path: root/idl/Accessibility_Registry.idl

/* 
 * AT-SPI - Assistive Technology Service Provider Interface 
 * (Gnome Accessibility Project; http://developer.gnome.org/projects/gap)
 *
 * Copyright 2001 Sun Microsystems Inc.
 *
 * 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.
 */

#include <Bonobo_Unknown.idl>
#include <Accessibility_Event.idl>
#include <Accessibility_Application.idl>
#include <Accessibility_Desktop.idl>

#ifndef _ACCESSIBILITY_REGISTRY_IDL_
#define _ACCESSIBILITY_REGISTRY_IDL_

module Accessibility {

  typedef sequence<Desktop> DesktopSeq;

  interface DeviceEventController;

    /** 
     * The Registry is a service through which applications providing 
     * accessibility services (servers) can rendezvous with consumers of those
     * services (Assistive Technologies).  The Registry is the first "port of call" for 
     * accessible applications and for assistive technologies wishing to query and
     * interact with those applications.
     *
     * The Registry service provides four basic functions to Assistive Technology (AT) clients:
     * \li it provides a list of the applications who have registered with the AT-SPI
     * framework, thereby announcing their participation in the AT-SPI framework;
     * \li it allows AT clients to register for notification of changes in application
     * state (at-spi Events);
     * \li it dispatches/relays said events from participating applications to
     * the registered listeners;
     * \li it gives access to system device events via the associated DeviceEventController
     * interface.
     *
     * From the point of view of accessible applications (i.e. AT-SPI service producers), 
     * the Registry is primarily a registration and event delivery service.  Applications 
     * normally only call the registerApplication and deregisterApplication Registry methods,
     * and its inherited EventListener::notifyEvent method.
     *
     * @note Although all application events are dispatched via the Registry, other AT client 
     * calls are serviced directly by the applications, rather than being relayed via the
     * Registry.  The AT client obtains references to these application objects
     * via the enumeration of Desktop instances whose children are Application instances
     * (Registry::getDesktopList) and via examination of the 'source' member of the Event 
     * structure. 
     *
     * The Registry normally lives in its own process space; communication via Registry and
     * both application services and AT clients takes place via IPC.  A process space diagram
     * illustrating the relationship between applications, Registry, and AT is shown below.
     * @image html "http://developer.gnome.org/projects/gap/tech-docs/SPIBlockDiagram.png"
     * 
     *
     * @see Desktop, Application, Event, EventListener
     **/
  interface Registry : EventListener {

  	/**
         * Register a new application with the accessibility broker.
         * @param application: a reference to the requesting Application
	 **/
        oneway void registerApplication (in Application application);

  	/**
         * De-register an application previously registered with the broker.
         * deregisterApplication:
         * @param application: a reference to the Application 
         * to be deregistered.
	 **/
        void deregisterApplication (in Application application);

  	/**
         * Register a client's interest in (all) application events of 
         * a certain type.
         * @param listener: a reference to the requesting ::EventListener.
         * @param eventName: a string which indicates the type of events about 
         * which the client desires notification.
	 **/
        void registerGlobalEventListener (in EventListener listener,
					  in string eventName);

  	/**
         * deregisterGlobalEventListenerAll:
         * @param listener: the requesting EventListener
         *
         * Request that a previously registered client stop receiving
         * global notifications for all events for which it was registered.
         *
	 **/
        void deregisterGlobalEventListenerAll (in EventListener listener);

  	/**
         * deregisterGlobalEventListener:
         * @param listener: the requesting EventListener
         * @param eventName: a string indicating the type of events
         *
         * Request that a previously registered client stop receiving
         * global notifications for events of a certain type.
         *
	 **/
        void deregisterGlobalEventListener (in EventListener listener, 
					    in string eventName);
        /** 
         * event types: "Window" "Desktop"
         *              "Window:Create" "Window:Destroy"
         *              "Window:Iconify" "Window:Restore"
         *              "Window:Fullscreen" "Window:Resize"
         *              "Desktop:Create" "Desktop:Destroy"  
         *              "Desktop:Focus" "Desktop:Defocus"
         *              "Desktop:Reorder" 
         *              "Focus"
         *              "GtkWidget:show"
         *              "GObject:notify:<propertyname>" 
         *
         *  ( not sure we should allow these last 2 forms, 
         *    since they are toolkit-specific, but they're powerful )
         *
         **/              

