Implement clipboard for Chromoting Linux hosts.

remoting/host/clipboard_linux.cc

 // Copyright (c) 2012 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.
 
 #include "remoting/host/clipboard.h"
 
+#include <X11/Xlib.h>
+
+#include "base/bind.h"
 #include "base/logging.h"
+#include "base/message_loop.h"
+#include "remoting/host/linux/x_server_clipboard.h"
+#include "remoting/proto/event.pb.h"
+#include "remoting/protocol/clipboard_stub.h"
 
 namespace remoting {
 
-class ClipboardLinux : public Clipboard {
+// This code is expected to be used on the desktop thread only.

[Wez, 2012/09/17 22:13:29]

nit: "used" is vague; do we expect to be _called_ from the desktop thread? 
What's special about the desktop thread from this class' perspective?

[Lambros, 2012/09/25 22:42:39]

Changed to "called".  This comment was specifically added for Sergey's request
in Patch #7.  I don't think there's anything special about the desktop thread,
except that it's the thread for EventExecutorLinux::task_runner_, where all
injection-related tasks are posted.

+class ClipboardLinux : public Clipboard,
+                       public MessageLoopForIO::Watcher {
  public:
   ClipboardLinux();
+  virtual ~ClipboardLinux();
 
-  // Must be called on the UI thread.
+  // Clipboard interface.
   virtual void Start(
       scoped_ptr<protocol::ClipboardStub> client_clipboard) OVERRIDE;

[Wez, 2012/09/17 22:13:29]

nit: I think Start & Stop should be StartClipboard/StopClipboard to avoid
clashes if a Clipboard implementation needs to implement some other interface as
well.

[Lambros, 2012/09/25 22:42:39]

Agreed, but that should be a separate CL as it affects all platforms.

   virtual void InjectClipboardEvent(
       const protocol::ClipboardEvent& event) OVERRIDE;
   virtual void Stop() OVERRIDE;
 
+  // MessageLoopForIO::Watcher interface.
+  virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
+  virtual void OnFileCanWriteWithoutBlocking(int fd) OVERRIDE;
+
  private:
+  void OnClipboardChanged(const std::string& mime_type,
+                          const std::string& data);
+  void PumpEvents();

[Wez, 2012/09/17 22:13:29]

nit: PumpXEvents?

[Lambros, 2012/09/25 22:42:39]

Done.

+
+  scoped_ptr<protocol::ClipboardStub> client_clipboard_;
+
+  XServerClipboard x_server_clipboard_;
+  Display* display_;
+
+  MessageLoopForIO::FileDescriptorWatcher x_connection_watcher_;
+
   DISALLOW_COPY_AND_ASSIGN(ClipboardLinux);
 };
 
+ClipboardLinux::ClipboardLinux()
+    : display_(NULL) {
+}
+
+ClipboardLinux::~ClipboardLinux() {
+  Stop();
+}
+
 void ClipboardLinux::Start(
     scoped_ptr<protocol::ClipboardStub> client_clipboard) {
-  NOTIMPLEMENTED();
+  // TODO(lambroslambrou): Share the X connection with EventExecutor.
+  display_ = XOpenDisplay(NULL);
+  if (!display_) {
+    LOG(ERROR) << "Couldn't open X display";
+    return;
+  }
+  client_clipboard_.swap(client_clipboard);
+
+  x_server_clipboard_.Init(display_,
+                           base::Bind(&ClipboardLinux::OnClipboardChanged,
+                                      base::Unretained(this)));
+
+  MessageLoopForIO::current()->WatchFileDescriptor(
+      ConnectionNumber(display_), true, MessageLoopForIO::WATCH_READ,
+      &x_connection_watcher_, this);
+  PumpEvents();
 }
 
 void ClipboardLinux::InjectClipboardEvent(
     const protocol::ClipboardEvent& event) {
-  NOTIMPLEMENTED();
+  x_server_clipboard_.SetClipboard(event.mime_type(), event.data());
 }
 
 void ClipboardLinux::Stop() {
-  NOTIMPLEMENTED();
+  client_clipboard_.reset();
+  x_connection_watcher_.StopWatchingFileDescriptor();
+
+  if (display_) {
+    XCloseDisplay(display_);
+    display_ = NULL;
+  }
+}
+
+void ClipboardLinux::OnFileCanReadWithoutBlocking(int fd) {
+  PumpEvents();
+}
+
+void ClipboardLinux::OnFileCanWriteWithoutBlocking(int fd) {
+}
+
+void ClipboardLinux::OnClipboardChanged(const std::string& mime_type,
+                                        const std::string& data) {
+  protocol::ClipboardEvent event;
+  event.set_mime_type(mime_type);
+  event.set_data(data);
+
+  if (client_clipboard_.get()) {
+    client_clipboard_->InjectClipboardEvent(event);
+  }
+}
+
+void ClipboardLinux::PumpEvents() {
+  DCHECK(display_);
+
+  while (XPending(display_)) {
+    XEvent event;
+    XNextEvent(display_, &event);
+    x_server_clipboard_.ProcessXEvent(&event);
+  }
 }
 
 scoped_ptr<Clipboard> Clipboard::Create() {
   return scoped_ptr<Clipboard>(new ClipboardLinux());
 }
 
 }  // namespace remoting