htmlwriter.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

		String name = map.getName();

		incrIndent();
		indentSmart();
		write("<map");
		if (name != null) {
		    write(" name=\"");
		    write(name);
		    write("\">");
		}
		else {
		    write('>');
		}
		writeLineSeparator();
		incrIndent();

		// Output the areas
		AttributeSet[] areas = map.getAreas();
		if (areas != null) {
		    for (int counter = 0, maxCounter = areas.length;
			 counter < maxCounter; counter++) {
			indentSmart();
			write("<area");
			writeAttributes(areas[counter]);
			write("></area>");
			writeLineSeparator();
		    }
		}
		decrIndent();
		indentSmart();
		write("</map>");
		writeLineSeparator();
		decrIndent();
	    }
	}
    }

    /**
     * Outputs the styles as a single element. Styles are not stored as
     * elements, but part of the document. For the time being styles are
     * written out as a comment, inside a style tag.
     */
    void writeStyles(StyleSheet sheet) throws IOException {
	if (sheet != null) {
	    Enumeration styles = sheet.getStyleNames();
	    if (styles != null) {
		boolean outputStyle = false;
		while (styles.hasMoreElements()) {
		    String name = (String)styles.nextElement();
		    // Don't write out the default style.
		    if (!StyleContext.DEFAULT_STYLE.equals(name) &&
			writeStyle(name, sheet.getStyle(name), outputStyle)) {
			outputStyle = true;
		    }
		}
		if (outputStyle) {
		    writeStyleEndTag();
		}
	    }
	}
    }

    /**
     * Outputs the named style. <code>outputStyle</code> indicates
     * whether or not a style has been output yet. This will return
     * true if a style is written.
     */
    boolean writeStyle(String name, Style style, boolean outputStyle)
	         throws IOException{
	boolean didOutputStyle = false;
	Enumeration attributes = style.getAttributeNames();
	if (attributes != null) {
	    while (attributes.hasMoreElements()) {
		Object attribute = attributes.nextElement();
		if (attribute instanceof CSS.Attribute) {
		    String value = style.getAttribute(attribute).toString();
		    if (value != null) {
			if (!outputStyle) {
			    writeStyleStartTag();
			    outputStyle = true;
			}
			if (!didOutputStyle) {
			    didOutputStyle = true;
			    indentSmart();
			    write(name);
			    write(" {");
			}
			else {
			    write(";");
			}
			write(' ');
			write(attribute.toString());
			write(": ");
			write(value);
		    }
		}
	    }
	}
	if (didOutputStyle) {
	    write(" }");
	    writeLineSeparator();
	}
	return didOutputStyle;
    }

    void writeStyleStartTag() throws IOException {
	indentSmart();
	write("<style type=\"text/css\">");
	incrIndent();
	writeLineSeparator();
	indentSmart();
	write("<!--");
	incrIndent();
	writeLineSeparator();
    }

    void writeStyleEndTag() throws IOException {
	decrIndent();
	indentSmart();
	write("-->");
	writeLineSeparator();
	decrIndent();
	indentSmart();
	write("</style>");
	writeLineSeparator();
	indentSmart();
    }

    // --- conversion support ---------------------------

    /**
     * Convert the give set of attributes to be html for
     * the purpose of writing them out.  Any keys that
     * have been converted will not appear in the resultant
     * set.  Any keys not converted will appear in the 
     * resultant set the same as the received set.<p>
     * This will put the converted values into <code>to</code>, unless
     * it is null in which case a temporary AttributeSet will be returned.
     */
    AttributeSet convertToHTML(AttributeSet from, MutableAttributeSet to) {
	if (to == null) {
	    to = convAttr;
	}
	to.removeAttributes(to);
	if (writeCSS) {
	    convertToHTML40(from, to);
	} else {
	    convertToHTML32(from, to);
	}
	return to;
    }

    /**
     * If true, the writer will emit CSS attributes in preference
     * to HTML tags/attributes (i.e. It will emit an HTML 4.0
     * style).
     */
    private boolean writeCSS = false;

    /**
     * Buffer for the purpose of attribute conversion
     */
    private MutableAttributeSet convAttr = new SimpleAttributeSet();