  	/**
         * getDesktopCount:
         *
         * Get the current number of desktops.
	 * @returns a short integer indicating the current number of 
         * Desktops.
	 **/
        short getDesktopCount ();

  	/**
         * getDesktop:
         * @n: the index of the requested Desktop.
         *
         * Get the nth accessible desktop. 
         *
	 * @returns a reference to the requested Desktop.
	 **/
        Desktop getDesktop (in short n);

  	/**
         * Get a list of accessible desktops. 
         *
	 * @returns: a sequence containing references to
         * the Desktops.
	 **/
        DesktopSeq getDesktopList ();

  	/**
         * Obtain an object which can be used to request device event notifications.
         *
	 * @returns: an object implementing DeviceEventController
	 **/
        DeviceEventController getDeviceEventController ();

	/** \cond
	 * unImplemented:
	 *
	 * placeholders for future expansion.
	 */
	void unImplemented ();
	void unImplemented2 ();
	void unImplemented3 ();
	void unImplemented4 ();
	void unImplemented5 ();
	void unImplemented6 ();
      /** \endcond */
    };

    /** Deprecated, DO NOT USE! */
  enum KeyEventType {
    KEY_PRESSED,
    KEY_RELEASED
  };

  /** Used to specify the event types of interest to an EventListener, or
   * to identify the type of an event for which notification has been sent. 
   * @see EventTypeSeq, DeviceEvent::type
   */
  enum EventType {
      KEY_PRESSED_EVENT, /**< key on a keyboard device was pressed. */
      KEY_RELEASED_EVENT, /**< key on a keyboard device was released. */
      BUTTON_PRESSED_EVENT,/**< button on a non-keyboard human interface device 
			    * (HID) was pressed */
      BUTTON_RELEASED_EVENT /**< button on a non-keyboard human interface device 
			     * (HID) was pressed */
  };

    /** Used when synthesizing keyboard input via DeviceEventController:generateKeyboardEvent.*/
  enum KeySynthType {
    KEY_PRESS,/** emulate the pressing of a hardware keyboard key. */
    KEY_RELEASE,/** emulate the release of a hardware keyboard key. */
    KEY_PRESSRELEASE,/** a hardware keyboard key is pressed and immediately released. */
    KEY_SYM,/** a symbolic key event is generated, without specifying a hardware key. 
	     * @note if the keysym is not present in the current keyboard map,
	     * the DeviceEventController instance has a limited ability to generate
	     * such keysyms on-the-fly.  Reliability of generateKeyboardEvent calls
	     * using out-of-keymap keysyms will vary from system to system, and on the
	     * number of different out-of-keymap being generated in quick succession.
	     * In practice this is rarely significant, since the keysyms of interest to
	     * AT clients and keyboard emulators are usually part of the current keymap, i.e.
	     * present on the system keyboard for the current locale (even if a physical
	     * hardware keyboard is not connected.
	     */
    KEY_STRING /** a string is converted to its equivalent keyboard events and emitted. 
		* If the string consists of complex character or composed characters
		* which are not in the current keymap, string emission is subject to the
		* out-of-keymap limitations described for KeySynthType::KEY_SYM.
		* In practice this limitation primarily effects Chinese and Japanese locales.
		*/
  };

  enum ModifierType {
    MODIFIER_SHIFT, /** The left or right 'Shift' key */
    MODIFIER_SHIFTLOCK, /** The ShiftLock or CapsLock key */
    MODIFIER_CONTROL,/** 'Control'/'Ctrl' */
    MODIFIER_ALT,/** The Alt key (as opposed to AltGr) */
    MODIFIER_META,/** depending on the platform this may map to 'Window', 'Function', 'Meta',
		   * 'Menu', or 'NumLock'.  
		   *  Such 'Meta keys' will map to one of META, META2, META3.
		   * On X Windows platforms these META values map to 
		   * the modifier masks Mod1Mask, Mod2Mask, Mod3Mask, e.g. an event having
		   * ModifierType::MODIFIER_META2 means that the 'Mod2Mask' bit is
		   * set in the corresponding XEvent.
		   */
    MODIFIER_META2,
    MODIFIER_META3,
    MODIFIER_NUMLOCK/** A symbolic meta key name that is mapped by AT-SPI to the 
		     *  appropriate META value, for the convenience of the client.
		     */
  };

