Merging in an interface for loading modules cleanly.

1 files changed, 290 insertions, 0 deletions

diff --git a/libindicator/indicator-object.c b/libindicator/indicator-object.c
new file mode 100644
index 0000000..ce07ad6
--- /dev/null
+++ b/libindicator/indicator-object.c
@@ -0,0 +1,290 @@
+/*
+An object to represent loadable indicator modules to make loading
+them easy and objectified.
+
+Copyright 2009 Canonical Ltd.
+
+Authors:
+    Ted Gould <ted@canonical.com>
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+version 3.0 as published by the Free Software Foundation.
+
+This library 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 version 3.0 for more details.
+
+You should have received a copy of the GNU General Public
+License along with this library. If not, see
+<http://www.gnu.org/licenses/>.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "indicator.h"
+#include "indicator-object.h"
+
+/**
+	IndicatorObjectPrivate:
+	@label: The label representing this indicator or #NULL if none.
+	@icon: The icon representing this indicator or #NULL if none.
+	@menu: The menu representing this indicator or #NULL if none.
+
+	Structure to define the memory for the private area
+	of the object instance.
+*/
+typedef struct _IndicatorObjectPrivate IndicatorObjectPrivate;
+struct _IndicatorObjectPrivate {
+	GtkLabel * label;
+	GtkImage * icon;
+	GtkMenu * menu;
+};
+
+#define INDICATOR_OBJECT_GET_PRIVATE(o) \
+			(G_TYPE_INSTANCE_GET_PRIVATE ((o), INDICATOR_OBJECT_TYPE, IndicatorObjectPrivate))
+
+static void indicator_object_class_init (IndicatorObjectClass *klass);
+static void indicator_object_init       (IndicatorObject *self);
+static void indicator_object_dispose    (GObject *object);
+static void indicator_object_finalize   (GObject *object);
+
+G_DEFINE_TYPE (IndicatorObject, indicator_object, G_TYPE_OBJECT);
+
+/* Setup the class and put the functions into the
+   class structure */
+static void
+indicator_object_class_init (IndicatorObjectClass *klass)
+{
+	GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+	g_type_class_add_private (klass, sizeof (IndicatorObjectPrivate));
+
+	object_class->dispose = indicator_object_dispose;
+	object_class->finalize = indicator_object_finalize;
+
+	return;
+}
+
+/* Initialize an instance */
+static void
+indicator_object_init (IndicatorObject *self)
+{
+	IndicatorObjectPrivate * priv = INDICATOR_OBJECT_GET_PRIVATE(self);
+
+	priv->label = NULL;
+	priv->icon = NULL;
+	priv->menu = NULL;
+
+	return;
+}
+
+/* Unref the objects that we're holding on to. */
+static void
+indicator_object_dispose (GObject *object)
+{
+	IndicatorObjectPrivate * priv = INDICATOR_OBJECT_GET_PRIVATE(object);
+	
+	if (priv->label != NULL) {
+		g_object_unref(priv->label);
+		priv->label = NULL;
+	}
+
+	if (priv->icon != NULL) {
+		g_object_unref(priv->icon);
+		priv->icon = NULL;
+	}
+
+	if (priv->menu != NULL) {
+		g_object_unref(priv->menu);
+		priv->menu = NULL;
+	}
+
+	G_OBJECT_CLASS (indicator_object_parent_class)->dispose (object);
+	return;
+}
+
+/* Free memory */
+static void
+indicator_object_finalize (GObject *object)
+{
+
+	G_OBJECT_CLASS (indicator_object_parent_class)->finalize (object);
+	return;
+}
+
+/**
+	indicator_object_new_from_file:
+	@file: Filename containing a loadable module
+
+	This function builds an #IndicatorObject using the symbols
+	that are found in @file.  The module is loaded and the
+	references are all kept by the object.  To unload the 
+	module the object must be destroyed.
+
+	Return value: A valid #IndicatorObject or #NULL if error.
