Implement a chromoting client using X11

remoting/client/x11_client.cc

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// This file implements a X11 chromoting client.
+
+#include <iostream>
+
+#include "base/at_exit.h"
+#include "base/message_loop.h"
+#include "base/stl_util-inl.h"
+#include "remoting/client/host_connection.h"
+#include "remoting/client/client_util.h"
+
+// Include Xlib at the end because it clashes with ClientMessage defined in
+// the protocol buffer.
+// x11_view.h also includes Xlib.h so put it behind all other headers but
+// before Xlib.h
+#include "remoting/client/x11_view.h"
+#include <X11/Xlib.h>
+
+namespace remoting {
+
+class X11Client : public base::RefCountedThreadSafe<X11Client>,
+                  public HostConnection::EventHandler {
+ public:
+  X11Client(std::string host_jid, std::string username, std::string auth_token)
+      : display_(NULL),
+        window_(0),
+        width_(0),
+        height_(0),
+        host_jid_(host_jid),
+        username_(username),
+        auth_token_(auth_token) {
+  }
+
+  virtual ~X11Client() {
+    DCHECK(!display_);
+    DCHECK(!window_);
+  }
+
+  // Starts the remoting client and the message loop. Returns only after
+  // the message loop has terminated.
+  void Run() {
+    message_loop_.PostTask(FROM_HERE,
+                        NewRunnableMethod(this, &X11Client::DoInitX11));
+    message_loop_.PostTask(FROM_HERE,
+                        NewRunnableMethod(this, &X11Client::DoInitConnection));
+    message_loop_.Run();
+  }
+
+  ////////////////////////////////////////////////////////////////////////////
+  // HostConnection::EventHandler implementations.
+  virtual void HandleMessages(HostConnection* conn,
+                              remoting::HostMessageList* messages) {
+    for (size_t i = 0; i < messages->size(); ++i) {
+      HostMessage* msg = (*messages)[i];
+      if (msg->has_init_client()) {
+        message_loop_.PostTask(
+            FROM_HERE, NewRunnableMethod(this, &X11Client::DoInitClient, msg));
+      } else if (msg->has_begin_update_stream()) {
+        message_loop_.PostTask(
+            FROM_HERE,
+            NewRunnableMethod(this, &X11Client::DoBeginUpdate, msg));
+      } else if (msg->has_update_stream_packet()) {
+        message_loop_.PostTask(
+            FROM_HERE,
+            NewRunnableMethod(this, &X11Client::DoHandleUpdate, msg));
+      } else if (msg->has_end_update_stream()) {
+        message_loop_.PostTask(
+            FROM_HERE, NewRunnableMethod(this, &X11Client::DoEndUpdate, msg));
+      } else {
+        NOTREACHED() << "Unknown message received";
+      }
+    }
+    // Assume we have processed all the messages.
+    messages->clear();
+  }
+
+  virtual void OnConnectionOpened(HostConnection* conn) {
+    std::cout << "Connection establised." << std::endl;
+  }
+
+  virtual void OnConnectionClosed(HostConnection* conn) {
+    std::cout << "Connection closed." << std::endl;
+    Exit();
+  }
+
+  virtual void OnConnectionFailed(HostConnection* conn) {
+    std::cout << "Conection failed." << std::endl;
+    Exit();
+  }
+
+ private:
+  void DoInitX11() {
+    display_ = XOpenDisplay(NULL);
+    if (!display_) {
+      std::cout << "Error - cannot open display" << std::endl;
+      Exit();
+    }
+
+    // Get properties of the screen.
+    int screen = DefaultScreen(display_);
+    int root_window = RootWindow(display_, screen);
+
+    // Creates the window.
+    window_ = XCreateSimpleWindow(display_, root_window, 1, 1, 640, 480, 0,
+                                  BlackPixel(display_, screen),
+                                  BlackPixel(display_, screen));
+    DCHECK(window_);
+    XStoreName(display_, window_, "X11 Remoting");
+
+    // Specifies what kind of messages we want to receive.
+    XSelectInput(display_, window_, ExposureMask | ButtonPressMask);
+    XMapWindow(display_, window_);
+  }
+
+  void DoInitConnection() {
+    // If the initialization of X11 has failed then return directly.
+    if (!display_)
+      return;
+
+    // Creates a HostConnection object and connection to the host.
+    LOG(INFO) << "Connecting...";
+    connection_.reset(new HostConnection(new ProtocolDecoder(), this));
+    connection_->Connect(username_, auth_token_, host_jid_);
+  }
+
+  void DoDestroyX11() {
+    if (display_ && window_) {
+      // Shutdown the window system.
