ui/gfx/x/x11_atom_cache.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_GFX_X_X11_ATOM_CACHE_H_
   6 #define UI_GFX_X_X11_ATOM_CACHE_H_
   7
   8 #include "base/basictypes.h"
   9 #include "ui/gfx/gfx_export.h"
  10
  11 #include <map>
  12 #include <string>
  13
  14 #include <X11/Xlib.h>
  15
  16 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
  17 #undef RootWindow
  18
  19 namespace ui {
  20
  21 // Pre-caches all Atoms on first use to minimize roundtrips to the X11
  22 // server. By default, GetAtom() will CHECK() that atoms accessed through
  23 // GetAtom() were passed to the constructor, but this behaviour can be changed
  24 // with allow_uncached_atoms().
  25 class GFX_EXPORT X11AtomCache {
  26  public:
  27   // Preinterns the NULL terminated list of string |to_cache_ on |xdisplay|.
  28   X11AtomCache(Display* xdisplay, const char** to_cache);
  29   ~X11AtomCache();
  30
  31   // Returns the pre-interned Atom without having to go to the x server.
  32   ::Atom GetAtom(const char*) const;
  33
  34   // When an Atom isn't in the list of items we've cached, we should look it
  35   // up, cache it locally, and then return the result.
  36   void allow_uncached_atoms() { uncached_atoms_allowed_ = true; }
  37
  38  private:
  39   Display* xdisplay_;
  40
  41   bool uncached_atoms_allowed_;
  42
  43   mutable std::map<std::string, ::Atom> cached_atoms_;
  44
  45   DISALLOW_COPY_AND_ASSIGN(X11AtomCache);
  46 };
  47
  48 }  // namespace ui
  49
  50 #endif  // UI_GFX_X_X11_ATOM_CACHE_H_