Java Reference
In-Depth Information
7
public
static
void
main(String[] args)
8
{
9
DrawRainbow panel =
new
DrawRainbow();
10
JFrame application =
new
JFrame();
11
12
application.setDefaultCloseOperation(
JFrame.EXIT_ON_CLOSE
);
13
application.add(panel);
14
application.setSize(
400
,
250
);
15
application.setVisible(
true
);
16
}
17
}
// end class DrawRainbowTest
Fig. 7.26
|
Test application to display a rainbow. (Part 2 of 2.)
GUI and Graphics Case Study Exercise
7.1
(Drawing Spirals)
In this exercise, you'll draw spirals with methods
drawLine
and
drawArc
.
a)
Draw a square-shaped spiral (as in the left screen capture of Fig. 7.27), centered on the
panel, using method
drawLine
. One technique is to use a loop that increases the line
length after drawing every second line. The direction in which to draw the next line
should follow a distinct pattern, such as down, left, up, right.
b)
Draw a circular spiral (as in the right screen capture of Fig. 7.27), using method
drawArc
to draw one semicircle at a time. Each successive semicircle should have a larger
radius (as specified by the bounding rectangle's width) and should continue drawing
where the previous semicircle finished.
Fig. 7.27
|
Drawing a spiral using
drawLine
(left) and
drawArc
(right).
