Package org.freedesktop.gstreamer.gst

Class DeviceMonitor

java.lang.Object

org.javagi.base.ProxyInstance

org.gnome.gobject.TypeInstance

org.gnome.gobject.GObject

org.gnome.gobject.InitiallyUnowned

org.freedesktop.gstreamer.gst.GstObject

org.freedesktop.gstreamer.gst.DeviceMonitor

All Implemented Interfaces:

Proxy

@Generated("io.github.jwharm.JavaGI")
public class DeviceMonitor
extends GstObject

Applications should create a GstDeviceMonitor when they want to probe, list and monitor devices of a specific type. The GstDeviceMonitor will create the appropriate GstDeviceProvider objects and manage them. It will then post messages on its GstBus for devices that have been added and removed.

The device monitor will monitor all devices matching the filters that the application has set.

The basic use pattern of a device monitor is as follows:

   static gboolean
   my_bus_func (GstBus * bus, GstMessage * message, gpointer user_data)
   {
      GstDevice *device;
      gchar *name;

      switch (GST_MESSAGE_TYPE (message)) {
        case GST_MESSAGE_DEVICE_ADDED:
          gst_message_parse_device_added (message, &device);
          name = gst_device_get_display_name (device);
          g_print("Device added: %s\\n", name);
          g_free (name);
          gst_object_unref (device);
          break;
        case GST_MESSAGE_DEVICE_REMOVED:
          gst_message_parse_device_removed (message, &device);
          name = gst_device_get_display_name (device);
          g_print("Device removed: %s\\n", name);
          g_free (name);
          gst_object_unref (device);
          break;
        default:
          break;
      }

      return G_SOURCE_CONTINUE;
   }

   GstDeviceMonitor *
   setup_raw_video_source_device_monitor (void) {
      GstDeviceMonitor *monitor;
      GstBus *bus;
      GstCaps *caps;

      monitor = gst_device_monitor_new ();

      bus = gst_device_monitor_get_bus (monitor);
      gst_bus_add_watch (bus, my_bus_func, NULL);
      gst_object_unref (bus);

      caps = gst_caps_new_empty_simple ("video/x-raw");
      gst_device_monitor_add_filter (monitor, "Video/Source", caps);
      gst_caps_unref (caps);

      gst_device_monitor_start (monitor);

      return monitor;
   }
 

Since:

1.4

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DeviceMonitor.Builder<B extends DeviceMonitor.Builder<B>>	Inner class implementing a builder pattern to construct a GObject with properties.
static class	DeviceMonitor.DeviceMonitorClass	Opaque device monitor class structure.

Nested classes/interfaces inherited from class org.freedesktop.gstreamer.gst.GstObject

GstObject.DeepNotifyCallback, GstObject.Object$Impl, GstObject.ObjectClass

Nested classes/interfaces inherited from class org.gnome.gobject.InitiallyUnowned

InitiallyUnowned.InitiallyUnownedClass

Nested classes/interfaces inherited from class org.gnome.gobject.GObject

GObject.NotifyCallback

Constructor Summary

Constructors

Constructor	Description
DeviceMonitor()	Creates a new DeviceMonitor.
DeviceMonitor(MemorySegment address)	Create a DeviceMonitor proxy instance for the provided memory address.

Method Summary

Modifier and Type	Method	Description
int	addFilter(@Nullable String classes, @Nullable Caps caps)	Adds a filter for which GstDevice will be monitored, any device that matches all these classes and the GstCaps will be returned.
protected DeviceMonitor	asParent()	Returns this instance as if it were its parent type.
static DeviceMonitor.Builder<? extends DeviceMonitor.Builder>	builder()	A DeviceMonitor.Builder object constructs a DeviceMonitor with the specified properties.
Bus	getBus()	Gets the GstBus of this GstDeviceMonitor
@Nullable List<Device>	getDevices()	Gets a list of devices from all of the relevant monitors.
static MemoryLayout	getMemoryLayout()	The memory layout of the native struct.
String[]	getProviders()	Get a list of the currently selected device provider factories.
boolean	getShowAllDevices()	Get if this DeviceMonitor is currently showing all devices, even those from hidden providers.
static @Nullable Type	getType()	Get the GType of the DeviceMonitor class
boolean	removeFilter(int filterId)	Removes a filter from the GstDeviceMonitor using the id that was returned by gst_device_monitor_add_filter().
void	setShowAllDevices(boolean showAll)	Set if all devices should be visible, even those devices from hidden providers.
boolean	start()	Starts monitoring the devices, one this has succeeded, the MessageType.DEVICE_ADDED and MessageType.DEVICE_REMOVED messages will be emitted on the bus when the list of devices changes.
void	stop()	Stops monitoring the devices.

