nsIAccessible Interface Reference

A cross-platform interface that supports platform-specific accessibility APIs like MSAA and ATK. More...

import "nsIAccessible.idl";

Inheritance diagram for nsIAccessible:

Collaboration diagram for nsIAccessible:

List of all members.

Public Member Functions
nsIDOMDOMStringList	getKeyBindings (in PRUint8 aActionIndex)
	Provides array of localized string of global keyboard accelerator for the given action index supported by accessible.
void	getState (out unsigned long aState, out unsigned long aExtraState)
	Accessible states -- bit fields which describe boolean properties of node.
void	groupPosition (out long aGroupLevel, out long aSimilarItemsInGroup, out long aPositionInGroup)
	Returns grouping information.
nsIAccessible	getChildAtPoint (in long x, in long y)
	Accessible child which contains the coordinate at (x, y) in screen pixels.
nsIAccessible	getDeepestChildAtPoint (in long x, in long y)
	Deepest accessible child which contains the coordinate at (x, y) in screen pixels.
nsIAccessible	getChildAt (in long aChildIndex)
	Nth accessible child using zero-based index or last child if index less than zero.
nsIAccessible	getAccessibleToRight ()
	Accessible node geometrically to the right of this one.
nsIAccessible	getAccessibleToLeft ()
	Accessible node geometrically to the left of this one.
nsIAccessible	getAccessibleAbove ()
	Accessible node geometrically above this one.
nsIAccessible	getAccessibleBelow ()
	Accessible node geometrically below this one.
nsIAccessibleRelation	getRelationByType (in unsigned long aRelationType)
	Return accessible relation by the given relation type (see.
nsIAccessibleRelation	getRelation (in unsigned long index)
	Returns one accessible relation for this object.
nsIArray	getRelations ()
	Returns multiple accessible relations for this object.
void	getBounds (out long x, out long y, out long width, out long height)
	Return accessible's x and y coordinates relative to the screen and accessible's width and height.
void	setSelected (in boolean isSelected)
	Add or remove this accessible to the current selection.
void	extendSelection ()
	Extend the current selection from its current accessible anchor node to this accessible.
void	takeSelection ()
	Select this accessible node only.
void	takeFocus ()
	Focus this accessible node, The state STATE_FOCUSABLE indicates whether this node is normally focusable.
AString	getActionName (in PRUint8 index)
	The name of the accessible action at the given zero-based index.
AString	getActionDescription (in PRUint8 aIndex)
	The description of the accessible action at the given zero-based index.
void	doAction (in PRUint8 index)
	Perform the accessible action at the given zero-based index Action number 0 is the default action.
void	getNativeInterface (out voidPtr aOutAccessible)
	Get a pointer to accessibility interface for this node, which is specific to the OS/accessibility toolkit we're running on.
Public Attributes
readonly attribute nsIAccessible	parent
	Parent node in accessible tree.
readonly attribute nsIAccessible	nextSibling
	Next sibling in accessible tree.
readonly attribute nsIAccessible	previousSibling
	Previous sibling in accessible tree.
readonly attribute nsIAccessible	firstChild
	First child in accessible tree.
readonly attribute nsIAccessible	lastChild
	Last child in accessible tree.
readonly attribute nsIArray	children
	Array of all this element's children.
readonly attribute long	childCount
	Number of accessible children.
readonly attribute long	indexInParent
	The 0-based index of this accessible in its parent's list of children, or -1 if this accessible does not have a parent.
attribute AString	name
	Accessible name -- the main text equivalent for this node.
readonly attribute AString	value
	Accessible value -- a number or a secondary text equivalent for this node Widgets that use role attribute can force a value using the valuenow attribute.
readonly attribute AString	description
	Accessible description -- long text associated with this node.
readonly attribute AString	keyboardShortcut
	Provides localized string of accesskey name, such as Alt+D.
readonly attribute AString	defaultKeyBinding
	Provides localized string of global keyboard accelerator for default action, such as Ctrl+O for Open file.
readonly attribute unsigned long	role
	Enumerated accessible role (see the constants defined in nsIAccessibleRole).
readonly attribute AString	help
	Help text associated with node.
readonly attribute nsIAccessible	focusedChild
	Focused accessible child of node.
readonly attribute nsIPersistentProperties	attributes
	Attributes of accessible.
readonly attribute unsigned long	relationsCount
	Returns the number of accessible relations for this object.
readonly attribute PRUint8	numActions
	The number of accessible actions associated with this accessible.

