Below is a draft of the XI2 protocol specification. There's a few fixmes in the document, and it's limited to requests that are in addition to XI 1.x requests. I'll get a server up that supports this set of the protocol so we can tell whether it all makes sense but IMO it's not a bad spec for now.
For those that want to track this work, the repositories will be available on git://people.freedesktop.org/~whot/inputproto.git git://people.freedesktop.org/~whot/xserver.git git://people.freedesktop.org/~whot/libXi.git I'll be rebasing and squashing frequently, expect non-fast-foward merges. Some notes (partly related to last draft [1]): - device presence events removed, merged into device hierarchy events - no proximity. If a device needs proximity, it needs a distance axis. - axis and button labelling as part of the protocol now. - screen coordinates bumped to 16.16 fixed point - valuators bumped to 32.32 fixed point - devices provide explicit keycodes rather than keycode ranges. Holes in a keycode range are allowed. - device events include xkb modifier and group state - some requests are the same as currently in master, but bumped to 16 bit deviceids - the server will reserve device ids 0 and 1 as special devices for event masks. Please note that this is not the final document. If you desire to correct typos, grammatical errors, etc. please reply off-list to keep the noise down. [1] http://lists.freedesktop.org/archives/xorg/2009-January/042441.html Cheers, Peter The X Input Extension Version 2.0 Peter Hutterer peter.hutte...@redhat.com Red Hat, Inc. 1. Introduction The X Input Extension version 2.0 (XI2) is the second major release of the X Input Extension. FIXME ❧❧❧❧❧❧❧❧❧❧❧ 2. Notations used in this document Notation for requests: ┌─── Name of request name of request field: type of request field name of request field: type of request field ▶ name of reply field: type of reply field └─── Notation for events: ┌─── Name of event name of field: type of field name of field: type of field └─── Complex fields are specified in the following notation: name of field: COMPLEXFIELDTYPE or, if multiple of these fields exist: name of field: LISTofCOMPLEXFIELDTYPE COMPLEXFIELDTYPE: { name of subfield: type of subfield, name of subfield: type of subfield } ❧❧❧❧❧❧❧❧❧❧❧ 3. Interoperability between version 1.x and 2.0 FIXME ❧❧❧❧❧❧❧❧❧❧❧ 4. The Master/Slave device hierarchy XI2 introduces a device hierarchy split up into so-called Master Devices (MD) and Slave Devices (SD). 4.1 Master devices An MD is a virtual device created and managed by the server. MDs may send core events and XI events. However, an MD does not represent a physical device and relies on SDs for event generation. MDs come in two forms: as master pointers or as master keyboards. A master pointer is represented by a visible cursor on the screen. A master keyboard is represented by a keyboard focus. Each master pointer is paired with the respective master keyboard and vice versa, and this pairing is constant for the lifetime of both input devices. Clients can utilise this pairing behaviour to implement input paradigms that require pointer and keyboard interation (e.g. SHIFT + Click). 4.2 Slave devices An SD is usually a physical device configured in the server. SDs are not represented by a cursor or keyboard focus and may be attached to a master pointer or master keyboard. SDs can only be attached to any master of the same type (e.g. a physical pointer device can be attached to any master pointer). If an event is generated by an SD - if the SD is attached to a master pointer, it changes the position and/or button state of the master pointer. - if the SD is attached to a master keyboard, it sends events to this keyboard's focus window (if applicable) and/or changes the modifier state of this keyboard. - if the SD is not attached to an SD ("floating"), it does not change the any master device. The SD has its own (invisible) sprite and its own focus. Both the sprite and the focus must be managed explicitly by the client program. 