maint: Use macros to begin/end C++ namespaces. * BaseControl.cc, BaseControl.h, ButtonControl.cc, ButtonControl.h, ButtonGroup.cc, ButtonGroup.h, Canvas.cc, Canvas.h, CheckBoxControl.cc, CheckBoxControl.h, Container.cc, Container.h, ContextMenu.cc, ContextMenu.h, EditControl.cc, EditControl.h, Figure.cc, Figure.h, FigureWindow.cc, FigureWindow.h, GLCanvas.cc, GLCanvas.h, GenericEventNotify.h, KeyMap.cc, KeyMap.h, ListBoxControl.cc, ListBoxControl.h, Logger.cc, Logger.h, Menu.cc, Menu.h, MenuContainer.h, Object.cc, Object.h, ObjectProxy.cc, ObjectProxy.h, Panel.cc, Panel.h, PopupMenuControl.cc, PopupMenuControl.h, PushButtonControl.cc, PushButtonControl.h, PushTool.cc, PushTool.h, QtHandlesUtils.cc, QtHandlesUtils.h, RadioButtonControl.cc, RadioButtonControl.h, SliderControl.cc, SliderControl.h, Table.cc, Table.h, TextControl.cc, TextControl.h, TextEdit.cc, TextEdit.h, ToggleButtonControl.cc, ToggleButtonControl.h, ToggleTool.cc, ToggleTool.h, ToolBar.cc, ToolBar.h, ToolBarButton.cc, ToolBarButton.h, annotation-dialog.cc, annotation-dialog.h, gl-select.cc, gl-select.h, qopengl-functions.h, qt-graphics-toolkit.cc, qt-graphics-toolkit.h, QTerminal.h, color-picker.cc, color-picker.h, command-widget.cc, command-widget.h, community-news.cc, community-news.h, dialog.cc, dialog.h, documentation-bookmarks.cc, documentation-bookmarks.h, documentation-dock-widget.cc, documentation-dock-widget.h, documentation.cc, documentation.h, dw-main-window.cc, dw-main-window.h, external-editor-interface.cc, external-editor-interface.h, files-dock-widget.cc, files-dock-widget.h, find-files-dialog.cc, find-files-dialog.h, find-files-model.cc, find-files-model.h, graphics-init.cc, graphics-init.h, gui-settings.cc, gui-settings.h, gui-utils.cc, gui-utils.h, history-dock-widget.cc, history-dock-widget.h, interpreter-qobject.cc, interpreter-qobject.h, led-indicator.cc, led-indicator.h, file-editor-interface.h, file-editor-tab.cc, file-editor-tab.h, file-editor.cc, file-editor.h, find-dialog.cc, find-dialog.h, marker.cc, marker.h, octave-qscintilla.cc, octave-qscintilla.h, octave-txt-lexer.cc, octave-txt-lexer.h, main-window.cc, main-window.h, news-reader.cc, news-reader.h, octave-dock-widget.cc, octave-dock-widget.h, octave-qobject.cc, octave-qobject.h, qt-application.cc, qt-application.h, qt-interpreter-events.cc, qt-interpreter-events.h, qt-utils.h, release-notes.cc, release-notes.h, resource-manager.cc, resource-manager.h, set-path-dialog.cc, set-path-dialog.h, set-path-model.cc, set-path-model.h, settings-dialog.cc, settings-dialog.h, shortcut-manager.cc, shortcut-manager.h, tab-bar.cc, tab-bar.h, terminal-dock-widget.cc, terminal-dock-widget.h, variable-editor-model.cc, variable-editor-model.h, variable-editor.cc, variable-editor.h, welcome-wizard.cc, welcome-wizard.h, workspace-model.cc, workspace-model.h, workspace-view.cc, workspace-view.h: Use new macros to begin/end C++ namespaces.

////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2019-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <QApplication>
#include <QMetaType>
#include <QThread>

#include "graphics-init.h"
#include "octave-qobject.h"
#include "qt-graphics-toolkit.h"
#include "QtHandlesUtils.h"

#include "graphics.h"
#include "gtk-manager.h"
#include "interpreter.h"

OCTAVE_BEGIN_NAMESPACE(octave)

  void graphics_init (interpreter& interp, base_qobject& oct_qobj)
  {
#if defined (HAVE_QT_GRAPHICS)

    gh_manager& gh_mgr = interp.get_gh_manager ();

    autolock guard (gh_mgr.graphics_lock ());

    qRegisterMetaType<graphics_object> ("graphics_object");

    gh_mgr.enable_event_processing (true);

    qt_graphics_toolkit *qt_gtk = new qt_graphics_toolkit (interp, oct_qobj);

    if (QThread::currentThread ()
        != QApplication::instance ()->thread ())
      qt_gtk->moveToThread (QApplication::instance ()->thread ());

    graphics_toolkit tk (qt_gtk);

    gtk_manager& gtk_mgr = interp.get_gtk_manager ();

    gtk_mgr.register_toolkit ("qt");

    gtk_mgr.load_toolkit (tk);

#else

    octave_unused_parameter (interp);
    octave_unused_parameter (oct_qobj);

#endif
  }

OCTAVE_END_NAMESPACE(octave)