Move native_widget_types and gtk_native_view_id_manager from base/gfx to...

base/gfx/gtk_native_view_id_manager.h

-// Copyright (c) 2009 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.
-
-#ifndef BASE_GFX_GTK_NATIVE_VIEW_ID_MANAGER_H_
-#define BASE_GFX_GTK_NATIVE_VIEW_ID_MANAGER_H_
-
-#include <map>
-
-#include "base/singleton.h"
-#include "base/gfx/native_widget_types.h"
-
-typedef unsigned long XID;
-
-// NativeViewIds are the opaque values which the renderer holds as a reference
-// to a window. These ids are often used in sync calls from the renderer and
-// one cannot terminate sync calls on the UI thread as that can lead to
-// deadlocks.
-//
-// Because of this, we have the BACKGROUND_X11 thread for these calls and this
-// thread has a separate X connection in order to answer them. But one cannot
-// use GTK on multiple threads, so the BACKGROUND_X11 thread deals only in Xlib
-// calls and, thus, XIDs.
-//
-// So we could make NativeViewIds be the X id of the window. However, at the
-// time when we need to tell the renderer about its NativeViewId, an XID isn't
-// availible and it goes very much against the grain of the code to make it so.
-// Also, we worry that GTK might choose to change the underlying X window id
-// when, say, the widget is hidden or repacked. Finally, if we used XIDs then a
-// compromised renderer could start asking questions about any X windows on the
-// system.
-//
-// Thus, we have this object. It produces random NativeViewIds from GtkWidget
-// pointers and observes the various signals from the widget for when an X
-// window is created, destroyed etc. Thus it provides a thread safe mapping
-// from NativeViewIds to the current XID for that widget.
-//
-// You get a reference to the global instance with:
-//   Singleton<GtkNativeViewManager>()
-class GtkNativeViewManager {
- public:
-  // Must be called from the UI thread:
-  //
-  // Return a NativeViewId for the given widget and attach to the various
-  // signals emitted by that widget. The NativeViewId is pseudo-randomly
-  // allocated so that a compromised renderer trying to guess values will fail
-  // with high probability. The NativeViewId will not be reused for the
-  // lifetime of the GtkWidget.
-  gfx::NativeViewId GetIdForWidget(gfx::NativeView widget);
-
-  // May be called from any thread:
-  //
-  // xid: (output) the resulting X window ID, or 0
-  // id: a value previously returned from GetIdForWidget
-  // returns: true if |id| is a valid id, false otherwise.
-  //
-  // If the widget referenced by |id| does not current have an X window id,
-  // |*xid| is set to 0.
-  bool GetXIDForId(XID* xid, gfx::NativeViewId id);
-
-  // These are actually private functions, but need to be called from statics.
-  void OnRealize(gfx::NativeView widget);
-  void OnUnrealize(gfx::NativeView widget);
-  void OnDestroy(gfx::NativeView widget);
-
- private:
-  // This object is a singleton:
-  GtkNativeViewManager();
-  friend struct DefaultSingletonTraits<GtkNativeViewManager>;
-
-  struct NativeViewInfo {
-    NativeViewInfo()
-        : x_window_id(0) {
-    }
-
-    XID x_window_id;
-  };
-
-  gfx::NativeViewId GetWidgetId(gfx::NativeView id);
-
-  // protects native_view_to_id_ and id_to_info_
-  Lock lock_;
-    // If asked for an id for the same widget twice, we want to return the same
-    // id. So this records the current mapping.
-    std::map<gfx::NativeView, gfx::NativeViewId> native_view_to_id_;
-    std::map<gfx::NativeViewId, NativeViewInfo> id_to_info_;
-
-  DISALLOW_COPY_AND_ASSIGN(GtkNativeViewManager);
-};
-
-#endif  // BASE_GFX_GTK_NATIVE_VIEW_ID_MANAGER_H_