+*/
+IndicatorObject *
+indicator_object_new_from_file (const gchar * file)
+{
+	/* Check to make sure the name exists and that the
+	   file itself exists */
+	if (file == NULL) {
+		g_warning("Invalid filename.");
+		return NULL;
+	}
+
+	if (!g_file_test(file, G_FILE_TEST_EXISTS)) {
+		g_warning("File '%s' does not exist.", file);
+		return NULL;
+	}
+
+	/* Grab the g_module reference, pull it in but let's
+	   keep the symbols local to avoid conflicts. */
+	GModule * module = g_module_open(file,
+                                     G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
+	if(module == NULL) {
+		g_warning("Unable to load module: %s", file);
+		return NULL;
+	}
+
+	/* Look for the version function, error if not found. */
+	get_version_t lget_version = NULL;
+	if (!g_module_symbol(module, INDICATOR_GET_VERSION_S, (gpointer *)(&lget_version))) {
+		g_warning("Unable to get the symbol for getting the version.");
+		return NULL;
+	}
+
+	/* Check the version with the macro and make sure we're
+	   all talking the same language. */
+	if (!INDICATOR_VERSION_CHECK(lget_version())) {
+		g_warning("Indicator using API version '%s' we're expecting '%s'", lget_version(), INDICATOR_VERSION);
+		return NULL;
+	}
+
+	/* A this point we allocate the object, any code beyond
+	   here needs to deallocate it if we're returning in an
+	   error'd state. */
+	GObject * object = g_object_new(INDICATOR_OBJECT_TYPE, NULL);
+	IndicatorObjectPrivate * priv = INDICATOR_OBJECT_GET_PRIVATE(object);
+
+	/* The function for grabbing a label from the module
+	   execute it, and make sure everything is a-okay */
+	get_label_t lget_label = NULL;
+	if (!g_module_symbol(module, INDICATOR_GET_LABEL_S, (gpointer *)(&lget_label))) {
+		g_warning("Unable to get '" INDICATOR_GET_LABEL_S "' symbol from module: %s", file);
+		goto unrefandout;
+	}
+	if (lget_label == NULL) {
+		g_warning("Symbol '" INDICATOR_GET_LABEL_S "' is (null) in module: %s", file);
+		goto unrefandout;
+	}
+	priv->label = lget_label();
+	if (priv->label) {
+		g_object_ref(G_OBJECT(priv->label));
+	}
+
+	/* The function for grabbing an icon from the module
+	   execute it, and make sure everything is a-okay */
+	get_icon_t lget_icon = NULL;
+	if (!g_module_symbol(module, INDICATOR_GET_ICON_S, (gpointer *)(&lget_icon))) {
+		g_warning("Unable to get '" INDICATOR_GET_ICON_S "' symbol from module: %s", file);
+		goto unrefandout;
+	}
+	if (lget_icon == NULL) {
+		g_warning("Symbol '" INDICATOR_GET_ICON_S "' is (null) in module: %s", file);
+		goto unrefandout;
+	}
+	priv->icon = lget_icon();
+	if (priv->icon) {
+		g_object_ref(G_OBJECT(priv->icon));
+	}
+
+	/* The function for grabbing a menu from the module
+	   execute it, and make sure everything is a-okay */
+	get_menu_t lget_menu = NULL;
+	if (!g_module_symbol(module, INDICATOR_GET_MENU_S, (gpointer *)(&lget_menu))) {
+		g_warning("Unable to get '" INDICATOR_GET_MENU_S "' symbol from module: %s", file);
+		goto unrefandout;
+	}
+	if (lget_menu == NULL) {
+		g_warning("Symbol '" INDICATOR_GET_MENU_S "' is (null) in module: %s", file);
+		goto unrefandout;
+	}
+	priv->menu = lget_menu();
+	if (priv->menu) {
+		g_object_ref(G_OBJECT(priv->menu));
+	}
+
+	if (priv->label == NULL && priv->icon == NULL) {
+		/* This is the case where there is nothing to display,
+		   kinda odd that we'd have a module with nothing. */
+		g_warning("No label or icon.  Odd.");
+		goto unrefandout;
+	}
+
+	return INDICATOR_OBJECT(object);
+
+	/* Error, let's drop the object and return NULL.  Sad when
+	   this happens. */
+unrefandout:
+	g_object_unref(object);
+	return NULL;
+}
+
+/**
+	indicator_object_get_label:
+	@io: An #IndicatorObject.
+
+	A function to get the label for a particular object.  This
+	function does not increase the refcount.  That's your job
+	if you want to do it.
+
+	Return value: A #GtkLabel or #NULL if unavailable.
+*/
+GtkLabel *
+indicator_object_get_label (IndicatorObject * io)
+{
+	g_return_val_if_fail(IS_INDICATOR_OBJECT(io), NULL);
+	IndicatorObjectPrivate * priv = INDICATOR_OBJECT_GET_PRIVATE(io);
+	return priv->label;
+}
+
+/**
+	indicator_object_get_icon:
+	@io: An #IndicatorObject.
+
+	A function to get the icon for a particular object.  This
+	function does not increase the refcount.  That's your job
+	if you want to do it.
+
+	Return value: A #GtkImage or #NULL if unavailable.
+*/
+GtkImage *
+indicator_object_get_icon (IndicatorObject * io)
+{
+	g_return_val_if_fail(IS_INDICATOR_OBJECT(io), NULL);
+	IndicatorObjectPrivate * priv = INDICATOR_OBJECT_GET_PRIVATE(io);
+	return priv->icon;
+}
+
+/**
+	indicator_object_get_menu:
+	@io: An #IndicatorObject.
+
+	A function to get the menu for a particular object.  This
+	function does not increase the refcount.  That's your job
+	if you want to do it.
+
+	Return value: A #GtkMenu or #NULL if unavailable.
+*/
+GtkMenu *
+indicator_object_get_menu (IndicatorObject * io)
+{
+	g_return_val_if_fail(IS_INDICATOR_OBJECT(io), NULL);
+	IndicatorObjectPrivate * priv = INDICATOR_OBJECT_GET_PRIVATE(io);
+	return priv->menu;
+}