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:

  • 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()
    Constructs a 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 Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Constructor Details

    • NavigationFilter

      public NavigationFilter()
      Constructs a NavigationFilter.

  • Method Details

    • 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 - if direction doesn't have one of the legal values above