Wt examples  4.10.4
SimpleChatWidget.C
Go to the documentation of this file.
1 /*
2  * Copyright (C) 2008 Emweb bv, Herent, Belgium.
3  *
4  * See the LICENSE file for terms of use.
5  */
6 
7 #include "SimpleChatWidget.h"
8 #include "SimpleChatServer.h"
9 
10 #include <Wt/WApplication.h>
11 #include <Wt/WContainerWidget.h>
12 #include <Wt/WEnvironment.h>
13 #include <Wt/WInPlaceEdit.h>
14 #include <Wt/WHBoxLayout.h>
15 #include <Wt/WVBoxLayout.h>
16 #include <Wt/WLabel.h>
17 #include <Wt/WLineEdit.h>
18 #include <Wt/WTemplate.h>
19 #include <Wt/WText.h>
20 #include <Wt/WTextArea.h>
21 #include <Wt/WPushButton.h>
22 #include <Wt/WCheckBox.h>
23 
24 #include <iostream>
25 
27  : WContainerWidget(),
28  server_(server),
29  loggedIn_(false),
30  userList_(0),
31  messageReceived_(nullptr)
32 {
34  letLogin();
35 }
36 
38 {
39  messageReceived_.reset();
40  logout();
41 }
42 
44 {
45  if (server_.connect
46  (this, std::bind(&SimpleChatWidget::processChatEvent, this, std::placeholders::_1)))
48 }
49 
51 {
52  if (server_.disconnect(this))
54 }
55 
57 {
58  clear();
59 
60  auto vLayout = setLayout(std::make_unique<Wt::WVBoxLayout>());
61 
62  auto hLayout_(std::make_unique<Wt::WHBoxLayout>());
63  auto hLayout = hLayout_.get();
64  vLayout->addLayout(std::move(hLayout_), 0,
66 
67  hLayout->addWidget(std::make_unique<Wt::WLabel>("User name:"),
69 
70  userNameEdit_ = hLayout->addWidget(std::make_unique<Wt::WLineEdit>(user_),
73 
74  auto button = hLayout->addWidget(std::make_unique<Wt::WPushButton>("Login"),
76 
77  button->clicked().connect(this, &SimpleChatWidget::login);
79 
80  statusMsg_ = vLayout->addWidget(std::make_unique<Wt::WText>());
82 }
83 
85 {
86  if (!loggedIn()) {
87  Wt::WString name = userNameEdit_->text();
88 
89  if (!messageReceived_)
90  messageReceived_ = std::make_unique<Wt::WSound>("sounds/message_received.mp3");
91 
92  if (!startChat(name))
93  statusMsg_->setText("Sorry, name '" + escapeText(name) +
94  "' is already taken.");
95  }
96 }
97 
99 {
100  if (loggedIn()) {
101  loggedIn_ = false;
103  disconnect();
104 
105  letLogin();
106  }
107 }
108 
109 void SimpleChatWidget::createLayout(std::unique_ptr<WWidget> messages, std::unique_ptr<WWidget> userList,
110  std::unique_ptr<WWidget> messageEdit,
111  std::unique_ptr<WWidget> sendButton, std::unique_ptr<WWidget> logoutButton)
112 {
113  /*
114  * Create a vertical layout, which will hold 3 rows,
115  * organized like this:
116  *
117  * WVBoxLayout
118  * --------------------------------------------
119  * | nested WHBoxLayout (vertical stretch=1) |
120  * | | |
121  * | messages | userList |
122  * | (horizontal stretch=1) | |
123  * | | |
124  * --------------------------------------------
125  * | message edit area |
126  * --------------------------------------------
127  * | WHBoxLayout |
128  * | send | logout |
129  * --------------------------------------------
130  */
131  auto vLayout = std::make_unique<Wt::WVBoxLayout>();
132 
133  // Create a horizontal layout for the messages | userslist.
