com.jgoodies.binding.adapter
Class DocumentAdapter

java.lang.Object
  extended by com.jgoodies.binding.adapter.DocumentAdapter
All Implemented Interfaces:
EventListener, DocumentListener, Document

public final class DocumentAdapter
extends Object
implements Document, DocumentListener

Converts the ValueModel interface into the Document interface, which is the model interface for Swing text components. It is used to bind String values to text components, for example a JTextField. At construction time the document is updated with the subject's contents.

Instead of extending AbstractDocument or the specialized PlainDocument this class holds a reference to a Document instance and forwards all Document messages to the corresponding method in the reference. By default the delegate is initialized as an instance of PlainDocument; the two parameter constructor allows to provide any other Document implementation. The latter can be useful if the text component uses a custom Document, for example a custom IntegerDocument or MaskedDocument.

This DocumentAdapter provides limited support for handling subject value modifications while updating the subject. If a Document change initiates a subject value update, the subject will be observed and a property change fired by the subject will be handled - if any. In most cases, the subject will notify about a change to the text that was just set by this DocumentAdapter. However, in some cases the subject may decide to modify this text, for example to ensure upper case characters. Since at this moment, this adapter's Document is still write-locked, the Document update is performed later using SwingUtilities#invokeLater. Note: Such an update will typically change the Caret position in JTextField's and other JTextComponent's that use this DocumentAdapter as model. Hence, the subject value modifications can be used with commit-on-focus-lost text components, but typically not with a commit-on-key-typed component. For the latter case, you may consider using a custom DocumentFilter.

Constraints: The ValueModel must be of type String.

Examples:

 ValueModel lastNameModel = new PropertyAdapter(customer, "lastName", true);
 JTextField lastNameField = new JTextField();
 lastNameField.setDocument(new DocumentAdapter(lastNameModel));
 
 ValueModel codeModel = new PropertyAdapter(shipment, "code", true);
 JTextField codeField = new JTextField();
 codeField.setDocument(new DocumentAdapter(codeModel), 
                       new MaskedDocument(...));
 

TODO: Consider changing the event source for DocumentEvents from the delegate to this DocumentAdapter. DocumentListeners may expect that the event source is the one they are registered with.

Version:
$Revision: 1.3 $
Author:
Karsten Lentzsch
See Also:
ValueModel, Document, PlainDocument

Field Summary
 
Fields inherited from interface javax.swing.text.Document
StreamDescriptionProperty, TitleProperty
 
Constructor Summary
DocumentAdapter(ValueModel subject)
          Constructs a DocumentAdapter on the specified String-typed subject ValueModel.
DocumentAdapter(ValueModel subject, boolean filterNewlines)
          Constructs a DocumentAdapter on the specified String-typed subject ValueModel.
DocumentAdapter(ValueModel subject, Document document)
          Constructs a DocumentAdapter on the specified String-typed subject ValueModel.
DocumentAdapter(ValueModel subject, Document document, boolean filterNewlines)
          Constructs a DocumentAdapter on the specified subject.
 
Method Summary
 void addDocumentListener(DocumentListener listener)
          Registers the given observer to begin receiving notifications when changes are made to the document.
 void addUndoableEditListener(UndoableEditListener listener)
          Registers the given observer to begin receiving notifications when undoable edits are made to the document.
 void changedUpdate(DocumentEvent e)
          An attribute or set of attributes has changed; do nothing.
 Position createPosition(int offs)
          This method allows an application to mark a place in a sequence of character content.
 Element getDefaultRootElement()
          Returns the root element that views should be based upon, unless some other mechanism for assigning views to element structures is provided.
 Position getEndPosition()
          Returns a position that represents the end of the document.
 int getLength()
          Returns number of characters of content currently in the document.
 Object getProperty(Object key)
          Gets the properties associated with the document.
 Element[] getRootElements()
          Returns all of the root elements that are defined.
 Position getStartPosition()
          Returns a position that represents the start of the document.
 String getText(int offset, int length)
          Fetches the text contained within the given portion of the document.
 void getText(int offset, int length, Segment txt)
          Fetches the text contained within the given portion of the document.
 void insertString(int offset, String str, AttributeSet a)
          Inserts a string of content.
 void insertUpdate(DocumentEvent e)
          There was an insert into the document; update the subject.
 void putProperty(Object key, Object value)
          Associates a property with the document.
 void remove(int offs, int len)
          Removes a portion of the content of the document.
 void removeDocumentListener(DocumentListener listener)
          Unregisters the given observer from the notification list so it will no longer receive change updates.
 void removeUndoableEditListener(UndoableEditListener listener)
          Unregisters the given observer from the notification list so it will no longer receive updates.
 void removeUpdate(DocumentEvent e)
          A portion of the document has been removed; update the subject.
 void render(Runnable r)
          This allows the model to be safely rendered in the presence of currency, if the model supports being updated asynchronously.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DocumentAdapter

public DocumentAdapter(ValueModel subject)
Constructs a DocumentAdapter on the specified String-typed subject ValueModel. Doesn't filter newline characters.

