adapterpluggablecoolbook.cs

  using System;
  using System.Collections.Generic;
  using System.Windows.Forms;
  using System.Drawing;
  using System.Threading;

  // Adapter Pattern Example            Judith Bishop Aug 2007
  // Sets up a Coolbook
  // This is D-J's as changed for the book
  class AdapterPattern {

    //class SpaceBookSystem {  

    public delegate void InputEventHandler(object sender, EventArgs e, string s);

    //Adapter
    public class MyCoolBook : MyOpenBook {
      static SortedList<string, MyCoolBook> community =
               new SortedList<string, MyCoolBook>(100);
      Interact visuals;

      public MyCoolBook(string name) : base(name) {
        // create interact on the relavent thread, and start it!
        new Thread(delegate() {
          visuals = new Interact("CoolBook Beta");
          visuals.InputEvent += new InputEventHandler(OnInput);
          visuals.FormClosed += new FormClosedEventHandler(OnFormClosed);
          Application.Run(visuals);
        }).Start();
        community[name] = this;

        while (visuals == null) {
          Application.DoEvents();
          Thread.Sleep(100);
        }

        Add("Welcome to CoolBook " + Name);
      }

      private void OnFormClosed(object sender, FormClosedEventArgs e) {
        community.Remove(Name);
      }

      private void OnInput(object sender, EventArgs e, string s) {
        Add("\r\n");
        Add(s, "Poked you");
      }

      public new void Poke(string who) {
        Add("\r\n");
        if (community.ContainsKey(who))
          community[who].Add(Name, "Poked you");
        else
          Add("Friend " + who + " is not part of the community");
      }

      public new void Add(string message) {
        visuals.Output(message);
      }

      public new void Add(string friend, string message) {
        if (community.ContainsKey(friend))
          community[friend].Add(Name + " : " + message);
        else
          Add("Friend " + friend + " is not part of the community");
      }
    }

    //New Implementation (Adaptee)
    public class Interact : Form {
      public TextBox Wall { get; set; }
      public Button Poke { get; set; }

      public Interact() { }

      public Interact(string title) {
        Control.CheckForIllegalCrossThreadCalls = true;
        Poke = new Button();
        Poke.Text = "Poke";
        this.Controls.Add(Poke);
        Poke.Click += new EventHandler(Input);
        Wall = new TextBox();
        Wall.Multiline = true;
        Wall.Location = new Point(0, 30);
        Wall.Width = 300;
        Wall.Height = 200;
                    Wall.Font = new Font(Wall.Font.Name, 12);
        Wall.AcceptsReturn = true;
        this.Text = title;
        this.Controls.Add(Wall);
      }

      public event InputEventHandler InputEvent;

      public void Input(object source, EventArgs e) {
        string who = Wall.SelectedText;
        if (InputEvent != null)
          InputEvent(this, EventArgs.Empty, who);
      }

      public void Output(string message) {
        if (this.InvokeRequired)
          this.Invoke((MethodInvoker)delegate() { Output(message); });
        else {
          Wall.AppendText(message + "\r\n");
          this.Show();
        }
      }

      protected override void OnFormClosed(FormClosedEventArgs e) {
        // Remove the interact and coolbook from the community here!
        base.OnFormClosed(e);
      }
    }

    // The RealSubject (ProxyPattern)
    // CANNOT CHANGE
    public class SpaceBook {
      static SortedList<string, SpaceBook> community =
            new SortedList<string, SpaceBook>(100);
      string pages;
      string name;
      string gap = "\n\t\t\t\t";

      static public bool Unique(string name) {
        return community.ContainsKey(name);
      }

      internal SpaceBook(string n) {
        name = n;
        community[n] = this;
      }

      internal string Add(string s) {
        pages += gap + s;
        return gap + "======== " + name + "'s SpaceBook =========\n" +
              pages +
              gap + "\n===================================";
      }

      internal string Add(string friend, string message) {
        return community[friend].Add(message);
      }

      internal void Poke(string who, string friend) {
        community[who].pages += gap + friend + " poked you";
      }
    }

    // Target (Adapter Pattern)
    //CANNOT CHANGE
    public class MyOpenBook {

      SpaceBook myOpenBook;
      public string Name { get; set; }
      public static int Users { get; set; }

      public MyOpenBook(string n) {
        Name = n;
        Users++;
        myOpenBook = new SpaceBook(Name + "-" + Users);
      }

      public void Add(string message) {
        Console.WriteLine(myOpenBook.Add(message));
      }

      public void Add(string friend, string message) {
        Console.WriteLine(myOpenBook.Add(friend, Name + " : " + message));
      }

      public void Poke(string who) {
        myOpenBook.Poke(who, Name);
      }

      public void SuperPoke(string who, string what) {
        myOpenBook.Add(who, what + " you");
      }
    }

    // The Client
    static void Main() {
      
      MyCoolBook judith = new MyCoolBook("Judith");
      judith.Add("Hello world");

      MyCoolBook tom = new MyCoolBook("Tom");
      tom.Poke("Judith");
      tom.Add("Hey, We are on CoolBook");
      judith.Poke("Tom");
      Console.ReadLine();
    }
  }