java.lang.Object
javax.swing.text.NavigationFilter
public class NavigationFilter extends Object
NavigationFilter
can be used to restrict where the cursor can
be positioned. When the default cursor positioning actions attempt to
reposition the cursor they will call into the
NavigationFilter
, assuming
the JTextComponent
has a non-null
NavigationFilter
set. In this manner
the NavigationFilter
can effectively restrict where the
cursor can be positioned. Similarly DefaultCaret
will call
into the NavigationFilter
when the user is changing the
selection to further restrict where the cursor can be positioned.
Subclasses can conditionally call into supers implementation to restrict
where the cursor can be placed, or call directly into the
FilterBypass
.
- Since:
- 1.4
- See Also:
Caret
,DefaultCaret
,View
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
NavigationFilter.FilterBypass
Used as a way to circumvent calling back into the caret to position the cursor. -
Constructor Summary
Constructors Constructor Description NavigationFilter()
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Method Summary
Modifier and Type Method Description int
getNextVisualPositionFrom(JTextComponent text, int pos, Position.Bias bias, int direction, Position.Bias[] biasRet)
Returns the next visual position to place the caret at from an existing position.void
moveDot(NavigationFilter.FilterBypass fb, int dot, Position.Bias bias)
Invoked prior to the Caret moving the dot.void
setDot(NavigationFilter.FilterBypass fb, int dot, Position.Bias bias)
Invoked prior to the Caret setting the dot.
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Constructor Details
-
NavigationFilter
public NavigationFilter()
-
-
Method Details
-
getNextVisualPositionFrom
public int getNextVisualPositionFrom(JTextComponent text, int pos, Position.Bias bias, int direction, Position.Bias[] biasRet) throws BadLocationExceptionReturns the next visual position to place the caret at from an existing position. The default implementation simply forwards the method to the root View. Subclasses may wish to further restrict the location based on additional criteria.- Parameters:
text
- JTextComponent containing textpos
- Position used in determining next positionbias
- Bias used in determining next positiondirection
- the direction from the current position that can be thought of as the arrow keys typically found on a keyboard. This will be one of the following values:- SwingConstants.WEST
- SwingConstants.EAST
- SwingConstants.NORTH
- SwingConstants.SOUTH
biasRet
- Used to return resulting Bias of next position- Returns:
- the location within the model that best represents the next location visual position
- Throws:
BadLocationException
- for a bad location within a document modelIllegalArgumentException
- ifdirection
doesn't have one of the legal values above