Graphics and Java 2D - Java: How to Program Early Objects - page 576

Positive angles Negative angles

90º 90º

180º 0º 180º 0º

270º 270º

Fig. 13.22 | Positive and negative arc angles.

Method Description

public void drawArc( int x, int y, int width, int height, int startAngle,
int arcAngle)
Draws an arc relative to the bounding rectangle's top-left x- and y- coordi-
nates with the specified width and height . The arc segment is drawn starting
at startAngle and sweeps arcAngle degrees.
public void fillArc( int x, int y, int width, int height, int startAngle,
int arcAngle)
Draws a filled arc (i.e., a sector) relative to the bounding rectangle's top-left
x - and y -coordinates with the specified width and height . The arc segment
is drawn starting at startAngle and sweeps arcAngle degrees.

Fig. 13.23 | Graphics methods for drawing arcs.

Figures 13.24-13.25 demonstrate the arc methods of Fig. 13.23. The application
draws six arcs (three unfilled and three filled). To illustrate the bounding rectangle that
helps determine where the arc appears, the first three arcs are displayed inside a red rect-
angle that has the same x , y , width and height arguments as the arcs.

1 // Fig. 13.24: ArcsJPanel.java

2

// Arcs displayed with drawArc and fillArc.

3

import java.awt.Color;

4

import java.awt.Graphics;

5 import javax.swing.JPanel;

6
7 public class ArcsJPanel extends JPanel

8 {

9 // draw rectangles and arcs

10 @Override

11 public void paintComponent(Graphics g)

12 {

13 super .paintComponent(g);

14

Fig. 13.24 | Arcs displayed with drawArc and fillArc . (Part 1 of 2.)