Implement clipboard for Chromoting Linux hosts.

remoting/host/x_server_clipboard.h

+// 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.
+
+// Don't include this file in any .h files because it pulls in some X headers.
+
+#ifndef REMOTING_HOST_X_SERVER_CLIPBOARD_H_
+#define REMOTING_HOST_X_SERVER_CLIPBOARD_H_
+
+#include <X11/Xatom.h>
+#include <X11/Xlib.h>
+
+#include <map>
+#include <set>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/callback_forward.h"
+#include "base/timer.h"
+
+namespace remoting {
+
+// A class to allow manipulation of the X clipboard, using low-level X
+// API calls.
+class XServerClipboard {
+ public:
+  typedef base::Callback<void(const std::string& mime_type,
+                              const std::string& data)>
+    ClipboardChangedCallback;
+
+  XServerClipboard();
+  ~XServerClipboard();
+
+  // The caller should ensure |display| remains valid as long as any other
+  // methods are called on this object.
+  void Init(Display* display, const ClipboardChangedCallback& callback);
+
+  void SetClipboard(const std::string& mime_type, const std::string& data);
+
+  // This method allows this object to be hooked up to the program's main event
+  // loop.  It should be called when the event loop receives an X event, and
+  // all methods of this object should be called on this thread.
+  void ProcessXEvent(XEvent* event);
+
+ private:
+  // This checks the state of the X selections.  If there is new text selected
+  // by another application, this will eventually trigger the registered
+  // ClipboardChangedCallback.  Of the two selections (PRIMARY and CLIPBOARD),
+  // the PRIMARY selection is tried first, and the CLIPBOARD selection is only
+  // used if it is newer than PRIMARY.  If there is no new text since the
+  // previous call, then no callback will be made.  Duplicate text is filtered
+  // out, so that the same text being selected again will not trigger the
+  // callback.
+  // The Init() method calls this to get the initial state of the X selections;
+  // no callback will be triggered in this case.
+  // If |selection| is CLIPBOARD or PRIMARY, it is checked.  If |selection| is
+  // None, both CLIPBOARD and PRIMARY are checked.  Other values of |selection|
+  // are ignored.
+  // If |timestamp| is non-zero, it is recorded as the "current selection time",
+  // and is treated as new.
+  void GetSelections(Atom selection, Time timestamp);
+
+  void FinishGetSelections();
+
+  void OnPropertyNotify(XEvent* event);
+  void OnSelectionNotify(XEvent* event);
+  void OnSelectionRequest(XEvent* event);
+
+  // This is called when the selection owner has replied to a request for
+  // information about a selection.
+  void DoSelectionNotify(XSelectionEvent* event,
+                         Atom type,
+                         int format,
+                         int item_count,
+                         void* data);
+
+  bool GotSelectionTimestamp(XSelectionEvent* event,
+                             int format,
+                             int item_count,
+                             void* data);
+  bool GotSelectionTargets(XSelectionEvent* event,
+                           int format,
+                           int item_count,
+                           void* data);
+  bool GotSelectionString(XSelectionEvent* event,
+                          int format,
+                          int item_count,
+                          void* data);
+  void GotCutTextUtf8(const std::string& text);
+  bool IsSelectionOwner(Atom selection);
+  void GetSelectionTimestamp(Atom selection, Time time);
+  void GetSelectionTargets(Atom selection);
+  void GetSelectionString(Atom selection, Atom target);
+
+  // Request that the window owns the given selection from the given time (the
+  // time should be taken from an X event).
+  void OwnSelection(Atom selection, Time time);
+
+  Display* display_;
+  Window clipboard_window_;
+  bool have_xfixes_;
+  int xfixes_event_base_;
+  int xfixes_error_base_;
+  Atom clipboard_atom_;
+  Atom large_selection_atom_;
+  Atom selection_string_atom_;
+  Atom targets_atom_;
+  Atom timestamp_atom_;
+  Atom utf8_string_atom_;
+  std::set<Atom> selections_owned_;
+  std::map<Atom, Time> selection_own_time_;
+  std::string data_;
+  Atom large_selection_property_;
+  Time current_selection_time_;
+  Atom new_selection_;
+  bool getting_initial_selection_;
+  bool new_cut_text_;
+  bool had_valid_timestamp_;
+  base::TimeTicks get_selections_time_;
+  ClipboardChangedCallback callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(XServerClipboard);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_X_SERVER_CLIPBOARD_H_