FileDocCategorySizeDatePackage
DocumentFilter.javaAPI DocJava SE 5 API7055Fri Aug 26 14:58:14 BST 2005javax.swing.text

DocumentFilter

public class DocumentFilter extends Object
DocumentFilter, as the name implies, is a filter for the Document mutation methods. When a Document containing a DocumentFilter is modified (either through insert or remove), it forwards the appropriate method invocation to the DocumentFilter. The default implementation allows the modification to occur. Subclasses can filter the modifications by conditionally invoking methods on the superclass, or invoking the necessary methods on the passed in FilterBypass. Subclasses should NOT call back into the Document for the modification instead call into the superclass or the FilterBypass.

When remove or insertString is invoked on the DocumentFilter, the DocumentFilter may callback into the FilterBypass multiple times, or for different regions, but it should not callback into the FilterBypass after returning from the remove or insertString method.

see
javax.swing.text.Document
version
1.6 12/19/03
since
1.4

Fields Summary
Constructors Summary
Methods Summary
public voidinsertString(javax.swing.text.DocumentFilter$FilterBypass fb, int offset, java.lang.String string, javax.swing.text.AttributeSet attr)
Invoked prior to insertion of text into the specified Document. Subclasses that want to conditionally allow insertion should override this and only call supers implementation as necessary, or call directly into the FilterBypass.

param
fb FilterBypass that can be used to mutate Document
param
offset the offset into the document to insert the content >= 0. All positions that track change at or after the given location will move.
param
string the string to insert
param
attr the attributes to associate with the inserted content. This may be null if there are no attributes.
exception
BadLocationException the given insert position is not a valid position within the document

        fb.insertString(offset, string, attr);
    
public voidremove(javax.swing.text.DocumentFilter$FilterBypass fb, int offset, int length)
Invoked prior to removal of the specified region in the specified Document. Subclasses that want to conditionally allow removal should override this and only call supers implementation as necessary, or call directly into the FilterBypass as necessary.

param
fb FilterBypass that can be used to mutate Document
param
offset the offset from the beginning >= 0
param
length the number of characters to remove >= 0
exception
BadLocationException some portion of the removal range was not a valid part of the document. The location in the exception is the first bad position encountered.

        fb.remove(offset, length);
    
public voidreplace(javax.swing.text.DocumentFilter$FilterBypass fb, int offset, int length, java.lang.String text, javax.swing.text.AttributeSet attrs)
Invoked prior to replacing a region of text in the specified Document. Subclasses that want to conditionally allow replace should override this and only call supers implementation as necessary, or call directly into the FilterBypass.

param
fb FilterBypass that can be used to mutate Document
param
offset Location in Document
param
length Length of text to delete
param
text Text to insert, null indicates no text to insert
param
attrs AttributeSet indicating attributes of inserted text, null is legal.
exception
BadLocationException the given insert position is not a valid position within the document

        fb.replace(offset, length, text, attrs);