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MinimalHTMLWriter.javaAPI DocJava SE 5 API18178Fri Aug 26 14:58:18 BST 2005javax.swing.text.html

MinimalHTMLWriter

public class MinimalHTMLWriter extends AbstractWriter
MinimalHTMLWriter is a fallback writer used by the HTMLEditorKit to write out HTML for a document that is a not produced by the EditorKit. The format for the document is:
<html>
<head>
<style>
<!-- list of named styles
p.normal {
font-family: SansSerif;
margin-height: 0;
font-size: 14
}
-->
</style>
</head>
<body>
<p style=normal>
Bold, italic, and underline attributes
of the run are emitted as HTML tags.
The remaining attributes are emitted as
part of the style attribute of a <span> tag.
The syntax is similar to inline styles.
</p>
</body>
</html>
author
Sunita Mani
version
1.14, 12/19/03

Fields Summary
private static final int
BOLD
These static finals are used to tweak and query the fontMask about which of these tags need to be generated or terminated.
private static final int
ITALIC
private static final int
UNDERLINE
private static final CSS
css
private int
fontMask
int
startOffset
int
endOffset
private AttributeSet
fontAttributes
Stores the attributes of the previous run. Used to compare with the current run's attributeset. If identical, then a <span> tag is not emitted.
private Hashtable
styleNameMapping
Maps from style name as held by the Document, to the archived style name (style name written out). These may differ.
Constructors Summary
public MinimalHTMLWriter(Writer w, StyledDocument doc)
Creates a new MinimalHTMLWriter.

param
w Writer
param
doc StyledDocument


                    
         
	super(w, doc);
    
public MinimalHTMLWriter(Writer w, StyledDocument doc, int pos, int len)
Creates a new MinimalHTMLWriter.

param
w Writer
param
doc StyledDocument
param
pos The location in the document to fetch the content.
param
len The amount to write out.

	super(w, doc, pos, len);
    
Methods Summary
private java.lang.StringaddStyleName(java.lang.String style)
Adds the style named style to the style mapping. This returns the name that should be used when outputting. CSS does not allow the full Unicode set to be used as a style name.

	if (styleNameMapping == null) {
	    return style;
	}
	StringBuffer sb = null;
	for (int counter = style.length() - 1; counter >= 0; counter--) {
	    if (!isValidCharacter(style.charAt(counter))) {
		if (sb == null) {
		    sb = new StringBuffer(style);
		}
		sb.setCharAt(counter, 'a");
	    }
	}
	String mappedName = (sb != null) ? sb.toString() : style;
	while (styleNameMapping.get(mappedName) != null) {
	    mappedName = mappedName + 'x";
	}
	styleNameMapping.put(style, mappedName);
	return mappedName;
    
protected voidendFontTag()
This is no longer used, instead <span> will be written out.

Writes out an end tag for the <font> tag.

exception
IOException on any I/O error

	write(NEWLINE);
	writeEndTag("</font>");
	fontAttributes = null;
    
private voidendSpanTag()
Writes out an end tag for the <span> tag.

exception
IOException on any I/O error

	write(NEWLINE);
	writeEndTag("</span>");
	fontAttributes = null;
    
protected booleaninFontTag()
Returns true if we are currently in a <font> tag.

	return (fontAttributes != null);
    
protected booleanisText(javax.swing.text.Element elem)
Returns true if the element is a text element.

	return (elem.getName() == AbstractDocument.ContentElementName);
    
private booleanisValidCharacter(char character)

	return ((character >= 'a" && character <= 'z") ||
		(character >= 'A" && character <= 'Z"));
    
private java.lang.StringmapStyleName(java.lang.String style)
Returns the mapped style name corresponding to style.

	if (styleNameMapping == null) {
	    return style;
	}
	String retValue = (String)styleNameMapping.get(style);
	return (retValue == null) ? style : retValue;
    
private voidsetFontMask(javax.swing.text.AttributeSet attr)
Tweaks the appropriate bits of fontMask to reflect whether the text is to be displayed in bold, italic, and/or with an underline.

	if (StyleConstants.isBold(attr)) {
	    fontMask |= BOLD;
	}

	if (StyleConstants.isItalic(attr)) {
	    fontMask |= ITALIC;
	}

	if (StyleConstants.isUnderline(attr)) {
	    fontMask |= UNDERLINE;
	}
    
protected voidstartFontTag(java.lang.String style)
This is no longer used, instead <span> will be written out.