4.3 Event processing for attached slave devices Whenever an SD changes its logical state, - the event is delivered as an XI event to any interested clients. If the device is floating, event processing stops. Otherwise, if the device is attached, - the master device changes its classes to reflect the SD's capabilities. All interested clients are notified of this device change. - then, the event is delivered as an XI event from the MD to any interested clients. If the event has been delivered, event processing stops. Otherwise, - the event is delivered as a core event to any interested clients. Given that W is the event window, and P the parent window of W, event delivery to P is only attempted if neither the XI event, nor the core event has been delivered on W. Once an event has been delivered as either XI or core event, event processing stops. ❧❧❧❧❧❧❧❧❧❧❧ 5. Data types BUTTONMASK A binary mask defined as (1 << button number). A SETofBUTTONMASK is a binary OR of zero or more BUTTONMASK. DEVICE { DEVICEID, AllDevices, AllMasterDevices } A DEVICE specifies either a DEVICEID or AllDevices or AllMasterDevices. DEVICEID { CARD16 } A DEVICEID is a numerical ID for a device currently available in the server. The server may re-use a device ID after a device's removal. The device IDs 0 and 1 are reserved. AllDevices ........ 0 AllMasterDevices .. 1 DEVICEUSE { MasterPointer, MasterKeyboard, SlavePointer, SlaveKeyboard, FloatingSlave } A DEVICEUSE field specifies the current use of a device in the MD/SD device hierarchy. See Section 4 for more information. EVENTMASK An EVENTMASK is a binary mask defined as (1 << event type). A SETofEVENTMASK is a binary OR of zero or more EVENTMASK. FP1616 Fixed point decimal in 16.16 format as 32 bit integer. The client is required to convert to 16.16 decimal format. FP3232 Fixed point decimal in 32.32 format as one INT32 and one CARD32. The INT32 contains the integral part, the CARD32 the decimal fraction shifted by 32. VALUATORMASK A binary mask defined as (1 << valuator number). A SETofVALUATORMASK is a binary OR of zero or more VALUATORMASK. ❧❧❧❧❧❧❧❧❧❧❧ 6. Errors Errors are sent using core X error reports. Device A value for a DEVICE argument does not specify a valid DEVICE. ❧❧❧❧❧❧❧❧❧❧❧ 7. Requests: The server does not guarantee that the length of a reply remains constant in future revisions of XI2. A client must always retrieve the exact length of the protocol reply from the connection, even if the reply is longer than defined for the XI2 version supported by the client. Additional bytes in a request may include data supported in later versions of XI2. Clients should ignore this data. 7.1 Requests introduced in version 2.0 ┌─── XIQueryVersion major_version: CARD16 minor_version: CARD16 ▶ num_devices: CARD16 major_version: CARD16 └─── The client sends the highest supported version to the server and the server sends the highest version it supports, but no higher than the requested version. Major versions changes can introduce incompatibilities in existing functionality, minor version changes introduce only backward compatible changes. It is the clients responsibility to ensure that the server supports a version which is compatible with its expectations. major_version major XI2 version minor_version minor XI2 version ┌─── XIQueryDevice DEVICE device ▶ num_devices: CARD16 deviceinfo: LISTofDEVICEINFO └─── DEVICEINFO { deviceid: DEVICEID use: DEVICEUSE attachment: DEVICEID enabled: BOOL num_classes: CARD16 name_len: CARD16 classes: LISTofCLASS name: LISTofCHAR8 } CLASS { BUTTONCLASS KEYCLASS, AXISCLASS } BUTTONCLASS { type: ButtonClass length: CARD16 num_buttons: CARD16 buttons: LISTofATOM } KEYCLASS { type: KeyClass length: CARD16 num_keys: CARD16 keys: LISTofCARD32 } AXISCLASS { type: AxisClass length: CARD16 axisnumber: CARD16 axisname: ATOM min: FP3232 max: FP3232 resolution: CARD32 } XIQueryDevices details information about the requested input devices. devices The device to list. If 'devices' is AllDevices, all enabled and disabled devices are listed. If 'devices' is AllMasterDevices, all enabled and disabled master devices are listed. If 'devices' is a valid DEVICE, only this DEVICE is listed and 'num_devices' is 1. num_devices The number of 'deviceinfos' returned. Each 'deviceinfo' is detailed as follows: deviceid The unique ID of the device. Device IDs may get