java.awt.im
Interface InputMethodRequests

All Known Subinterfaces:
InputMethodContext

public interface InputMethodRequests

This interface handles requests made by input methods on text editing components. A component must specify a handler for input methods that implements this interface, and which supports one of two user interfaces:

Since:
1.2
See Also:
Component.getInputMethodRequests(), InputMethodListener

Method Summary
 AttributedCharacterIterator cancelLatestCommittedText(AttributedCharacterIterator.Attribute[] attributes)
          Gets the latest committed text, and removes it from the component's text body.
 AttributedCharacterIterator getCommittedText(int beginIndex, int endIndex, AttributedCharacterIterator.Attribute[] attributes)
          Gets an interator which provides access to the text and its attributes, except for the uncommitted text.
 int getCommittedTextLength()
          Gets the length of committed text.
 int getInsertPositionOffset()
          Gets the offset where the committed text exists in the text editing component.
 TextHitInfo getLocationOffset(int x, int y)
          Get the text offset for the given screen coordinate.
 AttributedCharacterIterator getSelectedText(AttributedCharacterIterator.Attribute[] attributes)
          Gets the currently selected text.
 Rectangle getTextLocation(TextHitInfo offset)
          Gets the location of a given offset of the text.
 

Method Detail

getTextLocation

Rectangle getTextLocation(TextHitInfo offset)
Gets the location of a given offset of the text. This can be used to position a composition window near the location of where the composed text will be inserted.

If the component has composed text (from the most recent InputMethodEvent), then offset 0 indicates the location of the first character of this composed text. Otherwise, the offset is ignored, and the location should be the beginning of the final line of selected text (in horizontal left-to-right text, like English, this would be the lower left corner of the selction; in vertical top-to-bottom text, like Chinese, this would be the top right corner of the selection).

The location returned is a 0-thickness caret (either horizontal or vertical, depending on text flow), mapped to absolute screen coordinates.

Parameters:
offset - offset within composed text, or null
Returns:
the screen location of the caret at the offset

getLocationOffset

TextHitInfo getLocationOffset(int x,
                              int y)
Get the text offset for the given screen coordinate. The offset is relative to the composed text, and the return is null if it is outside the range of composed text. For example, this can be used to find where a mouse click should pop up a text composition window.

Parameters:
x - the x screen coordinate
y - the y screen coordinate
Returns:
a text hit info describing the composed text offset

getInsertPositionOffset

int getInsertPositionOffset()
Gets the offset where the committed text exists in the text editing component. This can be used to examine the text surrounding the insert position.

Returns:
the offset of the insert position

getCommittedText

AttributedCharacterIterator getCommittedText(int beginIndex,
                                             int endIndex,
                                             AttributedCharacterIterator.Attribute[] attributes)
Gets an interator which provides access to the text and its attributes, except for the uncommitted text. The input method may provide a list of attributes it is interested in; and the iterator need not provide information on the remaining attributes. If the attribute list is null, the iterator must list all attributes.

Parameters:
beginIndex - the index of the first character in the iteration
endIndex - the index of the last character in the iteration
attributes - a list of attributes interested in, or null
Returns:
an iterator over the region of text with its attributes

getCommittedTextLength

int getCommittedTextLength()
Gets the length of committed text.

Returns:
the number of committed characters

cancelLatestCommittedText

AttributedCharacterIterator cancelLatestCommittedText(AttributedCharacterIterator.Attribute[] attributes)
Gets the latest committed text, and removes it from the component's text body. This allows an input method to provide an "Undo" command. In general, this should only be supported immediately after a commit, and not when other actions intervene; if not supported, simply return null. The input method may provide a list of attributes it is interested in; and the iterator need not provide information on the remaining attributes. If the attribute list is null, the iterator must list all attributes.

Parameters:
attributes - a list of attributes interested in, or null
Returns:
the latest committed text, or null

getSelectedText

AttributedCharacterIterator getSelectedText(AttributedCharacterIterator.Attribute[] attributes)
Gets the currently selected text. One use of this is to implement a "Reconvert" feature in an input method, which modifies the selection based on the text in the composition window. The input method may provide a list of attributes it is interested in; and the iterator need not provide information on the remaining attributes. If the attribute list is null, the iterator must list all attributes.

Parameters:
attributes - a list of attributes interested in, or null
Returns:
the current selection