Class NavigationFilter
- 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
Nested Class Summary
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
Constructor | Description |
---|---|
NavigationFilter() |
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. |
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructor Detail
NavigationFilter
public NavigationFilter()
Method Detail
setDot
public void setDot(NavigationFilter.FilterBypass fb, int dot, Position.Bias bias)
Invoked prior to the Caret setting the dot. The default implementation calls directly into the FilterBypass
with the passed in arguments. Subclasses may wish to conditionally call super with a different location, or invoke the necessary method on the FilterBypass
- Parameters:
-
fb
- FilterBypass that can be used to mutate caret position -
dot
- the position >= 0 -
bias
- Bias to place the dot at
moveDot
public void moveDot(NavigationFilter.FilterBypass fb, int dot, Position.Bias bias)
Invoked prior to the Caret moving the dot. The default implementation calls directly into the FilterBypass
with the passed in arguments. Subclasses may wish to conditionally call super with a different location, or invoke the necessary methods on the FilterBypass
.
- Parameters:
-
fb
- FilterBypass that can be used to mutate caret position -
dot
- the position >= 0 -
bias
- Bias for new location
getNextVisualPositionFrom
public int getNextVisualPositionFrom(JTextComponent text, int pos, Position.Bias bias, int direction, Position.Bias[] biasRet) throws BadLocationException
Returns 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 text -
pos
- Position used in determining next position -
bias
- Bias used in determining next position -
direction
- 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 model -
IllegalArgumentException
- ifdirection
doesn't have one of the legal values above