[evince] [metadata] Add EvMetadata to handle gvfs metadata

[Carlos Garcia Campos <carlosgc src gnome org>]

commit c07587236140aca6f4bda452043fb043769f0a80
Author: Carlos Garcia Campos <carlosgc gnome org>
Date:   Sun Oct 11 14:28:41 2009 +0200

    [metadata] Add EvMetadata to handle gvfs metadata

 shell/Makefile.am   |    2 +
 shell/ev-metadata.c |  307 +++++++++++++++++++++++++++++++++++++++++++++++++++
 shell/ev-metadata.h |   68 +++++++++++
 3 files changed, 377 insertions(+), 0 deletions(-)
---
diff --git a/shell/Makefile.am b/shell/Makefile.am
index a8acf73..3ccc9ed 100644
--- a/shell/Makefile.am
+++ b/shell/Makefile.am
@@ -49,6 +49,8 @@ evince_SOURCES=				\
 	$(DBUS_SOURCES)			\
 	ev-message-area.c		\
 	ev-message-area.h		\
+	ev-metadata.c			\
+	ev-metadata.h			\
 	ev-metadata-manager.c		\
 	ev-metadata-manager.h		\
 	ev-navigation-action.c		\
diff --git a/shell/ev-metadata.c b/shell/ev-metadata.c
new file mode 100644
index 0000000..a8fde31
--- /dev/null
+++ b/shell/ev-metadata.c
@@ -0,0 +1,307 @@
+/* ev-metadata.c
+ *  this file is part of evince, a gnome document viewer
+ *
+ * Copyright (C) 2009 Carlos Garcia Campos  <carlosgc gnome org>
+ *
+ * Evince 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.
+ *
+ * Evince 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.
+ */
+
+#include <gio/gio.h>
+#include <string.h>
+
+#include "ev-metadata.h"
+
+struct _EvMetadata {
+	GObject base;
+
+	GFile      *file;
+	GHashTable *items;
+};
+
+struct _EvMetadataClass {
+	GObjectClass base_class;
+};
+
+G_DEFINE_TYPE (EvMetadata, ev_metadata, G_TYPE_OBJECT)
+
+#define EV_METADATA_NAMESPACE "metadata::evince"
+
+static void
+ev_metadata_finalize (GObject *object)
+{
+	EvMetadata *metadata = EV_METADATA (object);
+
+	if (metadata->items) {
+		g_hash_table_destroy (metadata->items);
+		metadata->items = NULL;
+	}
+
+	if (metadata->file) {
+		g_object_unref (metadata->file);
+		metadata->file = NULL;
+	}
+
+	G_OBJECT_CLASS (ev_metadata_parent_class)->finalize (object);
+}
+
+static void
+ev_metadata_init (EvMetadata *metadata)
+{
+	metadata->items = g_hash_table_new_full (g_str_hash,
+						 g_str_equal,
+						 g_free,
+						 g_free);
+}
+
+static void
+ev_metadata_class_init (EvMetadataClass *klass)
+{
+	GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+	gobject_class->finalize = ev_metadata_finalize;
+}
+
+static void
+ev_metadata_load (EvMetadata *metadata)
+{
+	GFileInfo *info;
+	gchar    **attrs;
+	gint       i;
+	GError    *error = NULL;
+
+	info = g_file_query_info (metadata->file, "metadata::*", 0, NULL, &error);
+	if (!info) {
+		g_warning ("%s", error->message);
+		g_error_free (error);
+
+		return;
+	}
+
+	if (!g_file_info_has_namespace (info, "metadata")) {
+		g_object_unref (info);
+
+		return;
+	}
+
+	attrs = g_file_info_list_attributes (info, "metadata");
+	for (i = 0; attrs[i]; i++) {
+		GFileAttributeType type;
+		gpointer           value;
+		const gchar       *key;
+
+		if (!g_str_has_prefix (attrs[i], EV_METADATA_NAMESPACE))
+			continue;
+
+		if (!g_file_info_get_attribute_data (info, attrs[i],
+						     &type, &value, NULL)) {
+			continue;
+		}
+
+		key = attrs[i] + strlen (EV_METADATA_NAMESPACE"::");
+
+		if (type == G_FILE_ATTRIBUTE_TYPE_STRING) {
