deviceprovider: Add method to hide devices from a provider

Add methods to add/remove the providers that should be hidden by this
provider. Also make a method to get a list of hidden providers.

This makes it possible to have multiple systems monitor the same devices
and remove duplicates.

3 files changed, 233 insertions, 7 deletions

diff --git a/gst/gstdevicemonitor.c b/gst/gstdevicemonitor.c
index 9784232ac..5d3c3ee7d 100644
--- a/gst/gstdevicemonitor.c
+++ b/gst/gstdevicemonitor.c
@@ -108,6 +108,7 @@ struct _GstDeviceMonitorPrivate
   GPtrArray *filters;
 
   guint last_id;
+  GList *hidden;
 };
 
 
@@ -142,6 +143,37 @@ gst_device_monitor_class_init (GstDeviceMonitorClass * klass)
   object_class->dispose = gst_device_monitor_dispose;
 }
 
+/* must be called with monitor lock */
+static gboolean
+is_provider_hidden (GList * hidden, GstDeviceProvider * provider)
+{
+  GstDeviceProviderFactory *factory;
+
+  factory = gst_device_provider_get_factory (provider);
+  if (g_list_find_custom (hidden, GST_OBJECT_NAME (factory),
+          (GCompareFunc) g_strcmp0))
+    return TRUE;
+
+  return FALSE;
+}
+
+/* must be called with monitor lock */
+static void
+update_hidden_list (GList ** hidden, GstDeviceProvider * provider)
+{
+  gchar **obs;
+
+  obs = gst_device_provider_get_hidden (provider);
+  if (obs) {
+    gint i;
+
+    for (i = 0; obs[i]; i++)
+      *hidden = g_list_prepend (*hidden, obs[i]);
+
+    g_free (obs);
+  }
+}
+
 static void
 bus_sync_message (GstBus * bus, GstMessage * message,
     GstDeviceMonitor * monitor)
@@ -151,6 +183,7 @@ bus_sync_message (GstBus * bus, GstMessage * message,
   if (type == GST_MESSAGE_DEVICE_ADDED || type == GST_MESSAGE_DEVICE_REMOVED) {
     gboolean matches;
     GstDevice *device;
+    GstDeviceProvider *provider;
 
     if (type == GST_MESSAGE_DEVICE_ADDED)
       gst_message_parse_device_added (message, &device);
@@ -158,7 +191,11 @@ bus_sync_message (GstBus * bus, GstMessage * message,
       gst_message_parse_device_removed (message, &device);
 
     GST_OBJECT_LOCK (monitor);
-    if (monitor->priv->filters->len) {
+    provider =
+        GST_DEVICE_PROVIDER (gst_object_get_parent (GST_OBJECT (device)));
+    if (is_provider_hidden (monitor->priv->hidden, provider)) {
+      matches = FALSE;
+    } else if (monitor->priv->filters->len) {
       guint i;
 
       for (i = 0; i < monitor->priv->filters->len; i++) {
@@ -258,7 +295,7 @@ gst_device_monitor_dispose (GObject * object)
 GList *
 gst_device_monitor_get_devices (GstDeviceMonitor * monitor)
 {
-  GList *devices = NULL;
+  GList *devices = NULL, *hidden = NULL;
   guint i;
   guint cookie;
 
@@ -281,7 +318,9 @@ gst_device_monitor_get_devices (GstDeviceMonitor * monitor)
 again:
 
   g_list_free_full (devices, gst_object_unref);
+  g_list_free_full (hidden, g_free);
   devices = NULL;
+  hidden = NULL;
 
   cookie = monitor->priv->cookie;
 
@@ -291,11 +330,17 @@ again:
         gst_object_ref (g_ptr_array_index (monitor->priv->providers, i));
     GList *item;
 
-    GST_OBJECT_UNLOCK (monitor);
+    if (!is_provider_hidden (hidden, provider)) {
+      GST_OBJECT_UNLOCK (monitor);
 
-    tmpdev = gst_device_provider_get_devices (provider);
+      tmpdev = gst_device_provider_get_devices (provider);
+
+      GST_OBJECT_LOCK (monitor);
+      update_hidden_list (&hidden, provider);
+    } else {
+      tmpdev = NULL;
+    }
 
