Class JTextComponent.AccessibleJTextComponent

public class JTextComponent.AccessibleJTextComponent
extends JComponent.AccessibleJComponent
implements AccessibleText, CaretListener, DocumentListener, AccessibleAction, AccessibleEditableText, AccessibleExtendedText

This class implements accessibility support for the JTextComponent class. It provides an implementation of the Java Accessibility API appropriate to menu user-interface elements.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans™ has been added to the java.beans package. Please see XMLEncoder.

Constructors

AccessibleJTextComponent

public AccessibleJTextComponent()

Constructs an AccessibleJTextComponent. Adds a listener to track caret change.

Methods

caretUpdate

public void caretUpdate(CaretEvent e)

Handles caret updates (fire appropriate property change event, which are AccessibleContext.ACCESSIBLE_CARET_PROPERTY and AccessibleContext.ACCESSIBLE_SELECTION_PROPERTY). This keeps track of the dot position internally. When the caret moves, the internal position is updated after firing the event.

Specified by:

caretUpdate in interface CaretListener

Parameters:

e - the CaretEvent

insertUpdate

public void insertUpdate(DocumentEvent e)

Handles document insert (fire appropriate property change event which is AccessibleContext.ACCESSIBLE_TEXT_PROPERTY). This tracks the changed offset via the event.

Specified by:

insertUpdate in interface DocumentListener

Parameters:

e - the DocumentEvent

removeUpdate

public void removeUpdate(DocumentEvent e)

Handles document remove (fire appropriate property change event, which is AccessibleContext.ACCESSIBLE_TEXT_PROPERTY). This tracks the changed offset via the event.

Specified by:

removeUpdate in interface DocumentListener

Parameters:

e - the DocumentEvent

changedUpdate

public void changedUpdate(DocumentEvent e)

Handles document remove (fire appropriate property change event, which is AccessibleContext.ACCESSIBLE_TEXT_PROPERTY). This tracks the changed offset via the event.

Specified by:

changedUpdate in interface DocumentListener

Parameters:

e - the DocumentEvent

getAccessibleStateSet

public AccessibleStateSet getAccessibleStateSet()

Gets the state set of the JTextComponent. The AccessibleStateSet of an object is composed of a set of unique AccessibleState's. A change in the AccessibleStateSet of an object will cause a PropertyChangeEvent to be fired for the AccessibleContext.ACCESSIBLE_STATE_PROPERTY property.

Overrides:

getAccessibleStateSet in class JComponent.AccessibleJComponent

Returns:

an instance of AccessibleStateSet containing the current state set of the object

See Also:

AccessibleStateSet, AccessibleState, JComponent.AccessibleJComponent.addPropertyChangeListener(java.beans.PropertyChangeListener)

getAccessibleRole

public AccessibleRole getAccessibleRole()

Gets the role of this object.

Overrides:

getAccessibleRole in class JComponent.AccessibleJComponent

Returns:

an instance of AccessibleRole describing the role of the object (AccessibleRole.TEXT)

See Also:

AccessibleRole

getAccessibleText

public AccessibleText getAccessibleText()

Get the AccessibleText associated with this object. In the implementation of the Java Accessibility API for this class, return this object, which is responsible for implementing the AccessibleText interface on behalf of itself.

Overrides:

getAccessibleText in class AccessibleContext

Returns:

this object

See Also:

AccessibleText

getIndexAtPoint

public int getIndexAtPoint(Point p)

Given a point in local coordinates, return the zero-based index of the character under that Point. If the point is invalid, this method returns -1.

Specified by:

getIndexAtPoint in interface AccessibleText

Parameters:

p - the Point in local coordinates

Returns:

the zero-based index of the character under Point p.

getCharacterBounds

public Rectangle getCharacterBounds(int i)

Determines the bounding box of the character at the given index into the string. The bounds are returned in local coordinates. If the index is invalid a null rectangle is returned. The screen coordinates returned are "unscrolled coordinates" if the JTextComponent is contained in a JScrollPane in which case the resulting rectangle should be composed with the parent coordinates. A good algorithm to use is:

Accessible a:
 AccessibleText at = a.getAccessibleText();
 AccessibleComponent ac = a.getAccessibleComponent();
 Rectangle r = at.getCharacterBounds();
 Point p = ac.getLocation();
 r.x += p.x;
 r.y += p.y;

Note: the JTextComponent must have a valid size (e.g. have been added to a parent container whose ancestor container is a valid top-level window) for this method to be able to return a meaningful (non-null) value.