+			g_hash_table_insert (metadata->items,
+					     g_strdup (key),
+					     g_strdup (value));
+		}
+	}
+	g_strfreev (attrs);
+	g_object_unref (info);
+}
+
+EvMetadata *
+ev_metadata_new (GFile *file)
+{
+	EvMetadata *metadata;
+
+	g_return_val_if_fail (G_IS_FILE (file), NULL);
+
+	metadata = EV_METADATA (g_object_new (EV_TYPE_METADATA, NULL));
+	metadata->file = g_object_ref (file);
+
+	ev_metadata_load (metadata);
+
+	return metadata;
+}
+
+gboolean
+ev_metadata_get_string (EvMetadata  *metadata,
+			const gchar *key,
+			gchar     **value)
+{
+	gchar *v;
+
+	v = g_hash_table_lookup (metadata->items, key);
+	if (!v)
+		return FALSE;
+
+	*value = v;
+	return TRUE;
+}
+
+static void
+metadata_set_callback (GObject      *file,
+		       GAsyncResult *result,
+		       EvMetadata   *metadata)
+{
+	GError *error = NULL;
+
+	if (!g_file_set_attributes_finish (G_FILE (file), result, NULL, &error)) {
+		g_warning ("%s", error->message);
+		g_error_free (error);
+	}
+}
+
+gboolean
+ev_metadata_set_string (EvMetadata  *metadata,
+			const gchar *key,
+			const gchar *value)
+{
+	GFileInfo *info;
+	gchar     *gio_key;
+
+	info = g_file_info_new ();
+
+	gio_key = g_strconcat (EV_METADATA_NAMESPACE"::", key, NULL);
+	if (value) {
+		g_file_info_set_attribute_string (info, gio_key, value);
+	} else {
+		g_file_info_set_attribute (info, gio_key,
+					   G_FILE_ATTRIBUTE_TYPE_INVALID,
+					   NULL);
+	}
+	g_free (gio_key);
+
+	g_hash_table_insert (metadata->items, g_strdup (key), g_strdup (value));
+	g_file_set_attributes_async (metadata->file,
+				     info,
+				     0,
+				     G_PRIORITY_DEFAULT,
+				     NULL,
+				     (GAsyncReadyCallback)metadata_set_callback,
+				     metadata);
+	g_object_unref (info);
+
+	return TRUE;
+}
+
+gboolean
+ev_metadata_get_int (EvMetadata  *metadata,
+		     const gchar *key,
+		     gint        *value)
+{
+	gchar *string_value;
+	gchar *endptr;
+	gint   int_value;
+
+	if (!ev_metadata_get_string (metadata, key, &string_value))
+		return FALSE;
+
+	int_value = g_ascii_strtoull (string_value, &endptr, 0);
+	if (int_value == 0 && string_value == endptr)
+		return FALSE;
+
+	*value = int_value;
+	return TRUE;
+}
+
+gboolean
+ev_metadata_set_int (EvMetadata  *metadata,
+		     const gchar *key,
+		     gint         value)
+{
+	gchar string_value[32];
+
+	g_snprintf (string_value, sizeof (string_value), "%d", value);
+
+	return ev_metadata_set_string (metadata, key, string_value);
+}
+
+gboolean
+ev_metadata_get_double (EvMetadata  *metadata,
+			const gchar *key,
+			gdouble     *value)
+{
+	gchar  *string_value;
+	gchar  *endptr;
+	gdouble double_value;
+
+	if (!ev_metadata_get_string (metadata, key, &string_value))
+		return FALSE;
+
+	double_value = g_ascii_strtod (string_value, &endptr);
+	if (double_value == 0. && string_value == endptr)
+		return FALSE;
+
+	*value = double_value;
+	return TRUE;
+}
+
+gboolean
+ev_metadata_set_double (EvMetadata  *metadata,
+			const gchar *key,
+			gdouble      value)
+{
+	gchar string_value[G_ASCII_DTOSTR_BUF_SIZE];
+
+	g_ascii_dtostr (string_value, G_ASCII_DTOSTR_BUF_SIZE, value);
+
+	return ev_metadata_set_string (metadata, key, string_value);
+}
+
+gboolean