  /** A structure that encapsulates the characteristics of the event notifications
   * that should be sent to an EventListener in response to a call to
   * DeviceEventController::registerKeystrokeListener or 
   * DeviceEventController::registerDeviceEventListener. */
  struct EventListenerMode {
    boolean synchronous; /**< If \c True, specifies that
			  * DeviceEventController should block while waiting 
			  * for client to process the requested event notifications; 
			  * ordinarily should be used only when client needs to perform
			  * operations synchronously with event delivery. Note that because
			  * of the architecture of device event systems in general,
			  * use of this flag may not block delivery of the event to 
			  * the currently focussed application unless it is used in 
			  * conjunction with the preemptive flag. */
    boolean preemptive; /**< If \c True, specifies that 
			 * Listener is allowed to pre-empt the delivery of the event,
			 * effectively "consuming" it such that it is not delivered 
			 * to the currently focussed desktop application. 
			 * Key events consumed via this API will not be 
			 * available for use by other applications or services, so this
			 * option should be used sparingly. */
    boolean global; /**< If \c True, specifies that
		     * Event notifications should be sent regardless of whether the
		     * currently focussed application participates in the AT-SPI 
		     * infrastructure.  On systems with the XEvIE X extension, this flag
		     * also allows access to events which are already subject to 
		     * interception via a "system keygrab" (as described in the X Window System
		     * documentation for XGrabKey).  The 'global' and 'preemptive' flags
		     * should only be used together for the purposes of registering
		     * "system global key shortcuts" i.e. command keys for use by the
		     * assistive technology. */
  };

  /** 
   * an unsigned short int consisting of zero or more of the following
   * values OR'ed together:
   *
   * \li \c 1<<::KEY_PRESSED_EVENT  = 1
   * \li \c 1<<::KEY_RELEASED_EVENT = 2
   * \li \c 1<<::BUTTON_PRESSED_EVENT = 3,
   * \li \c 1<<::BUTTON_RELEASED_EVENT = 4
   **/
  typedef unsigned long ControllerEventMask;

  /** A structure which encapsulates information about a device event. */
  struct DeviceEvent {
    EventType type; /**< Identifies the type of the containing DeviceEvent. */
    long  id; /**< an identifier which identifies this event in the event stream. 
	       * On X Window systems this corresponds to the XEvent serial number.
	       */
    short hw_code; /**< a numeric code which is hardware and system-dependent, identifying the
		    * specific hardware button or key on the device for which the event has
		    * occurred. On X Window systems, for global key notifications and for most
		    * non-global key notifications as well, this code corresponds to the
		    * XKeycode.  For switch and button events it indicates the switch
		    * or button number.
		    * @note
		    * For technical reasons, this code may differ from the XKeycode
		    * when generated by Java applications for consumption by non-global
		    * key listeners.  This is subject to change in future versions of the
		    * DeviceEventController implementation.
		    */

    unsigned short modifiers; /**< an unsigned short int consisting of zero or more of the following
			       * values OR'ed together:
			       * \li \c 1<<::MODIFIER_SHIFT   (=1, corresponds to Xlib's ShiftMask)
			       * \li \c 1<<::MODIFIER_SHIFTLOCK    (=2, corresponds to Xlib's LockMask)
			       * \li \c 1<<::MODIFIER_CONTROL (=4, corresponds to Xlib's ControlMask)
			       * \li \c 1<<::MODIFIER_ALT    (=8, corresponds to Xlib's Mod1Mask)
			       * \li \c 1<<::MODIFIER_META    (=16, corresponds to Xlib's Mod2Mask)
			       * \li \c 1<<::MODIFIER_META2    (=32, corresponds to Xlib's Mod3Mask)
			       * \li \c 1<<::MODIFIER_META3    (=64, corresponds to Xlib's Mod4Mask)
			       **/
    unsigned long timestamp; /**< an unsigned integer representing the time that the 
			      * event occurred.  On X Window systems this event is 
			      * a time in milliseconds from some arbitrary starting
			      * point; it therefore has a cycle time of approximately
			      * 50 days.
			      */
    string event_string; /**< A string representation of the event.  If is_text is
			  * \c True, then this string represents the character or typographic
			  * sequence that would be received by a focussed text input field.
			  * event_string is in general suitable for exposure to the
			  * end-user for purposes of keyboard echo.
			  */
    boolean is_text; /**< \c True if the event results in the insertion of characters 
		      * into an input text buffer, or would do so if delivered to a focussed
		      * text input field. ¨Typographical¨ key events have this field set to
		      * \c True, whereas ¨control¨ key events generally do not.
		      */
  };

