Enabled = state != SynthesizerState.Ready;
            mButtonPauseResume.Text = state == SynthesizerState.Paused ? "Resume" : "Pause";
            mButtonPauseResume.Image = state == SynthesizerState.Paused ? Properties.Resources.resultset_next : Properties.Resources.pause_icon;
        }

        private void OnButtonSpeakClick(object sender, EventArgs e)
        {
            SpeechController.Instance.Speak(mTextBoxSpeak.Text);
        }

        private void OnButtonPauseResumeClick(object sender, EventArgs e)
        {
            if (SpeechController.Instance.State == SynthesizerState.Paused)
            {
                SpeechController.Instance.ResumeSpeaking();
            }
            else
            {
                SpeechController.Instance.PauseSpeaking();
            }
        }

        private void OnButtonStopClick(object sender, EventArgs e)
        {
            SpeechController.Instance.StopSpeaking();
        }

        private void OnButtonClearRequestsClick(object sender, EventArgs e)
        {
            mTextBoxRequests.Text = string.Empty;
        }

        private void OnHttpRequestReceived(object source, RequestEventArgs e)
        {
            // A HttpRequest is processed by a thread from the thread pool,
            // not the GUI thread. Therefore we need to switch back to the
            // GUI thread before modifying any GUI controls.
            BeginInvoke(mShowHttpRequestDelegate, e.Request);
        }

        private void OnTextBufferChanged(object sender, EventArgs e)
        {
            // The TextBuffer is modified by a thread from the thread pool,
            // not the GUI thread. Therefore we need to switch back to the
            // GUI thread before modifying any GUI controls.
            BeginInvoke(mUpdateTextBoxDelegate, TextBuffer.Instance.Text);
        }

        private void UpdateTextBoxContents(string newContents)
        {
            mTextBoxSpeak.Text = newContents;
            ScrollTextBoxToEnd(mTextBoxSpeak);
        }

        private void ScrollTextBoxToEnd(TextBox textBox)
        {
            textBox.Select(textBox.Text.Length, 0);
            textBox.ScrollToCaret();
        }

        private void ShowHttpRequest(string request)
        {
            mTextBoxRequests.Text += request + "\r\n";
            ScrollTextBoxToEnd(mTextBoxRequests);
        }

        private delegate void ShowHttpRequestDelgate(string request);
        ShowHttpRequestDelgate mShowHttpRequestDelegate;

        private delegate void UpdateTextBoxDelgate(string newContents);
        UpdateTextBoxDelgate mUpdateTextBoxDelegate;

        private HttpCommandDispatcher mCmdDispatcher = new HttpCommandDispatcher(Properties.Resources.dummy);

        private void OnButtonAboutClick(object sender, EventArgs e)
        {
            AboutForm aboutForm = new AboutForm();
            aboutForm.ShowDialog();
        }
    }
}