com.jidesoft.editor
Class LazyLoadDocument

java.lang.Object
  javax.swing.text.AbstractDocument
      javax.swing.text.PlainDocument
          com.jidesoft.editor.SyntaxDocument
              com.jidesoft.editor.LazyLoadDocument

All Implemented Interfaces:

LineBreak, Serializable, Document

public class LazyLoadDocument
extends SyntaxDocument

This class is to provide lazy loading feature for CodeEditor to edit extremely large document.

Basically, this class will not load everything from the original file to save the memory. It will divide the file to many pages depending on getPageLineSize(). It will then load the page on request only. You don't have to manually load/unload the pages. The loading process is triggered by those methods like getText(int, int), getLineStartOffset(int) , etc. You could check if a line/offset is already loaded by isLineLoaded(int) and isOffsetLoaded(int). Those two methods will not trigger a page loading/unloading operation.

You could invoke setMaximumPages(int) to configure the maximum unmodified page in the memory. The less you configured, the less memory the document will use. However, you may have more chance to reload a new page, which takes time for a large file. You could also invoke setPageLineSize(int) to balance the memory usage and the performance.

We do provide page loading/loaded event. You could invoke addPageLoadingListener(PageLoadListener) to listen to that.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.jidesoft.editor.SyntaxDocument

SyntaxDocument.MyUndoableEditListener

Nested classes/interfaces inherited from class javax.swing.text.AbstractDocument

AbstractDocument.AbstractElement, AbstractDocument.AttributeContext, AbstractDocument.BranchElement, AbstractDocument.Content, AbstractDocument.DefaultDocumentEvent, AbstractDocument.ElementEdit, AbstractDocument.LeafElement

Field Summary

Fields inherited from class com.jidesoft.editor.SyntaxDocument

_compoundEdit, _compoundEditCount, _undoManager, tokenMarker

Fields inherited from class javax.swing.text.PlainDocument

lineLimitAttribute, tabSizeAttribute

Fields inherited from class javax.swing.text.AbstractDocument

BAD_LOCATION, BidiElementName, ContentElementName, ElementNameAttribute, listenerList, ParagraphElementName, SectionElementName

Fields inherited from interface com.jidesoft.editor.LineBreak

CR, LF, LINE_BREAK_CODE_EDITOR, LINE_BREAK_MAC, LINE_BREAK_MIXED, LINE_BREAK_PC, LINE_BREAK_UNIX, LINE_BREAK_UNKNOWN, STRING_CR, STRING_CR_LF, STRING_LF

Fields inherited from interface javax.swing.text.Document

StreamDescriptionProperty, TitleProperty

Constructor Summary

LazyLoadDocument()
Constructor

Method Summary

void	addPageLoadingListener(PageLoadListener listener) Add page loading listener.
char	charAt(int offset)
protected DocumentEvent	createCombinedDocumentEvent(int offset, DocumentEvent originalEvent) Create a DocumentEvent to file.
protected DocumentEvent	createCombinedDocumentEvent(int offset, int length, DocumentEvent.EventType type) Create a DocumentEvent to file.
protected AbstractDocument.AbstractElement	createDefaultRoot()
protected void	firePageLoadedEvent(int startLineIndex, boolean pageLoadThread) Fire page loaded event.
protected void	firePageStartLoadingEvent(int startLineIndex, boolean pageLoadThread) Fire page start loading event.
Element	getDefaultRootElement()
String	getFileName() Get the file name the CodeEditor is currently editing.
CharSequence	getLazyLoadText() Get the lazy load text for search purpose.
int	getLength()
int	getLineEndOffset(int line)
int	getLineNumber(int offset)
int	getLineStartOffset(int line)
String	getLineText(int offset)
int	getMaximumPages() Get maximum pages.
int	getPageLineSize() Get line size in a page.
PageLoadListener[]	getPageLoadListeners() Get all page load listeners.
String	getText(int offset, int length) Gets a sequence of text from the document.
void	getText(int offset, int length, Segment txt)
void	insertString(int offs, String str, AttributeSet a)
boolean	isLineLoaded(int line) Check if the line is loaded in memory already.
boolean	isOffsetLoaded(int offset) Check if the offset is loaded in memory already.
protected boolean	needUndoRedo(int offs, int length, DocumentEvent.EventType type) Configure if an operation is undoable/redoable.
void	remove(int offs, int len)
void	removePageLoadingListener(PageLoadListener listener) Remove page loading listener.
void	setFileName(String fileName) Set the file name the CodeEditor is currently editing.
void	setMaximumPages(int maximumPages) Set maximum pages.
void	setPageLineSize(int pageLineSize) Set line size in a page.
void	setTokenMarker(TokenMarker tm) Sets the token marker that is to be used to split lines of this document up into tokens.