Writes out a start tag for the <font> tag. Because font tags cannot be nested, this method closes out any enclosing font tag before writing out a new start tag.

exception
IOException on any I/O error

	boolean callIndent = false;
	if (inFontTag()) {
	    endFontTag();
	    callIndent = true;
	}
	writeStartTag("<font style=\"" + style + "\">");
	if (callIndent) {
	    indent();
	}
    
private voidstartSpanTag(java.lang.String style)
Writes out a start tag for the <font> tag. Because font tags cannot be nested, this method closes out any enclosing font tag before writing out a new start tag.

exception
IOException on any I/O error

	boolean callIndent = false;
	if (inFontTag()) {
	    endSpanTag();
	    callIndent = true;
	}
	writeStartTag("<span style=\"" + style + "\">");
	if (callIndent) {
	    indent();
	}
    
protected voidtext(javax.swing.text.Element elem)
Writes out text.

exception
IOException on any I/O error

	String contentStr = getText(elem);
	if ((contentStr.length() > 0) && 
	    (contentStr.charAt(contentStr.length()-1) == NEWLINE)) {
	    contentStr = contentStr.substring(0, contentStr.length()-1);
	}
	if (contentStr.length() > 0) {
	    write(contentStr);
	}
    
public voidwrite()
Generates HTML output from a StyledDocument.

exception
IOException on any I/O error
exception
BadLocationException if pos represents an invalid location within the document.

	styleNameMapping = new Hashtable();
	writeStartTag("<html>");
	writeHeader();
	writeBody();
	writeEndTag("</html>");
    
protected voidwriteAttributes(javax.swing.text.AttributeSet attr)
Writes out all the attributes for the following types: StyleConstants.ParagraphConstants, StyleConstants.CharacterConstants, StyleConstants.FontConstants, StyleConstants.ColorConstants. The attribute name and value are separated by a colon. Each pair is separated by a semicolon.

exception
IOException on any I/O error

	Enumeration attributeNames = attr.getAttributeNames();
	while (attributeNames.hasMoreElements()) {
	    Object name = attributeNames.nextElement();
	    if ((name instanceof StyleConstants.ParagraphConstants) ||
		(name instanceof StyleConstants.CharacterConstants) ||
		(name instanceof StyleConstants.FontConstants) ||
		(name instanceof StyleConstants.ColorConstants)) {
		indent();
		write(name.toString());
		write(':");
		write(css.styleConstantsValueToCSSValue
		      ((StyleConstants)name, attr.getAttribute(name)).
		      toString());
		write(';");
		write(NEWLINE);
	    }
	}
    
protected voidwriteBody()
Iterates over the elements in the document and processes elements based on whether they are branch elements or leaf elements. This method specially handles leaf elements that are text.

exception
IOException on any I/O error

	ElementIterator it = getElementIterator();

	/*
	  This will be a section element for a styled document.
	  We represent this element in HTML as the body tags.
	  Therefore we ignore it.
	 */
	it.current();

	Element next = null;

	writeStartTag("<body>");

	boolean inContent = false;

	while((next = it.next()) != null) {
	    if (!inRange(next)) {
		continue;
	    }
	    if (next instanceof AbstractDocument.BranchElement) {
		if (inContent) {
		    writeEndParagraph();
		    inContent = false;
		    fontMask = 0;
		}
		writeStartParagraph(next);
	    } else if (isText(next)) {
		writeContent(next, !inContent);
		inContent = true;
	    } else {
		writeLeaf(next);
		inContent = true;
	    }
	}
	if (inContent) {
	    writeEndParagraph();
	}
	writeEndTag("</body>");
    
protected voidwriteComponent(javax.swing.text.Element elem)
Responsible for handling Component Elements; deliberately unimplemented. How this method is implemented is a matter of policy.

    
protected voidwriteContent(javax.swing.text.Element elem, boolean needsIndenting)
Writes out the attribute set in an HTML-compliant manner.

exception
IOException on any I/O error
exception
BadLocationException if pos represents an invalid location within the document.