-    GST_OBJECT_LOCK (monitor);
 
     for (item = tmpdev; item; item = item->next) {
       GstDevice *dev = GST_DEVICE (item->data);
@@ -305,6 +350,7 @@ again:
       for (j = 0; j < monitor->priv->filters->len; j++) {
         struct DeviceFilter *filter =
             g_ptr_array_index (monitor->priv->filters, j);
+
         if (gst_caps_can_intersect (filter->caps, caps) &&
             gst_device_has_classesv (dev, filter->classesv)) {
           devices = g_list_prepend (devices, gst_object_ref (dev));
@@ -317,10 +363,10 @@ again:
     g_list_free_full (tmpdev, gst_object_unref);
     gst_object_unref (provider);
 
-
     if (monitor->priv->cookie != cookie)
       goto again;
   }
+  g_list_free_full (hidden, g_free);
 
   GST_OBJECT_UNLOCK (monitor);
 
@@ -478,6 +524,33 @@ gst_device_monitor_stop (GstDeviceMonitor * monitor)
 
 }
 
+static void
+hidden_added (GstDeviceProvider * provider, const gchar * hidden,
+    GstDeviceMonitor * monitor)
+{
+  GST_OBJECT_LOCK (monitor);
+  monitor->priv->hidden =
+      g_list_prepend (monitor->priv->hidden, g_strdup (hidden));
+  GST_OBJECT_UNLOCK (monitor);
+}
+
+static void
+hidden_removed (GstDeviceProvider * provider, const gchar * hidden,
+    GstDeviceMonitor * monitor)
+{
+  GList *find;
+
+  GST_OBJECT_LOCK (monitor);
+  find =
+      g_list_find_custom (monitor->priv->hidden, hidden,
+      (GCompareFunc) g_strcmp0);
+  if (find) {
+    g_free (find->data);
+    monitor->priv->hidden = g_list_delete_link (monitor->priv->hidden, find);
+  }
+  GST_OBJECT_UNLOCK (monitor);
+}
+
 /**
  * gst_device_monitor_add_filter:
  * @monitor: a device monitor
@@ -543,6 +616,12 @@ gst_device_monitor_add_filter (GstDeviceMonitor * monitor,
       if (provider) {
         GstBus *bus = gst_device_provider_get_bus (provider);
 
+        update_hidden_list (&monitor->priv->hidden, provider);
+        g_signal_connect (provider, "hidden-added",
+            (GCallback) hidden_added, monitor);
+        g_signal_connect (provider, "hidden-removed",
+            (GCallback) hidden_removed, monitor);
+
         matched = TRUE;
         gst_bus_enable_sync_message_emission (bus);
         g_signal_connect (bus, "sync-message",
diff --git a/gst/gstdeviceprovider.c b/gst/gstdeviceprovider.c
index 995c2ff8a..1d9df962f 100644
--- a/gst/gstdeviceprovider.c
+++ b/gst/gstdeviceprovider.c
@@ -55,8 +55,19 @@ struct _GstDeviceProviderPrivate
   GMutex start_lock;
 
   gboolean started_count;
+
+  GList *hidden_providers;
+};
+
+enum
+{
+  HIDDEN_PROVIDER_ADDED,
+  HIDDEN_PROVIDER_REMOVED,
+  LAST_SIGNAL
 };
 
+static guint gst_device_provider_signals[LAST_SIGNAL] = { 0 };
+
 /* this is used in gstelementfactory.c:gst_element_register() */
 GQuark __gst_deviceproviderclass_factory = 0;
 
@@ -134,6 +145,16 @@ gst_device_provider_class_init (GstDeviceProviderClass * klass)
 
   gobject_class->dispose = gst_device_provider_dispose;
   gobject_class->finalize = gst_device_provider_finalize;
+
+  gst_device_provider_signals[HIDDEN_PROVIDER_ADDED] =
+      g_signal_new ("hidden-provider-added", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_FIRST, 0, NULL,
+      NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, G_TYPE_STRING);
+
+  gst_device_provider_signals[HIDDEN_PROVIDER_REMOVED] =
+      g_signal_new ("hidden-provider-removed", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_FIRST, 0, NULL,
+      NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 1, G_TYPE_STRING);
 }
 