Methods inherited from class com.jidesoft.editor.SyntaxDocument

addUndoableEdit, beginCompoundEdit, convertLineBreaks, convertLineBreaks, endCompoundEdit, findNext, findNext, findPrevious, findPrevious, fireInsertUpdate, fireRemoveUpdate, fireRemovingUpdate, getLineCount, getLineLength, getLookupBufferSize, getTokenMarker, getUndoManager, isInCommentOrLiteral, isWordChar, redo, removeUpdate, setLookupBufferSize, setUndoManager, tokenizeLines, tokenizeLines, undo

Methods inherited from class javax.swing.text.PlainDocument

getParagraphElement, insertUpdate

Methods inherited from class javax.swing.text.AbstractDocument

addDocumentListener, addUndoableEditListener, createBranchElement, createLeafElement, createPosition, dump, fireChangedUpdate, fireUndoableEditUpdate, getAsynchronousLoadPriority, getAttributeContext, getBidiRootElement, getContent, getCurrentWriter, getDocumentFilter, getDocumentListeners, getDocumentProperties, getEndPosition, getListeners, getProperty, getRootElements, getStartPosition, getUndoableEditListeners, postRemoveUpdate, putProperty, readLock, readUnlock, removeDocumentListener, removeUndoableEditListener, render, replace, setAsynchronousLoadPriority, setDocumentFilter, setDocumentProperties, writeLock, writeUnlock

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LazyLoadDocument

public LazyLoadDocument()

Constructor

Method Detail

createCombinedDocumentEvent

protected DocumentEvent createCombinedDocumentEvent(int offset,
                                                    DocumentEvent originalEvent)

Create a DocumentEvent to file.

To fire correct document event from the user of LazyLoadDocument point of view, the document event is created independently. You may need override this method if you want to customize the event.

This method is invoked when the edit is inside a page.

Parameters:

offset - the start offset of the event

originalEvent - the original event from the underlying document

Returns:

the new document event to be fired.

createCombinedDocumentEvent

protected DocumentEvent createCombinedDocumentEvent(int offset,
                                                    int length,
                                                    DocumentEvent.EventType type)

Create a DocumentEvent to file.

To fire correct document event from the user of LazyLoadDocument point of view, the document event is created independently. You may need override this method if you want to customize the event.

This method is invoked when the edit is crossing multiple pages.

Parameters:

offset - the start offset of the event

length - the length of the event

type - the edit type of the event

Returns:

the new document event to be fired.

getFileName

public String getFileName()

Get the file name the CodeEditor is currently editing.

Returns:

the file name.

setFileName

public void setFileName(String fileName)

Set the file name the CodeEditor is currently editing.

Parameters:

fileName - the file name

getLength

public int getLength()

Specified by:

getLength in interface Document

Overrides:

getLength in class AbstractDocument

getDefaultRootElement

public Element getDefaultRootElement()

Specified by:

getDefaultRootElement in interface Document

Overrides:

getDefaultRootElement in class PlainDocument

createDefaultRoot

protected AbstractDocument.AbstractElement createDefaultRoot()

Overrides:

createDefaultRoot in class PlainDocument

getLineNumber

public int getLineNumber(int offset)

Overrides:

getLineNumber in class SyntaxDocument

getText

public String getText(int offset,
                      int length)
               throws BadLocationException

Gets a sequence of text from the document.

This method will copy all the texts inside the range to a String, which may consume memory if the length is huge. Please use getLazyLoadText() to get all the texts for searching or other implementations.

Specified by:

getText in interface Document

Overrides:

getText in class AbstractDocument

Parameters:

offset - the starting offset >= 0

length - the number of characters to retrieve >= 0

Returns:

the text

Throws:

BadLocationException - the range given includes a position that is not a valid position within the document

See Also:

Document.getText(int, int)

getText

public void getText(int offset,
                    int length,
                    Segment txt)
             throws BadLocationException

Specified by:

getText in interface Document

Overrides:

getText in class AbstractDocument

Throws:

BadLocationException

getLineText

public String getLineText(int offset)
                   throws BadLocationException

Overrides:

getLineText in class SyntaxDocument

Throws:

BadLocationException

getPageLineSize

public int getPageLineSize()

Get line size in a page.