Methods inherited from class org.freedesktop.gstreamer.gst.GstObject

addControlBinding, checkUniqueness, deepNotify, defaultDeepNotify, defaultError, emitDeepNotify, getControlBinding, getControlRate, getGValueArray, getName, getParent, getPathString, getValue, getValueArray, hasActiveControlBindings, hasAncestor, hasAsAncestor, hasAsParent, onDeepNotify, ref, refSink, removeControlBinding, replace, setControlBindingDisabled, setControlBindingsDisabled, setControlRate, setName, setParent, suggestNextSync, syncValues, unparent, unref

Methods inherited from class org.gnome.gobject.GObject

addToggleRef, addWeakPointer, bindProperty, bindProperty, bindProperty, bindPropertyFull, bindPropertyFull, bindPropertyWithClosures, bindPropertyWithClosures, compatControl, connect, connect, connect, constructed, disconnect, dispatchPropertiesChanged, dispose, dupData, dupQdata, emit, emitNotify, finalize_, forceFloating, freezeNotify, get, getData, getProperty, getProperty, getProperty, getQdata, getv, interfaceFindProperty, interfaceInstallProperty, interfaceListProperties, isFloating, newInstance, newInstance, newv, notify, notify, notifyByPspec, onNotify, refSink, removeToggleRef, removeWeakPointer, replaceData, replaceQdata, runDispose, set, setData, setDataFull, setProperty, setProperty, setProperty, setQdata, setQdataFull, setv, stealData, stealQdata, takeRef, thawNotify, watchClosure, weakRef, weakUnref, withProperties

Methods inherited from class org.gnome.gobject.TypeInstance

callParent, callParent, cast, getPrivate, readGClass, writeGClass

Methods inherited from class org.javagi.base.ProxyInstance

equals, handle, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DeviceMonitor

public DeviceMonitor(MemorySegment address)

Create a DeviceMonitor proxy instance for the provided memory address.

Parameters:

address - the memory address of the native object

DeviceMonitor

public DeviceMonitor()

Creates a new DeviceMonitor.

Method Details

getType

public static @Nullable Type getType()

Get the GType of the DeviceMonitor class

Returns:

the GType

getMemoryLayout

public static MemoryLayout getMemoryLayout()

The memory layout of the native struct.

Returns:

the memory layout

asParent

protected DeviceMonitor asParent()

Returns this instance as if it were its parent type. This is mostly synonymous to the Java super keyword, but will set the native typeclass function pointers to the parent type. When overriding a native virtual method in Java, "chaining up" with super.methodName() doesn't work, because it invokes the overridden function pointer again. To chain up, call asParent().methodName(). This will call the native function pointer of this virtual method in the typeclass of the parent type.

Overrides:

asParent in class GstObject

addFilter

public int addFilter(@Nullable String classes,
 @Nullable Caps caps)

Adds a filter for which GstDevice will be monitored, any device that matches all these classes and the GstCaps will be returned.

If this function is called multiple times to add more filters, each will be matched independently. That is, adding more filters will not further restrict what devices are matched.

The GstCaps supported by the device as returned by gst_device_get_caps() are not intersected with caps filters added using this function.

Filters must be added before the GstDeviceMonitor is started.

Parameters:

classes - device classes to use as filter or null for any class

caps - the GstCaps to filter or null for ANY

Returns:

The id of the new filter or 0 if no provider matched the filter's classes.

Since:

1.4

getBus

public Bus getBus()

Gets the GstBus of this GstDeviceMonitor

Returns:

a GstBus

Since:

1.4

getDevices

public @Nullable List<Device> getDevices()

Gets a list of devices from all of the relevant monitors. This may actually probe the hardware if the monitor is not currently started.

Returns:

a GList of GstDevice

Since:

1.4

getProviders

public String[] getProviders()

Get a list of the currently selected device provider factories.

This

Returns:

A list of device provider factory names that are currently being monitored by this DeviceMonitor or null when nothing is being monitored.

Since:

1.6

getShowAllDevices

public boolean getShowAllDevices()

Get if this DeviceMonitor is currently showing all devices, even those from hidden providers.

Returns:

true when all devices will be shown.

Since:

1.6

removeFilter

public boolean removeFilter(int filterId)

Removes a filter from the GstDeviceMonitor using the id that was returned by gst_device_monitor_add_filter().

Parameters:

filterId - the id of the filter

Returns:

true of the filter id was valid, false otherwise

Since:

1.4

setShowAllDevices

public void setShowAllDevices(boolean showAll)

Set if all devices should be visible, even those devices from hidden providers. Setting showAll to true might show some devices multiple times.

Parameters:

showAll - show all devices

Since:

1.6

start

public boolean start()

Starts monitoring the devices, one this has succeeded, the MessageType.DEVICE_ADDED and MessageType.DEVICE_REMOVED messages will be emitted on the bus when the list of devices changes.

Returns:

true if the device monitoring could be started, i.e. at least a single device provider was started successfully.

Since:

1.4

stop

public void stop()

Stops monitoring the devices.

Since:

1.4

builder

public static DeviceMonitor.Builder<? extends DeviceMonitor.Builder> builder()

A DeviceMonitor.Builder object constructs a DeviceMonitor with the specified properties. Use the various set...() methods to set properties, and finish construction with DeviceMonitor.Builder.build().

Returns:

the builder object