Public Member Functions | Protected Member Functions | Private Types | Private Member Functions | Private Attributes

SimpleChatWidget Class Reference
[Chat example]

A self-contained chat widget. More...

#include <SimpleChatWidget.h>

Inheritance diagram for SimpleChatWidget:
Inheritance graph
[legend]

List of all members.

Public Member Functions

 SimpleChatWidget (SimpleChatServer &server, Wt::WContainerWidget *parent=0)
 Create a chat widget that will connect to the given server.
 ~SimpleChatWidget ()
 Delete a chat widget.
void letLogin ()
 Show a simple login screen.
bool startChat (const Wt::WString &user)
 Start a chat for the given user.
void logout ()
SimpleChatServerserver ()
int userCount ()

Protected Member Functions

virtual void createLayout (WWidget *messages, WWidget *userList, WWidget *messageEdit, WWidget *sendButton, WWidget *logoutButton)
virtual void updateUsers ()

Private Types

typedef std::map< Wt::WString,
bool > 
UserMap

Private Member Functions

void login ()
void send ()
void updateUser ()
void processChatEvent (const ChatEvent &event)

Private Attributes

UserMap users_
SimpleChatServerserver_
Wt::WApplicationapp_
Wt::JSlot clearInput_
Wt::WString user_
Wt::WLineEdituserNameEdit_
Wt::WTextstatusMsg_
Wt::WContainerWidgetmessages_
Wt::WContainerWidgetmessageEditArea_
Wt::WTextAreamessageEdit_
Wt::WPushButtonsendButton_
Wt::WContainerWidgetuserList_
boost::signals::connection eventConnection_
Wt::WSound messageReceived_

Detailed Description

A self-contained chat widget.

Definition at line 33 of file SimpleChatWidget.h.


Member Typedef Documentation

typedef std::map<Wt::WString, bool> SimpleChatWidget::UserMap [private]

Definition at line 68 of file SimpleChatWidget.h.


Constructor & Destructor Documentation

SimpleChatWidget::SimpleChatWidget ( SimpleChatServer server,
Wt::WContainerWidget parent = 0 
)

Create a chat widget that will connect to the given server.

Definition at line 26 of file SimpleChatWidget.C.

  : WContainerWidget(parent),
    server_(server),
    app_(WApplication::instance()),
    messageReceived_("sounds/message_received.mp3")
{
  user_ = server_.suggestGuest();
  letLogin();
}
SimpleChatWidget::~SimpleChatWidget (  )

Delete a chat widget.

Definition at line 37 of file SimpleChatWidget.C.

{
  logout();
}

Member Function Documentation

virtual void SimpleChatWidget::createLayout ( WWidget messages,
WWidget userList,
WWidget messageEdit,
WWidget sendButton,
WWidget logoutButton 
) [protected, virtual]
void SimpleChatWidget::letLogin (  )

Show a simple login screen.

Definition at line 42 of file SimpleChatWidget.C.

{
  clear();

  WVBoxLayout *vLayout = new WVBoxLayout();
  setLayout(vLayout, AlignLeft | AlignTop);

  WHBoxLayout *hLayout = new WHBoxLayout();
  vLayout->addLayout(hLayout);

  hLayout->addWidget(new WLabel("User name:"), 0, AlignMiddle);
  hLayout->addWidget(userNameEdit_ = new WLineEdit(user_), 0, AlignMiddle);
  userNameEdit_->setFocus();

  WPushButton *b = new WPushButton("Login");
  hLayout->addWidget(b, 0, AlignMiddle);
  hLayout->addStretch(1);

  b->clicked().connect(this, &SimpleChatWidget::login);
  userNameEdit_->enterPressed().connect(this, &SimpleChatWidget::login);

  vLayout->addWidget(statusMsg_ = new WText());
  statusMsg_->setTextFormat(PlainText);
}
void SimpleChatWidget::login (  ) [private]

Definition at line 67 of file SimpleChatWidget.C.

