* 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
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*
* @author Timothy Prinzing
* @see Document
* @see AbstractDocument
*/
@SuppressWarnings("serial") // Same-version serialization only
public class PlainDocument extends AbstractDocument {
/**
* Name of the attribute that specifies the tab
* size for tabs contained in the content. The
* type for the value is Integer.
*/
public static final String tabSizeAttribute = "tabSize";
/**
* 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.
*/
public static final String lineLimitAttribute = "lineLimit";
/**
* Constructs a plain text document. A default model using
* GapContent is constructed and set.
*/
public PlainDocument() {
this(new GapContent());
}
/**
* Constructs a plain text document. A default root element is created,
* and the tab size set to 8.
*
* @param c the container for the content
*/
public PlainDocument(Content c) {
super(c);
putProperty(tabSizeAttribute, Integer.valueOf(8));
defaultRoot = createDefaultRoot();
}
/**
* 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
* Concurrency
* in Swing for more information.
*
* @param offs the starting offset >= 0
* @param str the string to insert; does nothing with null/empty strings
* @param a the attributes for the inserted content
* @exception BadLocationException the given insert position is not a valid
* position within the document
* @see Document#insertString
*/
public void insertString(int offs, String str, AttributeSet a) throws BadLocationException {
// fields don't want to have multiple lines. We may provide a field-specific
// model in the future in which case the filtering logic here will no longer
// be needed.
Object filterNewlines = getProperty("filterNewlines");
if ((filterNewlines instanceof Boolean) && filterNewlines.equals(Boolean.TRUE)) {
if ((str != null) && (str.indexOf('\n') >= 0)) {
StringBuilder filtered = new StringBuilder(str);
int n = filtered.length();
for (int i = 0; i < n; i++) {
if (filtered.charAt(i) == '\n') {
filtered.setCharAt(i, ' ');
}
}
str = filtered.toString();
}
}
super.insertString(offs, str, a);
}
/**
* Gets the default root element for the document model.
*
* @return the root
* @see Document#getDefaultRootElement
*/
public Element getDefaultRootElement() {
return defaultRoot;
}
/**
* Creates the root element to be used to represent the
* default document structure.
*
* @return the element base
*/
protected AbstractElement createDefaultRoot() {
BranchElement map = (BranchElement) createBranchElement(null, null);
Element line = createLeafElement(map, null, 0, 1);
Element[] lines = new Element[1];
lines[0] = line;
map.replace(0, 0, lines);
return map;
}
/**
* Get the paragraph element containing the given position. Since this
* document only models lines, it returns the line instead.
*/
public Element getParagraphElement(int pos){
Element lineMap = getDefaultRootElement();
return lineMap.getElement( lineMap.getElementIndex( pos ) );
}
/**
* 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.
*
* @param chng the change event describing the dit
* @param attr the set of attributes for the inserted text
*/
protected void insertUpdate(DefaultDocumentEvent chng, AttributeSet attr) {
removed.removeAllElements();
added.removeAllElements();
BranchElement lineMap = (BranchElement) getDefaultRootElement();
int offset = chng.getOffset();
int length = chng.getLength();
if (offset > 0) {
offset -= 1;
length += 1;
}
int index = lineMap.getElementIndex(offset);
Element rmCandidate = lineMap.getElement(index);
int rmOffs0 = rmCandidate.getStartOffset();
int rmOffs1 = rmCandidate.getEndOffset();
int lastOffset = rmOffs0;
try {
if (s == null) {
s = new Segment();
}
getContent().getChars(offset, length, s);
boolean hasBreaks = false;
for (int i = 0; i < length; i++) {
char c = s.array[s.offset + i];
if (c == '\n') {
int breakOffset = offset + i + 1;
added.addElement(createLeafElement(lineMap, null, lastOffset, breakOffset));
lastOffset = breakOffset;
hasBreaks = true;
}
}
if (hasBreaks) {
removed.addElement(rmCandidate);
if ((offset + length == rmOffs1) && (lastOffset != rmOffs1) &&
((index+1) < lineMap.getElementCount())) {
Element e = lineMap.getElement(index+1);
removed.addElement(e);
rmOffs1 = e.getEndOffset();
}
if (lastOffset < rmOffs1) {
added.addElement(createLeafElement(lineMap, null, lastOffset, rmOffs1));
}
Element[] aelems = new Element[added.size()];
added.copyInto(aelems);
Element[] relems = new Element[removed.size()];
removed.copyInto(relems);
ElementEdit ee = new ElementEdit(lineMap, index, relems, aelems);
chng.addEdit(ee);
lineMap.replace(index, relems.length, aelems);
}
if (Utilities.isComposedTextAttributeDefined(attr)) {
insertComposedTextUpdate(chng, attr);
}
} catch (BadLocationException e) {
throw new Error("Internal error: " + e.toString());
}
super.insertUpdate(chng, attr);
}
/**
* 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.