	AttributeSet attr = elem.getAttributes();
	writeNonHTMLAttributes(attr);
	if (needsIndenting) {
	    indent();
	}
	writeHTMLTags(attr);
	text(elem);
    
private voidwriteEndMask(int mask)
Writes out end tags for <u>, <i>, and <b> based on the mask settings.

exception
IOException on any I/O error

	if (mask != 0) {
	    if ((mask & BOLD) != 0) {
		write("</b>");
	    }
	    if ((mask & ITALIC) != 0) {
		write("</i>");
	    }
	    if ((mask & UNDERLINE) != 0) {
		write("</u>");
	    }
	}
    
protected voidwriteEndParagraph()
Emits an end tag for a <p> tag. Before writing out the tag, this method ensures that all other tags that have been opened are appropriately closed off.

exception
IOException on any I/O error

	writeEndMask(fontMask);
	if (inFontTag()) {
	    endSpanTag();
	} else {
	    write(NEWLINE);
	}
	writeEndTag("</p>");
    
protected voidwriteEndTag(java.lang.String endTag)
Writes out an end tag appropriately indented. Also decrements the indent level.

exception
IOException on any I/O error

	decrIndent();
	indent();
	write(endTag);
	write(NEWLINE);
    
protected voidwriteHTMLTags(javax.swing.text.AttributeSet attr)
Generates bold <b>, italic <i>, and <u> tags for the text based on its attribute settings.

exception
IOException on any I/O error


	int oldMask = fontMask;
	setFontMask(attr);

	int endMask = 0;
	int startMask = 0;
	if ((oldMask & BOLD) != 0) {
	    if ((fontMask & BOLD) == 0) {
		endMask |= BOLD;
	    }
	} else if ((fontMask & BOLD) != 0) {
	    startMask |= BOLD;
	}

	if ((oldMask & ITALIC) != 0) {
	    if ((fontMask & ITALIC) == 0) {
		endMask |= ITALIC;
	    }
	} else if ((fontMask & ITALIC) != 0) {
	    startMask |= ITALIC;
	}

	if ((oldMask & UNDERLINE) != 0) {
	    if ((fontMask & UNDERLINE) == 0) {
		endMask |= UNDERLINE;
	    }
	} else if ((fontMask & UNDERLINE) != 0) {
	    startMask |= UNDERLINE;
	}
	writeEndMask(endMask);
	writeStartMask(startMask);
    
protected voidwriteHeader()
Writes out the <head> and <style> tags, and then invokes writeStyles() to write out all the named styles as the content of the <style> tag. The content is surrounded by valid HTML comment markers to ensure that the document is viewable in applications/browsers that do not support the tag.

exception
IOException on any I/O error

	writeStartTag("<head>");
	writeStartTag("<style>");
	writeStartTag("<!--");
	writeStyles();
	writeEndTag("-->");
	writeEndTag("</style>");
	writeEndTag("</head>");
    
protected voidwriteImage(javax.swing.text.Element elem)
Responsible for handling Icon Elements; deliberately unimplemented. How to implement this method is an issue of policy. For example, if you're generating an <img> tag, how should you represent the src attribute (the location of the image)? In certain cases it could be a URL, in others it could be read from a stream.

param
elem element of type StyleConstants.IconElementName

    
protected voidwriteLeaf(javax.swing.text.Element elem)
Responsible for writing out other non-text leaf elements.