re-used when a device is removed. use If the device is a master pointer, 'use' is MasterPointer. If the device is a master keyboard, 'use' is MasterKeyboard. If the device is a slave pointer, 'use' is SlavePointer If the device is a slave keyboard, 'use' is SlaveKeyboard If the device is a floating slave, 'use' is FloatingSlave attachment If the device is a master pointer or a master keyboard, 'attachment' specifies the paired master keyboard, or the paired master pointer, respectively. If the device is a non-floating slave device 'attachment' specifies the master device this device is attached to. If the device is a floating slave, 'attachment' is undefined. enabled Zero if the device is disabled, non-zero otherwise. num_classes Number of 'classes' provided name_len Length of the name in bytes. classes Details the available classes provided by the device in an undefined order. name The device's name. For all classes, 'type' specifies the device class. Clients are required to ignore unknown device classes. The 'length' field specifies the length of the class in 4 byte units. The following classes may occur only once: ButtonClass, KeyClass ButtonClass: type Always ButtonClass length Length in 4 byte units num_buttons Number of buttons provided by the device. buttons List of Atoms specifying the type of each button. An atom of 0 specifies an unnamed button. KeyClass: type Always KeyClass length Length in 4 byte units num_keys Number of keycodes provided by the device. keys List of keycodes provided. AxisClass: type Always AxisClass length Length in 4 byte units axisnumber Axis number of this axis. axisname Atom specifying the axis name. An Atom of 0 specifies an unnamed axis. min Minimum value. max Minimum value. resolution Resolution in counts/meter. mode Relative or Absolute An axis in Relative mode may specify 'min' and 'max' as a hint to the client. If no 'min' and 'max' information is available, both must be 0. ┌─── XISelectEvents window: Window num_masks: CARD16 masks: ListOfDEVICEEVENTMASK └─── DEVICEEVENTMASK { deviceid: DEVICE, mask_len: CARD16, mask: SETofEVENTMASK window The window to select the events on. num_masks Number of items in mask. deviceid Numerical deviceid, or AllDevices, or AllMasterDevices mask_len Length of mask in 4 byte units. mask Event mask. An event mask for an event type T is defined as (1 << T). XISelectEvents selects for XI2 events on 'window'. If 'num_masks' is 0, a BadValue error occurs. Each 'mask' sets the (and overwrites a previous) event mask for the DEVICE specified through 'deviceid'. The device 'AllDevices' or 'AllMasterDevices' is treated as a separate device by server. A client's event mask is the union of 'AllDevices', 'AllMasterDevices' and the per-device event mask. The removal of device from the server unsets the event masks for the device. If an event mask is set for AllDevices or AllMasterDevices, the event mask is not cleared on device removal and affects all future devices. If 'mask_len' is 0, the event mask for the given device is cleared. ┌─── XIQueryDevicePointer window: Window deviceid: DEVICEID ▶ root: Window child: Window root_x: FP1616 root_y: FP1616 win_x: FP1616 win_y: FP1616 same_screen: BOOL └─── Query a master pointer device for its current position. root The root window the pointer is logically on. child The child window of 'window' that contains the pointer or None. root_x root_y Pointer position relative to the root window's origin. win_x win_y Pointer position relative to 'window' or 0 if 'same_screen' is false. same_screen TRUE if 'window' is on the same screen as the pointer. ┌─── XIWarpDevicePointer src_win: Window dst_win: Window src_x: FP1616 src_y: FP1616 src_width: INT16 src_height: INT16 dst_x: FP1616 dst_y: FP1616 deviceid: DEVICEID └─── WarpDevicePointer moves the pointer of 'deviceid' as if the user had moved the pointer. WarpDevicePointer can only be called for MasterPointer and FloatingSlave devices. src_win If src_window is not None, the move only takes place if src_window contains the pointer and the pointer is contained in the specified rectangle of src_window. dst_win If dst_win is None, this request moves the pointer by offsets 'dst_x'/'dst_y' relative