GUsb.Context¶

Subclasses:: None

Methods¶

Inherited:: GObject.Object (37), Gio.Initable (2)
Structs:: GObject.ObjectClass (5)

class	`error_quark` ()
class	`new` ()
	`enumerate` ()
	`find_by_bus_address` (bus, address)
	`find_by_platform_id` (platform_id)
	`find_by_vid_pid` (vid, pid)
	`get_devices` ()
	`get_flags` ()
	`get_hotplug_poll_interval` ()
	`get_main_context` ()
	`get_source` (main_ctx)
	`load` (json_object)
	`load_with_tag` (json_object, tag)
	`save` (json_builder)
	`save_with_tag` (json_builder, tag)
	`set_debug` (flags)
	`set_flags` (flags)
	`set_hotplug_poll_interval` (hotplug_poll_interval)
	`set_main_context` (main_ctx)
	`wait_for_replug` (device, timeout_ms)

Virtual Methods¶

Inherited:: GObject.Object (7), Gio.Initable (1)

	`do_device_added` (device)
	`do_device_changed` (device)
	`do_device_removed` (device)

Properties¶

Name	Type	Flags	Short Description
`debug-level`	`int`	r/w
`libusb-context`	`int`	r

Signals¶

Inherited:: GObject.Object (1)

Name	Short Description
`device-added`	This signal is emitted when a USB device is added.
`device-changed`	This signal is emitted when a USB device is changed.
`device-removed`	This signal is emitted when a USB device is removed.

Fields¶

Inherited:: GObject.Object (1)

Name	Type	Access	Description
parent_instance	`GObject.Object`	r

Class Details¶

class GUsb.Context(**kwargs)¶

Bases:: GObject.Object, Gio.Initable
Abstract:: No
Structure:: GUsb.ContextClass

classmethod error_quark()¶

Returns:: Our personal error quark.
Return type:: int

New in version 0.1.0.

classmethod new()¶

Raises:: GLib.Error
Returns:: a new GUsb.Context object or None on error.
Return type:: GUsb.Context

Creates a new context for accessing USB devices.

New in version 0.1.0.

enumerate()¶

Enumerates all the USB devices and adds them to the context.

You only need to call this function once, and any subsequent calls are silently ignored.

New in version 0.2.2.

find_by_bus_address(bus, address)¶

Parameters:

bus (int) – a bus number
address (int) – a bus address

Raises:

GLib.Error

Returns:

a new GUsb.Device, or None if not found.

Return type:

GUsb.Device

Finds a device based on its bus and address values.

New in version 0.2.2.

find_by_platform_id(platform_id)¶

Parameters:: platform_id (str) – a platform id, e.g. “usb:00:03:03:02”
Raises:: GLib.Error
Returns:: a new GUsb.Device, or None if not found.
Return type:: GUsb.Device

Finds a device based on its platform id value.

New in version 0.2.4.

find_by_vid_pid(vid, pid)¶

Parameters:

vid (int) – a vendor ID
pid (int) – a product ID

Raises:

GLib.Error

Returns:

a new GUsb.Device, or None if not found.

Return type:

GUsb.Device

Finds a device based on its bus and address values.

New in version 0.2.2.

get_devices()¶

Returns:: a new GLib.PtrArray of GUsb.Device's.
Return type:: [GUsb.Device]

New in version 0.2.2.

get_flags()¶

Returns:: the GUsb.ContextFlags, e.g. GUsb.ContextFlags.AUTO_OPEN_DEVICES
Return type:: GUsb.ContextFlags

Sets the flags to use for the context.

New in version 0.2.11.

get_hotplug_poll_interval()¶

Returns:: interval in ms
Return type:: int

Gets the poll interval for platforms like Windows that do not support LIBUSB_CAP_HAS_HOTPLUG.

New in version 0.3.10.

get_main_context()¶

Returns:: the GLib.MainContext
Return type:: GLib.MainContext

Gets the internal GLib.MainContext to use for synchronous methods. By default the value is set to the value of GLib.MainContext.default()

New in version 0.2.5.

get_source(main_ctx)¶

Parameters:: main_ctx (GLib.MainContext) – a GLib.MainContext, or None
Returns:: the GUsb.Source.
Return type:: GUsb.Source

This function does nothing.