    /**
     * Buffer for the purpose of attribute conversion. This can be
     * used if convAttr is being used.
     */
    private MutableAttributeSet oConvAttr = new SimpleAttributeSet();

    /**
     * Create an older style of HTML attributes.  This will 
     * convert character level attributes that have a StyleConstants
     * mapping over to an HTML tag/attribute.  Other CSS attributes
     * will be placed in an HTML style attribute.
     */
    private static void convertToHTML32(AttributeSet from, MutableAttributeSet to) {
	if (from == null) {
	    return;
	}
	Enumeration keys = from.getAttributeNames();
	String value = "";
	while (keys.hasMoreElements()) {
	    Object key = keys.nextElement();
	    if (key instanceof CSS.Attribute) {
		if ((key == CSS.Attribute.FONT_FAMILY) ||
		    (key == CSS.Attribute.FONT_SIZE) ||
		    (key == CSS.Attribute.COLOR)) {
		    
		    createFontAttribute((CSS.Attribute)key, from, to);
		} else if (key == CSS.Attribute.FONT_WEIGHT) {
		    // add a bold tag is weight is bold
		    CSS.FontWeight weightValue = (CSS.FontWeight) 
			from.getAttribute(CSS.Attribute.FONT_WEIGHT);
		    if ((weightValue != null) && (weightValue.getValue() > 400)) {
			addAttribute(to, HTML.Tag.B, SimpleAttributeSet.EMPTY);
		    }
		} else if (key == CSS.Attribute.FONT_STYLE) {
		    String s = from.getAttribute(key).toString();
		    if (s.indexOf("italic") >= 0) {
			addAttribute(to, HTML.Tag.I, SimpleAttributeSet.EMPTY);
		    }
		} else if (key == CSS.Attribute.TEXT_DECORATION) {
		    String decor = from.getAttribute(key).toString();
		    if (decor.indexOf("underline") >= 0) {
			addAttribute(to, HTML.Tag.U, SimpleAttributeSet.EMPTY);
		    }
		    if (decor.indexOf("line-through") >= 0) {
			addAttribute(to, HTML.Tag.STRIKE, SimpleAttributeSet.EMPTY);
		    }
		} else if (key == CSS.Attribute.VERTICAL_ALIGN) {
		    String vAlign = from.getAttribute(key).toString();
		    if (vAlign.indexOf("sup") >= 0) {
			addAttribute(to, HTML.Tag.SUP, SimpleAttributeSet.EMPTY);
		    }
		    if (vAlign.indexOf("sub") >= 0) {
			addAttribute(to, HTML.Tag.SUB, SimpleAttributeSet.EMPTY);
		    }
		} else if (key == CSS.Attribute.TEXT_ALIGN) {
		    addAttribute(to, HTML.Attribute.ALIGN, 
				    from.getAttribute(key).toString());
		} else {
		    // default is to store in a HTML style attribute
		    if (value.length() > 0) {
			value = value + "; ";
		    }
		    value = value + key + ": " + from.getAttribute(key);
		}
	    } else {
		Object attr = from.getAttribute(key);
		if (attr instanceof AttributeSet) {
		    attr = ((AttributeSet)attr).copyAttributes();
		} 
		addAttribute(to, key, attr);
	    }
	}
	if (value.length() > 0) {
	    to.addAttribute(HTML.Attribute.STYLE, value);
	}
    }

    /**
     * Add an attribute only if it doesn't exist so that we don't
     * loose information replacing it with SimpleAttributeSet.EMPTY
     */
    private static void addAttribute(MutableAttributeSet to, Object key, Object value) {
	Object attr = to.getAttribute(key);
	if (attr == null || attr == SimpleAttributeSet.EMPTY) {
            to.addAttribute(key, value);
	} else {
	    if (attr instanceof MutableAttributeSet &&
		value instanceof AttributeSet) {
		((MutableAttributeSet)attr).addAttributes((AttributeSet)value);
	    }
	}
    }

