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 <map>
   9 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "ui/gfx/gfx_export.h"
  13 #include "ui/gfx/x/x11_types.h"
  14
  15 namespace ui {
  16
  17 // Pre-caches all Atoms on first use to minimize roundtrips to the X11
  18 // server. By default, GetAtom() will CHECK() that atoms accessed through
  19 // GetAtom() were passed to the constructor, but this behaviour can be changed
  20 // with allow_uncached_atoms().
  21 class GFX_EXPORT X11AtomCache {
  22  public:
  23   // Preinterns the NULL terminated list of string |to_cache_ on |xdisplay|.
  24   X11AtomCache(XDisplay* xdisplay, const char** to_cache);
  25   ~X11AtomCache();
  26
  27   // Returns the pre-interned Atom without having to go to the x server.
  28   XAtom GetAtom(const char*) const;
  29
  30   // When an Atom isn't in the list of items we've cached, we should look it
  31   // up, cache it locally, and then return the result.
  32   void allow_uncached_atoms() { uncached_atoms_allowed_ = true; }
  33
  34  private:
  35   XDisplay* xdisplay_;
  36
  37   bool uncached_atoms_allowed_;
  38
  39   mutable std::map<std::string, XAtom> cached_atoms_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(X11AtomCache);
  42 };
  43
  44 }  // namespace ui
  45
  46 #endif  // UI_GFX_X_X11_ATOM_CACHE_H_