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	connect ()
void	disconnect ()
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 ()
const Wt::WString &	userName () const
Protected Member Functions
virtual void	createLayout (Wt::WWidget messages, Wt::WWidget userList, Wt::WWidget messageEdit, Wt::WWidget sendButton, Wt::WWidget *logoutButton)
virtual void	updateUsers ()
virtual void	newMessage ()
virtual void	render (Wt::WFlags< Wt::RenderFlag > flags)
bool	loggedIn () const
Private Types
typedef std::map< Wt::WString, bool >	UserMap
Private Member Functions
void	login ()
void	changeName (const Wt::WString &name)
void	send ()
void	updateUser ()
void	processChatEvent (const ChatEvent &event)
Private Attributes
UserMap	users_
SimpleChatServer &	server_
bool	loggedIn_
Wt::JSlot	clearInput_
Wt::WString	user_
Wt::WLineEdit *	userNameEdit_
Wt::WText *	statusMsg_
Wt::WContainerWidget *	messages_
Wt::WTextArea *	messageEdit_
Wt::WPushButton *	sendButton_
Wt::WContainerWidget *	userList_
Wt::WSound *	messageReceived_

Detailed Description

A self-contained chat widget.

Definition at line 34 of file SimpleChatWidget.h.

Member Typedef Documentation

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

Definition at line 82 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 28 of file SimpleChatWidget.C.

  : WContainerWidget(parent),
    server_(server),
    loggedIn_(false),
    userList_(0),
    messageReceived_(0)
{
  user_ = server_.suggestGuest();
  letLogin();
}

SimpleChatWidget::~SimpleChatWidget ( )

Delete a chat widget.

Definition at line 40 of file SimpleChatWidget.C.

{
  delete messageReceived_;
  logout();
}

Member Function Documentation

void SimpleChatWidget::changeName ( const Wt::WString & name ) [private]

Definition at line 305 of file SimpleChatWidget.C.

{
  if (!name.empty()) {
    if (server_.changeName(user_, name))
      user_ = name;
  }
}

void SimpleChatWidget::connect ( )

Definition at line 46 of file SimpleChatWidget.C.

{
  if (server_.connect
      (this, boost::bind(&SimpleChatWidget::processChatEvent, this, _1)))
    Wt::WApplication::instance()->enableUpdates(true);
}

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

Reimplemented in PopupChatWidget.

Definition at line 108 of file SimpleChatWidget.C.

{
  /*
   * Create a vertical layout, which will hold 3 rows,
   * organized like this:
   *
   * WVBoxLayout
   * --------------------------------------------
   * | nested WHBoxLayout (vertical stretch=1)  |
   * |                              |           |
   * |  messages                    | userList  |
   * |   (horizontal stretch=1)     |           |
   * |                              |           |
   * --------------------------------------------
   * | message edit area                        |
   * --------------------------------------------
   * | WHBoxLayout                              |
   * | send | logout                            |
   * --------------------------------------------
   */
  WVBoxLayout *vLayout = new WVBoxLayout();

  // Create a horizontal layout for the messages | userslist.
  WHBoxLayout *hLayout = new WHBoxLayout();

  // Add widget to horizontal layout with stretch = 1
  hLayout->addWidget(messages, 1);
  messages->setStyleClass("chat-msgs");

    // Add another widget to horizontal layout with stretch = 0
  hLayout->addWidget(userList);
  userList->setStyleClass("chat-users");

  hLayout->setResizable(0, true);

  // Add nested layout to vertical layout with stretch = 1
  vLayout->addLayout(hLayout, 1);

  // Add widget to vertical layout with stretch = 0
  vLayout->addWidget(messageEdit);
  messageEdit->setStyleClass("chat-noedit");

  // Create a horizontal layout for the buttons.
  hLayout = new WHBoxLayout();

  // Add button to horizontal layout with stretch = 0
  hLayout->addWidget(sendButton);

  // Add button to horizontal layout with stretch = 0
  hLayout->addWidget(logoutButton);

  // Add nested layout to vertical layout with stretch = 0
  vLayout->addLayout(hLayout, 0, AlignLeft);

  setLayout(vLayout);
}

void SimpleChatWidget::disconnect ( )

Definition at line 53 of file SimpleChatWidget.C.

{
  if (server_.disconnect(this))
    Wt::WApplication::instance()->enableUpdates(false);
}

void SimpleChatWidget::letLogin ( )

Show a simple login screen.

Definition at line 59 of file SimpleChatWidget.C.

{
  clear();

  WVBoxLayout *vLayout = new WVBoxLayout();
  setLayout(vLayout);

  WHBoxLayout *hLayout = new WHBoxLayout();
  vLayout->addLayout(hLayout, 0, AlignTop | AlignLeft);

  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);

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

  vLayout->addWidget(statusMsg_ = new WText());
  statusMsg_->setTextFormat(PlainText);
}

bool SimpleChatWidget::loggedIn ( ) const [protected]

Definition at line 167 of file SimpleChatWidget.C.

