devicemonitor: Add GstDeviceMonitor and related

Also add GstDevice and GstDeviceMonitorFactory
And add code to the registry to save them

https://bugzilla.gnome.org/show_bug.cgi?id=678402

gst/Makefile.am

@@ -71,6 +71,9 @@ libgstreamer_@GST_API_VERSION@_la_SOURCES = \
 	gstcontrolsource.c \
 	gstdatetime.c		\
 	gstdebugutils.c		\
+	gstdevice.c		\
+	gstdevicemonitor.c	\
+	gstdevicemonitorfactory.c \
 	gstelement.c		\
 	gstelementfactory.c	\
 	gsterror.c		\
@@ -172,6 +175,9 @@ gst_headers =			\
 	gstdebugutils.h		\
 	gstelement.h		\
 	gstelementmetadata.h	\
+	gstdevice.h		\
+	gstdevicemonitor.h	\
+	gstdevicemonitorfactory.h \
 	gstelementfactory.h	\
 	gsterror.h		\
 	gstevent.h		\

gst/gst.h

@@ -42,6 +42,8 @@
 #include <gst/gstcontrolsource.h>
 #include <gst/gstdatetime.h>
 #include <gst/gstdebugutils.h>
+#include <gst/gstdevice.h>
+#include <gst/gstdevicemonitor.h>
 #include <gst/gstelement.h>
 #include <gst/gstelementmetadata.h>
 #include <gst/gsterror.h>

gst/gst_private.h

@@ -54,6 +54,9 @@ extern const char             g_log_domain_gstreamer[];
 /* for GstElement */
 #include "gstelement.h"
 
+/* for GstDeviceMonitor */
+#include "gstdevicemonitor.h"
+
 /* for GstToc */
 #include "gsttoc.h"
 
@@ -393,5 +396,24 @@ struct _GstElementFactoryClass {
   gpointer _gst_reserved[GST_PADDING];
 };
 
+struct _GstDeviceMonitorFactory {
+  GstPluginFeature           feature;
+  /* <private> */
+
+  GType                      type;              /* unique GType the device factory or 0 if not loaded */
+
+  volatile GstDeviceMonitor *monitor;
+  gpointer                   metadata;
+
+  gpointer _gst_reserved[GST_PADDING];
+};
+
+struct _GstDeviceMonitorFactoryClass {
+  GstPluginFeatureClass         parent;
+  /* <private> */
+
+  gpointer _gst_reserved[GST_PADDING];
+};
+
 G_END_DECLS
 #endif /* __GST_PRIVATE_H__ */

