Line break for textlayout

[Java Tip]

Code:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.font.FontRenderContext;
import java.awt.font.LineBreakMeasurer;
import java.awt.font.TextAttribute;
import java.awt.font.TextLayout;
import java.text.AttributedCharacterIterator;
import java.text.AttributedString;
import java.util.Hashtable;

import javax.swing.JApplet;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class LineBreakSample extends JPanel {

  private LineBreakMeasurer lineMeasurer;

  // the first character in the paragraph.
  private int paragraphStart;

  // the first character after the end of the paragraph.
  private int paragraphEnd;

  private static final Hashtable map = new Hashtable();
  static {
    map.put(TextAttribute.SIZE, new Float(18.0));
  }

  private static AttributedString vanGogh = new AttributedString(
      "Many people believe that Vincent van Gogh painted his best works "
          + "during the two-year period he spent in Provence. Here is where he "
          + "painted The Starry Night--which some consider to be his greatest "
          + "work of all. However, as his artistic brilliance reached new heights "
          + "in Provence, his physical and mental health plummeted. ",
      map);

  public LineBreakSample() {
    AttributedCharacterIterator paragraph = vanGogh.getIterator();
    paragraphStart = paragraph.getBeginIndex();
    paragraphEnd = paragraph.getEndIndex();

    // Create a new LineBreakMeasurer from the paragraph.
    lineMeasurer = new LineBreakMeasurer(paragraph,
        new FontRenderContext(null, false, false));
  }
  public void paintComponent(Graphics g) {

    super.paintComponent(g);
    setBackground(Color.white);

    Graphics2D graphics2D = (Graphics2D) g;

    // Set formatting width to width of Component.
    Dimension size = getSize();
    float formatWidth = (float) size.width;

    float drawPosY = 0;

    lineMeasurer.setPosition(paragraphStart);

    // Get lines from lineMeasurer until the entire
    // paragraph has been displayed.
    while (lineMeasurer.getPosition() < paragraphEnd) {

      // Retrieve next layout.
      TextLayout layout = lineMeasurer.nextLayout(formatWidth);
      // Move y-coordinate by the ascent of the layout.
      drawPosY += layout.getAscent();

      // Compute pen x position. If the paragraph is
      // right-to-left, we want to align the TextLayouts
      // to the right edge of the panel.
      float drawPosX;
      if (layout.isLeftToRight()) {
        drawPosX = 0;
      } else {
        drawPosX = formatWidth - layout.getAdvance();
      }

      // Draw the TextLayout at (drawPosX, drawPosY).
      layout.draw(graphics2D, drawPosX, drawPosY);

      // Move y-coordinate in preparation for next layout.
      drawPosY += layout.getDescent() + layout.getLeading();
    }
  }
  public static void main(String[] args) {
    JFrame f = new JFrame("");

    f.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });

    LineBreakSample controller = new LineBreakSample();
    f.getContentPane().add(controller,"Center");
    f.setSize(new Dimension(400, 250));
    f.setVisible(true);
  }
}