Plugin system for backends. Fixes bug #351348.

2007-12-28  Carlos Garcia Campos  <carlosgc@gnome.org>
	* configure.ac:
	* Makefile.am:
	* po/POTFILES.in:
	* backend/comics/Makefile.am:
	* backend/comics/comics-document.[ch]:
	* backend/comics/comicsdocument.evince-backend.in:
	* backend/djvu/Makefile.am:
	* backend/djvu/djvu-document.[ch]:
	* backend/djvu/djvudocument.evince-backend.in:
	* backend/dvi/Makefile.am:
	* backend/dvi/dvi-document.[c]:
	* backend/dvi/dvidocument.evince-backend.in:
	* backend/impress/Makefile.am:
	* backend/impress/impress-document.[ch]:
	* backend/impress/impressdocument.evince-backend.in:
	* backend/pdf/Makefile.am:
	* backend/pdf/ev-poppler.cc:
	* backend/pdf/ev-poppler.h:
	* backend/pdf/pdfdocument.evince-backend.in:
	* backend/pixbuf/Makefile.am:
	* backend/pixbuf/pixbuf-document.[ch]:
	* backend/pixbuf/pixbufdocument.evince-backend.in:
	* backend/ps/Makefile.am:
	* backend/ps/ev-spectre.[ch]:
	* backend/ps/ps-document.[ch]:
	* backend/ps/psdocument.evince-backend.in:
	* backend/tiff/Makefile.am:
	* backend/tiff/tiff-document.[ch]:
	* backend/tiff/tiffdocument.evince-backend.in:
	* libdocument/Makefile.am:
	* libdocument/ev-backends-manager.[ch]:
	* libdocument/ev-module.[ch]:
	* libdocument/ev-document.h:
	* libdocument/ev-document-factory.[ch]:
	(gdk_pixbuf_mime_type_list), (mime_type_supported_by_gdk_pixbuf),
	(get_compression_from_mime_type), (get_document_from_uri),
	(ev_document_factory_get_document), (file_filter_add_mime_types),
	(ev_document_factory_add_filters):
	* shell/Makefile.am:
	* shell/ev-window-title.c: (get_filename_from_uri):
	* shell/main.c: (main):
	* thumbnailer/Makefile.am:
	* thumbnailer/evince-thumbnailer.c: (main):
	Plugin system for backends. Fixes bug #351348.

svn path=/trunk/; revision=2786

1 files changed, 190 insertions, 0 deletions

diff --git a/libdocument/ev-module.c b/libdocument/ev-module.c
new file mode 100644
index 0000000..f2aebe7
--- /dev/null
+++ b/libdocument/ev-module.c
@@ -0,0 +1,190 @@
+/*
+ * ev-module.c
+ * This file is part of Evince
+ *
+ * Copyright (C) 2005 - Paolo Maggi 
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, 
+ * Boston, MA 02111-1307, USA. 
+ */
+ 
+/* This is a modified version of ephy-module.c from Epiphany source code.
+ * Here the original copyright assignment:
+ *
+ *  Copyright (C) 2003 Marco Pesenti Gritti
+ *  Copyright (C) 2003, 2004 Christian Persch
+ *
+ */
+
+/*
+ * Modified by the gedit Team, 2005. See the AUTHORS file for a 
+ * list of people on the gedit Team.  
+ * See the ChangeLog files for a list of changes. 
+ *
+ * $Id: gedit-module.c 5367 2006-12-17 14:29:49Z pborelli $
+ */
+
+/* Modified by evince team */
+
+#include "config.h"
+
+#include "ev-module.h"
+
+#include <gmodule.h>
+
+typedef struct _EvModuleClass EvModuleClass;
+
+struct _EvModuleClass {
+        GTypeModuleClass parent_class;
+};
+
+struct _EvModule {
+        GTypeModule parent_instance;
+
+        GModule *library;
+
+        gchar *path;
+        GType type;
+};
+
+typedef GType (*EvModuleRegisterFunc) (GTypeModule *);
+
+static void ev_module_init       (EvModule *action);
+static void ev_module_class_init (EvModuleClass *class);
+
+G_DEFINE_TYPE (EvModule, ev_module, G_TYPE_TYPE_MODULE)
+
+static gboolean
+ev_module_load (GTypeModule *gmodule)
+{
+        EvModule *module = EV_MODULE (gmodule);
+        EvModuleRegisterFunc register_func;
+
+        module->library = g_module_open (module->path, 0);
+
+        if (!module->library) {
+                g_warning (g_module_error ());
+
+                return FALSE;
+        }
+
+        /* extract symbols from the lib */
+        if (!g_module_symbol (module->library, "register_evince_backend",
+                              (void *) &register_func)) {
+                g_warning (g_module_error ());
+                g_module_close (module->library);
+
+                return FALSE;
+        }
+
+        /* symbol can still be NULL even though g_module_symbol
+         * returned TRUE */
+        if (!register_func) {
+                g_warning ("Symbol 'register_evince_backend' should not be NULL");
+                g_module_close (module->library);
+
+                return FALSE;
+        }
+
+        module->type = register_func (gmodule);
+
+        if (module->type == 0) {
+                g_warning ("Invalid evince backend contained by module %s", module->path);
+		
+                return FALSE;
+        }
+
+        return TRUE;
+}
+
+static void
+ev_module_unload (GTypeModule *gmodule)
+{
+        EvModule *module = EV_MODULE (gmodule);
+
+        g_module_close (module->library);
+
+        module->library = NULL;
+        module->type = 0;
+}
+
+const gchar *
+ev_module_get_path (EvModule *module)
+{
+        g_return_val_if_fail (EV_IS_MODULE (module), NULL);
+
+        return module->path;
+}
+
+GObject *
+ev_module_new_object (EvModule *module)
+{
+	g_return_val_if_fail (EV_IS_MODULE (module), NULL);
+	
+        if (module->type == 0)
+                return NULL;
+
+        return g_object_new (module->type, NULL);
+}
+
+GType
+ev_module_get_object_type (EvModule *module)
+{
+	g_return_val_if_fail (EV_IS_MODULE (module), 0);
+
+	return module->type;
+}
+
+static void
+ev_module_init (EvModule *module)
+{
+}
+
+static void
+ev_module_finalize (GObject *object)
+{
+        EvModule *module = EV_MODULE (object);
+
+        g_free (module->path);
+
+        G_OBJECT_CLASS (ev_module_parent_class)->finalize (object);
+}
+
+static void
+ev_module_class_init (EvModuleClass *class)
+{
+        GObjectClass *object_class = G_OBJECT_CLASS (class);
+        GTypeModuleClass *module_class = G_TYPE_MODULE_CLASS (class);
+
+        object_class->finalize = ev_module_finalize;
+
+        module_class->load = ev_module_load;
+        module_class->unload = ev_module_unload;
+}
+
+EvModule *
+ev_module_new (const gchar *path)
+{
+        EvModule *result;
+
+	g_return_val_if_fail (path != NULL && path[0] != '\0', NULL);
+
+        result = g_object_new (EV_TYPE_MODULE, NULL);
+
+        g_type_module_set_name (G_TYPE_MODULE (result), path);
+        result->path = g_strdup (path);
+
+        return result;
+}