gst/gstdevice.c

+/* GStreamer
+ * Copyright (C) 2012 Olivier Crete <olivier.crete@collabora.com>
+ *
+ * gstdevice.c: Device discovery
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gst/gst_private.h"
+
+#include <gst/gstdevice.h>
+#include <gst/gst.h>
+
+enum
+{
+  PROP_DISPLAY_NAME = 1,
+  PROP_CAPS
+};
+
+enum
+{
+  REMOVED,
+  LAST_SIGNAL
+};
+
+struct _GstDevicePrivate
+{
+  GstCaps *caps;
+  gchar *display_name;
+};
+
+
+static guint signals[LAST_SIGNAL];
+
+G_DEFINE_ABSTRACT_TYPE (GstDevice, gst_device, GST_TYPE_OBJECT);
+
+static void gst_device_get_property (GObject * object, guint property_id,
+    GValue * value, GParamSpec * pspec);
+static void gst_device_set_property (GObject * object, guint property_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_device_finalize (GObject * object);
+
+
+static void
+gst_device_class_init (GstDeviceClass * klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  g_type_class_add_private (klass, sizeof (GstDevicePrivate));
+
+  object_class->get_property = gst_device_get_property;
+  object_class->set_property = gst_device_set_property;
+  object_class->finalize = gst_device_finalize;
+
+  g_object_class_install_property (object_class, PROP_DISPLAY_NAME,
+      g_param_spec_string ("display-name", "Display Name",
+          "The user-friendly name of the device", "",
+          G_PARAM_STATIC_STRINGS | G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
+  g_object_class_install_property (object_class, PROP_CAPS,
+      g_param_spec_boxed ("caps", "Device Caps",
+          "The possible caps of a device", GST_TYPE_CAPS,
+          G_PARAM_STATIC_STRINGS | G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
+
+  signals[REMOVED] = g_signal_new ("removed", G_TYPE_FROM_CLASS (klass),
+      G_SIGNAL_RUN_LAST, 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
+}
+
+static void
+gst_device_init (GstDevice * device)
+{
+  device->priv = G_TYPE_INSTANCE_GET_PRIVATE (device, GST_TYPE_DEVICE,
+      GstDevicePrivate);
+}
+
+static void
+gst_device_finalize (GObject * object)
+{
+  GstDevice *device = GST_DEVICE (object);
+
+  gst_caps_replace (&device->priv->caps, NULL);
+
+  g_free (device->priv->display_name);
+
+  G_OBJECT_CLASS (gst_device_parent_class)->finalize (object);
+}
+
+static void
+gst_device_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstDevice *gstdevice;
+
+  gstdevice = GST_DEVICE_CAST (object);
+
+  switch (prop_id) {
+    case PROP_DISPLAY_NAME:
+      g_value_take_string (value, gst_device_get_display_name (gstdevice));
+      break;
+    case PROP_CAPS:
+      if (gstdevice->priv->caps)
+        g_value_take_boxed (value, gst_device_get_caps (gstdevice));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+
+static void
+gst_device_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstDevice *gstdevice;
+
+  gstdevice = GST_DEVICE_CAST (object);
+
+  switch (prop_id) {
+    case PROP_DISPLAY_NAME:
+      gstdevice->priv->display_name = g_value_dup_string (value);
+      break;
+    case PROP_CAPS:
+      gst_caps_replace (&gstdevice->priv->caps, g_value_get_boxed (value));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+/**
+ * gst_device_create_element:
+ * @device: a #GstDevice
+ * @name: (allow-none): name of new element, or NULL to automatically
+ * create a unique name.
+ *
+ * Returns: (transfer full): a new #GstElement configured to use this device
+ *
+ * Since: 1.4
+ */
+GstElement *
+gst_device_create_element (GstDevice * device, const gchar * name)
+{
+  GstDeviceClass *klass = GST_DEVICE_GET_CLASS (device);
+
+  if (klass->create_element)
+    return klass->create_element (device, name);
+  else
+    return NULL;
+}
+
+/**
+ * gst_device_get_caps:
+ * @device: a #GstDevice
+ *
+ * Getter for the #GstCaps that this device supports.
+ *
+ * Returns: The #GstCaps supported by this device. Unref with
+ * gst_caps_unref() when done.
+ *
+ * Since: 1.4
+ */
+GstCaps *
+gst_device_get_caps (GstDevice * device)
+{
+  if (device->priv->caps)
+    return gst_caps_ref (device->priv->caps);
+  else
+    return NULL;
+}
+
+/**
+ * gst_device_get_display_name:
+ * @device: a #GstDevice
+ *
+ * Gets the user-friendly name of the device.
+ *
+ * Returns: The device name. Free with g_free() after use.
+ *
+ * Since: 1.4
+ */
+gchar *
+gst_device_get_display_name (GstDevice * device)
+{
+  return g_strdup (device->priv->display_name);
+}
+
+/**
+ * gst_device_reconfigure_element:
+ * @device: a #GstDevice
+ * @element: a #GstElement
+ *
+ * Tries to reconfigure an existing element to use the device. If this
+ * function fails, then one must destroy the element and create a new one
+ * using gst_device_create_element().
+ *
+ * Note: This should only be implemented for elements can change their
+ * device in the PLAYING state.
+ *
+ * Returns: %TRUE if the element could be reconfigured to use this device,
+ * %FALSE otherwise.
+ *
+ * Since: 1.4
+ */
+gboolean
+gst_device_reconfigure_element (GstDevice * device, GstElement * element)
+{
+  GstDeviceClass *klass = GST_DEVICE_GET_CLASS (device);
+
+  if (klass->reconfigure_element)
+    return klass->reconfigure_element (device, element);
+  else
+    return FALSE;
+}

