File	Doc	Category	Size	Date	Package
AbstractWriter.java	API Doc	Java SE 5 API	19412	Fri Aug 26 14:58:14 BST 2005	javax.swing.text

AbstractWriter

• java.lang.Object

Fields Summary
private ElementIterator	it
private Writer	out
private int	indentLevel
private int	indentSpace
private Document	doc
private int	maxLineLength
private int	currLength
private int	startOffset
private int	endOffset
private int	offsetIndent
private String	lineSeparator String used for end of line. If the Document has the property EndOfLineStringProperty, it will be used for newlines. Otherwise the System property line.separator will be used. The line separator can also be set.
private boolean	canWrapLines True indicates that when writing, the line can be split, false indicates that even if the line is > than max line length it should not be split.
private boolean	isLineEmpty True while the current line is empty. This will remain true after indenting.
private char[]	indentChars Used when indenting. Will contain the spaces.
private char[]	tempChars Used when writing out a string.
private char[]	newlineChars This is used in writeLineSeparator instead of tempChars. If tempChars were used it would mean write couldn't invoke writeLineSeparator as it might have been passed tempChars.
private Segment	segment Used for writing text.
protected static final char	NEWLINE How the text packages models newlines.

Constructors Summary
protected AbstractWriter(Writer w, Document doc) Creates a new AbstractWriter. Initializes the ElementIterator with the default root of the document. param w a Writer. param doc a Document this(w, doc, 0, doc.getLength());
protected AbstractWriter(Writer w, Document doc, int pos, int len) Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in. param w a Writer param doc an Element param pos The location in the document to fetch the content. param len The amount to write out. this.doc = doc; it = new ElementIterator(doc.getDefaultRootElement()); out = w; startOffset = pos; endOffset = pos + len; Object docNewline = doc.getProperty(DefaultEditorKit. EndOfLineStringProperty); if (docNewline instanceof String) { setLineSeparator((String)docNewline); } else { String newline = null; try { newline = System.getProperty("line.separator"); } catch (SecurityException se) {} if (newline == null) { // Should not get here, but if we do it means we could not // find a newline string, use \n in this case. newline = "\n"; } setLineSeparator(newline); } canWrapLines = true;
protected AbstractWriter(Writer w, Element root) Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in. param w a Writer param root an Element this(w, root, 0, root.getEndOffset());
protected AbstractWriter(Writer w, Element root, int pos, int len) Creates a new AbstractWriter. Initializes the ElementIterator with the element passed in. param w a Writer param root an Element param pos The location in the document to fetch the content. param len The amount to write out. this.doc = root.getDocument(); it = new ElementIterator(root); out = w; startOffset = pos; endOffset = pos + len; canWrapLines = true;

