Wt examples 3.1.10
Public Member Functions | Protected Member Functions | Private Types | Private Member Functions | Private Attributes
SimpleChatWidget Class Reference

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 (Wt::WWidget *messages, Wt::WWidget *userList, Wt::WWidget *messageEdit, Wt::WWidget *sendButton, Wt::WWidget *logoutButton)
virtual void updateUsers ()
virtual void render (Wt::WFlags< Wt::RenderFlag > flags)

Private Types

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

Private Member Functions

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

Private Attributes

UserMap users_
SimpleChatServerserver_
Wt::JSlot clearInput_
Wt::WString user_
Wt::WLineEdituserNameEdit_
Wt::WTextstatusMsg_
Wt::WContainerWidgetmessages_
Wt::WContainerWidgetmessageEditArea_
Wt::WTextAreamessageEdit_
Wt::WPushButtonsendButton_
Wt::WContainerWidgetuserList_
Wt::WSoundmessageReceived_

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 70 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.

SimpleChatWidget::~SimpleChatWidget ( )

Delete a chat widget.

Definition at line 36 of file SimpleChatWidget.C.

{
  delete messageReceived_;
  logout();
}

Member Function Documentation

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 90 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 |       stretch = 1        |
   * --------------------------------------------
   */
  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 hirozontal 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 stretching spacer to horizontal layout
  hLayout->addStretch(1);

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

  setLayout(vLayout);
}
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);
}
bool SimpleChatWidget::loggedIn ( ) const [private]

Definition at line 152 of file SimpleChatWidget.C.

{
  return !userNameEdit_;
}
void SimpleChatWidget::login ( ) [private]

Definition at line 67 of file SimpleChatWidget.C.

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

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

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

Definition at line 79 of file SimpleChatWidget.C.

{
  if (loggedIn()) {
    server_.logout(user_);

    WApplication::instance()->enableUpdates(false);

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

Definition at line 300 of file SimpleChatWidget.C.

{
  // While in principle we are not receiving chat events when not logged in,
  // We do get the notification that we are logging in, while we are logging in
  if (!loggedIn())
    return;

  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();
  }

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

  if (display) {
    WText *w = new WText(event.formattedHTML(user_), messages_);
    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();
  }

  /*
   * This is the server push action: we propagate the updated UI to the client,
   * (when the event was triggered by another user)
   */
  app->triggerUpdate();
}
void SimpleChatWidget::render ( Wt::WFlags< Wt::RenderFlag >  flags) [protected, virtual]

Definition at line 157 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 258 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 172 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,
                    boost::bind(&SimpleChatWidget::processChatEvent, this, _1))) {
    WApplication::instance()->enableUpdates(true);

    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); }");

    // 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 294 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 264 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

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

Generated on Mon Nov 14 2011 for the C++ Web Toolkit (Wt) by doxygen 1.7.4