Parameters:
subject - the underlying String typed ValueModel
Throws:
NullPointerException - if the subject is null

DocumentAdapter

public DocumentAdapter(ValueModel subject,
                       boolean filterNewlines)
Constructs a DocumentAdapter on the specified String-typed subject ValueModel. The boolean parameter specifies if newline characters shall be filtered or retained.

Parameters:
subject - the underlying String typed ValueModel
filterNewlines - true to filter newline characters, false to retain them
Throws:
NullPointerException - if the subject is null

DocumentAdapter

public DocumentAdapter(ValueModel subject,
                       Document document)
Constructs a DocumentAdapter on the specified String-typed subject ValueModel. Doesn't filter newline characters.

Parameters:
subject - the underlying String-typed ValueModel
document - the underlying Document implementation
Throws:
NullPointerException - if the subject or document is null

DocumentAdapter

public DocumentAdapter(ValueModel subject,
                       Document document,
                       boolean filterNewlines)
Constructs a DocumentAdapter on the specified subject. The subject must return values of type String. The boolean parameter specifies if newline characters shall be filtered or retained.

Parameters:
subject - the underlying String typed ValueModel
document - the underlying Document implementation
filterNewlines - true to filter newline characters, false to retain them
Throws:
NullPointerException - if the subject or document is null
Method Detail

insertUpdate

public void insertUpdate(DocumentEvent e)
There was an insert into the document; update the subject.

Specified by:
insertUpdate in interface DocumentListener
Parameters:
e - the document event

removeUpdate

public void removeUpdate(DocumentEvent e)
A portion of the document has been removed; update the subject.

Specified by:
removeUpdate in interface DocumentListener
Parameters:
e - the document event

changedUpdate

public void changedUpdate(DocumentEvent e)
An attribute or set of attributes has changed; do nothing.

Specified by:
changedUpdate in interface DocumentListener
Parameters:
e - the document event

getLength

public int getLength()
Returns number of characters of content currently in the document.

Specified by:
getLength in interface Document
Returns:
number of characters >= 0

addDocumentListener

public void addDocumentListener(DocumentListener listener)
Registers the given observer to begin receiving notifications when changes are made to the document.

Specified by:
addDocumentListener in interface Document
Parameters:
listener - the observer to register
See Also:
Document.removeDocumentListener(javax.swing.event.DocumentListener)

removeDocumentListener

public void removeDocumentListener(DocumentListener listener)
Unregisters the given observer from the notification list so it will no longer receive change updates.

Specified by:
removeDocumentListener in interface Document
Parameters:
listener - the observer to register
See Also:
Document.addDocumentListener(javax.swing.event.DocumentListener)

addUndoableEditListener

public void addUndoableEditListener(UndoableEditListener listener)
Registers the given observer to begin receiving notifications when undoable edits are made to the document.

Specified by:
addUndoableEditListener in interface Document
Parameters:
listener - the observer to register
See Also:
UndoableEditEvent

removeUndoableEditListener

public void removeUndoableEditListener(UndoableEditListener listener)
Unregisters the given observer from the notification list so it will no longer receive updates.

Specified by:
removeUndoableEditListener in interface Document
Parameters:
listener - the observer to register
See Also:
UndoableEditEvent

getProperty

public Object getProperty(Object key)
Gets the properties associated with the document.

Specified by:
getProperty in interface Document
Parameters:
key - a non-null property key
Returns:
the properties
See Also:
putProperty(Object, Object)

putProperty

public void putProperty(Object key,
                        Object value)
Associates a property with the document. Two standard property keys provided are: StreamDescriptionProperty and TitleProperty. Other properties, such as author, may also be defined.

Specified by:
putProperty in interface Document
Parameters:
key - the non-null property key
value - the property value
See Also:
getProperty(Object)

remove

public void remove(int offs,
                   int len)
            throws BadLocationException
Removes a portion of the content of the document. This will cause a DocumentEvent of type DocumentEvent.EventType.REMOVE to be sent to the registered DocumentListeners, unless an exception is thrown. The notification will be sent to the listeners by calling the removeUpdate method on the DocumentListeners.

To ensure reasonable behavior in the face of concurrency, the event is dispatched after the mutation has occurred. This means that by the time a notification of removal is dispatched, the document has already been updated and any marks created by createPosition have already changed. For a removal, the end of the removal range is collapsed down to the start of the range, and any marks in the removal range are collapsed down to the start of the range.

Diagram shows removal of 'quick' from 'The quick brown fox.'

If the Document structure changed as result of the removal, the details of what Elements were inserted and removed in response to the change will also be contained in the generated DocumentEvent. It is up to the implementation of a Document to decide how the structure should change in response to a remove.