gst/gstdevice.h

+/* GStreamer
+ * Copyright (C) 2012 Olivier Crete <olivier.crete@collabora.com>
+ *
+ * gstdevice.c: Device discovery
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+
+#ifndef __GST_DEVICE_H__
+#define __GST_DEVICE_H__
+
+typedef struct _GstDevice GstDevice;
+typedef struct _GstDeviceClass GstDeviceClass;
+
+#include <gst/gstelement.h>
+#include <gst/gstcaps.h>
+
+
+G_BEGIN_DECLS
+
+typedef struct _GstDevicePrivate GstDevicePrivate;
+
+#define GST_TYPE_DEVICE                 (gst_device_get_type())
+#define GST_IS_DEVICE(obj)              (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_DEVICE))
+#define GST_IS_DEVICE_CLASS(klass)      (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_DEVICE))
+#define GST_DEVICE_GET_CLASS(obj)       (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_DEVICE, GstDeviceClass))
+#define GST_DEVICE(obj)                 (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_DEVICE, GstDevice))
+#define GST_DEVICE_CLASS(klass)         (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_DEVICE, GstDeviceClass))
+#define GST_DEVICE_CAST(obj)            ((GstDevice *)(obj))
+
+
+struct _GstDevice {
+  GstObject         parent;
+
+  /*< private >*/
+  GstDevicePrivate *priv;
+
+  gpointer _gst_reserved[GST_PADDING];
+};
+
+struct _GstDeviceClass {
+  GstObjectClass    parent_class;
+
+  GstElement * (*create_element) (GstDevice * device, const gchar * name);
+  gboolean (*reconfigure_element) (GstDevice * device, GstElement * element);
+
+  /*< private >*/
+  gpointer _gst_reserved[GST_PADDING];
+};
+
+GType        gst_device_get_type (void);
+
+GstElement * gst_device_create_element (GstDevice * device, const gchar * name);
+
+GstCaps *    gst_device_get_caps (GstDevice * device);
+gchar *      gst_device_get_display_name (GstDevice * device);
+gboolean     gst_device_reconfigure_element (GstDevice * device,
+                                             GstElement * element);
+
+G_END_DECLS
+
+#endif /* __GST_DEVICE_H__ */

