pls: Add new Grilo Playlist lib

This utility library allows both plugins and applications to read
playlists as if they were containers, using an API similar to the
Sources.

With additional fixes from Juan A. Suarez Romero and
Bastien Nocera.

https://bugzilla.gnome.org/show_bug.cgi?id=695303

Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>

2 files changed, 250 insertions, 1 deletions

diff --git a/examples/Makefile.am b/examples/Makefile.am
index 2e95ff4..2432e5d 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -1,11 +1,14 @@
 AM_CFLAGS = $(DEPS_CFLAGS) -I$(top_srcdir)/src -I$(top_srcdir)/src/data
 LDADD = $(DEPS_LIBS) $(top_builddir)/src/lib@GRL_NAME@.la
 
-noinst_PROGRAMS = browsing configuring-plugins efficient-metadata-resolution	\
+noinst_PROGRAMS = browsing browsing-pls configuring-plugins efficient-metadata-resolution	\
 	loading-plugins multivalues searching
 
 browsing_SOURCES = browsing.c
 
+browsing_pls_SOURCES = browsing-pls.c
+browsing_pls_LDADD = $(LDADD) $(top_builddir)/libs/pls/libgrlpls-@GRL_MAJORMINOR@.la
+
 configuring_plugins_SOURCES = configuring-plugins.c
 