If the Document supports undo/redo, an UndoableEditEvent will also be generated.

Specified by:
remove in interface Document
Parameters:
offs - the offset from the beginning >= 0
len - the number of characters to remove >= 0
Throws:
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.
See Also:
DocumentEvent, DocumentListener, UndoableEditEvent, UndoableEditListener

insertString

public void insertString(int offset,
                         String str,
                         AttributeSet a)
                  throws BadLocationException
Inserts a string of content. This will cause a DocumentEvent of type DocumentEvent.EventType.INSERT to be sent to the registered DocumentListers, unless an exception is thrown. The DocumentEvent will be delivered by calling the insertUpdate method on the DocumentListener. The offset and length of the generated DocumentEvent will indicate what change was actually made to the Document.

Diagram shows insertion of 'quick' in 'The quick brown fox'

If the Document structure changed as result of the insertion, the details of what Elements were inserted and removed in response to the change will also be contained in the generated DocumentEvent. It is up to the implementation of a Document to decide how the structure should change in response to an insertion.

If the Document supports undo/redo, an UndoableEditEvent will also be generated.

Specified by:
insertString in interface Document
Parameters:
offset - the offset into the document to insert the content >= 0. All positions that track change at or after the given location will move.
str - the string to insert
a - the attributes to associate with the inserted content. This may be null if there are no attributes.
Throws:
BadLocationException - the given insert position is not a valid position within the document
See Also:
DocumentEvent, DocumentListener, UndoableEditEvent, UndoableEditListener

getText

public String getText(int offset,
                      int length)
               throws BadLocationException
Fetches the text contained within the given portion of the document.

Specified by:
getText in interface Document
Parameters:
offset - the offset into the document representing the desired start of the text >= 0
length - the length of the desired string >= 0
Returns:
the text, in a String of length >= 0
Throws:
BadLocationException - some portion of the given range was not a valid part of the document. The location in the exception is the first bad position encountered.

getText

public void getText(int offset,
                    int length,
                    Segment txt)
             throws BadLocationException
Fetches the text contained within the given portion of the document.

If the partialReturn property on the txt parameter is false, the data returned in the Segment will be the entire length requested and may or may not be a copy depending upon how the data was stored. If the partialReturn property is true, only the amount of text that can be returned without creating a copy is returned. Using partial returns will give better performance for situations where large parts of the document are being scanned. The following is an example of using the partial return to access the entire document:



   int nleft = doc.getDocumentLength();
   Segment text = new Segment();
   int offs = 0;
   text.setPartialReturn(true);   
   while (nleft > 0) {
       doc.getText(offs, nleft, text);
       // do someting with text
       nleft -= text.count;
       offs += text.count;
   }

 

Specified by:
getText in interface Document
Parameters:
offset - the offset into the document representing the desired start of the text >= 0
length - the length of the desired string >= 0
txt - the Segment object to return the text in
Throws:
BadLocationException - Some portion of the given range was not a valid part of the document. The location in the exception is the first bad position encountered.

getStartPosition

public Position getStartPosition()
Returns a position that represents the start of the document. The position returned can be counted on to track change and stay located at the beginning of the document.

Specified by:
getStartPosition in interface Document
Returns:
the position

getEndPosition

public Position getEndPosition()
Returns a position that represents the end of the document. The position returned can be counted on to track change and stay located at the end of the document.

Specified by:
getEndPosition in interface Document
Returns:
the position

createPosition

public Position createPosition(int offs)
                        throws BadLocationException
This method allows an application to mark a place in a sequence of character content. This mark can then be used to tracks change as insertions and removals are made in the content. The policy is that insertions always occur prior to the current position (the most common case) unless the insertion location is zero, in which case the insertion is forced to a position that follows the original position.

Specified by:
createPosition in interface Document
Parameters:
offs - the offset from the start of the document >= 0
Returns:
the position
Throws:
BadLocationException - if the given position does not represent a valid location in the associated document

getRootElements

public Element[] getRootElements()
Returns all of the root elements that are defined.

Typically there will be only one document structure, but the interface supports building an arbitrary number of structural projections over the text data. The document can have multiple root elements to support multiple document structures. Some examples might be:

Specified by:
getRootElements in interface Document
Returns:
the root element

getDefaultRootElement

public Element getDefaultRootElement()
Returns the root element that views should be based upon, unless some other mechanism for assigning views to element structures is provided.

Specified by:
getDefaultRootElement in interface Document
Returns:
the root element

render

public void render(Runnable r)
This allows the model to be safely rendered in the presence of currency, if the model supports being updated asynchronously. The given runnable will be executed in a way that allows it to safely read the model with no changes while the runnable is being executed. The runnable itself may not make any mutations.

Specified by:
render in interface Document
Parameters:
r - a Runnable used to render the model


Copyright © 2002-2006 JGoodies Karsten Lentzsch. All Rights Reserved.