+      XDestroyWindow(display_, window_);
+      XCloseDisplay(display_);
+      display_ = NULL;
+      window_ = 0;
+    }
+  }
+
+  void DoDisconnect() {
+    if (connection_.get())
+      connection_->Disconnect();
+  }
+
+  void Exit() {
+    // Disconnect the jingle channel and client.
+    message_loop_.PostTask(FROM_HERE,
+                        NewRunnableMethod(this, &X11Client::DoDisconnect));
+
+    // Post a task to shutdown X11.
+    message_loop_.PostTask(FROM_HERE,
+                        NewRunnableMethod(this, &X11Client::DoDestroyX11));
+
+    // Quit the current message loop.
+    message_loop_.PostTask(FROM_HERE, new MessageLoop::QuitTask());
+  }
+
+  // This method is executed on the main loop.
+  void DoInitClient(HostMessage* msg) {
+    DCHECK_EQ(&message_loop_, MessageLoop::current());
+    DCHECK(msg->has_init_client());
+    scoped_ptr<HostMessage> deleter(msg);
+
+    // Saves the dimension and resize the window.
+    width_ = msg->init_client().width();
+    height_ = msg->init_client().height();
+    LOG(INFO) << "Init client receievd: " << width_ << "x" << height_;
+    XResizeWindow(display_, window_, width_, height_);
+
+    // Now construct the X11View that renders the remote desktop.
+    view_ = new X11View(display_, window_, width_, height_);
+
+    // Schedule the event handler to process the event queue of X11.
+    ScheduleX11EventHandler();
+  }
+
+  // The following methods are executed on the same thread as libjingle.
+  void DoBeginUpdate(HostMessage* msg) {
+    DCHECK_EQ(&message_loop_, MessageLoop::current());
+    DCHECK(msg->has_begin_update_stream());
+
+    view_->HandleBeginUpdateStream(msg);
+  }
+
+  void DoHandleUpdate(HostMessage* msg) {
+    DCHECK_EQ(&message_loop_, MessageLoop::current());
+    DCHECK(msg->has_update_stream_packet());
+
+    view_->HandleUpdateStreamPacket(msg);
+  }
+
+  void DoEndUpdate(HostMessage* msg) {
+    DCHECK_EQ(&message_loop_, MessageLoop::current());
+    DCHECK(msg->has_end_update_stream());
+
+    view_->HandleEndUpdateStream(msg);
+  }
+
+  void DoProcessX11Events() {
+    DCHECK_EQ(&message_loop_, MessageLoop::current());
+    if (XPending(display_)) {
+      XEvent e;
+      XNextEvent(display_, &e);
+      if (e.type == Expose) {
+        // Tell the ChromotingView to paint again.
+        view_->Paint();
+      } else if (e.type == ButtonPress) {
+        // TODO(hclam): Implement.
+        NOTIMPLEMENTED();
+      } else {
+        // TODO(hclam): Implement.
+        NOTIMPLEMENTED();
+      }
+    }
+
+    // Schedule the next event handler.
+    ScheduleX11EventHandler();
+  }
+
+  void ScheduleX11EventHandler() {
+    // Schedule a delayed task to process X11 events in 10ms.
+    static const int kProcessEventsInterval = 10;
+    message_loop_.PostDelayedTask(
+        FROM_HERE,
+        NewRunnableMethod(this, &X11Client::DoProcessX11Events),
+        kProcessEventsInterval);
+  }
+
+  // Members used for display.
+  Display* display_;
+  Window window_;
+
+  // Dimension of the window. They are initialized when InitClient message is
+  // received.
+  int width_;
+  int height_;
+
+  std::string host_jid_;
+  std::string username_;
+  std::string auth_token_;
+  scoped_ptr<HostConnection> connection_;
+  scoped_refptr<ChromotingView> view_;
+
+  MessageLoop message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(X11Client);
+};
+
+}  // namespace remoting
+
+int main() {
+  base::AtExitManager at_exit;
+  std::string host_jid, username, auth_token;
+
+  if (!remoting::GetLoginInfo(host_jid, username, auth_token)) {
+    std::cout << "Cannot obtain login info" << std::endl;
+    return 1;
+  }
+
+  scoped_refptr<remoting::X11Client> client =
+      new remoting::X11Client(host_jid, username, auth_token);
+  client->Run();
+}