fontmetricsdemo.java

java 完全探索的随书源码

// FontMetricsDemo.java

import java.awt.*;
import java.applet.Applet;

public class FontMetricsDemo extends Applet
{
   String the = "The ";

   String [] msgs =
   {
      " method is handy for centering text.",
      " method is handy for spacing between rows of text.",
      " method returns the maximum ascent of any character.",
      " method returns the maximum descent of any character."
   };

   String [] methods =
   {
      "stringWidth",
      "getHeight",
      "getMaxAscent",
      "getMaxDescent"
   };

   public void paint (Graphics g)
   {
      // Create a Bold Serif font, establish this font
      // as the graphics context font, and obtain font
      // metrics for this font.

      Font f1 = new Font ("Serif", Font.BOLD, 12);
      g.setFont (f1);
      FontMetrics fm = g.getFontMetrics ();

      // Create an array to hold method name widths.

      int [] wMethod = new int [methods.length];

      // For each method name in the methods array,
      // compute its width (in pixels) when displayed
      // using the Bold font.

      for (int i = 0; i < wMethod.length; i++)
           wMethod [i] = fm.stringWidth (methods [i]);

      // Establish a Plain Serif font as the graphics
      // context font.

      Font f2 = new Font ("Serif", Font.PLAIN, 12);
      g.setFont (f2);
      fm = g.getFontMetrics ();

      // Calculate the width (in pixels) of the string
      // referenced by the, when displayed using Plain
      // Serif.

      int wThe = fm.stringWidth (the);

      // Calculate a width array for all messages.

      int [] wMsg = new int [msgs.length];

      // Compute each message's display width based on
      // Plain Serif.

      for (int i = 0; i < wMsg.length; i++)
           wMsg [i] = fm.stringWidth (msgs [i]);

      // For each message, determine the horizontal
      // start position so that the message can be
      // horizontally centered.  Then, obtain the
      // current display row (taking baseline into
      // account), and draw the message.  Change
      // fonts (accordingly) so that method names
      // appear in Bold Serif and the rest of the
      // text appears in Plain Serif.

      for (int i = 0; i < msgs.length; i++)
      {
           int x = getSize ().width - wThe - wMethod [i] - wMsg [i];
           x  >>= 1; // A faster way of dividing by 2.

           int y = fm.getHeight () * (i + 1);

           g.drawString (the, x, y);
           x += wThe;

           g.setFont (f1);

           g.drawString (methods [i], x, y);
           x += wMethod [i];

           g.setFont (f2);
           fm = g.getFontMetrics ();

           g.drawString (msgs [i], x, y);
      }
   }
}