---

Detailed Description

A cross-platform interface that supports platform-specific accessibility APIs like MSAA and ATK.

Contains the sum of what's needed to support IAccessible as well as ATK's generic accessibility objects. Can also be used by in-process accessibility clients to get information about objects in the accessible tree. The accessible tree is a subset of nodes in the DOM tree -- such as documents, focusable elements and text. Mozilla creates the implementations of nsIAccessible on demand. See http://www.mozilla.org/projects/ui/accessibility for more information.

---

Member Function Documentation

void nsIAccessible::doAction

(

in PRUint8

index

)

Perform the accessible action at the given zero-based index Action number 0 is the default action.

void nsIAccessible::extendSelection

(

)

Extend the current selection from its current accessible anchor node to this accessible.

nsIAccessible nsIAccessible::getAccessibleAbove

(

)

Accessible node geometrically above this one.

nsIAccessible nsIAccessible::getAccessibleBelow

(

)

Accessible node geometrically below this one.

nsIAccessible nsIAccessible::getAccessibleToLeft

(

)

Accessible node geometrically to the left of this one.

nsIAccessible nsIAccessible::getAccessibleToRight

(

)

Accessible node geometrically to the right of this one.

AString nsIAccessible::getActionDescription

(

in PRUint8

aIndex

)

The description of the accessible action at the given zero-based index.

AString nsIAccessible::getActionName

(

in PRUint8

index

)

The name of the accessible action at the given zero-based index.

void nsIAccessible::getBounds	(	out long	x,
		out long	y,
		out long	width,
		out long	height
	)

Return accessible's x and y coordinates relative to the screen and accessible's width and height.

nsIAccessible nsIAccessible::getChildAt

(

in long

aChildIndex

)

Nth accessible child using zero-based index or last child if index less than zero.

nsIAccessible nsIAccessible::getChildAtPoint	(	in long	x,
		in long	y
	)

Accessible child which contains the coordinate at (x, y) in screen pixels.

If the point is in the current accessible but not in a child, the current accessible will be returned. If the point is in neither the current accessible or a child, then null will be returned.

Parameters:

	x	screen's x coordinate
	y	screen's y coordinate

Returns:

the deepest accessible child containing the given point

nsIAccessible nsIAccessible::getDeepestChildAtPoint	(	in long	x,
		in long	y
	)

Deepest accessible child which contains the coordinate at (x, y) in screen pixels.

If the point is in the current accessible but not in a child, the current accessible will be returned. If the point is in neither the current accessible or a child, then null will be returned.

Parameters:

	x	screen's x coordinate
	y	screen's y coordinate

Returns:

the deepest accessible child containing the given point

nsIDOMDOMStringList nsIAccessible::getKeyBindings

(

in PRUint8

aActionIndex

)

Provides array of localized string of global keyboard accelerator for the given action index supported by accessible.

Parameters:

aActionIndex

- index of the given action

void nsIAccessible::getNativeInterface

(

out voidPtr

aOutAccessible

)

Get a pointer to accessibility interface for this node, which is specific to the OS/accessibility toolkit we're running on.

nsIAccessibleRelation nsIAccessible::getRelation

(

in unsigned long

index

)

Returns one accessible relation for this object.

Parameters:

index

- relation index (0-based)

nsIAccessibleRelation nsIAccessible::getRelationByType

(

in unsigned long

aRelationType

)

Return accessible relation by the given relation type (see.

constants defined in nsIAccessibleRelation).

nsIArray nsIAccessible::getRelations

(

)

Returns multiple accessible relations for this object.

void nsIAccessible::getState	(	out unsigned long	aState,
		out unsigned long	aExtraState
	)

Accessible states -- bit fields which describe boolean properties of node.