to the current position of the pointer. If dst_window is a window, this request moves the pointer to 'dst_x'/'dst_y' relative to dst_win's origin. src_x src_y src_width src_height Specifies the source window rectangle. dst_x dst_y The relative coordinates to move the pointer if 'dst_win' is None, or the absolute coordinates if 'dst_win' is a window. deviceid The device to warp. This request cannot be used to move the pointer outside the confine-to window of an active pointer grab. An attempt will only move the pointer as far as the closest edge of the confine-to window. This request will generate events just as if the user had instantaneously moved the pointer. ┌─── XIChangeDeviceCursor win: Window cursor: Cursor deviceid: DEVICEID └─── Change a master pointer's cursor on the specified window. window The window cursor The new cursor or None deviceid The master pointer device. Whenever 'device' enters a window W, the cursor shape is selected in the following order: - if the current window has a device cursor C(d) defined for 'device', display this cursor C(d). - otherwise, if the current window has a cursor C(w) defined in the core protocol's window attributes, display cursor C(w). - repeat on parent window until a cursor has been found. ┌─── XIChangeDeviceHierarchy num_changes: CARD8 changes: LISTofHIERARCHYCHANGES └─── HIERARCHYCHANGE { CREATEMASTER, REMOVEMASTER, CHANGEATTACHMENT } HIERARCHYCHANGETYPE { CreateMaster, RemoveMaster, ChangeAttachment } CHANGEMODE { Float, Attach } CREATEMASTER { type: HIERARCHYCHANGETYPE length: CARD16 name_len: CARD16 send_core: BOOL enable: BOOL name: LISTofCHAR8 } REMOVEMASTER { type: HIERARCHYCHANGETYPE length: CARD16 deviceid: DEVICEID return_mode: CHANGEMODE return_pointer: DEVICEID return_keyboard: DEVICEID } {CHANGEATTACHMENT type: HIERARCHYCHANGETYPE length: CARD16 deviceid: DEVICEID change_mode: CHANGEMODE master: DEVICEID } XIChangeDeviceHierarchy allows a client to modify the MD/SD device hierarchy (see Section 4). num_changes The number of changes to apply to the current hierarchy. changes The list of changes. The server processes the changes one by one and applies changes immediately. If an error occurs, processing stops at the current change and the error is returned to the client. CREATEMASTER creates a pair of master devices. type CreateMaster length Length in 4 byte units. name_len Length of 'name' in bytes. send_core TRUE if the device should send core events. enable TRUE if the device is to be enabled immediately. name The name for the new master devices. The master pointer's name is automatically appended with " pointer", the master keyboard's name is automatically appended with " keyboard". REMOVEMASTER removes an existing master device. type RemoveMaster length Length in 4 byte units deviceid The device to remove. return_mode Return mode for attached slave devices. If 'return_mode' is Float, all slave devices are set to floating. If 'return_mode' is Attach, slave pointers are attached to 'return_pointer' and slave keyboards are attached to 'return_keyboard'. return_pointer return_keyboard The master pointer and master keyboard to attach slave devices to, if 'return_mode' is Attach. Removing a master pointer removes the paired master keyboard and vice versa. CHANGEATTACHMENT changes the attachment of a slave device. type ChangeAttachment length Length in 4 byte units. deviceid Deviceid of the slave device change_mode Attachment mode for the slave device. If 'change_mode' is Attach, 'master' specifies the new master device. If 'change_mode' is Float, the slave device is set floating. master The new master device to attach this slave device to, if 'change_mode' is floating. ┌─── XISetClientPointer win: Window deviceid: DEVICEID └─── Set the ClientPointer for the client owning 'win' to the given device. win Window or client ID deviceid The master pointer or master keyboard that acts as ClientPointer. Some protocol requests are ambiguous and the server has to choose a device to provide data for a request or a reply. By default, the server will choose a client's ClientPointer device to provide the data, unless the client currently has a grab on another device. ┌─── XISetClientPointer