gst/gstdevicemonitor.c

+/* GStreamer
+ * Copyright (C) 2012 Olivier Crete <olivier.crete@collabora.com>
+ *
+ * gstdevicemonitor.c: Device probing and monitoring
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gstdevicemonitor.h>
+
+#include "gst/gst_private.h"
+#include <gst/gst.h>
+
+#include <gst/gstelementmetadata.h>
+#include <gst/gstquark.h>
+
+struct _GstDeviceMonitorPrivate
+{
+  GstBus *bus;
+
+  GMutex start_lock;
+
+  gboolean started_count;
+};
+
+/* this is used in gstelementfactory.c:gst_element_register() */
+GQuark __gst_devicemonitorclass_factory = 0;
+
+static void gst_device_monitor_class_init (GstDeviceMonitorClass * klass);
+static void gst_device_monitor_init (GstDeviceMonitor * element);
+static void gst_device_monitor_base_class_init (gpointer g_class);
+static void gst_device_monitor_base_class_finalize (gpointer g_class);
+static void gst_device_monitor_dispose (GObject * object);
+static void gst_device_monitor_finalize (GObject * object);
+
+static gpointer gst_device_monitor_parent_class = NULL;
+
+GType
+gst_device_monitor_get_type (void)
+{
+  static volatile gsize gst_device_monitor_type = 0;
+
+  if (g_once_init_enter (&gst_device_monitor_type)) {
+    GType _type;
+    static const GTypeInfo element_info = {
+      sizeof (GstDeviceMonitorClass),
+      gst_device_monitor_base_class_init,
+      gst_device_monitor_base_class_finalize,
+      (GClassInitFunc) gst_device_monitor_class_init,
+      NULL,
+      NULL,
+      sizeof (GstDeviceMonitor),
+      0,
+      (GInstanceInitFunc) gst_device_monitor_init,
+      NULL
+    };
+
+    _type = g_type_register_static (GST_TYPE_OBJECT, "GstDeviceMonitor",
+        &element_info, G_TYPE_FLAG_ABSTRACT);
+
+    __gst_devicemonitorclass_factory =
+        g_quark_from_static_string ("GST_DEVICEMONITORCLASS_FACTORY");
+    g_once_init_leave (&gst_device_monitor_type, _type);
+  }
+  return gst_device_monitor_type;
+}
+
+static void
+gst_device_monitor_base_class_init (gpointer g_class)
+{
+  GstDeviceMonitorClass *klass = GST_DEVICE_MONITOR_CLASS (g_class);
+
+  /* Copy the element details here so elements can inherit the
+   * details from their base class and classes only need to set
+   * the details in class_init instead of base_init */
+  klass->metadata =
+      klass->metadata ? gst_structure_copy (klass->metadata) :
+      gst_structure_new_empty ("metadata");
+
+  klass->factory = g_type_get_qdata (G_TYPE_FROM_CLASS (klass),
+      __gst_devicemonitorclass_factory);
+}
+
+static void
+gst_device_monitor_base_class_finalize (gpointer g_class)
+{
+  GstDeviceMonitorClass *klass = GST_DEVICE_MONITOR_CLASS (g_class);
+
+  gst_structure_free (klass->metadata);
+}
+
+static void
+gst_device_monitor_class_init (GstDeviceMonitorClass * klass)
+{
+  GObjectClass *gobject_class = (GObjectClass *) klass;
+
+  gst_device_monitor_parent_class = g_type_class_peek_parent (klass);
+
+  g_type_class_add_private (klass, sizeof (GstDeviceMonitorPrivate));
+
+  gobject_class->dispose = gst_device_monitor_dispose;
+  gobject_class->finalize = gst_device_monitor_finalize;
+}
+
+static void
+gst_device_monitor_init (GstDeviceMonitor * monitor)
+{
+  monitor->priv = G_TYPE_INSTANCE_GET_PRIVATE (monitor,
+      GST_TYPE_DEVICE_MONITOR, GstDeviceMonitorPrivate);
+
+  g_mutex_init (&monitor->priv->start_lock);
+
+  monitor->priv->bus = gst_bus_new ();
+  gst_bus_set_flushing (monitor->priv->bus, TRUE);
+}
+
+
+static void
+gst_device_monitor_dispose (GObject * object)
+{
+  GstDeviceMonitor *monitor = GST_DEVICE_MONITOR (object);
+
+  gst_object_replace ((GstObject **) & monitor->priv->bus, NULL);
+
+  GST_OBJECT_LOCK (monitor);
+  g_list_free_full (monitor->devices, (GDestroyNotify) gst_object_unparent);
+  monitor->devices = NULL;
+  GST_OBJECT_UNLOCK (monitor);
+
+  G_OBJECT_CLASS (gst_device_monitor_parent_class)->dispose (object);
+}
+
+static void
+gst_device_monitor_finalize (GObject * object)
+{
+  GstDeviceMonitor *monitor = GST_DEVICE_MONITOR (object);
+
+  g_mutex_clear (&monitor->priv->start_lock);
+
+  G_OBJECT_CLASS (gst_device_monitor_parent_class)->finalize (object);