*
* @param chng the change event describing the edit
*/
protected void removeUpdate(DefaultDocumentEvent chng) {
removed.removeAllElements();
BranchElement map = (BranchElement) getDefaultRootElement();
int offset = chng.getOffset();
int length = chng.getLength();
int line0 = map.getElementIndex(offset);
int line1 = map.getElementIndex(offset + length);
if (line0 != line1) {
// a line was removed
for (int i = line0; i <= line1; i++) {
removed.addElement(map.getElement(i));
}
int p0 = map.getElement(line0).getStartOffset();
int p1 = map.getElement(line1).getEndOffset();
Element[] aelems = new Element[1];
aelems[0] = createLeafElement(map, null, p0, p1);
Element[] relems = new Element[removed.size()];
removed.copyInto(relems);
ElementEdit ee = new ElementEdit(map, line0, relems, aelems);
chng.addEdit(ee);
map.replace(line0, relems.length, aelems);
} else {
//Check for the composed text element
Element line = map.getElement(line0);
if (!line.isLeaf()) {
Element leaf = line.getElement(line.getElementIndex(offset));
if (Utilities.isComposedTextElement(leaf)) {
Element[] aelem = new Element[1];
aelem[0] = createLeafElement(map, null,
line.getStartOffset(), line.getEndOffset());
Element[] relem = new Element[1];
relem[0] = line;
ElementEdit ee = new ElementEdit(map, line0, relem, aelem);
chng.addEdit(ee);
map.replace(line0, 1, aelem);
}
}
}
super.removeUpdate(chng);
}
//
// Inserts the composed text of an input method. The line element
// where the composed text is inserted into becomes an branch element
// which contains leaf elements of the composed text and the text
// backing store.
//
private void insertComposedTextUpdate(DefaultDocumentEvent chng, AttributeSet attr) {
added.removeAllElements();
BranchElement lineMap = (BranchElement) getDefaultRootElement();
int offset = chng.getOffset();
int length = chng.getLength();
int index = lineMap.getElementIndex(offset);
Element elem = lineMap.getElement(index);
int elemStart = elem.getStartOffset();
int elemEnd = elem.getEndOffset();
BranchElement[] abelem = new BranchElement[1];
abelem[0] = (BranchElement) createBranchElement(lineMap, null);
Element[] relem = new Element[1];
relem[0] = elem;
if (elemStart != offset)
added.addElement(createLeafElement(abelem[0], null, elemStart, offset));
added.addElement(createLeafElement(abelem[0], attr, offset, offset+length));
if (elemEnd != offset+length)
added.addElement(createLeafElement(abelem[0], null, offset+length, elemEnd));
Element[] alelem = new Element[added.size()];
added.copyInto(alelem);
ElementEdit ee = new ElementEdit(lineMap, index, relem, abelem);
chng.addEdit(ee);
abelem[0].replace(0, 0, alelem);
lineMap.replace(index, 1, abelem);
}
private AbstractElement defaultRoot;
private Vector