Java Reference
In-Depth Information
Graphics
methods
fillRect
and
fillOval
draw filled rectangles and ovals, respec-
tively. These have the same parameters as
drawRect
and
drawOval
; the first two are the
coordinates for the
upper-left corner
of the shape, while the next two determine the
width
and
height
. The example in Figs. 6.11-6.12 demonstrates colors and filled shapes by
drawing and displaying a yellow smiley face on the screen.
1
// Fig. 6.11: DrawSmiley.java
2
// Drawing a smiley face using colors and filled shapes.
3
4
import
java.awt.Color;
import
java.awt.Graphics;
5
import
javax.swing.JPanel;
6
7
public class
DrawSmiley
extends
JPanel
8
{
9
public
void
paintComponent(Graphics g)
10
{
11
super
.paintComponent(g);
12
13
// draw the face
14
g.setColor(
Color.YELLOW
);
g.fillOval(
10
,
10
,
200
,
200
);
15
16
17
// draw the eyes
18
g.setColor(
Color.BLACK
);
g.fillOval(
55
,
65
,
30
,
30
);
g.fillOval(
135
,
65
,
30
,
30
);
19
20
21
22
// draw the mouth
23
g.fillOval(
50
,
110
,
120
,
60
);
24
25
// "touch up" the mouth into a smile
26
g.setColor(
Color.YELLOW
);
g.fillRect(
50
,
110
,
120
,
30
);
g.fillOval(
50
,
120
,
120
,
40
);
27
28
29
}
30
}
// end class DrawSmiley
Fig. 6.11
|
Drawing a smiley face using colors and filled shapes.
The
import
statements in lines 3-5 of Fig. 6.11 import classes
Color
,
Graphics
and
JPanel
. Class
DrawSmiley
(lines 7-30) uses class
Color
to specify drawing colors, and uses
class
Graphics
to draw.
Class
JPanel
again provides the area in which we draw. Line 14 in method
paint-
Component
uses
Graphics
method
setColor
to set the current drawing color to
Color.YELLOW
. Method
setColor
requires one argument, the
Color
to set as the drawing
color. In this case, we use the predefined object
Color.YELLOW
.
Line 15 draws a circle with diameter 200 to represent the face—when the width and
height arguments are identical, method
fillOval
draws a circle. Next, line 18 sets the
color to
Color.Black
, and lines 19-20 draw the eyes. Line 23 draws the mouth as an oval,
but this is not quite what we want.
