| Index: chrome/browser/gtk/owned_widget_gtk.h
|
| diff --git a/chrome/browser/gtk/owned_widget_gtk.h b/chrome/browser/gtk/owned_widget_gtk.h
|
| index b5299c9760a21343a7531b48f82f49740323bdf2..62f9c7e4e4b74b5483aec421005c167e21087e94 100644
|
| --- a/chrome/browser/gtk/owned_widget_gtk.h
|
| +++ b/chrome/browser/gtk/owned_widget_gtk.h
|
| @@ -1,90 +1,12 @@
|
| -// Copyright (c) 2009 The Chromium Authors. All rights reserved.
|
| +// Copyright (c) 2011 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.
|
|
|
| -// This class assists you in dealing with a specific situation when managing
|
| -// ownership between a C++ object and a GTK widget. It is common to have a
|
| -// C++ object which encapsulates a GtkWidget, and that widget is exposed from
|
| -// the object for use outside of the class. In this situation, you commonly
|
| -// want the GtkWidget's lifetime to match its C++ object's lifetime. Using an
|
| -// OwnedWigetGtk will take ownership over the initial reference of the
|
| -// GtkWidget, so that it is "owned" by the C++ object. Example usage:
|
| -//
|
| -// class FooViewGtk() {
|
| -// public:
|
| -// FooViewGtk() { }
|
| -// ~FooViewGtk() { widget_.Destroy(); }
|
| -// void Init() { vbox_.Own(gtk_vbox_new()); }
|
| -// GtkWidget* widget() { return vbox_.get() }; // Host my widget!
|
| -// private:
|
| -// OwnedWidgetGtk vbox_;
|
| -// };
|
| -//
|
| -// This design will ensure that the widget stays alive from the call to Own()
|
| -// until the call to Destroy().
|
| -//
|
| -// - Details of the problem and OwnedWidgetGtk's solution:
|
| -// In order to make passing ownership more convenient for newly created
|
| -// widgets, GTK has a concept of a "floating" reference. All GtkObjects (and
|
| -// thus GtkWidgets) inherit from GInitiallyUnowned. When they are created, the
|
| -// object starts with a reference count of 1, but has its floating flag set.
|
| -// When it is put into a container for the first time, that container will
|
| -// "sink" the floating reference, and the count will still be 1. Now the
|
| -// container owns the widget, and if we remove the widget from the container,
|
| -// the widget is destroyed. This style of ownership often causes problems when
|
| -// you have an object encapsulating the widget. If we just use a raw
|
| -// GtkObject* with no specific ownership management, we push the widget's
|
| -// ownership onto the user of the class. Now the C++ object can't depend on
|
| -// the widget being valid, since it doesn't manage its lifetime. If the widget
|
| -// was removed from a container, removing its only reference, it would be
|
| -// destroyed (from the C++ object's perspective) unexpectantly destroyed. The
|
| -// solution is fairly simple, make sure that the C++ object owns the widget,
|
| -// and thus it is also responsible for destroying it. This boils down to:
|
| -// GtkWidget* widget = gtk_widget_new();
|
| -// g_object_ref_sink(widget); // Claim the initial floating reference.
|
| -// ...
|
| -// gtk_destroy_widget(widget); // Ask all code to destroy their references.
|
| -// g_object_unref(widget); // Destroy the initial reference we had claimed.
|
| -
|
| #ifndef CHROME_BROWSER_GTK_OWNED_WIDGET_GTK_H_
|
| #define CHROME_BROWSER_GTK_OWNED_WIDGET_GTK_H_
|
| #pragma once
|
|
|
| -#include "base/basictypes.h"
|
| -
|
| -typedef struct _GtkWidget GtkWidget;
|
| -
|
| -class OwnedWidgetGtk {
|
| - public:
|
| - // Create an instance that isn't managing any ownership.
|
| - OwnedWidgetGtk() : widget_(NULL) { }
|
| - // Create an instance that owns |widget|.
|
| - explicit OwnedWidgetGtk(GtkWidget* widget) : widget_(NULL) { Own(widget); }
|
| -
|
| - ~OwnedWidgetGtk();
|
| -
|
| - // Return the currently owned widget, or NULL if no widget is owned.
|
| - GtkWidget* get() const { return widget_; }
|
| - GtkWidget* operator->() const { return widget_; }
|
| -
|
| - // Takes ownership of a widget, by taking the initial floating reference of
|
| - // the GtkWidget. It is expected that Own() is called right after the widget
|
| - // has been created, and before any other references to the widget might have
|
| - // been added. It is valid to never call Own(), in which case Destroy() will
|
| - // do nothing. If Own() has been called, you must explicitly call Destroy().
|
| - void Own(GtkWidget* widget);
|
| -
|
| - // You must call Destroy() after you have called Own(). Calling Destroy()
|
| - // will call gtk_widget_destroy(), and drop our reference to the widget.
|
| - // After a call to Destroy(), you may call Own() again. NOTE: It is expected
|
| - // that after gtk_widget_destroy we will be holding the only reference left
|
| - // on the object. We assert this in debug mode to help catch any leaks.
|
| - void Destroy();
|
| -
|
| - private:
|
| - GtkWidget* widget_;
|
| -
|
| - DISALLOW_COPY_AND_ASSIGN(OwnedWidgetGtk);
|
| -};
|
| +#include "chrome/browser/ui/gtk/owned_widget_gtk.h"
|
| +// TODO(msw): remove this file once all includes have been updated.
|
|
|
| #endif // CHROME_BROWSER_GTK_OWNED_WIDGET_GTK_H_
|
|
|