 efficient_metadata_resolution_SOURCES = efficient-metadata-resolution.c
diff --git a/examples/browsing-pls.c b/examples/browsing-pls.c
new file mode 100644
index 0000000..9f6ad33
--- /dev/null
+++ b/examples/browsing-pls.c
@@ -0,0 +1,246 @@
+/*
+ * Browsing in Grilo.
+ * Shows the first BROWSE_CHUNK_SIZE elements of each browsable source
+ *
+ * XXX: No pagination yet! See grilo-test-ui. It's somewhat complicated.
+ */
+
+#include <grilo.h>
+#include <gio/gio.h>
+#include <glib.h>
+#include <glib/gprintf.h>
+#include "../libs/pls/grl-pls.h"
+
+#define GRL_LOG_DOMAIN_DEFAULT  example_log_domain
+GRL_LOG_DOMAIN_STATIC(example_log_domain);
+
+#define BROWSE_CHUNK_SIZE 10
+
+static void source_browser (gpointer data,
+                            gpointer user_data);
+static void element_browser (gpointer data,
+                             gpointer user_data);
+
+static void
+element_browser (gpointer data,
+                 gpointer user_data)
+{
+  GrlMedia *media = GRL_MEDIA (data);
+  GrlSource *source = GRL_SOURCE (user_data);
+
+  /* Check if we got a valid media object as some plugins may call the callback
+     with a NULL media under certain circumstances (for example when they
+     cannot estimate the number of remaining results and they find suddenly they
+     don't have any more results to send) */
+  if (!media) {
+    g_debug ("Media element is NULL!");
+    goto out;
+  }
+
+  const gchar *title = grl_media_get_title (media);
+
+  /* If the media is a container (box), that means we will browse it again */
+  if (GRL_IS_MEDIA_BOX (media)) {
+    guint childcount = grl_media_box_get_childcount (GRL_MEDIA_BOX (media));
+    g_debug ("\t Got '%s' (container with %d elements)", title, childcount);
+
+    source_browser (source, media);
+  } else {
+    const gchar *url = grl_media_get_url (media);
+    const gchar *mime = grl_media_get_mime (media);
+    GDateTime *date = grl_media_get_modification_date (media);
+    time_t rawdate = g_date_time_to_unix(date);
+    g_printf ("\t Got '%s', of type '%s', ctime is '%s'\n", title, mime, ctime(&rawdate));
+    g_printf ("\t\t URL: %s\n", url);
+  }
+
+out:
+  g_object_unref (media);
+}
+
+static void
+source_browser (gpointer data,
+                gpointer user_data)
+{
+  GrlSource *source = GRL_SOURCE (data);
+  GrlMedia *media = GRL_MEDIA (user_data);
+  GList *media_elements;
+  GError *error = NULL;
+  GList *keys;
+  GrlOperationOptions *options;
+  GrlCaps *caps;
+
+  keys = grl_metadata_key_list_new (GRL_METADATA_KEY_TITLE,
+                                    GRL_METADATA_KEY_URL,
+                                    GRL_METADATA_KEY_MODIFICATION_DATE,
+                                    GRL_METADATA_KEY_MIME,
+                                    GRL_METADATA_KEY_CHILDCOUNT,
+                                    NULL);
+
+  g_debug ("Detected new source available: '%s'",
+	   grl_source_get_name (source));
+
+  if (!(grl_source_supported_operations (source) & GRL_OP_BROWSE))
+    goto out;
+
+  g_debug ("Browsing source: %s", grl_source_get_name (source));
+  /* Here is how you can browse a source, you have to provide:
+     1) The source you want to browse contents from.
+     2) The container object you want to browse (NULL for the root container)
+     3) A list of metadata keys we are interested in.
+     4) Options to control certain aspects of the browse operation.
+     5) A callback that the framework will invoke for each available result
+     6) User data for the callback
+     It returns an operation identifier that you can use to match results
+     with the corresponding request (we ignore it here) */
+
+  caps = grl_source_get_caps (source, GRL_OP_BROWSE);
+  options = grl_operation_options_new (caps);
+  grl_operation_options_set_count (options, BROWSE_CHUNK_SIZE);
+  grl_operation_options_set_flags (options, GRL_RESOLVE_IDLE_RELAY);
+  media_elements = grl_pls_browse_sync (GRL_SOURCE (source),
+                                        media, keys,
+                                        options,
+                                        NULL,
+                                        &error);
+  if (!media_elements) {
+    g_debug ("No elements found for source: %s!",
+             grl_source_get_name (source));
+    goto out;
+  }
+
+  if (error)
+    g_error ("Failed to browse source: %s", error->message);
+
+  g_list_foreach (media_elements, element_browser, source);
+
+out:
+  g_list_free (keys);
+  g_object_unref (options);
+}
+
+static void
+load_plugins (gchar* playlist)
+{
+  GrlRegistry *registry;
+  GrlSource *source;
+  GError *error = NULL;
+  GList *keys;
+  GrlOperationOptions *options;
+  GrlCaps *caps;
+  GrlMedia* media;
+  gboolean pls_media;
+  const gchar *mime;
+
+  registry = grl_registry_get_default ();
+
+  /* Load plugin */
+  if (!grl_registry_load_plugin_by_id (registry, "grl-filesystem", &error))
+    g_error ("Failed to load plugin: %s", error->message);
+
+  source = grl_registry_lookup_source (registry, "grl-filesystem");
+  if (!source)
+    g_error ("Unable to load grl-filesystem plugin");
+
+  if (!(grl_source_supported_operations (source) & GRL_OP_MEDIA_FROM_URI))
+    g_error ("Unable to get media from URI");
+
+  keys = grl_metadata_key_list_new (GRL_METADATA_KEY_TITLE, GRL_METADATA_KEY_URL, GRL_METADATA_KEY_MIME, NULL);
+  if (!keys)
+    g_error ("Unable to create key list");
+
+  caps = grl_source_get_caps (source, GRL_OP_MEDIA_FROM_URI);
+  if (!caps)
+    g_error ("Unable to get source caps");
+
+  options = grl_operation_options_new (caps);
+  if (!options)
+    g_error ("Unable to create operation options");
+
+  media = grl_source_get_media_from_uri_sync (source, playlist, keys, options, &error);
+  if (!media)
+    g_error ("Unable to get GrlMedia for playlist %s", playlist);
+
+  g_object_unref (options);
+
+  mime = grl_media_get_mime (media);
+
+  pls_media = grl_pls_media_is_playlist (media);
+
+  g_printf("Got Media for %s - mime=%s\n", playlist, mime);
+  g_printf("\tgrl_pls_media_is_playlist = %d\n", pls_media);
+
+  if (pls_media) {
+    source_browser (source, media);
+  }
+
+  g_object_unref (media);
+  g_object_unref (source);
+}
+
+static void
+config_plugins (gchar* chosen_test_path)
+{
+  GrlRegistry *registry;
+  GrlConfig *config;
+
+  registry = grl_registry_get_default ();
+
+  /* Configure plugin */
+  config = grl_config_new ("grl-filesystem", "Filesystem");
+  grl_config_set_string (config, "base-path", chosen_test_path);
+  grl_registry_add_config (registry, config, NULL);
+
+  g_printf ("config_plugin with %s\n", chosen_test_path);
+}
+
+gint
+main (int     argc,
+      gchar  *argv[])
+{
+  gchar *chosen_test_path;
+  gchar *file_uri;
+  GError *error = NULL;
+
+  grl_init (&argc, &argv);
+  GRL_LOG_DOMAIN_INIT (example_log_domain, "example");
+
+  if (argc != 2) {
+    g_printf ("Usage: %s <path to browse>\n", argv[0]);
+    return 1;
+  }
+
+  chosen_test_path = argv[1];
+  GFile *file = g_file_new_for_path (chosen_test_path);
+  if (!file) {
+    g_printf ("Invalid file/directory %s\n", argv[1]);
+    return 1;
+  }
+
+  GFileInfo *info = g_file_query_info (file,
+               G_FILE_ATTRIBUTE_STANDARD_TYPE,
+               0,
+               NULL,
+               &error);
+  if (!info) {
+    g_printf ("Invalid file/directory information\n");
+    return 1;
+  }
+
+  if (g_file_info_get_file_type (info) != G_FILE_TYPE_REGULAR) {
+    return 1;
+  }
+
+  gchar *dirname = g_path_get_dirname(chosen_test_path);
+  config_plugins (dirname);
+  g_free (dirname);
+
+  file_uri = g_filename_to_uri (chosen_test_path, NULL, &error);
+
+  g_object_unref (file);
+  g_object_unref (info);
+  load_plugins (file_uri);
+  g_free (file_uri);
+
+  return 0;
+}