Methods Summary
protected void	decrIndent() Decrements the indent level. if (offsetIndent > 0) { --offsetIndent; } else { indentLevel--; }
protected boolean	getCanWrapLines() Returns whether or not the lines can be wrapped. If this is false no lineSeparator's will be output. since 1.3 return canWrapLines;
protected int	getCurrentLineLength() Returns the current line length. since 1.3. return currLength;
protected javax.swing.text.Document	getDocument() Fetches the document. return the Document. return doc;
protected javax.swing.text.ElementIterator	getElementIterator() Fetches the ElementIterator. return the ElementIterator. return it;
public int	getEndOffset() Returns the last offset to be output. since 1.3 return endOffset;
protected int	getIndentLevel() Returns the current indentation level. That is, the number of times incrIndent has been invoked minus the number of times decrIndent has been invoked. since 1.3 return indentLevel;
protected int	getIndentSpace() Returns the amount of space to indent. since 1.3 return indentSpace;
protected int	getLineLength() Returns the maximum line length. since 1.3 return maxLineLength;
public java.lang.String	getLineSeparator() Returns the string used to represent newlines. since 1.3 return lineSeparator;
public int	getStartOffset() Returns the first offset to be output. since 1.3 return startOffset;
protected java.lang.String	getText(javax.swing.text.Element elem) Returns the text associated with the element. The assumption here is that the element is a leaf element. Throws a BadLocationException when encountered. param elem an Element exception BadLocationException if pos represents an invalid location within the document return the text as a String return doc.getText(elem.getStartOffset(), elem.getEndOffset() - elem.getStartOffset());
protected java.io.Writer	getWriter() Returns the Writer that is used to output the content. since 1.3 return out;
protected boolean	inRange(javax.swing.text.Element next) This method determines whether the current element is in the range specified. When no range is specified, the range is initialized to be the entire document. inRange() returns true if the range specified intersects with the element's range. param next an Element. return boolean that indicates whether the element is in the range. int startOffset = getStartOffset(); int endOffset = getEndOffset(); if ((next.getStartOffset() >= startOffset && next.getStartOffset() < endOffset) || (startOffset >= next.getStartOffset() && startOffset < next.getEndOffset())) { return true; } return false;
protected void	incrIndent() Increments the indent level. If indenting would cause getIndentSpace() *getIndentLevel() to be > than getLineLength() this will not cause an indent. // Only increment to a certain point. if (offsetIndent > 0) { offsetIndent++; } else { if (++indentLevel * getIndentSpace() >= getLineLength()) { offsetIndent++; --indentLevel; } }
protected void	indent() Does indentation. The number of spaces written out is indent level times the space to map mapping. If the current line is empty, this will not make it so that the current line is still considered empty. exception IOException on any I/O error int max = getIndentLevel() * getIndentSpace(); if (indentChars == null || max > indentChars.length) { indentChars = new char[max]; for (int counter = 0; counter < max; counter++) { indentChars[counter] = ' "; } } int length = getCurrentLineLength(); boolean wasEmpty = isLineEmpty(); output(indentChars, 0, max); if (wasEmpty && length == 0) { isLineEmpty = true; }
private int	indexOf(char[] chars, char sChar, int startIndex, int endIndex) Support method to locate an occurence of a particular character. while(startIndex < endIndex) { if (chars[startIndex] == sChar) { return startIndex; } startIndex++; } return -1;
protected boolean	isLineEmpty() Returns true if the current line should be considered empty. This is true when getCurrentLineLength == 0 || indent has been invoked on an empty line. since 1.3 return isLineEmpty;
protected void	output(char[] content, int start, int length) The last stop in writing out content. All the write methods eventually make it to this method, which invokes write on the Writer. This method also updates the line length based on length. If this is invoked to output a newline, the current line length will need to be reset as will no longer be valid. If it is up to the caller to do this. Use writeLineSeparator to write out a newline, which will property update the current line length. since 1.3 getWriter().write(content, start, length); setCurrentLineLength(getCurrentLineLength() + length);
protected void	setCanWrapLines(boolean newValue) Sets whether or not lines can be wrapped. This can be toggled during the writing of lines. For example, outputting HTML might set this to false when outputting a quoted string. since 1.3 canWrapLines = newValue;
protected void	setCurrentLineLength(int length) Sets the current line length. since 1.3. currLength = length; isLineEmpty = (currLength == 0);
protected void	setIndentSpace(int space) Enables subclasses to specify how many spaces an indent maps to. When indentation takes place, the indent level is multiplied by this mapping. The default is 2. param space an int representing the space to indent mapping. indentSpace = space;
protected void	setLineLength(int l) Enables subclasses to set the number of characters they want written per line. The default is 100. param l the maximum line length. maxLineLength = l;
public void	setLineSeparator(java.lang.String value) Sets the String used to reprsent newlines. This is initialized in the constructor from either the Document, or the System property line.separator. since 1.3 lineSeparator = value;