+ev_metadata_get_boolean (EvMetadata  *metadata,
+			 const gchar *key,
+			 gboolean    *value)
+{
+	gint int_value;
+
+	if (!ev_metadata_get_int (metadata, key, &int_value))
+		return FALSE;
+
+	*value = int_value;
+	return TRUE;
+}
+
+gboolean
+ev_metadata_set_boolean (EvMetadata  *metadata,
+			 const gchar *key,
+			 gboolean     value)
+{
+	return ev_metadata_set_string (metadata, key, value ? "1" : "0");
+}
+
+gboolean
+ev_is_metadata_supported_for_file (GFile *file)
+{
+	GFileAttributeInfoList *namespaces;
+	gint i;
+	gboolean retval = FALSE;
+
+	namespaces = g_file_query_writable_namespaces (file, NULL, NULL);
+	if (!namespaces)
+		return retval;
+
+	for (i = 0; i < namespaces->n_infos; i++) {
+		if (strcmp (namespaces->infos[i].name, "metadata") == 0) {
+			retval = TRUE;
+			break;
+		}
+	}
+
+	g_file_attribute_info_list_unref (namespaces);
+
+	return retval;
+}
diff --git a/shell/ev-metadata.h b/shell/ev-metadata.h
new file mode 100644
index 0000000..044e1b0
--- /dev/null
+++ b/shell/ev-metadata.h
@@ -0,0 +1,68 @@
+/* ev-metadata.h
+ *  this file is part of evince, a gnome document viewer
+ *
+ * Copyright (C) 2009 Carlos Garcia Campos  <carlosgc gnome org>
+ *
+ * Evince 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.
+ *
+ * Evince 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.
+ */
+
+#ifndef EV_METADATA_H
+#define EV_METADATA_H
+
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+#define EV_TYPE_METADATA         (ev_metadata_get_type())
+#define EV_METADATA(object)      (G_TYPE_CHECK_INSTANCE_CAST((object), EV_TYPE_METADATA, EvMetadata))
+#define EV_METADATA_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass), EV_TYPE_METADATA, EvMetadataClass))
+#define EV_IS_METADATA(object)   (G_TYPE_CHECK_INSTANCE_TYPE((object), EV_TYPE_METADATA))
+
+typedef struct _EvMetadata      EvMetadata;
+typedef struct _EvMetadataClass EvMetadataClass;
+
+GType       ev_metadata_get_type              (void) G_GNUC_CONST;
+EvMetadata *ev_metadata_new                   (GFile       *file);
+
+gboolean    ev_metadata_get_string            (EvMetadata  *metadata,
+					       const gchar *key,
+					       gchar     **value);
+gboolean    ev_metadata_set_string            (EvMetadata  *metadata,
+					       const gchar *key,
+					       const gchar *value);
+gboolean    ev_metadata_get_int               (EvMetadata  *metadata,
+					       const gchar *key,
+					       gint        *value);
+gboolean    ev_metadata_set_int               (EvMetadata  *metadata,
+					       const gchar *key,
+					       gint         value);
+gboolean    ev_metadata_get_double            (EvMetadata  *metadata,
+					       const gchar *key,
+					       gdouble     *value);
+gboolean    ev_metadata_set_double            (EvMetadata  *metadata,
+					       const gchar *key,
+					       gdouble      value);
+gboolean    ev_metadata_get_boolean           (EvMetadata  *metadata,
+					       const gchar *key,
+					       gboolean    *value);
+gboolean    ev_metadata_set_boolean           (EvMetadata  *metadata,
+					       const gchar *key,
+					       gboolean     value);
+
+gboolean    ev_is_metadata_supported_for_file (GFile       *file);
+
+G_END_DECLS
+
+#endif /* EV_METADATA_H */