/*******************************************************************************
* Copyright (c) 2000, 2010, 2012 IBM Corporation, Gerhardt Informatics Kft. and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* Gerhardt Informatics Kft. - GEFGWT port
*******************************************************************************/
package org.eclipse.swt.accessibility;
import org.eclipse.swt.events.SWTEventListener;
/**
* Classes that implement this interface provide methods that deal with the
* events that are generated when an accessibility client sends a message to a
* control.
* <p>
* After creating an instance of a class that implements this interface it can
* be added to a control using the <code>addAccessibleControlListener</code>
* method and removed using the <code>removeAccessibleControlListener</code>
* method. When a client requests information the appropriate method will be
* invoked.
* </p>
* <p>
* Note: Accessibility clients use child identifiers to specify whether they
* want information about a control or one of its children. Child identifiers
* are increasing integers beginning with 0. The identifier CHILDID_SELF
* represents the control itself.
* </p>
* <p>
* Note: This interface is typically used by implementors of a custom control to
* provide very detailed information about the control instance to accessibility
* clients.
* </p>
*
* @see AccessibleControlAdapter
* @see AccessibleControlEvent
*
* @since 2.0
*/
public interface AccessibleControlListener extends SWTEventListener {
/**
* Sent when an accessibility client requests the identifier of the control
* child at the specified display coordinates.
* <p>
* Return the identifier of the child at display point (x, y) in the
* <code>childID</code> field of the event object. Return CHILDID_SELF if
* point (x, y) is in the control itself and not in any child. Return
* CHILDID_NONE if point (x, y) is not contained in either the control or
* any of its children.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>x, y [IN] - the specified point in display coordinates</li>
* <li>childID [Typical OUT] - the ID of the child at point, or
* CHILDID_SELF, or CHILDID_NONE</li>
* <li>accessible [Optional OUT] - the accessible object for the
* control or child may be returned instead of the childID</li>
* </ul>
*/
public void getChildAtPoint(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the location of the control,
* or the location of a child of the control.
* <p>
* Return a rectangle describing the location of the specified control or
* child in the <code>x, y, width, and height</code> fields of the event
* object.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>childID [IN] - an identifier specifying the control or one
* of its children</li>
* <li>x, y, width, height [OUT] - the control or child location
* in display coordinates</li>
* </ul>
*/
public void getLocation(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the accessible object for a
* child of the control by index or childID, or when a client requests the
* index of an accessible object in its parent.
* <p>
* The childID field in the event object can be one of the following:
* <ul>
* <li>an integer child ID - return the accessible object for the specified
* child ID, or null if the specified child does not have its own accessible
* </li>
* <li>{@link ACC#CHILDID_CHILD_AT_INDEX} - return the accessible child
* object at the specified index, or null if this object has no children</li>
* <li>{@link ACC#CHILDID_CHILD_INDEX} - return the index of this accessible
* in its parent</li>
* </ul>
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>childID [IN] - an identifier specifying a child of the
* control, or one of the predefined CHILDID constants</li>
* <li>detail [Optional IN] - the index of the child accessible
* to be returned when childID = CHILDID_CHILD_AT_INDEX</li>
* <li>detail [Optional OUT] - the index of this accessible in
* its parent when childID = CHILDID_CHILD_INDEX</li>
* <li>accessible [Optional OUT] - an Accessible for the
* specified childID or index, or null if one does not exist</li>
* </ul>
*/
public void getChild(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the number of children in the
* control.
* <p>
* Return the number of child items in the <code>detail</code> field of the
* event object.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>detail [OUT] - the number of child items in this control</li>
* </ul>
*/
public void getChildCount(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the default action of the
* control, or the default action of a child of the control.
* <p>
* This string is typically a verb describing what the user does to it. For
* example, a Push Button's default action is "Press", a Check Button's is
* "Check" or "UnCheck", and List items have the default action
* "Double Click".
* </p>
* <p>
* Return a string describing the default action of the specified control or
* child in the <code>result</code> field of the event object. Returning
* null tells the client to use the platform default action string.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>childID [IN] - an identifier specifying the control or one
* of its children</li>
* <li>result [OUT] - the requested default action string, or
* null</li>
* </ul>
*/
public void getDefaultAction(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the identity of the child or
* control that has keyboard focus.
* <p>
* Return the identifier of the child that has focus in the
* <code>childID</code> field of the event object. Return CHILDID_SELF if
* the control itself has keyboard focus. Return CHILDID_NONE if neither the
* control nor any of its children has focus.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>childID [Typical OUT] - the ID of the child with focus, or
* CHILDID_SELF, or CHILDID_NONE</li>
* <li>accessible [Optional OUT] - the accessible object for a
* child may be returned instead of its childID</li>
* </ul>
*/
public void getFocus(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the role of the control, or
* the role of a child of the control.
* <p>
* Return a role constant (constant defined in ACC beginning with ROLE_)
* that describes the role of the specified control or child in the
* <code>detail</code> field of the event object.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>childID [IN] - an identifier specifying the control or one
* of its children</li>
* <li>detail [OUT] - a role constant describing the role of the
* control or child</li>
* </ul>
*/
public void getRole(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the identity of the child or
* control that is currently selected.
* <p>
* Return the identifier of the selected child in the <code>childID</code>
* field of the event object. Return CHILDID_SELF if the control itself is
* selected. Return CHILDID_MULTIPLE if multiple children are selected, and
* return an array of childIDs in the <code>children</code> field. Return
* CHILDID_NONE if neither the control nor any of its children are selected.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>childID [Typical OUT] - the ID of the selected child, or
* CHILDID_SELF, or CHILDID_MULTIPLE, or CHILDID_NONE</li>
* <li>children [Optional OUT] - the array of childIDs for the
* selected children if CHILDID_MULTIPLE is returned</li>
* <li>accessible [Optional OUT] - the accessible object for the
* control or child may be returned instead of the childID</li>
* </ul>
*/
public void getSelection(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the state of the control, or
* the state of a child of the control.
* <p>
* Return a state mask (mask bit constants defined in ACC beginning with
* STATE_) that describes the current state of the specified control or
* child in the <code>detail</code> field of the event object.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>childID [IN] - an identifier specifying the control or one
* of its children</li>
* <li>detail [OUT] - a state mask describing the current state
* of the control or child</li>
* </ul>
*/
public void getState(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the value of the control, or
* the value of a child of the control.
* <p>
* Many controls do not return a value. Examples of controls that do are:
* Combo returns the text string, Text returns its contents, ProgressBar
* returns a string representing a percentage, and Tree items return a
* string representing their level in the tree.
* </p>
* <p>
* Return a string describing the value of the specified control or child in
* the <code>result</code> field of the event object. Returning null tells
* the client to use the platform value string.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>childID [IN] - an identifier specifying the control or one
* of its children</li>
* <li>result [OUT] - the requested value string, or null</li>
* </ul>
*/
public void getValue(AccessibleControlEvent e);
/**
* Sent when an accessibility client requests the children, or visible
* children, of the control.
* <p>
* Return the children as an array of childIDs or accessibles in the
* <code>children</code> field of the event object.
* </p>
*
* @param e
* an event object containing the following fields:
* <ul>
* <li>detail [IN] - a flag that may have one of the following
* values:
* <ul>
* <li>0 (default) - return all children</li>
* <li>VISIBLE - return all visible children</li>
* </ul>
* <li>children [Typical OUT] - an array of childIDs</li>
* <li>children [Optional OUT] - an array of accessible objects
* for the children may be returned instead of the childIDs</li>
* </ul>
*/
public void getChildren(AccessibleControlEvent e);
}