New in version 0.1.0.

load(json_object)¶

Parameters:: json_object (Json.Object) – a Json.Object
Raises:: GLib.Error
Returns:: True on success
Return type:: bool

Loads the context from a JSON object.

New in version 0.4.0.

load_with_tag(json_object, tag)¶

Parameters:

json_object (Json.Object) – a Json.Object
tag (str) – a string tag, e.g. runtime-reload, or None

Raises:

GLib.Error

Returns:

True on success

Return type:

bool

Loads any devices with a specified tag into the context from a JSON object.

New in version 0.4.1.

save(json_builder)¶

Parameters:: json_builder (Json.Builder) – a Json.Builder
Raises:: GLib.Error
Returns:: True on success
Return type:: bool

Saves the context to an existing JSON builder.

New in version 0.4.0.

save_with_tag(json_builder, tag)¶

Parameters:

json_builder (Json.Builder) – a Json.Builder
tag (str) – a string tag, e.g. runtime-reload, or None

Raises:

GLib.Error

Returns:

True on success

Return type:

bool

Saves any devices with a specified tag into an existing JSON builder.

New in version 0.4.1.

set_debug(flags)¶

Parameters:: flags (GLib.LogLevelFlags) – a GLib.LogLevelFlags such as GLib.LogLevelFlags.LEVEL_ERROR | GLib.LogLevelFlags.LEVEL_INFO, or 0

Sets the debug flags which control what is logged to the console.

Using GLib.LogLevelFlags.LEVEL_INFO will output to standard out, and everything else logs to standard error.

New in version 0.1.0.

set_flags(flags)¶

Parameters:: flags (GUsb.ContextFlags) – some GUsb.ContextFlags, e.g. GUsb.ContextFlags.AUTO_OPEN_DEVICES

Sets the flags to use for the context. These should be set before GUsb.Context.enumerate() is called.

New in version 0.2.11.

set_hotplug_poll_interval(hotplug_poll_interval)¶

Parameters:: hotplug_poll_interval (int) – the interval in ms

Sets the poll interval for platforms like Windows that do not support LIBUSB_CAP_HAS_HOTPLUG. This defaults to 1000ms and can be changed before or after GUsb.Context.enumerate() has been called.

New in version 0.3.10.

set_main_context(main_ctx)¶

Parameters:: main_ctx (GLib.MainContext) –

Sets the internal GLib.MainContext to use for synchronous methods.

New in version 0.2.5.

wait_for_replug(device, timeout_ms)¶

Parameters:

device (GUsb.Device) – a GUsb.Device
timeout_ms (int) – timeout to wait

Raises:

GLib.Error

Returns:

a new GUsb.Device, or None for invalid

Return type:

GUsb.Device

Waits for the device to be replugged. It may come back with a different VID:PID.

Warning: This is synchronous and blocks until the device comes back or the timeout triggers.

New in version 0.2.9.

do_device_added(device) virtual¶

Parameters:: device (GUsb.Device) –

do_device_changed(device) virtual¶

Parameters:: device (GUsb.Device) –

do_device_removed(device) virtual¶

Parameters:: device (GUsb.Device) –

Signal Details¶

GUsb.Context.signals.device_added(context, device)¶

Signal Name:

device-added

Flags:

RUN_LAST

Parameters:

context (GUsb.Context) – The object which received the signal
device (GUsb.Device) – A GUsb.Device

This signal is emitted when a USB device is added.

GUsb.Context.signals.device_changed(context, device)¶

Signal Name:

device-changed

Flags:

RUN_LAST

Parameters:

context (GUsb.Context) – The object which received the signal
device (GUsb.Device) – A GUsb.Device

This signal is emitted when a USB device is changed.

GUsb.Context.signals.device_removed(context, device)¶

Signal Name:

device-removed

Flags:

RUN_LAST

Parameters:

context (GUsb.Context) – The object which received the signal
device (GUsb.Device) – A GUsb.Device

This signal is emitted when a USB device is removed.

Property Details¶

GUsb.Context.props.debug_level¶

Name:: debug-level
Type:: int
Default Value:: 0
Flags:: READABLE, WRITABLE

GUsb.Context.props.libusb_context¶

Name:: libusb-context
Type:: int
Default Value:: None
Flags:: READABLE