import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.util.StringTokenizer;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class TextLayoutCenter extends JPanel {
Dimension d;
Font f = new Font("fontname", Font.PLAIN, 20);
FontMetrics fm;
int fh, ascent;
int space;
public static void main(String[] a) {
JFrame f = new JFrame();
f.setSize(300, 300);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(new TextLayoutCenter());
f.setVisible(true);
}
public void paint(Graphics g) {
d = getSize();
g.setFont(f);
if (fm == null) {
fm = g.getFontMetrics();
ascent = fm.getAscent();
fh = ascent + fm.getDescent();
space = fm.stringWidth(" ");
}
g.setColor(Color.black);
StringTokenizer st = new StringTokenizer("this is a text. this is a test
this is a text. this is a test");
int x = 0;
int nextx;
int y = 0;
String word, sp;
int wordCount = 0;
String line = "";
while (st.hasMoreTokens()) {
word = st.nextToken();
if (word.equals("
")) {
drawString(g, line, wordCount, fm.stringWidth(line), y + ascent);
line = "";
wordCount = 0;
x = 0;
y = y + (fh * 2);
} else {
int w = fm.stringWidth(word);
if ((nextx = (x + space + w)) > d.width) {
drawString(g, line, wordCount, fm.stringWidth(line), y + ascent);
line = "";
wordCount = 0;
x = 0;
y = y + fh;
}
if (x != 0) {
sp = " ";
} else {
sp = "";
}
line = line + sp + word;
x = x + space + w;
wordCount++;
}
}
drawString(g, line, wordCount, fm.stringWidth(line), y + ascent);
}
public void drawString(Graphics g, String line, int wc, int lineW, int y) {
g.drawString(line, (d.width - lineW) / 2, y);//center
}
}