{
  return loggedIn_;
}

void SimpleChatWidget::login ( ) [private]

Definition at line 83 of file SimpleChatWidget.C.

{
  if (!loggedIn()) {
    WString name = userNameEdit_->text();

    if (!messageReceived_)
      messageReceived_ = new WSound("sounds/message_received.mp3");

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

void SimpleChatWidget::logout ( )

Definition at line 97 of file SimpleChatWidget.C.

{
  if (loggedIn()) {
    loggedIn_ = false;
    server_.logout(user_);
    disconnect();

    letLogin();
  }
}

void SimpleChatWidget::newMessage ( ) [protected, virtual]

Reimplemented in PopupChatWidget.

Definition at line 349 of file SimpleChatWidget.C.

{ }

void SimpleChatWidget::processChatEvent ( const ChatEvent & event ) [private]

Definition at line 358 of file SimpleChatWidget.C.

{
  WApplication *app = WApplication::instance();

  /*
   * This is where the "server-push" happens. The chat server posts to this
   * event from other sessions, see SimpleChatServer::postChatEvent()
   */

  /*
   * 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
   */

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

    updateUsers();
  }

  /*
   * This is the server call: we (schedule to) propagate the updated UI to
   * the client.
   *
   * This schedules an update and returns immediately
   */
  app->triggerUpdate();

  newMessage();

  /*
   * Anything else doesn't matter if we are not logged in.
   */
  if (!loggedIn())
    return;

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

  if (display) {
    WText *w = new WText(messages_);

    /*
     * If it fails, it is because the content wasn't valid XHTML
     */
    if (!w->setText(event.formattedHTML(user_, XHTMLText))) {
      w->setText(event.formattedHTML(user_, PlainText));
      w->setTextFormat(XHTMLText);
    }

    w->setInline(false);
    w->setStyleClass("chat-msg");

    /*
     * Leave no 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_)
      messageReceived_->play();
  }
}

void SimpleChatWidget::render ( Wt::WFlags< Wt::RenderFlag > flags ) [protected, virtual]

Definition at line 172 of file SimpleChatWidget.C.

{
  if (flags & RenderFull) {
    if (loggedIn()) {
      /* Handle a page refresh correctly */
      messageEdit_->setText(WString::Empty);
      doJavaScript("setTimeout(function() { "
                   + messages_->jsRef() + ".scrollTop += "
                   + messages_->jsRef() + ".scrollHeight;}, 0);");
    }
  }

  WContainerWidget::render(flags);
}

void SimpleChatWidget::send ( ) [private]

Definition at line 313 of file SimpleChatWidget.C.

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

SimpleChatServer& SimpleChatWidget::server ( ) [inline]

Definition at line 62 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 187 of file SimpleChatWidget.C.

{
  /*
   * When logging in, we pass our processChatEvent method as the function that
   * is used to indicate a new chat event for this user.
   */
  if (server_.login(user)) {
    loggedIn_ = true;
    connect();

    user_ = user;    

    clear();
    userNameEdit_ = 0;

    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); }");

    /*
     * Set the connection monitor
     *
     * The connection monitor is a javascript monitor that will
     * nootify the given object by calling the onChange method to
     * inform of connection change (use of websockets, connection
     * online/offline) Here we just disable the TextEdit when we are
     * offline and enable it once we're back online
     */
    WApplication::instance()->setConnectionMonitor(
                "window.monitor={ "
                "'onChange':function(type, newV) {"
                  "var connected = window.monitor.status.connectionStatus != 0;"
                  "if(connected) {"
                        + messageEdit_->jsRef() + ".disabled=false;"
                        + messageEdit_->jsRef() + ".placeholder='';"
                  "} else { "
                        + messageEdit_->jsRef() + ".disabled=true;"
                        + messageEdit_->jsRef() + ".placeholder='connection lost';"
                  "}"
                "}"
                "}"
                );

    // 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((WWidget *)messageEdit_,
                                   &WWidget::setFocus);
    messageEdit_->enterPressed().connect((WWidget *)messageEdit_,
                                         &WWidget::setFocus);

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

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

    WInPlaceEdit *nameEdit = new WInPlaceEdit();
    nameEdit->addStyleClass("name-edit");
    nameEdit->setButtonsEnabled(false);
    nameEdit->setText(user_);
    nameEdit->valueChanged().connect(this, &SimpleChatWidget::changeName);

    WTemplate *joinMsg = new WTemplate(tr("join-msg.template"), messages_);
    joinMsg->bindWidget("name", nameEdit);
    joinMsg->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 352 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 319 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(escapeText(*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");
    }
  }
}