public AttributedCharacterIterator cancelLatestCommittedText(Attribute[] attributes)
Gets the latest committed text from the text editing component and
removes it from the component's text body.
This is used for the "Undo Commit" feature in some input methods, where
the committed text reverts to its previous composed state. The composed
text will be sent to the component using an InputMethodEvent.


Generally, this feature should only be supported immediately after the
text was committed, not after the user performed other operations on the
text. When the feature is not supported, return null.


The input method may provide a list of attributes that it is
interested in. In that case, information about other attributes that
the implementor may have need not be made accessible through the
iterator. If the list is null, all available attribute information
should be made accessible.

 public AttributedCharacterIterator getCommittedText(int beginIndex,
    int endIndex,
    Attribute[] attributes)
Gets an iterator providing access to the entire text and attributes
contained in the text editing component except for uncommitted
text. Uncommitted (composed) text should be ignored for index
calculations and should not be made accessible through the iterator.


The input method may provide a list of attributes that it is
interested in. In that case, information about other attributes that
the implementor may have need not be made accessible through the
iterator. If the list is null, all available attribute information
should be made accessible.

 public int getCommittedTextLength()
Gets the length of the entire text contained in the text
editing component except for uncommitted (composed) text.

 public int getInsertPositionOffset()
Gets the offset of the insert position in the committed text contained
in the text editing component. This is the offset at which characters
entered through an input method are inserted. This information is used
by an input method, for example, to examine the text surrounding the
insert position.

 public TextHitInfo getLocationOffset(int x,
    int y)
Gets the offset within the composed text for the specified absolute x
and y coordinates on the screen. This information is used, for example
to handle mouse clicks and the mouse cursor. The offset is relative to
the composed text, so offset 0 indicates the beginning of the composed
text.


Return null if the location is outside the area occupied by the composed
text.

 public AttributedCharacterIterator getSelectedText(Attribute[] attributes)
Gets the currently selected text from the text editing component.
This may be used for a variety of purposes.
One of them is the "Reconvert" feature in some input methods.
In this case, the input method will typically send an input method event
to replace the selected text with composed text. Depending on the input
method's capabilities, this may be the original composed text for the
selected text, the latest composed text entered anywhere in the text, or
a version of the text that's converted back from the selected text.


The input method may provide a list of attributes that it is
interested in. In that case, information about other attributes that
the implementor may have need not be made accessible through the
iterator. If the list is null, all available attribute information
should be made accessible.

 public Rectangle getTextLocation(TextHitInfo offset)
Gets the location of a specified offset in the current composed text,
or of the selection in committed text.
This information is, for example, used to position the candidate window
near the composed text, or a composition window near the location
where committed text will be inserted.


If the component has composed text (because the most recent
InputMethodEvent sent to it contained composed text), then the offset is
relative to the composed text - offset 0 indicates the first character
in the composed text. The location returned should be for this character.


If the component doesn't have composed text, the offset should be ignored,
and the location returned should reflect the beginning (in line
direction) of the highlight in the last line containing selected text.
For example, for horizontal left-to-right text (such as English), the
location to the left of the left-most character on the last line
containing selected text is returned. For vertical top-to-bottom text,
with lines proceding from right to left, the location to the top of the
left-most line containing selected text is returned.


The location is represented as a 0-thickness caret, that is, it has 0
width if the text is drawn horizontally, and 0 height if the text is
drawn vertically. Other text orientations need to be mapped to
horizontal or vertical orientation. The rectangle uses absolute screen
coordinates.