/examples/src/in_action/chapter10/FoobarSvgHandler.java

/* in_action/chapter10/FoobarSvgHandler */

package in_action.chapter10;



import java.awt.Color;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.util.StringTokenizer;



import javax.xml.parsers.FactoryConfigurationError;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.parsers.SAXParser;

import javax.xml.parsers.SAXParserFactory;



import org.xml.sax.Attributes;

import org.xml.sax.InputSource;

import org.xml.sax.SAXException;

import org.xml.sax.helpers.DefaultHandler;



import com.lowagie.text.BadElementException;

import com.lowagie.text.Image;

import com.lowagie.text.html.WebColors;

import com.lowagie.text.pdf.PdfContentByte;

import com.lowagie.text.pdf.PdfTemplate;

import com.lowagie.text.pdf.PdfWriter;



/**

 * This example was written by Bruno Lowagie. It is part of the book 'iText in

 * Action' by Manning Publications. 

 * ISBN: 1932394796

 * http://www.1t3xt.com/docs/book.php 

 * http://www.manning.com/lowagie/

 * 

 * WARNING: iText doesn't really do SVG parsing. You should use Batik in

 * combination with iText's PdfGraphics2D if you want full blown SVG parsing.

 * This class only demonstrates how you could write an SVG parser if you would

 * want to.

 */

public class FoobarSvgHandler extends DefaultHandler {

	/** Inner class that holds an int and two floats */

	protected class iXY {

		/** position of the next character in a data string */

		public int i;



		/** x coordinate */

		public float x;



		/** y coordinate */

		public float y;



		/**

		 * @param value

		 * @param pos

		 */

		public iXY(String value, int pos) {

			i = pos;

			char digit;

			// skip extra non-numerical characters

			while (i < value.length()) {

				digit = value.charAt(i);

				if (digit >= '0' && digit <= '9')

					break;

				if (digit == '.')

					break;

				i++;

			}

			pos = i;

			// retrieve the x value

			while (i < value.length()) {

				digit = value.charAt(i);

				if (digit != '.' && (digit < '0' || digit > '9')) {

					x = getFloat(value.substring(pos));

					break;

				}

				i++;

			}

			// skip extra non-numerical characters

			while (i < value.length()) {

				digit = value.charAt(i);

				if (digit >= '0' && digit <= '9')

					break;

				if (digit == '.')

					break;

				i++;

			}

			pos = i;

			// retrieve the y value

			while (i < value.length()) {

				digit = value.charAt(i);

				if (digit != '.' && (digit < '0' || digit > '9')) {

					y = getFloat(value.substring(pos));

					break;

				}

				i++;

				if (i == value.length()) {

					y = getFloat(value.substring(pos));

				}

			}

		}

	}



	/** The PdfWriter that is writing the PDF. */

	protected PdfWriter writer;



	/** The PdfContentByte we are going to draw to. */

	protected PdfTemplate template = null;



	/** Content between the tags. */

	protected StringBuffer buf = new StringBuffer();



	/** PageSize and Viewbox parameters. */

	protected float[] coordinates = new float[6];



	/**

	 * Creates a FoobarSvgHandler that will create a PdfTemplate for the writer,

	 * containing the image that is provided through InputSource.

	 * 

	 * @param writer

	 *            the PdfWriter responsible for the PDF

	 * @param is

	 *            the inputstream with the SVG

	 * @throws SAXException

	 * @throws ParserConfigurationException

	 * @throws FactoryConfigurationError

	 * @throws IOException

	 * @throws FileNotFoundException

	 */

	public FoobarSvgHandler(PdfWriter writer, InputSource is)

			throws FileNotFoundException, SAXException, IOException,

			ParserConfigurationException, FactoryConfigurationError {

		this.writer = writer;

		SAXParser parser = SAXParserFactory.newInstance().newSAXParser();

		parser.parse(is, this);

	}



	/**

	 * @see org.xml.sax.ContentHandler#startElement(java.lang.String,

	 *      java.lang.String, java.lang.String, org.xml.sax.Attributes)

	 */

	public void startElement(String uri, String localName, String qName,

			Attributes attributes) throws SAXException {

		if ("polyline".equals(qName)) {

			drawPolyline(attributes);

		} else if ("path".equals(qName)) {

			drawPath(attributes);

		} else if ("svg".equals(qName)) {

			calcSize(attributes);

		}

	}



	/**

	 * @see org.xml.sax.ContentHandler#endElement(java.lang.String,

	 *      java.lang.String, java.lang.String)

	 */

	public void endElement(String uri, String localName, String qName)

			throws SAXException {

		buf = new StringBuffer();

	}



	/**

	 * @see org.xml.sax.ContentHandler#characters(char[], int, int)

	 */

	public void characters(char[] ch, int start, int length)

			throws SAXException {

		buf.append(ch, start, length);

	}



	/**

	 * Draws a polyline.

	 * 

	 * @param attributes

	 *            the attributes of the polyline-tag

	 */

	private void drawPolyline(Attributes attributes) {

		template.saveState();

		setFill(attributes);

		setStroke(attributes);

		computePoints(attributes);

		template.stroke();

		template.restoreState();

	}



	/**

	 * Draws a path.

	 * 

	 * @param attributes

	 *            the attributes of the path-tag

	 */

	private void drawPath(Attributes attributes) {

		template.saveState();

		setFill(attributes);

		setStroke(attributes);

		computeData(attributes);

		template.stroke();

		template.restoreState();

	}



	/**

	 * Sets the fill color.

