javax.swing.text
class PlainDocument

java.lang.Object javax.swing.text.AbstractDocument javax.swing.text.PlainDocument

All Implemented Interfaces:

Serializable, Document

public class PlainDocument
extends AbstractDocument

A plain document that maintains no character attributes. The default element structure for this document is a map of the lines in the text. The Element returned by getDefaultRootElement is a map of the lines, and each child element represents a line. This model does not maintain any character level attributes, but each line can be tagged with an arbitrary set of attributes. Line to offset, and offset to line translations can be quickly performed using the default root element. The structure information of the DocumentEvent's fired by edits will indicate the line structure changes.

The default content storage management is performed by a gapped buffer implementation (GapContent). It supports editing reasonably large documents with good efficiency when the edits are contiguous or clustered, as is typical.

Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans^TM has been added to the java.beans package. Please see {@link java.beans.XMLEncoder}.

lineLimitAttribute

public static final String lineLimitAttribute

Name of the attribute that specifies the maximum length of a line, if there is a maximum length. The type for the value is Integer.

tabSizeAttribute

public static final String tabSizeAttribute

Name of the attribute that specifies the tab size for tabs contained in the content. The type for the value is Integer.

PlainDocument

public PlainDocument()

Constructs a plain text document. A default model using GapContent is constructed and set.

PlainDocument

public PlainDocument(AbstractDocument.Content c)

Constructs a plain text document. A default root element is created, and the tab size set to 8.

Parameters:

c - the container for the content

createDefaultRoot

protected AbstractDocument.AbstractElement createDefaultRoot()

Creates the root element to be used to represent the default document structure.

Returns:

the element base

getDefaultRootElement

public Element getDefaultRootElement()

Gets the default root element for the document model.

Overrides:

getDefaultRootElement in class AbstractDocument

Returns:

the root

getParagraphElement

public Element getParagraphElement(int pos)

Get the paragraph element containing the given position. Since this document only models lines, it returns the line instead.

Overrides:

getParagraphElement in class AbstractDocument

Parameters:

pos

insertString

public void insertString(int offs,
                         String str,
                         AttributeSet a)
                  throws BadLocationException

Inserts some content into the document. Inserting content causes a write lock to be held while the actual changes are taking place, followed by notification to the observers on the thread that grabbed the write lock.

This method is thread safe, although most Swing methods are not. Please see How to Use Threads for more information.

Overrides:

insertString in class AbstractDocument

Parameters:

offs - the starting offset >= 0

str - the string to insert; does nothing with null/empty strings

a - the attributes for the inserted content

Throws:

BadLocationException - the given insert position is not a valid position within the document

insertUpdate

protected void insertUpdate(AbstractDocument.DefaultDocumentEvent chng,
                            AttributeSet attr)

Updates document structure as a result of text insertion. This will happen within a write lock. Since this document simply maps out lines, we refresh the line map.

Overrides:

insertUpdate in class AbstractDocument

Parameters:

chng - the change event describing the dit

attr - the set of attributes for the inserted text

removeUpdate

protected void removeUpdate(AbstractDocument.DefaultDocumentEvent chng)

Updates any document structure as a result of text removal. This will happen within a write lock. Since the structure represents a line map, this just checks to see if the removal spans lines. If it does, the two lines outside of the removal area are joined together.

Overrides:

removeUpdate in class AbstractDocument

Parameters:

chng - the change event describing the edit