LineBreakSample.java Source code

Introduction

Here is the source code for LineBreakSample.java

Source

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);
    }
}