GoogleWebFontHelper.java

package src.com.fxexperience.javafx.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javafx.scene.text.Font;

/**
 * This is a simple helper class that lets you use fonts from the Google Web
 * Fonts service inside JavaFX. You can use the fonts in code or CSS.
 * 
 * In Code all you need to do is: Font myFont =
 * Font.font(GoogleWebFontHelper.loadFont("http://....."), 40);
 * 
 * In CSS you need to first load the font in Code early in your app before you
 * load any stylesheets. Using a line like:
 * Font.font(GoogleWebFontHelper.loadFont("http://....."), 40); Then you can
 * just use the name of the font in CSS like: #MyNodeID { -fx-font-family:
 * 'Seaweed Script'; -fx-font-size: 30px; }
 * 
 * In both of these uses the http://..... is the URL to the stylesheet you get
 * from the google web fonts quick use page. They have something like this:
 * 
 * 3. Add this code to your website: <link
 * href='http://fonts.googleapis.com/css?family=Raleway:100' rel='stylesheet'
 * type='text/css'>
 * 
 * All you need is the http url to copy and paste into your loadFont() call.
 * 
 * @author Jasper Potts
 */
public class GoogleWebFontHelper {

	private static final Pattern TTF_PATTERN = Pattern.compile("http:.*\\.ttf");
	private static final Pattern OTF_PATTERN = Pattern.compile("http:.*\\.otf");

	/**
	 * Load a font from Google Web Fonts Service
	 * 
	 * Note: this is only designed to work with simple stylesheets with single
	 * font in them.
	 * 
	 * @param googleFontCssUrl
	 *            The url to css stylesheet with @fontface definition
	 * @return The name of the font family, or "System" if there was a error
	 */
	public static String loadFont(String googleFontCssUrl) {

		String fontName = "System";
		try {
			URL cssUrl = new URL(googleFontCssUrl);
			URLConnection con = cssUrl.openConnection();
			InputStream in = con.getInputStream();
			BufferedReader reader = new BufferedReader(
					new InputStreamReader(in));

			String line = null;
			String fontUrl = null;
			StringBuilder srcs = new StringBuilder();
			while ((line = reader.readLine()) != null) {
				// System.out.println(line);
				if (line.contains("src:")) {
					Matcher matcher = TTF_PATTERN.matcher(line);
					if (matcher.find()) {
						fontUrl = matcher.group(0);
						// System.out.println("FOUND fontUrl = " + fontUrl);
						break;
					}
					matcher = OTF_PATTERN.matcher(line);
					if (matcher.find()) {
						fontUrl = matcher.group(0);
						// System.out.println("FOUND fontUrl = " + fontUrl);
						break;
					}
					srcs.append(line);
					srcs.append('\n');
				}
			}
			if (fontUrl != null) {
				Font font = Font.loadFont(fontUrl, 10);
				fontName = font.getFamily();
			} else {
				System.err.println("Failed to find any supported fonts "
						+ "(TTF or OTF) in CSS src:\n" + srcs.toString());
			}
		} catch (IOException ex) {
			System.err.println("Error loading Google Font CSS");
		}
		return fontName;
	}
}