 static void
@@ -598,3 +619,123 @@ gst_device_provider_device_remove (GstDeviceProvider * provider,
   if (item)
     gst_object_unparent (GST_OBJECT (device));
 }
+
+/**
+ * gst_device_provider_get_hidden_providers:
+ * @provider: a #GstDeviceProvider
+ *
+ * Get the provider factory names of the #GstDeviceProvider instances that
+ * are hidden by @provider.
+ *
+ * Returns: (transfer full) (array zero-terminated=1) (element-type gchar*):
+ *   a list of hidden providers factory names or %NULL when
+ *   nothing is hidden by @provider. Free with g_strfreev.
+ *
+ * Since: 1.6
+ */
+gchar **
+gst_device_provider_get_hidden_providers (GstDeviceProvider * provider)
+{
+  GList *walk;
+  guint i, len;
+  gchar **res = NULL;
+
+  g_return_val_if_fail (GST_IS_DEVICE_PROVIDER (provider), NULL);
+
+  GST_OBJECT_LOCK (provider);
+  len = g_list_length (provider->priv->hidden_providers);
+  if (len == 0)
+    goto done;
+
+  res = g_new (gchar *, len + 1);
+  for (i = 0, walk = provider->priv->hidden_providers; walk;
+      walk = g_list_next (walk), i++)
+    res[i] = g_strdup (walk->data);
+  res[i] = NULL;
+
+done:
+  GST_OBJECT_UNLOCK (provider);
+
+  return res;
+}
+
+/**
+ * gst_device_provider_add_hidden_provider:
+ * @provider: a #GstDeviceProvider
+ * @hidden: an hidden provider factory name
+ *
+ * Add the @hidden factory name to @provider.
+ *
+ * This function is used when @provider will also provide the devices reported
+ * by @hidden provider factory name. A monitor should stop monitoring the
+ * device provider with name @hidden to avoid duplicate devices.
+ *
+ * Since: 1.6
+ */
+void
+gst_device_provider_add_hidden_provider (GstDeviceProvider * provider,
+    const gchar * hidden)
+{
+  GList *find;
+  const gchar *name = NULL;
+
+  g_return_if_fail (GST_IS_DEVICE_PROVIDER (provider));
+  g_return_if_fail (hidden != NULL);
+
+  GST_OBJECT_LOCK (provider);
+  find =
+      g_list_find_custom (provider->priv->hidden_providers, hidden,
+      (GCompareFunc) g_strcmp0);
+  if (find == NULL) {
+    name = hidden;
+    provider->priv->hidden_providers =
+        g_list_prepend (provider->priv->hidden_providers, g_strdup (hidden));
+  }
+  GST_OBJECT_UNLOCK (provider);
+
+  if (name)
+    g_signal_emit (provider, gst_device_provider_signals[HIDDEN_PROVIDER_ADDED],
+        0, name);
+}
+
+/**
+ * gst_device_provider_remove_hidden_provider:
+ * @provider: a #GstDeviceProvider
+ * @hidden: an hidden provider factory name
+ *
+ * Remove the @hidden factory name from @provider.
+ *
+ * This function is used when @provider will no longer provide the devices
+ * reported by @hidden provider factory name. A monitor should start
+ * monitoring the devices from @hidden provider factory in order to see
+ * all devices again.
+ *
+ * Since: 1.6
+ */
+void
+gst_device_provider_remove_hidden_provider (GstDeviceProvider * provider,
+    const gchar * hidden)
+{
+  GList *find;
+  gchar *name = NULL;
+
+  g_return_if_fail (GST_IS_DEVICE_PROVIDER (provider));
+  g_return_if_fail (hidden != NULL);
+
+  GST_OBJECT_LOCK (provider);
+  find =
+      g_list_find_custom (provider->priv->hidden_providers, hidden,
+      (GCompareFunc) g_strcmp0);
+  if (find) {
+    name = find->data;
+    provider->priv->hidden_providers =
+        g_list_delete_link (provider->priv->hidden_providers, find);
+  }
+  GST_OBJECT_UNLOCK (provider);
+
+  if (name) {
+    g_signal_emit (provider,
+        gst_device_provider_signals[HIDDEN_PROVIDER_REMOVED], 0, name);
+    g_free (name);
+  }
+}
diff --git a/gst/gstdeviceprovider.h b/gst/gstdeviceprovider.h
index 3982f3b89..57d1c596a 100644
--- a/gst/gstdeviceprovider.h
+++ b/gst/gstdeviceprovider.h
@@ -113,7 +113,13 @@ GstBus *    gst_device_provider_get_bus        (GstDeviceProvider * provider);
 void        gst_device_provider_device_add     (GstDeviceProvider * provider,
                                                 GstDevice * device);
 void        gst_device_provider_device_remove  (GstDeviceProvider * provider,
-                                               GstDevice * device);
+                                                GstDevice * device);
+
+gchar **    gst_device_provider_get_hidden_providers   (GstDeviceProvider * provider);
+void        gst_device_provider_add_hidden_provider    (GstDeviceProvider * provider,
+                                                        const gchar       * hidden);
+void        gst_device_provider_remove_hidden_provider (GstDeviceProvider * provider,
+                                                        const gchar       * hidden);
 
 
 /* device provider class meta data */