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NavigationFilter.javaAPI DocJava SE 5 API5021Fri Aug 26 14:58:16 BST 2005javax.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.

see
javax.swing.text.Caret
see
javax.swing.text.DefaultCaret
see
javax.swing.text.View
version
1.4 12/19/03
since
1.4

Fields Summary
Constructors Summary
Methods Summary
public intgetNextVisualPositionFrom(javax.swing.text.JTextComponent text, int pos, javax.swing.text.Position$Bias bias, int direction, javax.swing.text.Position$Bias[] biasRet)
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.

param
text JTextComponent containing text
param
pos Position used in determining next position
param
bias Bias used in determining next position
param
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
param
biasRet Used to return resulting Bias of next position
return
the location within the model that best represents the next location visual position
exception
BadLocationException
exception
IllegalArgumentException if direction doesn't have one of the legal values above

        return text.getUI().getNextVisualPositionFrom(text, pos, bias,
                                                      direction, biasRet);
    
public voidmoveDot(javax.swing.text.NavigationFilter$FilterBypass fb, int dot, javax.swing.text.Position$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.

param
fb FilterBypass that can be used to mutate caret position
param
dot the position >= 0
param
bias Bias for new location

        fb.moveDot(dot, bias);
    
public voidsetDot(javax.swing.text.NavigationFilter$FilterBypass fb, int dot, javax.swing.text.Position$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

param
fb FilterBypass that can be used to mutate caret position
param
dot the position >= 0
param
bias Bias to place the dot at

        fb.setDot(dot, bias);