- java.lang.Object
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- javax.swing.text.NavigationFilter
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public class NavigationFilter extends Object
NavigationFiltercan 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 theNavigationFilter, assuming theJTextComponenthas a non-nullNavigationFilterset. In this manner theNavigationFiltercan effectively restrict where the cursor can be positioned. SimilarlyDefaultCaretwill call into theNavigationFilterwhen 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 classNavigationFilter.FilterBypassUsed as a way to circumvent calling back into the caret to position the cursor.
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Constructor Summary
Constructors Constructor Description NavigationFilter()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description intgetNextVisualPositionFrom(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.voidmoveDot(NavigationFilter.FilterBypass fb, int dot, Position.Bias bias)Invoked prior to the Caret moving the dot.voidsetDot(NavigationFilter.FilterBypass fb, int dot, Position.Bias bias)Invoked prior to the Caret setting the dot.
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Method Detail
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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 theFilterBypasswith the passed in arguments. Subclasses may wish to conditionally call super with a different location, or invoke the necessary method on theFilterBypass- Parameters:
fb- FilterBypass that can be used to mutate caret positiondot- the position >= 0bias- Bias to place the dot at
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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 theFilterBypasswith the passed in arguments. Subclasses may wish to conditionally call super with a different location, or invoke the necessary methods on theFilterBypass.- Parameters:
fb- FilterBypass that can be used to mutate caret positiondot- the position >= 0bias- Bias for new location
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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 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- ifdirectiondoesn't have one of the legal values above
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