gplugin/gplugin

Fix some issues with the gtk3 and gtk4 includes when not used in a subproject

Testing Done:
Ran the unit tests and gplugin-gtk4-viewer and verified no issues.

Bugs closed: GPLUGIN-145

Reviewed at https://reviews.imfreedom.org/r/1469/
/*
* Copyright 2021 Elliott Sales de Andrade <quantum.analyst@gmail.com>
*
* This program 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.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef GPLUGIN_GTK_VIEWER_WINDOW_H
#define GPLUGIN_GTK_VIEWER_WINDOW_H
#include <gtk/gtk.h>
#include <gplugin-gtk.h>
G_BEGIN_DECLS
#define GPLUGIN_GTK_VIEWER_TYPE_WINDOW (gplugin_gtk_viewer_window_get_type())
G_DECLARE_FINAL_TYPE(
GPluginGtkViewerWindow,
gplugin_gtk_viewer_window,
GPLUGIN_GTK_VIEWER,
WINDOW,
GtkApplicationWindow)
GPluginGtkView *gplugin_gtk_viewer_window_get_view(
GPluginGtkViewerWindow *window);
G_END_DECLS
#endif /* GPLUGIN_GTK_VIEWER_WINDOW_H */