  /** 
   * A structure which defines the identity of a key for which notifications
   * are to be requested.  The data in the members of a ::KeyDefinition are used to
   * determine which keyboard events 'match' the notification request filed by a client.
   *
   * @note Ordinarily a KeyDefinition specifies one and only one of the criteria below; 
   * the result of using a KeyDefinition with multiple members defined as nonzero is
   * undefined.
   *
   * @param keycode if nonzero, the numeric, system-dependent value corresponding to a 
   * physical key on the keyboard.  Keycode values have no semantic meaning to the end-user,
   * and may depend on the user's hardware and operating environment.  They therefore are
   * rarely useful "as-is" to AT clients, unless the client has used operating system
   * services to identify the hardward keycode associated with a particular key symbol.
   * Notifications for key events requested by keycode are less dependent on modifier state
   * than \c keysym based notifications, but some hardware (notably many laptops) may generate
   * more than one keycode for the same physical key, depending on the state of physical 
   * shift/modifier keys.
   * @param keysym if nonzero, the numeric value corresponding to the X Keysym of the key for which 
   * notification is requested.  Note that the presence of active modifiers will affect
   * whether notification for key events requested via "keysym" specification takes place, 
   * since the keysym depends on the modifier state for most keys.
   * @param keystring if non-NULL, the string value of the inserted characters if the corresponding
   * key event has ::KeyEvent:is_text set to \c True, or the string representing the
   * 'name' of the key.  On X11 systems, the string 'name' of non-printing keysyms corresponds
   * to the values in "keysymdef.h" as provided by Xlib, with the leading "XK_" stripped off.
   **/
  struct KeyDefinition {
    long keycode;
    long keysym;
    string keystring;
    long unused;
  };	

  typedef sequence< KeyDefinition > KeySet;
  typedef sequence< EventType > KeyEventTypeSeq;
  typedef sequence< EventType > EventTypeSeq;

  /** This interface should be implemented by AT-SPI clients who wish to 
   * make use of the DeviceEventController to receive device event notifications.
   * DeviceEvents include keyboard events and mouse button/motion events.
   **/
  interface DeviceEventListener : Bonobo::Unknown {
      /** Notify an interested DeviceEventListener that a DeviceEvent has occurred.
       * @returns \c True if the recipient/consumer wishes to consume the event, i.e.
       * prevent it from being delivered to the desktop, \c False if the event should 
       * continue to be delivered as normal.
       */
        boolean notifyEvent (in DeviceEvent event);
      /** \cond */
        void    unImplemented__ ();
        void    unImplemented_2_ ();
        void    unImplemented_3_ ();
        void    unImplemented_4_ ();
        void    unImplemented_5_ ();
        void    unImplemented_6_ ();
      /** \endcond */
  };

  /** 
   * The interface via which clients request notification of device events, and
   * through which device events may be simulated.
   ***/
  interface DeviceEventController : Bonobo::Unknown {

  	/**
         * Register to intercept keyboard events, and either pass them on or
         * consume them. 
         *
         * @param listener: a DeviceEventListener which will intercept key events.
         * @param keys:     a KeySet indicating which keys to intercept, or KEYSET_ALL_KEYS.
         * @param mask:     a ControllerEventMask filtering the intercepted key events.
	 * @param type:     a KeyEventTypeSeq that may created by ORing event types together.
	 * @param mode: an EventListenerMode indicating whether the listener should 
	 *            receive the events synchronously, potentially consuming them,
	 *            or just be notified asynchronously of those events that have
	 *            been generated.
	 * @note Some platforms have limited support for global, preemptive EventListenerMode.
	 * Such a registration may fail if another client already has priority for preemptive
	 * access to one or more of the members of the KeySet.  AT consumers have the option
	 * of re-trying the request without the global flag, or without the preemptive flag,
	 * or of re-trying with a different KeySet.  The best support for pre-emptive
	 * global keyboard listeners is provided on platforms whose Xserver implementation
	 * provides the XEvIE extension.
	 *
	 * @returns \c True if the DeviceEventListener was successfully registered
	 * for the requested KeySet, ControllerEventMask, event types, and EventListenerMode; 
	 * otherwise returns \c False.
	 **/
        boolean registerKeystrokeListener (in DeviceEventListener listener,
					in KeySet keys,
					in ControllerEventMask mask,
					in KeyEventTypeSeq type,
					in EventListenerMode mode);
    