+}
+
+/**
+ * gst_device_monitor_class_add_metadata:
+ * @klass: class to set metadata for
+ * @key: the key to set
+ * @value: the value to set
+ *
+ * Set @key with @value as metadata in @klass.
+ */
+void
+gst_device_monitor_class_add_metadata (GstDeviceMonitorClass * klass,
+    const gchar * key, const gchar * value)
+{
+  g_return_if_fail (GST_IS_DEVICE_MONITOR_CLASS (klass));
+  g_return_if_fail (key != NULL);
+  g_return_if_fail (value != NULL);
+
+  gst_structure_set ((GstStructure *) klass->metadata,
+      key, G_TYPE_STRING, value, NULL);
+}
+
+/**
+ * gst_device_monitor_class_add_static_metadata:
+ * @klass: class to set metadata for
+ * @key: the key to set
+ * @value: the value to set
+ *
+ * Set @key with @value as metadata in @klass.
+ *
+ * Same as gst_device_monitor_class_add_metadata(), but @value must be a static string
+ * or an inlined string, as it will not be copied. (GStreamer plugins will
+ * be made resident once loaded, so this function can be used even from
+ * dynamically loaded plugins.)
+ *
+ * Since: 1.4
+ */
+void
+gst_device_monitor_class_add_static_metadata (GstDeviceMonitorClass * klass,
+    const gchar * key, const gchar * value)
+{
+  GValue val = G_VALUE_INIT;
+
+  g_return_if_fail (GST_IS_DEVICE_MONITOR_CLASS (klass));
+  g_return_if_fail (key != NULL);
+  g_return_if_fail (value != NULL);
+
+  g_value_init (&val, G_TYPE_STRING);
+  g_value_set_static_string (&val, value);
+  gst_structure_take_value ((GstStructure *) klass->metadata, key, &val);
+}
+
+/**
+ * gst_device_monitor_class_set_metadata:
+ * @klass: class to set metadata for
+ * @longname: The long English name of the device monitor. E.g. "File Sink"
+ * @classification: String describing the type of device monitor, as an unordered list
+ * separated with slashes ('/'). See draft-klass.txt of the design docs
+ * for more details and common types. E.g: "Sink/File"
+ * @description: Sentence describing the purpose of the device monitor.
+ * E.g: "Write stream to a file"
+ * @author: Name and contact details of the author(s). Use \n to separate
+ * multiple author metadata. E.g: "Joe Bloggs &lt;joe.blogs at foo.com&gt;"
+ *
+ * Sets the detailed information for a #GstDeviceMonitorClass.
+ * <note>This function is for use in _class_init functions only.</note>
+ *
+ * Since: 1.4
+ */
+void
+gst_device_monitor_class_set_metadata (GstDeviceMonitorClass * klass,
+    const gchar * longname, const gchar * classification,
+    const gchar * description, const gchar * author)
+{
+  g_return_if_fail (GST_IS_DEVICE_MONITOR_CLASS (klass));
+  g_return_if_fail (longname != NULL && *longname != '\0');
+  g_return_if_fail (classification != NULL && *classification != '\0');
+  g_return_if_fail (description != NULL && *description != '\0');
+  g_return_if_fail (author != NULL && *author != '\0');
+
+  gst_structure_id_set ((GstStructure *) klass->metadata,
+      GST_QUARK (ELEMENT_METADATA_LONGNAME), G_TYPE_STRING, longname,
+      GST_QUARK (ELEMENT_METADATA_KLASS), G_TYPE_STRING, classification,
+      GST_QUARK (ELEMENT_METADATA_DESCRIPTION), G_TYPE_STRING, description,
+      GST_QUARK (ELEMENT_METADATA_AUTHOR), G_TYPE_STRING, author, NULL);
+}
+
+/**
+ * gst_device_monitor_class_set_static_metadata:
+ * @klass: class to set metadata for
+ * @longname: The long English name of the element. E.g. "File Sink"
+ * @classification: String describing the type of element, as an unordered list
+ * separated with slashes ('/'). See draft-klass.txt of the design docs
+ * for more details and common types. E.g: "Sink/File"
+ * @description: Sentence describing the purpose of the element.
+ * E.g: "Write stream to a file"
+ * @author: Name and contact details of the author(s). Use \n to separate
+ * multiple author metadata. E.g: "Joe Bloggs &lt;joe.blogs at foo.com&gt;"
+ *
+ * Sets the detailed information for a #GstDeviceMonitorClass.
+ * <note>This function is for use in _class_init functions only.</note>
+ *
+ * Same as gst_device_monitor_class_set_metadata(), but @longname, @classification,
+ * @description, and @author must be static strings or inlined strings, as