Really slow obtaining font metrics.

Question

So the problem I have is that I start my application by displaying a simple menu. To size and align the text correctly I need to obtain font metrics and I cannot find a way to do it quickly. I tested my program and it looks like whatever method I use to obtain font metrics the first call takes over 500 milliseconds!? Because of it the time it takes to start-up my application is much longer than necessary.

I don't know if it is platform specific or not, but just in case, I'm using Mac OS 10.6.2 on MacBook Pro (hardware isn't an issue here).

If you know a way of obtaining font metrics quicker please help.

I tried these 3 methods for obtaining the font metrics and the first call is always very slow, no matter which method I choose.

import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.font.FontRenderContext;
import java.awt.font.LineMetrics;

import javax.swing.JFrame;

public class FontMetricsTest extends JFrame {
 public FontMetricsTest() {
  setVisible(true);
  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 }

 @Override
 public void paint(Graphics g) {
  Graphics2D g2 = (Graphics2D) g;

  Font font = new Font("Dialog", Font.BOLD, 10);
  long start = System.currentTimeMillis();

  FontMetrics fontMetrics = g2.getFontMetrics(font);
//  LineMetrics fontMetrics1 =
//     font.getLineMetrics("X", new FontRenderContext(null, false, false));
//  FontMetrics fontMetrics2 = g.getFontMetrics();

  long end = System.currentTimeMillis();
  System.out.println(end - start);
  g2.setFont(font);
 }

 public static void main(String[] args) {
  new FontMetricsTest();
 }
}

Answer 1

No real clue as for why it's so slow, but for method 3, shouldn't you be calling 'setFont' first?

public void paint(Graphics g) {
    g.setFont(font);
    FontMetrics fm = g.getFontMetrics();
}

It doesn't make a difference speed-wise, though :-(

Also, it's a bit uneconomic to create a new Font each time paint() is called (which happens a lot), you could move that to your constructor. But that cannot be the problem here, as you start measuring the time only after the Font has been created.