protected void	text(javax.swing.text.Element elem) Writes out text. If a range is specified when the constructor is invoked, then only the appropriate range of text is written out. param elem an Element. exception IOException on any I/O error exception BadLocationException if pos represents an invalid location within the document. int start = Math.max(getStartOffset(), elem.getStartOffset()); int end = Math.min(getEndOffset(), elem.getEndOffset()); if (start < end) { if (segment == null) { segment = new Segment(); } getDocument().getText(start, end - start, segment); if (segment.count > 0) { write(segment.array, segment.offset, segment.count); } }
protected abstract void	write() This abstract method needs to be implemented by subclasses. Its responsibility is to iterate over the elements and use the write() methods to generate output in the desired format.
protected void	write(char ch) Writes out a character. This is implemented to invoke the write method that takes a char[]. param ch a char. exception IOException on any I/O error if (tempChars == null) { tempChars = new char[128]; } tempChars[0] = ch; write(tempChars, 0, 1);
protected void	write(java.lang.String content) Writes out a string. This is implemented to invoke the write method that takes a char[]. param content a String. exception IOException on any I/O error if (content == null) { return; } int size = content.length(); if (tempChars == null || tempChars.length < size) { tempChars = new char[size]; } content.getChars(0, size, tempChars, 0); write(tempChars, 0, size);
protected void	write(char[] chars, int startIndex, int length) All write methods call into this one. If getCanWrapLines() returns false, this will call output with each sequence of chars that doesn't contain a NEWLINE, followed by a call to writeLineSeparator. On the other hand, if getCanWrapLines() returns true, this will split the string, as necessary, so getLineLength is honored. The only exception is if the current string contains no whitespace, and won't fit in which case the line length will exceed getLineLength. since 1.3 if (!getCanWrapLines()) { // We can not break string, just track if a newline // is in it. int lastIndex = startIndex; int endIndex = startIndex + length; int newlineIndex = indexOf(chars, NEWLINE, startIndex, endIndex); while (newlineIndex != -1) { if (newlineIndex > lastIndex) { output(chars, lastIndex, newlineIndex - lastIndex); } writeLineSeparator(); lastIndex = newlineIndex + 1; newlineIndex = indexOf(chars, '\n", lastIndex, endIndex); } if (lastIndex < endIndex) { output(chars, lastIndex, endIndex - lastIndex); } } else { // We can break chars if the length exceeds maxLength. int lastIndex = startIndex; int endIndex = startIndex + length; int lineLength = getCurrentLineLength(); int maxLength = getLineLength(); while (lastIndex < endIndex) { int newlineIndex = indexOf(chars, NEWLINE, lastIndex, endIndex); boolean needsNewline = false; boolean forceNewLine = false; lineLength = getCurrentLineLength(); if (newlineIndex != -1 && (lineLength + (newlineIndex - lastIndex)) < maxLength) { if (newlineIndex > lastIndex) { output(chars, lastIndex, newlineIndex - lastIndex); } lastIndex = newlineIndex + 1; forceNewLine = true; } else if (newlineIndex == -1 && (lineLength + (endIndex - lastIndex)) < maxLength) { if (endIndex > lastIndex) { output(chars, lastIndex, endIndex - lastIndex); } lastIndex = endIndex; } else { // Need to break chars, find a place to split chars at, // from lastIndex to endIndex, // or maxLength - lineLength whichever is smaller int breakPoint = -1; int maxBreak = Math.min(endIndex - lastIndex, maxLength - lineLength - 1); int counter = 0; while (counter < maxBreak) { if (Character.isWhitespace(chars[counter + lastIndex])) { breakPoint = counter; } counter++; } if (breakPoint != -1) { // Found a place to break at. breakPoint += lastIndex + 1; output(chars, lastIndex, breakPoint - lastIndex); lastIndex = breakPoint; needsNewline = true; } else { // No where good to break. // find the next whitespace, or write out the // whole string. // maxBreak will be negative if current line too // long. counter = Math.max(0, maxBreak); maxBreak = endIndex - lastIndex; while (counter < maxBreak) { if (Character.isWhitespace(chars[counter + lastIndex])) { breakPoint = counter; break; } counter++; } if (breakPoint == -1) { output(chars, lastIndex, endIndex - lastIndex); breakPoint = endIndex; } else { breakPoint += lastIndex; if (chars[breakPoint] == NEWLINE) { output(chars, lastIndex, breakPoint++ - lastIndex); forceNewLine = true; } else { output(chars, lastIndex, ++breakPoint - lastIndex); needsNewline = true; } } lastIndex = breakPoint; } } if (forceNewLine || needsNewline || lastIndex < endIndex) { writeLineSeparator(); if (lastIndex < endIndex || !forceNewLine) { indent(); } } } }
protected void	writeAttributes(javax.swing.text.AttributeSet attr) Writes out the set of attributes as " =" pairs. It throws an IOException when encountered. param attr an AttributeSet. exception IOException on any I/O error Enumeration names = attr.getAttributeNames(); while (names.hasMoreElements()) { Object name = names.nextElement(); write(" " + name + "=" + attr.getAttribute(name)); }
protected void	writeLineSeparator() Writes the line separator. This invokes output directly as well as setting the lineLength to 0. since 1.3 String newline = getLineSeparator(); int length = newline.length(); if (newlineChars == null || newlineChars.length < length) { newlineChars = new char[length]; } newline.getChars(0, length, newlineChars, 0); output(newlineChars, 0, length); setCurrentLineLength(0);