  	/**
         * De-register a previously registered keyboard eventlistener.
         * @param listener: a DeviceEventListener which will intercept key events.
         * @param keys:     a KeySet indicating which keys to intercept, or KEYSET_ALL_KEYS.
         * @param mask:     a ControllerEventMask filtering the intercepted key events.
	 * @param type:     an EventType mask that may created by ORing event types together.
	 **/
        void deregisterKeystrokeListener (in DeviceEventListener listener,
					  in KeySet keys,
					  in ControllerEventMask mask,
					  in KeyEventTypeSeq type);
    
  	/**
         * Register to intercept events, and either pass them on or
         * consume them. To listen to keyboard events use registerKeystrokeListener
	 * instead.
         * @param listener: a DeviceEventListener which will intercept events.
	 * @param typeseq:  an EventTypeSeq indicating which event types to listen for.
	 * @returns \c True if successful, \c False if not
	 **/
        boolean registerDeviceEventListener (in DeviceEventListener listener,
					     in EventTypeSeq typeseq);
    
  	/**
         * De-register a previously registered keyboard eventlistener.
         * @param listener: a DeviceEventListener which will intercept events.
	 * @param typeseq:  an EventTypeSeq indicating which event types to stop
	 *            listening for.
	 **/
        void deregisterDeviceEventListener (in DeviceEventListener listener,
					    in EventTypeSeq typeseq);
    
      /** 
       * Notify the Registry instance that a device event has taken place, and
       *       allow pre-emptive listeners the opportunity to 'consume' the event
       *       and thus prevent its further issuance/forwarding.  This is the 
       *       method used by accessibility bridges to forward "toolkit dependent"
       *       device events to the Registry from the application's process space.
       *
       * @note AT clients do not normally need to use this method, it is intended for use
       *       by toolkit bridges and special-purpose applications.
       *
       * @returns \c True if the event was consumed by a (pre-emptive) listener,
       *          \c False if not (in which case the device event will be forwarded
       *          as normal to any application which would normally receive it, e.g.
       *          the currently active application in the case of mouse or keyboard events).
       **/
        boolean notifyListenersSync (in DeviceEvent event);

      /** 
       * Notify the Registry instance that a device event has taken place in
       *       an asynchronous manner.  This is the 
       *       method used by accessibility bridges to forward "toolkit dependent"
       *       device events to the Registry from the application's process space.
       *       If the event in question is potentially pre-emptible.
       *       ::notifyListenersSync should be used instead.
       *
       * @note AT clients do not normally need to use this method, it is intended for use
       *       by toolkit bridges and special-purpose applications.
       **/
        oneway void notifyListenersAsync (in DeviceEvent event);

        /**
         * Synthesize a keyboard event.
         * @param keycode: a long integer indicating the keycode of
	 *          the keypress to be synthesized.
	 * @param keystring: an optional UTF-8 string indicating a complex
	 *          keyboard input event.
	 * @param type: a KeySynthType indicating the type of event(s) to be 
	 *          synthesized: a key press, release, press-release pair,
	 *          or a complex input string (for instance from an
	 *          internationalized or complex text input method, or
	 *          a composed character).
	 *
	 * @note keycode may be truncated before being
	 *          processed, as keycode length may be platform-dependent
	 *          and keycode ranges are generally much smaller than
	 *          CORBA_long. 
	 * One or the other of keycode or keystring are generally NULL, 
	 *          (but not both), depending on the value of \c type.
	 *
         **/
         void generateKeyboardEvent (in long keycode, 
				     in string keystring, 
				     in KeySynthType type);

        /**
         * Synthesize a mouse event.
         * @param x: a long integer indicating the screen x coord for the mouse event.
         * @param y: a long integer indicating the screen y coord for the mouse event.
         * @param eventName: a string indicating the type of mouse event, e.g. "button1up"
         **/
         void generateMouseEvent (in long x, in long y, in string eventName);

	 /** \cond
	  * unImplemented:
	  *
	  * placeholders for future expansion.
	  */
	 void unImplemented ();
	 void unImplemented2 ();
	 void unImplemented3 ();
	 void unImplemented4 ();
      /** \endcond */
    }; 
};

#endif