Introduction to Parameters and Objects - Building Java Programs: A Back to Basics Approach - page 205

Figure 3G.11

Output of DrawFonts

3G.2 Procedural Decomposition with Graphics

If you write complex drawing programs, you will want to break them down into sev-
eral static methods to structure the code and to remove redundancy. When you do
this, you'll have to pass the Graphics object to each static method that you intro-
duce. For a quick example, the DrawStringMessage1 program from the previous
section could be split into a main method and a drawText method, as follows:

1 // Draws a message several times using a static method.
2
3 import java.awt.*;
4
5 public class DrawStringMessage2 {
6 public static void main(String[] args) {

7 DrawingPanel panel = new DrawingPanel(200, 100);

8 panel.setBackground(Color.YELLOW);

9
10 Graphics g = panel.getGraphics();

11 drawText(g);

12 }

13
14 public static void drawText(Graphics g) {

15 for ( int i = 0; i < 10; i++) {

16 g.drawString("There is no place like home",

17 i * 5, 10 + i * 10);

18 }

19 }

20 }
This program produces the same output as the original program (Figure 3G.10).
The program wouldn't compile without passing Graphics g to the drawText method,
because g is needed to call drawing methods such as drawString and fillRect .