Returns:

the line size.

See Also:

setPageLineSize(int)

setPageLineSize

public void setPageLineSize(int pageLineSize)

Set line size in a page.

By default, the value is 10000. You could reduce the value to save memory or enlarge the value to reduce the chance to reload new pages.

Parameters:

pageLineSize - the line size

getLazyLoadText

public CharSequence getLazyLoadText()

Get the lazy load text for search purpose.

If you want to implement search functionality over LazyLoadDocument, please try not use getText(int, int) just in case memory is used up if you have an extremely huge file.

Returns:

the lazy load char sequence.

charAt

public char charAt(int offset)
            throws BadLocationException

Overrides:

charAt in class SyntaxDocument

Throws:

BadLocationException

setTokenMarker

public void setTokenMarker(TokenMarker tm)

Description copied from class: SyntaxDocument

Sets the token marker that is to be used to split lines of this document up into tokens. May throw an exception if this is not supported for this type of document.

Overrides:

setTokenMarker in class SyntaxDocument

Parameters:

tm - The new token marker

isLineLoaded

public boolean isLineLoaded(int line)

Check if the line is loaded in memory already. This method will not trigger a page loading operation.

If you only have offset on your hand and want to check if the offset is loaded, please use isOffsetLoaded(int). It will not trigger the page loading process. However, if you try to invoke getLineNumber(int) to get line number for the offset then invoke this method, you will always get true because the getLineNumber(int) will trigger page loading process.

Overrides:

isLineLoaded in class SyntaxDocument

Parameters:

line - the line index

Returns:

true if the line is already loaded in memory. Otherwise false.

See Also:

isOffsetLoaded(int)

isOffsetLoaded

public boolean isOffsetLoaded(int offset)

Check if the offset is loaded in memory already. This method will not trigger a page loading operation.

Overrides:

isOffsetLoaded in class SyntaxDocument

Parameters:

offset - the offset to check

Returns:

true if the offset is already loaded in memory. Otherwise false.

getMaximumPages

public int getMaximumPages()

Get maximum pages.

Returns:

the maximum pages

See Also:

setMaximumPages(int)

setMaximumPages

public void setMaximumPages(int maximumPages)

Set maximum pages.

By default, the value is 5. You could reduce the value to save memory or enlarge the value to reduce the chance to reload new pages.

Parameters:

maximumPages - the maximum pages.

addPageLoadingListener

public void addPageLoadingListener(PageLoadListener listener)

Add page loading listener.

Parameters:

listener - the listener

See Also:

removePageLoadingListener(PageLoadListener), getPageLoadListeners()

removePageLoadingListener

public void removePageLoadingListener(PageLoadListener listener)

Remove page loading listener.

Parameters:

listener - the listener

getPageLoadListeners

public PageLoadListener[] getPageLoadListeners()

Get all page load listeners.

Returns:

the listener array.

firePageStartLoadingEvent

protected void firePageStartLoadingEvent(int startLineIndex,
                                         boolean pageLoadThread)

Fire page start loading event.

Parameters:

startLineIndex - the start line index

pageLoadThread - the flag indicating if the event is fired from page load thread

firePageLoadedEvent

protected void firePageLoadedEvent(int startLineIndex,
                                   boolean pageLoadThread)

Fire page loaded event.

Parameters:

startLineIndex - the start line index

pageLoadThread - the flag indicating if the event is fired from page load thread

needUndoRedo

protected boolean needUndoRedo(int offs,
                               int length,
                               DocumentEvent.EventType type)

Configure if an operation is undoable/redoable.

By default, it just returns true. You could override this method to save memory for some operations if you don't care much about the undo/redo functionality for the operation.

Parameters:

offs - the start offset

length - the length

type - the edit type

Returns:

true if the operation is undoable. Otherwise false.

insertString

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

Specified by:

insertString in interface Document

Overrides:

insertString in class PlainDocument

Throws:

BadLocationException

remove

public void remove(int offs,
                   int len)
            throws BadLocationException

Specified by:

remove in interface Document

Overrides:

remove in class AbstractDocument

Throws:

BadLocationException

getLineStartOffset

public int getLineStartOffset(int line)

Overrides:

getLineStartOffset in class SyntaxDocument

getLineEndOffset

public int getLineEndOffset(int line)

Overrides:

getLineEndOffset in class SyntaxDocument