win: Window ▶ set: BOOL deviceid: DEVICEID └─── Query the ClientPointer for the client owning 'win'. win The window or client ID. set TRUE if the client has an explicitly set ClientPointer. deviceid The master pointer that acts as a ClientPointer if 'set' is TRUE. 8. Events: An event specifies its length in 4-byte units after the initial 32 bytes. Future versions of the protocol may provide additional information in the same event, thus increasing the event size. Clients are required to always read the number of bytes specified by the event, not the size of the event they may have been compiled against. The following event types are available in XI2. Version 2.0: HierarchyChanged DeviceChanged KeyPress KeyRelease ButtonPress ButtonRelease Motion RawEvent Enter Leave All events have a set of common fields specified as EVENTHEADER. EVENTHEADER { type: BYTE extension: BYTE sequenceNumber: CARD16 length: CARD32 evtype: CARD16 deviceid: DEVICEID time: Time } type Always GenericEvent. extension Always the X Input extension offset. sequenceNumber Sequence number of last request processed by the server. length Length in 4-byte units after the initial 32 bytes. evtype XI-specific event type. deviceid Numerical device id for a device. time Time in ms. ┌─── DeviceHierarchyEvent: EVENTHEADER flags: SETofHIERARCHYMASK num_devices: CARD16 deviceinfo: LISTofHIERARCHYINFO └─── HIERARCHYMASK { MasterAdded, MasterRemoved, SlaveAttached, SlaveDetached, SlaveAdded, SlaveRemoved, DeviceEnabled, DeviceDisabled } HIERARCHYINFO { deviceid: DEVICEID, attachment: DEVICEID, type: DEVICEUSE enabled: BOOL } flags Set of the changes that have occured, causing this event. num_devices The number of devices present in the hierarchy. devices The current hierarchy layout for each device. An XDeviceHierarchyEvent is sent whenever the device hierarchy been changed. The 'flags' specify all types of hierarchy modifiations that have occured. For all devices, 'deviceinfo' details the hierarchy information after the modification of the hierarchy has occured. For each device specified with 'deviceid': - if 'type' is MasterPointer or MasterKeyboard, 'attachment' decribes the pairing of this device. - if 'type' is SlavePointer or SlaveKeyboard, 'attachment' describes the master device this device is attached to. - if 'type' is FloatingSlave device, 'attachment' is undefined. enabled TRUE if the device is enabled and can send events. A disabled master device will not forward events from an attached, enabled slave device. Note: Multiple devices may be affected in one hierarchy change, 'deviceid' in an XDeviceHierarchyChangedEvent is always the first affected device. Clients should ignore deviceid and instead use the 'devices' list. ┌─── DeviceChangedEvent: EVENTHEADER reason: CHANGEREASON source: DEVICEID num_classes: CARD16 classes: LISTofCLASS └─── CHANGEREASON { SlaveSwitch, DeviceChange } A DeviceChangeEvent is sent whenever a device changes it's capabilities. This can happen either by a new slave device sending events through a master device, or by a physical device changing capabilities at runtime. reason The reason for generating this event. If 'reason' is SlaveSwitch, the slave device sending events through this device has changed and 'source' specifies the new slave device. A SlaveSwitch 'reason' can only occur on a master device. If 'reason' is DeviceChange, the device itself has changed through other means (e.g. a physical device change) and 'source' is undefined. A DeviceChange can only occur on a slave device. source The source of the new classes. Only defined in 'reason' is SlaveSwitch. num_classes Number of 'classes' provided classes Details the available classes provided by the device. The order the classes are provided in is undefined. For a detailed description of 'classes', see the XQueryInputDevice request. ┌─── DeviceEvent: EVENTHEADER detail: CARD32 root: Window event: Window child: Window root_x: FP1616 root_y: FP1616 event_x: FP1616 event_y: FP1616 buttons_len: CARD16 valuators_len: CARD16 sourceid: DEVICEID mods: MODIFIERINFO group: GROUPINFO buttons: SETofBUTTONMASK valuators: SETofVALUATORMASK axisvalues: LISTofFP3232 └─── BUTTONBIT { (1 << Button1), (1 << Button2), ... , (1 << ButtonN) } VALUATORBIT { (1 << 1), ( 1 << 2), ... ( 1 << n) } MODIFIERINFO { base_mods: CARD32, latched_mods: CARD32, locked_mods: CARD32} GROUPINFO { base_group: CARD8, latched_group: CARD8, locked_group: CARD8 } An XDeviceEvent is generated whenever the logical state of a device changes in response to a button press, a button release, a motion, a key press or a key release. detail The button number or key code, or 0. root event child The root window, event window or subwindow, respectively. See core protocol specification for more detail. root_x root_y The position of the pointer in screen coordinates (16.16 fixed point). event_x event_y The position of the pointer in screen coordinates relative to the event window (16.16 fixed point). buttons_len The length of 'buttons' in 4 byte units. valuators_len The length of 'valuators' in 4 byte units. sourceid The source device that originally generated the event. mods XKB modifier state before the event occured. group XKB group state before the event. buttons Button state before the event valuators Bitmask of valuators provided in 'axisvalues'. axisvalues Valuator data in device-native resolution. Modifier state in 'mods' is detailed as follows: base_mods XKB base modifier state latched_mods XKB latched modifier state locked_mods XKB locked modifier state Group state in 'group' is detailed as follows: base_group XKB base group state latched_group XKB latched group state locked_group XKB locked group state ┌─── RawEvent EVENTHEADER eventtype: RAWTYPE detail: CARD32 buttons_len: CARD16 valuators_len: CARD16 buttons: SETofBUTTONMASK valuators: SETofVALUATORMASK valuators_unaccel: SETofVALUATORMASK axisvalues: LISTofFP3232 axisvalues_unaccel: LISTofFP3232 └─── RAWTYPE { Motion, KeyPress, KeyRelease, ButtonPress, ButtonRelease } A RawDevice event provides the information provided by the driver to the client. RawDevice events are only generated for slave devices. Unaccelerated and accelerated valuator data is provided if applicable. RawDeviceEvents are sent exclusively to all root windows or to the client that grabbed the device only. eventtype The type of event that occured on the device. detail The button number or keycode. buttons_len The length of 'buttons' in 4 byte units. valuators_len The length of 'valuators' in 4 byte units. buttons Button state before the event valuators Bitmask of valuators provided in 'axisvalues'. valuators_unaccel Bitmask of valuators provided in 'axisvalues_unaccel'. axisvalues Valuator data in device-native resolution. axisvalues_unaccel Unaccelerated valuator data in device-native resolution. ┌─── Enter or Leave EVENTHEADER root: Window event: Window child: Window sourceid: DEVICEID root_x: FP1616 root_y: FP1616 event_x FP1616 event_y: FP1616 mode: NOTIFYMODE detail: NOTIFYDETAIL same_screen: BOOL focus: BOOL └─── NOTIFYMODE { Normal, Grab, Ungrab } NOTIFYDETAIL { Ancestor, Virtual, Inferior, Nonlinear, NonlinearVirtual, Pointer, PointerRoot, None } Enter or Leave events are sent whenever a device's pointer enters or leaves a window. The enter/leave model is described in the core protocol specification, Section 11. (EnterNotify, LeaveNotify events). root event child The root window, event window, and child window, respectively. See the core protocol specification for more detail. sourceid The device that caused the pointer to move. root_x root_y The pointer coordinates relative to the root window. event_x event_y The pointer coordinates relative to the event window. mode Normal pointer motion events have mode Normal. Pseudo-motion events when a grab activates have mode Grab, and pseudo-motion events when a grab deactivates have mode Ungrab. detail Specifies the relation of the event window to the window the pointer entered or left. See the core protocol spec for details. same_screen TRUE if the event window is on the same screen as the pointer's root window. focus If the event window is the focus window or an inferior of the focus window, then focus is True. Otherwise, focus is False. ❧❧❧❧❧❧❧❧❧❧❧ _______________________________________________ xorg mailing list xorg@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/xorg