Class AccessibilityManager

java.lang.Object

com.codename1.ui.accessibility.AccessibilityManager

public final class AccessibilityManager
extends Object

Builds, caches, diffs, and dispatches actions for the portable semantic tree.

The tree is always constructed on the Codename One EDT. Native ports read the last immutable snapshot and post actions through performAction(long, String, Object), so native accessibility threads never synchronously enter application code.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	CHANGE_ACTIONS
static final int	CHANGE_ALL
static final int	CHANGE_BOUNDS
static final int	CHANGE_CONTENT
static final int	CHANGE_FOCUS
static final int	CHANGE_LIVE_REGION
static final int	CHANGE_PANE
static final int	CHANGE_STATE
static final int	CHANGE_STRUCTURE
static final int	CHANGE_VALUE

Method Summary

Modifier and Type	Method	Description
int	cachedRootCount()	How many roots currently have a cached tree.
int	dirtyRootCount()	How many roots are currently recorded as stale.
AccessibilityTreeSnapshot	emptySnapshot()	A tree describing nothing.
AccessibilityTreeSnapshot	getCurrentSnapshot()
static AccessibilityManager	getInstance()
int	getPendingChanges()
AccessibilityTreeSnapshot	getSnapshot(Form form)
AccessibilityTreeSnapshot	getSnapshot(TopLevelContainer top)	The accessibility tree for a top level, which may be a com.codename1.ui.Window rather than a Form.
void	invalidate(Component component, int changeType)
void	invalidateAll()
boolean	performAction(long nodeId, String actionId, Object argument)
void	releaseRoot(Container root)	Drops any snapshot cached for a root that is going away.

Methods inherited from class Object

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

Field Details

CHANGE_STRUCTURE

public static final int CHANGE_STRUCTURE

See Also:

• Constant Field Values

CHANGE_CONTENT

public static final int CHANGE_CONTENT

See Also:

• Constant Field Values

CHANGE_STATE

public static final int CHANGE_STATE

See Also:

• Constant Field Values

CHANGE_VALUE

public static final int CHANGE_VALUE

See Also:

• Constant Field Values

CHANGE_BOUNDS

public static final int CHANGE_BOUNDS

See Also:

• Constant Field Values

CHANGE_FOCUS

public static final int CHANGE_FOCUS

See Also:

• Constant Field Values

CHANGE_ACTIONS

public static final int CHANGE_ACTIONS

See Also:

• Constant Field Values

CHANGE_LIVE_REGION

public static final int CHANGE_LIVE_REGION

See Also:

• Constant Field Values

CHANGE_PANE

public static final int CHANGE_PANE

See Also:

• Constant Field Values

CHANGE_ALL

public static final int CHANGE_ALL

See Also:

• Constant Field Values

Method Details

dirtyRootCount

public int dirtyRootCount()

How many roots are currently recorded as stale.

Returns

the size of the dirty set

emptySnapshot

public AccessibilityTreeSnapshot emptySnapshot()

A tree describing nothing.

For a surface that no longer exists. A port can outlive a window -- an accessibility bridge is held by the platform and asked for its tree after the window it describes has been disposed -- and the alternatives are both wrong: the last tree built anywhere belongs to some other window, and rebuilding is impossible with nothing to walk.

Returns

an empty snapshot, never null

cachedRootCount

public int cachedRootCount()

How many roots currently have a cached tree.

Returns

the size of the snapshot cache

getInstance

public static AccessibilityManager getInstance()

invalidate

public void invalidate(Component component,
 int changeType)

invalidateAll

public void invalidateAll()

getCurrentSnapshot

public AccessibilityTreeSnapshot getCurrentSnapshot()

getSnapshot

public AccessibilityTreeSnapshot getSnapshot(TopLevelContainer top)

The accessibility tree for a top level, which may be a com.codename1.ui.Window rather than a Form.

Parameters

• top: the top level to describe, may be null

Returns

the snapshot, never null

releaseRoot

public void releaseRoot(Container root)

Drops any snapshot cached for a root that is going away.

Parameters

• root: the root being disposed

getSnapshot

public AccessibilityTreeSnapshot getSnapshot(Form form)

getPendingChanges

public int getPendingChanges()

performAction

public boolean performAction(long nodeId,
 String actionId,
 Object argument)