Many states are only valid given a certain role attribute that supports them.

Parameters:

	aState	- the first bit field (see nsIAccessibleStates::STATE_* constants)
	aExtraState	- the second bit field (see nsIAccessibleStates::EXT_STATE_* constants)

void nsIAccessible::groupPosition	(	out long	aGroupLevel,
		out long	aSimilarItemsInGroup,
		out long	aPositionInGroup
	)

Returns grouping information.

Used for tree items, list items, tab panel labels, radio buttons, etc. Also used for collectons of non-text objects.

Parameters:

	groupLevel	- 1-based, similar to ARIA 'level' property
	similarItemsInGroup	- 1-based, similar to ARIA 'setsize' property, inclusive of the current item
	positionInGroup	- 1-based, similar to ARIA 'posinset' property

void nsIAccessible::setSelected

(

in boolean

isSelected

)

Add or remove this accessible to the current selection.

void nsIAccessible::takeFocus

(

)

Focus this accessible node, The state STATE_FOCUSABLE indicates whether this node is normally focusable.

It is the callers responsibility to determine whether this node is focusable. accTakeFocus on a node that is not normally focusable (such as a table), will still set focus on that node, although normally that will not be visually indicated in most style sheets.

void nsIAccessible::takeSelection

(

)

Select this accessible node only.

---

Member Data Documentation

readonly attribute nsIPersistentProperties nsIAccessible::attributes

Attributes of accessible.

readonly attribute long nsIAccessible::childCount

Number of accessible children.

readonly attribute nsIArray nsIAccessible::children

Array of all this element's children.

readonly attribute AString nsIAccessible::defaultKeyBinding

Provides localized string of global keyboard accelerator for default action, such as Ctrl+O for Open file.

readonly attribute AString nsIAccessible::description

Accessible description -- long text associated with this node.

readonly attribute nsIAccessible nsIAccessible::firstChild

First child in accessible tree.

readonly attribute nsIAccessible nsIAccessible::focusedChild

Focused accessible child of node.

readonly attribute AString nsIAccessible::help

Help text associated with node.

readonly attribute long nsIAccessible::indexInParent

The 0-based index of this accessible in its parent's list of children, or -1 if this accessible does not have a parent.

readonly attribute AString nsIAccessible::keyboardShortcut

Provides localized string of accesskey name, such as Alt+D.

The modifier may be affected by user and platform preferences. Usually alt+letter, or just the letter alone for menu items.

readonly attribute nsIAccessible nsIAccessible::lastChild

Last child in accessible tree.

attribute AString nsIAccessible::name

Accessible name -- the main text equivalent for this node.

The name is specified by ARIA or by native markup. Example of ARIA markup is aria-labelledby attribute placed on element of this accessible. Example of native markup is HTML label linked with HTML element of this accessible.

Value can be string or null. A null value indicates that AT may attempt to compute the name. Any string value, including the empty string, should be considered author-intentional, and respected.

readonly attribute nsIAccessible nsIAccessible::nextSibling

Next sibling in accessible tree.

readonly attribute PRUint8 nsIAccessible::numActions

The number of accessible actions associated with this accessible.

readonly attribute nsIAccessible nsIAccessible::parent

Parent node in accessible tree.

readonly attribute nsIAccessible nsIAccessible::previousSibling

Previous sibling in accessible tree.

readonly attribute unsigned long nsIAccessible::relationsCount

Returns the number of accessible relations for this object.

readonly attribute unsigned long nsIAccessible::role

Enumerated accessible role (see the constants defined in nsIAccessibleRole).

Note:

The values might depend on platform because of variations. Widgets can use ARIA role attribute to force the final role.

readonly attribute AString nsIAccessible::value

Accessible value -- a number or a secondary text equivalent for this node Widgets that use role attribute can force a value using the valuenow attribute.

---

The documentation for this interface was generated from the following file:

• nsIAccessible.idl