A self-contained chat widget. More...

#include <SimpleChatWidget.h>

Inheritance diagram for SimpleChatWidget:

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 ()
SimpleChatServer &	server ()
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_
SimpleChatServer &	server_
Wt::WApplication *	app_
Wt::JSlot	clearInput_
Wt::WString	user_
Wt::WLineEdit *	userNameEdit_
Wt::WText *	statusMsg_
Wt::WContainerWidget *	messages_
Wt::WContainerWidget *	messageEditArea_
Wt::WTextArea *	messageEdit_
Wt::WPushButton *	sendButton_
Wt::WContainerWidget *	userList_
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.

{
  if (!messageEdit_->text().empty())
    server_.sendMessage(user_, messageEdit_->text());
}

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");
    }
  }
}