Specified by:

getCharacterBounds in interface AccessibleText

Parameters:

i - the index into the String ≥ 0

Returns:

the screen coordinates of the character's bounding box

getCharCount

public int getCharCount()

Returns the number of characters (valid indices)

Specified by:

getCharCount in interface AccessibleText

Returns:

the number of characters ≥ 0

getCaretPosition

public int getCaretPosition()

Returns the zero-based offset of the caret. Note: The character to the right of the caret will have the same index value as the offset (the caret is between two characters).

Specified by:

getCaretPosition in interface AccessibleText

Returns:

the zero-based offset of the caret.

getCharacterAttribute

public AttributeSet getCharacterAttribute(int i)

Returns the AttributeSet for a given character (at a given index).

Specified by:

getCharacterAttribute in interface AccessibleText

Parameters:

i - the zero-based index into the text

Returns:

the AttributeSet of the character

getSelectionStart

public int getSelectionStart()

Returns the start offset within the selected text. If there is no selection, but there is a caret, the start and end offsets will be the same. Return 0 if the text is empty, or the caret position if no selection.

Specified by:

getSelectionStart in interface AccessibleText

Returns:

the index into the text of the start of the selection ≥ 0

getSelectionEnd

public int getSelectionEnd()

Returns the end offset within the selected text. If there is no selection, but there is a caret, the start and end offsets will be the same. Return 0 if the text is empty, or the caret position if no selection.

Specified by:

getSelectionEnd in interface AccessibleText

Returns:

the index into the text of the end of the selection ≥ 0

getSelectedText

public String getSelectedText()

Returns the portion of the text that is selected.

Specified by:

getSelectedText in interface AccessibleText

Returns:

the text, null if no selection

getAtIndex

public String getAtIndex(int part,
                         int index)

Returns the String at a given index. Whitespace between words is treated as a word.

Specified by:

getAtIndex in interface AccessibleText

Parameters:

part - the CHARACTER, WORD, or SENTENCE to retrieve

index - an index within the text

Returns:

the letter, word, or sentence.

getAfterIndex

public String getAfterIndex(int part,
                            int index)

Returns the String after a given index. Whitespace between words is treated as a word.

Specified by:

getAfterIndex in interface AccessibleText

Parameters:

part - the CHARACTER, WORD, or SENTENCE to retrieve

index - an index within the text

Returns:

the letter, word, or sentence.

getBeforeIndex

public String getBeforeIndex(int part,
                             int index)

Returns the String before a given index. Whitespace between words is treated a word.

Specified by:

getBeforeIndex in interface AccessibleText

Parameters:

part - the CHARACTER, WORD, or SENTENCE to retrieve

index - an index within the text

Returns:

the letter, word, or sentence.

getAccessibleEditableText

public AccessibleEditableText getAccessibleEditableText()

Returns the AccessibleEditableText interface for this text component.

Overrides:

getAccessibleEditableText in class AccessibleContext

Returns:

the AccessibleEditableText interface

Since:

1.4

See Also:

AccessibleEditableText

setTextContents

public void setTextContents(String s)

Sets the text contents to the specified string.

Specified by:

setTextContents in interface AccessibleEditableText

Parameters:

s - the string to set the text contents

Since:

1.4

insertTextAtIndex

public void insertTextAtIndex(int index,
                              String s)

Inserts the specified string at the given index

Specified by:

insertTextAtIndex in interface AccessibleEditableText

Parameters:

index - the index in the text where the string will be inserted

s - the string to insert in the text

Since:

1.4

getTextRange

public String getTextRange(int startIndex,
                           int endIndex)

Returns the text string between two indices.

Specified by:

getTextRange in interface AccessibleEditableText

Specified by:

getTextRange in interface AccessibleExtendedText

Parameters:

startIndex - the starting index in the text

endIndex - the ending index in the text

Returns:

the text string between the indices

Since:

1.4

delete

public void delete(int startIndex,
                   int endIndex)

Deletes the text between two indices

Specified by:

delete in interface AccessibleEditableText

Parameters:

startIndex - the starting index in the text

endIndex - the ending index in the text

Since:

1.4

cut

public void cut(int startIndex,
                int endIndex)

Cuts the text between two indices into the system clipboard.

Specified by:

cut in interface AccessibleEditableText

Parameters:

startIndex - the starting index in the text

endIndex - the ending index in the text

Since:

1.4

paste

public void paste(int startIndex)

Pastes the text from the system clipboard into the text starting at the specified index.

Specified by:

paste in interface AccessibleEditableText

Parameters:

startIndex - the starting index in the text

Since:

1.4

replaceText

public void replaceText(int startIndex,
                        int endIndex,
                        String s)

Replaces the text between two indices with the specified string.