{
  WString name = WWebWidget::escapeText(userNameEdit_->text());

  if (!startChat(name))
    statusMsg_->setText("Sorry, name '" + name + "' is already taken.");
}
void SimpleChatWidget::logout (  )

Definition at line 75 of file SimpleChatWidget.C.

{
  if (eventConnection_.connected()) {
    eventConnection_.disconnect(); // do not listen for more events
    server_.logout(user_);

    app_->enableUpdates(false);

    letLogin();
  }
}
void SimpleChatWidget::processChatEvent ( const ChatEvent event ) [private]

Definition at line 277 of file SimpleChatWidget.C.

{
  /*
   * This is where the "server-push" happens. This method is called
   * when a new event or message needs to be notified to the user. In
   * general, it is called from another session.
   */

  /*
   * First, take the lock to safely manipulate the UI outside of the
   * normal event loop, by having exclusive access to the session.
   */
  WApplication::UpdateLock lock(app_);

  if (lock) {
    /*
     * Format and append the line to the conversation.
     *
     * This is also the step where the automatic XSS filtering will kick in:
     * - if another user tried to pass on some JavaScript, it is filtered away.
     * - if another user did not provide valid XHTML, the text is automatically
     *   interpreted as PlainText
     */
    bool needPush = false;

    /*
     * If it is not a normal message, also update the user list.
     */
    if (event.type() != ChatEvent::Message) {
      if (event.type() == ChatEvent::Rename
          && event.user() == user_)
        user_ = event.data();

      needPush = true;
      updateUsers();
    }

    bool display = event.type() != ChatEvent::Message
      || !userList_
      || (users_.find(event.user()) != users_.end() && users_[event.user()]);

    if (display) {
      needPush = true;

      WText *w = new WText(event.formattedHTML(user_), messages_);
      w->setInline(false);
      w->setStyleClass("chat-msg");

      /*
       * Leave not more than 100 messages in the back-log
       */
      if (messages_->count() > 100)
        delete messages_->children()[0];

      /*
       * Little javascript trick to make sure we scroll along with new content
       */
      app_->doJavaScript(messages_->jsRef() + ".scrollTop += "
                         + messages_->jsRef() + ".scrollHeight;");

      /* If this message belongs to another user, play a received sound */
      if (event.user() != user_)
        messageReceived_.play();
    }

    if (needPush)
      app_->triggerUpdate();
  }
}
void SimpleChatWidget::send (  ) [private]

Definition at line 235 of file SimpleChatWidget.C.

SimpleChatServer& SimpleChatWidget::server (  ) [inline]

Definition at line 56 of file SimpleChatWidget.h.

{ return server_; }
bool SimpleChatWidget::startChat ( const Wt::WString user )

Start a chat for the given user.

Returns false if the user could not login.

Definition at line 149 of file SimpleChatWidget.C.

{
  if (server_.login(user)) {
    // this widget supports server-side updates its processChatEvent()
    // method is connected to a slot that is triggered from outside this
    // session's event loop (usually because another user enters text).
    app_->enableUpdates(true);

    // FIXME, chatEvent() needs to be protected by the server mutex too
    eventConnection_
      = server_.chatEvent().connect(this, &SimpleChatWidget::processChatEvent);
    user_ = user;    

    clear();

    messages_ = new WContainerWidget();
    userList_ = new WContainerWidget();
    messageEdit_ = new WTextArea();
    messageEdit_->setRows(2);
    messageEdit_->setFocus();

    // Display scroll bars if contents overflows
    messages_->setOverflow(WContainerWidget::OverflowAuto);
    userList_->setOverflow(WContainerWidget::OverflowAuto);

    sendButton_ = new WPushButton("Send");
    WPushButton *logoutButton = new WPushButton("Logout");

    createLayout(messages_, userList_, messageEdit_, sendButton_, logoutButton);

    /*
     * Connect event handlers:
     *  - click on button
     *  - enter in text area
     *
     * We will clear the input field using a small custom client-side
     * JavaScript invocation.
     */