    /**
     * Create/update an HTML &lt;font&gt; tag attribute.  The
     * value of the attribute should be a MutableAttributeSet so
     * that the attributes can be updated as they are discovered.
     */
    private static void createFontAttribute(CSS.Attribute a, AttributeSet from, 
				    MutableAttributeSet to) {
	MutableAttributeSet fontAttr = (MutableAttributeSet) 
	    to.getAttribute(HTML.Tag.FONT);
	if (fontAttr == null) {
	    fontAttr = new SimpleAttributeSet();
	    to.addAttribute(HTML.Tag.FONT, fontAttr);
	}
	// edit the parameters to the font tag
	String htmlValue = from.getAttribute(a).toString();
	if (a == CSS.Attribute.FONT_FAMILY) {
	    fontAttr.addAttribute(HTML.Attribute.FACE, htmlValue);
	} else if (a == CSS.Attribute.FONT_SIZE) {
	    fontAttr.addAttribute(HTML.Attribute.SIZE, htmlValue);
	} else if (a == CSS.Attribute.COLOR) {
	    fontAttr.addAttribute(HTML.Attribute.COLOR, htmlValue);
	}
    }
	
    /**
     * Copies the given AttributeSet to a new set, converting
     * any CSS attributes found to arguments of an HTML style
     * attribute.
     */
    private static void convertToHTML40(AttributeSet from, MutableAttributeSet to) {
	Enumeration keys = from.getAttributeNames();
	String value = "";
	while (keys.hasMoreElements()) {
	    Object key = keys.nextElement();
	    if (key instanceof CSS.Attribute) {
		value = value + " " + key + "=" + from.getAttribute(key) + ";";
	    } else {
		to.addAttribute(key, from.getAttribute(key));
	    }
	}
	if (value.length() > 0) {
	    to.addAttribute(HTML.Attribute.STYLE, value);
	}
    }

    //
    // Overrides the writing methods to only break a string when
    // canBreakString is true.
    // In a future release it is likely AbstractWriter will get this
    // functionality.
    //

    /**
     * Writes the line separator. This is overriden to make sure we don't
     * replace the newline content in case it is outside normal ascii.
     * @since 1.3
     */
    protected void writeLineSeparator() throws IOException {
	boolean oldReplace = replaceEntities;
	replaceEntities = false;
	super.writeLineSeparator();
	replaceEntities = oldReplace;
        indented = false;
    }

    /**
     * This method is overriden to map any character entities, such as
     * &lt; to &amp;lt;. <code>super.output</code> will be invoked to
     * write the content.
     * @since 1.3
     */
    protected void output(char[] chars, int start, int length)
	           throws IOException {
	if (!replaceEntities) {
	    super.output(chars, start, length);
	    return;
	}
	int last = start;
	length += start;
	for (int counter = start; counter < length; counter++) {
	    // This will change, we need better support character level
	    // entities.
	    switch(chars[counter]) {
		// Character level entities.
	    case '<':
		if (counter > last) {
		    super.output(chars, last, counter - last);
		}
		last = counter + 1;
		output("&lt;");
		break;
	    case '>':
		if (counter > last) {
		    super.output(chars, last, counter - last);
		}
		last = counter + 1;
		output("&gt;");
		break;
	    case '&':
		if (counter > last) {
		    super.output(chars, last, counter - last);
		}
		last = counter + 1;
		output("&amp;");
		break;
	    case '"':
		if (counter > last) {
		    super.output(chars, last, counter - last);
		}
		last = counter + 1;
		output("&quot;");
		break;
		// Special characters
	    case '\n':
	    case '\t':
	    case '\r':
		break;
	    default:
		if (chars[counter] < ' ' || chars[counter] > 127) {
		    if (counter > last) {
			super.output(chars, last, counter - last);
		    }
		    last = counter + 1;
		    // If the character is outside of ascii, write the
		    // numeric value.
		    output("&#");
		    output(String.valueOf((int)chars[counter]));
		    output(";");
		}
		break;
	    }
	}
	if (last < length) {
	    super.output(chars, last, length - last);
	}
    }

    /**
     * This directly invokes super's <code>output</code> after converting
     * <code>string</code> to a char[].
     */
    private void output(String string) throws IOException {
	int length = string.length();
	if (tempChars == null || tempChars.length < length) {
	    tempChars = new char[length];
	}
	string.getChars(0, length, tempChars, 0);
	super.output(tempChars, 0, length);
    }

    private boolean indented = false;

    /**
     * Writes indent only once per line.
     */
    private void indentSmart() throws IOException {
        if (!indented) {
            indent();
            indented = true;
        }
    }
}