Specified by:

replaceText in interface AccessibleEditableText

Parameters:

startIndex - the starting index in the text

endIndex - the ending index in the text

s - the string to replace the text between two indices

Since:

1.4

selectText

public void selectText(int startIndex,
                       int endIndex)

Selects the text between two indices.

Specified by:

selectText in interface AccessibleEditableText

Parameters:

startIndex - the starting index in the text

endIndex - the ending index in the text

Since:

1.4

setAttributes

public void setAttributes(int startIndex,
                          int endIndex,
                          AttributeSet as)

Sets attributes for the text between two indices.

Specified by:

setAttributes in interface AccessibleEditableText

Parameters:

startIndex - the starting index in the text

endIndex - the ending index in the text

as - the attribute set

Since:

1.4

See Also:

AttributeSet

getTextSequenceAt

public AccessibleTextSequence getTextSequenceAt(int part,
                                                int index)

Returns the AccessibleTextSequence at a given index.

Specified by:

getTextSequenceAt in interface AccessibleExtendedText

Parameters:

part - the CHARACTER, WORD, SENTENCE, LINE or ATTRIBUTE_RUN to retrieve

index - an index within the text

Returns:

an AccessibleTextSequence specifying the text if part and index are valid. Otherwise, null is returned

Since:

1.6

See Also:

AccessibleText.CHARACTER, AccessibleText.WORD, AccessibleText.SENTENCE, AccessibleExtendedText.LINE, AccessibleExtendedText.ATTRIBUTE_RUN

getTextSequenceAfter

public AccessibleTextSequence getTextSequenceAfter(int part,
                                                   int index)

Returns the AccessibleTextSequence after a given index.

Specified by:

getTextSequenceAfter in interface AccessibleExtendedText

Parameters:

part - the CHARACTER, WORD, SENTENCE, LINE or ATTRIBUTE_RUN to retrieve

index - an index within the text

Returns:

an AccessibleTextSequence specifying the text if part and index are valid. Otherwise, null is returned

Since:

1.6

See Also:

AccessibleText.CHARACTER, AccessibleText.WORD, AccessibleText.SENTENCE, AccessibleExtendedText.LINE, AccessibleExtendedText.ATTRIBUTE_RUN

getTextSequenceBefore

public AccessibleTextSequence getTextSequenceBefore(int part,
                                                    int index)

Returns the AccessibleTextSequence before a given index.

Specified by:

getTextSequenceBefore in interface AccessibleExtendedText

Parameters:

part - the CHARACTER, WORD, SENTENCE, LINE or ATTRIBUTE_RUN to retrieve

index - an index within the text

Returns:

an AccessibleTextSequence specifying the text if part and index are valid. Otherwise, null is returned

Since:

1.6

See Also:

AccessibleText.CHARACTER, AccessibleText.WORD, AccessibleText.SENTENCE, AccessibleExtendedText.LINE, AccessibleExtendedText.ATTRIBUTE_RUN

getTextBounds

public Rectangle getTextBounds(int startIndex,
                               int endIndex)

Returns the Rectangle enclosing the text between two indicies.

Specified by:

getTextBounds in interface AccessibleExtendedText

Parameters:

startIndex - the start index in the text

endIndex - the end index in the text

Returns:

the bounding rectangle of the text if the indices are valid. Otherwise, null is returned

Since:

1.6

getAccessibleAction

public AccessibleAction getAccessibleAction()

Description copied from class: AccessibleContext

Gets the AccessibleAction associated with this object that supports one or more actions.

Overrides:

getAccessibleAction in class AccessibleContext

Returns:

AccessibleAction if supported by object; else return null

See Also:

AccessibleAction

getAccessibleActionCount

public int getAccessibleActionCount()

Returns the number of accessible actions available in this object If there are more than one, the first one is considered the "default" action of the object.

Specified by:

getAccessibleActionCount in interface AccessibleAction

Returns:

the zero-based number of Actions in this object

Since:

1.4

getAccessibleActionDescription

public String getAccessibleActionDescription(int i)

Returns a description of the specified action of the object.

Specified by:

getAccessibleActionDescription in interface AccessibleAction

Parameters:

i - zero-based index of the actions

Returns:

a String description of the action

Since:

1.4

See Also:

getAccessibleActionCount()

doAccessibleAction

public boolean doAccessibleAction(int i)

Performs the specified Action on the object

Specified by:

doAccessibleAction in interface AccessibleAction

Parameters:

i - zero-based index of actions

Returns:

true if the action was performed; otherwise false.

Since:

1.4

See Also:

getAccessibleActionCount()