Java Reference
In-Depth Information
To create a happy face, we'll touch up the mouth. Line 26 sets the color to
Color.YELLOW
, so any shapes we draw will blend in with the face. Line 27 draws a rectangle
that's half the mouth's height. This erases the top half of the mouth, leaving just the
bottom half. To create a better smile, line 28 draws another oval to slightly cover the upper
portion of the mouth. Class
DrawSmileyTest
(Fig. 6.12) creates and displays a
JFrame
containing the drawing. When the
JFrame
is displayed, the system calls method
paint-
Component
to draw the smiley face.
1
// Fig. 6.12: DrawSmileyTest.java
2
// Test application that displays a smiley face.
3
import
javax.swing.JFrame;
4
5
public
class
DrawSmileyTest
6
{
7
public
static
void
main(String[] args)
8
{
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DrawSmiley panel =
new
DrawSmiley();
10
JFrame application =
new
JFrame();
11
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application.setDefaultCloseOperation(
JFrame.EXIT_ON_CLOSE
);
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application.add(panel);
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application.setSize(
230
,
250
);
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application.setVisible(
true
);
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}
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}
// end class DrawSmileyTest
Fig. 6.12
|
Test application that displays a smiley face.
GUI and Graphics Case Study Exercises
6.1
Using method
fillOval
, draw a bull's-eye that alternates between two random colors, as in
Fig. 6.13. Use the constructor
Color(int
r,
int
g,
int
b
) with random arguments to generate ran-
dom colors.
6.2
Create a program that draws 10 random filled shapes in random colors, positions and sizes
(Fig. 6.14).
Method paintComponent
should contain a loop that iterates 10 times. In each iteration,
the loop should determine whether to draw a filled rectangle or an oval, create a random color and
choose coordinates and dimensions at random. The coordinates should be chosen based on the pan-
el's width and height. Lengths of sides should be limited to half the width or height of the window.