134  auto hLayout = std::make_unique<Wt::WHBoxLayout>();
135 
136  // Choose JavaScript implementation explicitly to avoid log warning (needed for resizable layout)
137  hLayout->setPreferredImplementation(Wt::LayoutImplementation::JavaScript);
138 
139  // Add widget to horizontal layout with stretch = 1
140  messages->setStyleClass("chat-msgs");
141  hLayout->addWidget(std::move(messages), 1);
142 
143  // Add another widget to horizontal layout with stretch = 0
144  userList->setStyleClass("chat-users");
145  hLayout->addWidget(std::move(userList));
146 
147  hLayout->setResizable(0, true);
148 
149  // Add nested layout to vertical layout with stretch = 1
150  vLayout->addLayout(std::move(hLayout), 1);
151 
152  // Add widget to vertical layout with stretch = 0
153  messageEdit->setStyleClass("chat-noedit");
154  vLayout->addWidget(std::move(messageEdit));
155 
156  // Create a horizontal layout for the buttons.
157  hLayout = std::make_unique<Wt::WHBoxLayout>();
158 
159  // Add button to horizontal layout with stretch = 0
160  hLayout->addWidget(std::move(sendButton));
161 
162  // Add button to horizontal layout with stretch = 0
163  hLayout->addWidget(std::move(logoutButton));
164 
165  // Add nested layout to vertical layout with stretch = 0
166  vLayout->addLayout(std::move(hLayout), 0, Wt::AlignmentFlag::Left);
167 
168  this->setLayout(std::move(vLayout));
169 }
170 
172 {
173  return loggedIn_;
174 }
175 
177 {
178  if (flags.test(Wt::RenderFlag::Full)) {
179  if (loggedIn()) {
180  /* Handle a page refresh correctly */
182  doJavaScript("setTimeout(function() { "
183  + messages_->jsRef() + ".scrollTop += "
184  + messages_->jsRef() + ".scrollHeight;}, 0);");
185  }
186  }
187 
188  WContainerWidget::render(flags);
189 }
190 
192 {
193  /*
194  * When logging in, we pass our processChatEvent method as the function that
195  * is used to indicate a new chat event for this user.
196  */
197  if (server_.login(user)) {
198  loggedIn_ = true;
199  connect();
200 
201  user_ = user;
202 
203  clear();
204  userNameEdit_ = 0;
205 
206  auto messagesPtr = std::make_unique<WContainerWidget>();
207  auto userListPtr = std::make_unique<WContainerWidget>();
208  auto messageEditPtr = std::make_unique<Wt::WTextArea>();
209  auto sendButtonPtr = std::make_unique<Wt::WPushButton>("Send");
210  auto logoutButtonPtr = std::make_unique<Wt::WPushButton>("Logout");
211 
212  messages_ = messagesPtr.get();
213  userList_ = userListPtr.get();
214  messageEdit_ = messageEditPtr.get();
215  sendButton_ = sendButtonPtr.get();
216  Wt::Core::observing_ptr<Wt::WPushButton> logoutButton = logoutButtonPtr.get();
217 
218  messageEdit_->setRows(2);
220 
221  // Display scroll bars if contents overflows
223  userList_->setOverflow(Wt::Overflow::Auto);
224 
225  createLayout(std::move(messagesPtr), std::move(userListPtr),
226  std::move(messageEditPtr),
227  std::move(sendButtonPtr), std::move(logoutButtonPtr));
228 
229  /*
230  * Connect event handlers:
231  * - click on button
232  * - enter in text area
233  *
234  * We will clear the input field using a small custom client-side
235  * JavaScript invocation.
236  */
237 
238  // Create a JavaScript 'slot' (JSlot). The JavaScript slot always takes
239  // 2 arguments: the originator of the event (in our case the
240  // button or text area), and the JavaScript event object.
242  ("function(o, e) { setTimeout(function() {"
243  "" + messageEdit_->jsRef() + ".value='';"
244  "}, 0); }");
245 
246  /*
247  * Set the connection monitor
248  *
249  * The connection monitor is a javascript monitor that will
250  * nootify the given object by calling the onChange method to
251  * inform of connection change (use of websockets, connection
252  * online/offline) Here we just disable the TextEdit when we are
253  * offline and enable it once we're back online
254  */
256  "window.monitor={ "
257  "'onChange':function(type, newV) {"
258  "var connected = window.monitor.status.connectionStatus != 0;"
259  "if(connected) {"
260  + messageEdit_->jsRef() + ".disabled=false;"
261  + messageEdit_->jsRef() + ".placeholder='';"
262  "} else { "
263  + messageEdit_->jsRef() + ".disabled=true;"
264  + messageEdit_->jsRef() + ".placeholder='connection lost';"
265  "}"
266  "}"
267  "}"
268  );
269 
270  // Bind the C++ and JavaScript event handlers.