exception
IOException on any I/O error

	indent();
	if (elem.getName() == StyleConstants.IconElementName) {
	    writeImage(elem);
	} else if (elem.getName() == StyleConstants.ComponentElementName) {
	    writeComponent(elem);
	}
    
protected voidwriteNonHTMLAttributes(javax.swing.text.AttributeSet attr)
Writes out the remaining character-level attributes (attributes other than bold, italic, and underline) in an HTML-compliant way. Given that attributes such as font family and font size have no direct mapping to HTML tags, a <span> tag is generated and its style attribute is set to contain the list of remaining attributes just like inline styles.

exception
IOException on any I/O error


	String style = "";
	String separator = "; ";

	if (inFontTag() && fontAttributes.isEqual(attr)) {
	    return;
	}

	boolean first = true;
	Color color = (Color)attr.getAttribute(StyleConstants.Foreground);
	if (color != null) {
	    style += "color: " + css.styleConstantsValueToCSSValue
		                    ((StyleConstants)StyleConstants.Foreground,
				     color);
	    first = false;
	}
	Integer size = (Integer)attr.getAttribute(StyleConstants.FontSize);
	if (size != null) {
	    if (!first) {
		style += separator;
	    }
	    style += "font-size: " + size.intValue() + "pt";
	    first = false;
	}

	String family = (String)attr.getAttribute(StyleConstants.FontFamily);
	if (family != null) {
	    if (!first) {
		style += separator;
	    }
	    style += "font-family: " + family;
	    first = false;
	}

	if (style.length() > 0) {
	    if (fontMask != 0) {
		writeEndMask(fontMask);
		fontMask = 0;
	    }
	    startSpanTag(style);
	    fontAttributes = attr;
	}
	else if (fontAttributes != null) {
	    writeEndMask(fontMask);
	    fontMask = 0;
	    endSpanTag();
	}
    
private voidwriteStartMask(int mask)
Writes out start tags <u>, <i>, and <b> based on the mask settings.

exception
IOException on any I/O error

	if (mask != 0) {
	    if ((mask & UNDERLINE) != 0) {
		write("<u>");
	    }
	    if ((mask & ITALIC) != 0) {
		write("<i>");
	    }
	    if ((mask & BOLD) != 0) {
		write("<b>");
	    }
	}
    
protected voidwriteStartParagraph(javax.swing.text.Element elem)
Emits the start tag for a paragraph. If the paragraph has a named style associated with it, then this method also generates a class attribute for the <p> tag and sets its value to be the name of the style.

exception
IOException on any I/O error

	AttributeSet attr = elem.getAttributes();
	Object resolveAttr = attr.getAttribute(StyleConstants.ResolveAttribute);
	if (resolveAttr instanceof StyleContext.NamedStyle) {
	    writeStartTag("<p class=" + mapStyleName(((StyleContext.NamedStyle)resolveAttr).getName()) + ">");
	} else {
	    writeStartTag("<p>");
	}
    
protected voidwriteStartTag(java.lang.String tag)
Writes out a start tag appropriately indented. Also increments the indent level.

exception
IOException on any I/O error

	indent();
	write(tag);
	write(NEWLINE);
	incrIndent();
    
protected voidwriteStyles()
Writes out all the named styles as the content of the <style> tag.

exception
IOException on any I/O error

	/*
	 *  Access to DefaultStyledDocument done to workaround
	 *  a missing API in styled document to access the
	 *  stylenames.
	 */
	DefaultStyledDocument styledDoc =  ((DefaultStyledDocument)getDocument());
	Enumeration styleNames = styledDoc.getStyleNames();

	while (styleNames.hasMoreElements()) {
	    Style s = styledDoc.getStyle((String)styleNames.nextElement());

	    /** PENDING: Once the name attribute is removed
		from the list we check check for 0. **/
	    if (s.getAttributeCount() == 1 &&
		s.isDefined(StyleConstants.NameAttribute)) {
		continue;
	    }
	    indent();
	    write("p." + addStyleName(s.getName()));
	    write(" {\n");
	    incrIndent();
	    writeAttributes(s);
	    decrIndent();
	    indent();
	    write("}\n");
	}