    // Create a JavaScript 'slot' (JSlot). The JavaScript slot always takes
    // 2 arguments: the originator of the event (in our case the
    // button or text area), and the JavaScript event object.
    clearInput_.setJavaScript
      ("function(o, e) { setTimeout(function() {"
       "" + messageEdit_->jsRef() + ".value='';"
       "}, 0); }");

    // Bind the C++ and JavaScript event handlers.
    sendButton_->clicked().connect(this, &SimpleChatWidget::send);
    messageEdit_->enterPressed().connect(this, &SimpleChatWidget::send);
    sendButton_->clicked().connect(clearInput_);
    messageEdit_->enterPressed().connect(clearInput_);
    sendButton_->clicked().connect(messageEdit_, &WLineEdit::setFocus);
    messageEdit_->enterPressed().connect(messageEdit_, &WLineEdit::setFocus);

    // Prevent the enter from generating a new line, which is its default
    // action
    messageEdit_->enterPressed().preventDefaultAction();

    logoutButton->clicked().connect(this, &SimpleChatWidget::logout);

    WText *msg = new WText
      ("<div><span class='chat-info'>You are joining as "
       + user_ + ".</span></div>", messages_);
    msg->setStyleClass("chat-msg");

    if (!userList_->parent()) {
      delete userList_;
      userList_ = 0;
    }

    if (!sendButton_->parent()) {
      delete sendButton_;
      sendButton_ = 0;
    }

    if (!logoutButton->parent())
      delete logoutButton;

    updateUsers();
    
    return true;
  } else
    return false;
}
void SimpleChatWidget::updateUser (  ) [private]

Definition at line 271 of file SimpleChatWidget.C.

{
  WCheckBox *b = dynamic_cast<WCheckBox *>(sender());
  users_[b->text()] = b->isChecked();
}
void SimpleChatWidget::updateUsers (  ) [protected, virtual]

Reimplemented in PopupChatWidget.

Definition at line 241 of file SimpleChatWidget.C.

{
  if (userList_) {
    userList_->clear();

    SimpleChatServer::UserSet users = server_.users();

    UserMap oldUsers = users_;
    users_.clear();

    for (SimpleChatServer::UserSet::iterator i = users.begin();
         i != users.end(); ++i) {
      WCheckBox *w = new WCheckBox(*i, userList_);
      w->setInline(false);

      UserMap::const_iterator j = oldUsers.find(*i);
      if (j != oldUsers.end())
        w->setChecked(j->second);
      else
        w->setChecked(true);

      users_[*i] = w->isChecked();
      w->changed().connect(this, &SimpleChatWidget::updateUser);

      if (*i == user_)
        w->setStyleClass("chat-self");
    }
  }
}
int SimpleChatWidget::userCount (  ) [inline]

Definition at line 58 of file SimpleChatWidget.h.

{ return users_.size(); }

Member Data Documentation

Definition at line 72 of file SimpleChatWidget.h.

Definition at line 74 of file SimpleChatWidget.h.

boost::signals::connection SimpleChatWidget::eventConnection_ [private]

Definition at line 87 of file SimpleChatWidget.h.

Definition at line 83 of file SimpleChatWidget.h.

Definition at line 82 of file SimpleChatWidget.h.

Definition at line 89 of file SimpleChatWidget.h.

Definition at line 81 of file SimpleChatWidget.h.

Definition at line 84 of file SimpleChatWidget.h.

Definition at line 71 of file SimpleChatWidget.h.

Definition at line 79 of file SimpleChatWidget.h.

Definition at line 76 of file SimpleChatWidget.h.

Definition at line 85 of file SimpleChatWidget.h.

Definition at line 78 of file SimpleChatWidget.h.

Definition at line 69 of file SimpleChatWidget.h.


The documentation for this class was generated from the following files:

Generated on Fri Feb 4 2011 for the C++ Web Toolkit (Wt) by doxygen 1.7.2