271  if (sendButton_) {
272  sendButton_->clicked().connect(this, &SimpleChatWidget::send);
273  sendButton_->clicked().connect(clearInput_);
274  sendButton_->clicked().connect((WWidget *)messageEdit_,
275  &WWidget::setFocus);
276  }
280  &WWidget::setFocus);
281 
282  // Prevent the enter from generating a new line, which is its default
283  // action
285 
286  if (logoutButton)
287  logoutButton->clicked().connect(this, &SimpleChatWidget::logout);
288 
289  auto nameEdit = std::make_unique<Wt::WInPlaceEdit>();
290  nameEdit->addStyleClass("name-edit");
291  nameEdit->setButtonsEnabled(false);
292  nameEdit->setText(user_);
293  nameEdit->valueChanged().connect(this, &SimpleChatWidget::changeName);
294 
295  Wt::WTemplate *joinMsg = messages_->addWidget(std::make_unique<Wt::WTemplate>(tr("join-msg.template")));
296  joinMsg->bindWidget("name", std::move(nameEdit));
297  joinMsg->setStyleClass("chat-msg");
298 
299  updateUsers();
300 
301  return true;
302  } else
303  return false;
304 }
305 
307 {
308  if (!name.empty()) {
309  if (server_.changeName(user_, name))
310  user_ = name;
311  }
312 }
313 
315 {
316  if (!messageEdit_->text().empty())
318 }
319 
321 {
322  if (userList_) {
323  userList_->clear();
324 
326 
327  UserMap oldUsers = users_;
328  users_.clear();
329 
330  for (SimpleChatServer::UserSet::iterator i = users.begin();
331  i != users.end(); ++i) {
332  Wt::WCheckBox *w = userList_->addWidget(std::make_unique<Wt::WCheckBox>(escapeText(*i)));
333  w->setInline(false);
334 
335  UserMap::const_iterator j = oldUsers.find(*i);
336  if (j != oldUsers.end())
337  w->setChecked(j->second);
338  else
339  w->setChecked(true);
340 
341  users_[*i] = w->isChecked();
342  w->changed().connect(std::bind(&SimpleChatWidget::updateUser, this, w));
343 
344  if (*i == user_)
345  w->setStyleClass("chat-self");
346  }
347  }
348 }
349 
351 { }
352 
354 {
355  users_[b->text()] = b->isChecked();
356 }
357 
359 {
361 
362  /*
363  * This is where the "server-push" happens. The chat server posts to this
364  * event from other sessions, see SimpleChatServer::postChatEvent()
365  */
366 
367  /*
368  * Format and append the line to the conversation.
369  *
370  * This is also the step where the automatic XSS filtering will kick in:
371  * - if another user tried to pass on some JavaScript, it is filtered away.
372  * - if another user did not provide valid XHTML, the text is automatically
373  * interpreted as PlainText
374  */
375 
376  /*
377  * If it is not a plain message, also update the user list.
378  */
379  if (event.type() != ChatEvent::Message) {
380  if (event.type() == ChatEvent::Rename && event.user() == user_)
381  user_ = event.data();
382 
383  updateUsers();
384  }
385 
386  /*
387  * This is the server call: we (schedule to) propagate the updated UI to
388  * the client.
389  *
390  * This schedules an update and returns immediately
391  */
392  app->triggerUpdate();
393 
394  newMessage();
395 
396  /*
397  * Anything else doesn't matter if we are not logged in.
