org.eclipse.swt.accessibility
Class Accessible

java.lang.Object
  |
  +--org.eclipse.swt.accessibility.Accessible

public class Accessible

extends Object

Instances of this class provide a bridge between application code and assistive technology clients. Many platforms provide default accessible behavior for most widgets, and this class allows that default behavior to be overridden. Applications can get the default Accessible object for a control by sending it getAccessible, and then add an accessible listener to override simple items like the name and help string, or they can add an accessible control listener to override complex items. As a rule of thumb, an application would only want to use the accessible control listener to implement accessibility for a custom control.

Since:

2.0

See Also:

Control.getAccessible(), AccessibleListener, AccessibleEvent, AccessibleControlListener, AccessibleControlEvent

Method Summary

void	addAccessibleControlListener(AccessibleControlListener listener) Adds the listener to the collection of listeners who will be notifed when an accessible client asks for custom control specific information.
void	addAccessibleListener(AccessibleListener listener) Adds the listener to the collection of listeners who will be notifed when an accessible client asks for certain strings, such as name, description, help, or keyboard shortcut.
void	internal_dispose_Accessible() Invokes platform specific functionality to dispose an accessible object.
static Accessible	internal_new_Accessible(Control control) Invokes platform specific functionality to allocate a new accessible object.
int	internal_WM_GETOBJECT(int wParam, int lParam) Invokes platform specific functionality to handle a window message.
void	removeAccessibleControlListener(AccessibleControlListener listener) Removes the listener from the collection of listeners who will be notifed when an accessible client asks for custom control specific information.
void	removeAccessibleListener(AccessibleListener listener) Removes the listener from the collection of listeners who will be notifed when an accessible client asks for certain strings, such as name, description, help, or keyboard shortcut.
void	setFocus(int childID) Sends a message to accessible clients indicating that the focus has changed within a custom control.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

internal_new_Accessible

public static Accessible internal_new_Accessible(Control control)

Invokes platform specific functionality to allocate a new accessible object.

IMPORTANT: This method is not part of the public API for Accessible. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.

Parameters:

control - the control to get the accessible object for

Returns:

the platform specific accessible object

addAccessibleListener

public void addAccessibleListener(AccessibleListener listener)

Adds the listener to the collection of listeners who will be notifed when an accessible client asks for certain strings, such as name, description, help, or keyboard shortcut. The listener is notified by sending it one of the messages defined in the AccessibleListener interface.

Parameters:

listener - the listener that should be notified when the receiver is asked for a name, description, help, or keyboard shortcut string

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control

See Also:

AccessibleListener, removeAccessibleListener(org.eclipse.swt.accessibility.AccessibleListener)

removeAccessibleListener

public void removeAccessibleListener(AccessibleListener listener)

Removes the listener from the collection of listeners who will be notifed when an accessible client asks for certain strings, such as name, description, help, or keyboard shortcut.

Parameters:

listener - the listener that should no longer be notified when the receiver is asked for a name, description, help, or keyboard shortcut string

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control

See Also:

AccessibleListener, #addDisposeListener

addAccessibleControlListener

public void addAccessibleControlListener(AccessibleControlListener listener)

Adds the listener to the collection of listeners who will be notifed when an accessible client asks for custom control specific information. The listener is notified by sending it one of the messages defined in the AccessibleControlListener interface.

Parameters:

listener - the listener that should be notified when the receiver is asked for custom control specific information

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control

See Also:

AccessibleControlListener, removeAccessibleControlListener(org.eclipse.swt.accessibility.AccessibleControlListener)

removeAccessibleControlListener

public void removeAccessibleControlListener(AccessibleControlListener listener)

Removes the listener from the collection of listeners who will be notifed when an accessible client asks for custom control specific information.

Parameters:

listener - the listener that should no longer be notified when the receiver is asked for custom control specific information

Throws:

IllegalArgumentException -

• ERROR_NULL_ARGUMENT - if the listener is null

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control

See Also:

AccessibleControlListener, addAccessibleControlListener(org.eclipse.swt.accessibility.AccessibleControlListener)

setFocus

public void setFocus(int childID)

Sends a message to accessible clients indicating that the focus has changed within a custom control.

Parameters:

childID - an identifier specifying a child of the control

Throws:

SWTException -

• ERROR_WIDGET_DISPOSED - if the receiver's control has been disposed
• ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver's control

internal_dispose_Accessible

public void internal_dispose_Accessible()

Invokes platform specific functionality to dispose an accessible object.

IMPORTANT: This method is not part of the public API for Accessible. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.

internal_WM_GETOBJECT

public int internal_WM_GETOBJECT(int wParam,
                                 int lParam)

Invokes platform specific functionality to handle a window message.

IMPORTANT: This method is not part of the public API for Accessible. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.