	 * 

	 * @param attributes

	 *            attributes that can contain a fill attribute

	 */

	private void setFill(Attributes attributes) {

		String name = attributes.getValue("fill");

		if (name == null || "none".equals(name))

			return;

		Color c = WebColors.getRGBColor(name);

		if (c != null) {

			template.setColorFill(c);

		}

	}



	/**

	 * Sets the stroke color.

	 * 

	 * @param attributes

	 *            attributes that can contain a fill attribute

	 */

	private void setStroke(Attributes attributes) {

		String name = attributes.getValue("stroke");

		if (name == null || "none".equals(name))

			return;

		Color c = WebColors.getRGBColor(name);

		if (c != null) {

			template.setColorStroke(c);

		}

		name = attributes.getValue("stroke-width");

		if (name == null)

			return;

		float w = getPixels(name);

		template.setLineWidth(w);

	}



	/**

	 * Computes the data of the <code>d</code> attribute.

	 * 

	 * @param attributes

	 */

	private void computeData(Attributes attributes) {

		String value = attributes.getValue("d");

		if (value == null)

			return;

		int digit;

		iXY ixy;

		for (int i = 0; i < value.length(); i++) {

			digit = (int) value.charAt(i);

			switch (digit) {

			case 'M':

				ixy = new iXY(value, i);

				template.moveTo(ixy.x, coordinates[5] - ixy.y);

				i = ixy.i;

				break;

			case 'm':

				break;

			case 'L':

				ixy = new iXY(value, i);

				template.lineTo(ixy.x, coordinates[5] - ixy.y);

				i = ixy.i;

				break;

			case 'l':

				break;

			case 'z':

			case 'Z':

				template.closePathFillStroke();

				break;

			}

		}

	}



	/**

	 * Computes the data of the <code>d</code> attribute.

	 * 

	 * @param attributes

	 */

	private void computePoints(Attributes attributes) {

		String value = attributes.getValue("points");

		if (value == null)

			return;

		int i = 0;

		iXY ixy = new iXY(value, i);

		template.moveTo(ixy.x, coordinates[5] - ixy.y);

		i = ixy.i;

		while (i < value.length()) {

			ixy = new iXY(value, i);

			template.lineTo(ixy.x, coordinates[5] - ixy.y);

			i = ixy.i;

		}

	}



	/**

	 * Sets the pages size of the document.

	 * 

	 * @param attributes

	 *            the attributes of the svg-tag.

	 */

	private void calcSize(Attributes attributes) {

		String width, height;

		width = attributes.getValue("width");

		coordinates[0] = getPixels(width);

		height = attributes.getValue("height");

		coordinates[1] = getPixels(height);

		coordinates[2] = 0;

		coordinates[3] = 0;

		coordinates[4] = coordinates[0];

		coordinates[5] = coordinates[1];

		String viewBox = attributes.getValue("viewBox");

		if (viewBox != null) {

			StringTokenizer tokenizer = new StringTokenizer(viewBox);

			if (tokenizer.hasMoreElements()) {

				coordinates[2] = getFloat(tokenizer.nextToken());

			}

			if (tokenizer.hasMoreElements()) {

				coordinates[3] = getFloat(tokenizer.nextToken());

			}

			if (tokenizer.hasMoreElements()) {

				coordinates[4] = getFloat(tokenizer.nextToken());

			}

			if (tokenizer.hasMoreElements()) {

				coordinates[5] = getFloat(tokenizer.nextToken());

			}

		}

		PdfContentByte content = writer.getDirectContent();

		template = content.createTemplate(coordinates[4], coordinates[5]);

	}



	/**

	 * Parses a string that represents a float.

	 * 

	 * @param value

	 *            the string

	 * @return the float defined by the String

	 */

	private float getFloat(String value) {

		char digit;

		float total = 0;

		int decimals = 0;

		boolean decimal = false;

		for (int i = 0; i < value.length(); i++) {

			digit = value.charAt(i);

			if (digit == '.') {

				decimal = true;

				continue;

			}

			if (digit < '0' || digit > '9') {

				break;

			}

			total = (total * 10) + (digit - '0');

			if (decimal)

				decimals++;

		}

		total = total / (float) Math.pow(10, decimals);

		return total;

	}



	/**

	 * Parses a string that represents a length.

	 * 

	 * @param length

	 *            the string

	 * @return the length defined by the String in pixels.

	 */

	private float getPixels(String length) {

		float total = getFloat(length);

		if (length.endsWith("pt"))

			return total / 1.25f;

		if (length.endsWith("pc"))

			return total / 15f;

		if (length.endsWith("pt"))

			return total / 1.25f;

		if (length.endsWith("mm"))

			return total / 3.543307f;

		if (length.endsWith("cm"))

			return total / 35.443307f;

		if (length.endsWith("in"))

			return total / 90f;

		return total;

	}



	/**

	 * Returns the PdfTemplate as a com.lowagie.text.Image.

	 * 

	 * @return a com.lowagie.text.Image

	 * @throws BadElementException

	 */

	public Image getImage() throws BadElementException {

		return Image.getInstance(template);

	}



	/**

	 * Returns the PdfTemplate.

	 * 

	 * @return a com.lowagie.text.pdf.PdfTemplate

	 */

	public PdfTemplate getTemplate() {

		return template;

	}

}