398  */
399  if (!loggedIn())
400  return;
401 
402  bool display = event.type() != ChatEvent::Message
403  || !userList_
404  || (users_.find(event.user()) != users_.end() && users_[event.user()]);
405 
406  if (display) {
407  Wt::WText *w = messages_->addWidget(std::make_unique<Wt::WText>());
408 
409  /*
410  * If it fails, it is because the content wasn't valid XHTML
411  */
415  }
416 
417  w->setInline(false);
418  w->setStyleClass("chat-msg");
419 
420  /*
421  * Leave no more than 100 messages in the back-log
422  */
423  if (messages_->count() > 100)
425 
426  /*
427  * Little javascript trick to make sure we scroll along with new content
428  */
429  app->doJavaScript(messages_->jsRef() + ".scrollTop += "
430  + messages_->jsRef() + ".scrollHeight;");
431 
432  /* If this message belongs to another user, play a received sound */
433  if (event.user() != user_ && messageReceived_)
434  messageReceived_->play();
435  }
436 }
Encapsulate a chat event.
const Wt::WString & user() const
Get the user who caused the event.
const Wt::WString formattedHTML(const Wt::WString &user, Wt::TextFormat format) const
Get the message formatted as HTML, rendered for the given user.
Type type() const
Get the event type.
A simple chat server.
bool changeName(const Wt::WString &user, const Wt::WString &newUser)
Changes the name.
bool disconnect(Client *client)
Disconnect from the chat server.
UserSet users()
Get the users currently logged in.
void logout(const Wt::WString &user)
Logout from the server.
std::set< Wt::WString > UserSet
Typedef for a collection of user names.
bool connect(Client *client, const ChatEventCallback &handleEvent)
Connects to the chat server.
void sendMessage(const Wt::WString &user, const Wt::WString &message)
Send a message on behalve of a user.
Wt::WString suggestGuest()
Get a suggestion for a guest user name.
bool login(const Wt::WString &user)
Try to login with given user name.
bool startChat(const Wt::WString &user)
Start a chat for the given user.
virtual void updateUsers()
void updateUser(Wt::WCheckBox *b)
Wt::WContainerWidget * messages_
Wt::WTextArea * messageEdit_
Wt::WLineEdit * userNameEdit_
SimpleChatWidget(SimpleChatServer &server)
Create a chat widget that will connect to the given server.
void letLogin()
Show a simple login screen.
std::unique_ptr< Wt::WSound > messageReceived_
bool loggedIn() const
Wt::WText * statusMsg_
virtual void createLayout(std::unique_ptr< Wt::WWidget > messages, std::unique_ptr< Wt::WWidget > userList, std::unique_ptr< Wt::WWidget > messageEdit, std::unique_ptr< Wt::WWidget > sendButton, std::unique_ptr< Wt::WWidget > logoutButton)
virtual void render(Wt::WFlags< Wt::RenderFlag > flags)
Wt::Core::observing_ptr< Wt::WContainerWidget > userList_
SimpleChatServer & server_
virtual void newMessage()
Wt::Core::observing_ptr< Wt::WPushButton > sendButton_
void changeName(const Wt::WString &name)
void processChatEvent(const ChatEvent &event)
std::map< Wt::WString, bool > UserMap
~SimpleChatWidget()
Delete a chat widget.
T * get() const noexcept
void preventDefaultAction(bool prevent=true)
Wt::Signals::connection connect(F function)
void setJavaScript(const std::string &javaScript, int nbArgs=0)
void setChecked(bool checked)
const WString text() const
void doJavaScript(const std::string &javascript, bool afterLoaded=true)
static WApplication * instance()
void setConnectionMonitor(const std::string &jsObject)
void enableUpdates(bool enabled=true)
virtual int count() const
virtual void clear()
void setLayout(std::unique_ptr< WLayout > layout)
virtual void addWidget(std::unique_ptr< WWidget > widget)
void setOverflow(Overflow overflow, WFlags< Orientation > orientation=(Orientation::Horizontal|Orientation::Vertical))
bool test(EnumType flag) const
EventSignal & changed()
EventSignal & enterPressed()
const WString & text() const
std::unique_ptr< WObject > removeChild(WObject *child)
bool empty() const
static const WString Empty
virtual void bindWidget(const std::string &varName, std::unique_ptr< WWidget > widget)
virtual void setText(const WString &text)
void setRows(int rows)
const WString & text() const
bool setText(const WString &text)
bool setTextFormat(TextFormat format)
virtual std::vector< WWidget * > children() const override
virtual void doJavaScript(const std::string &javascript) override
virtual void setStyleClass(const WString &styleClass) override
virtual void setInline(bool isInline) override
virtual void setFocus(bool focus) override
std::string jsRef() const
static WString tr(const char *key)