Java Reference
In-Depth Information
40
new
ActionListener()
// anonymous inner class
41
{
42
// display new internal window
43
@Override
44
public
void
actionPerformed(ActionEvent event)
45
{
46
// create internal frame
47
JInternalFrame frame =
new
JInternalFrame(
"Internal Frame"
,
true
,
true
,
true
,
true
);
48
49
50
MyJPanel panel =
new
MyJPanel();
51
frame.add(panel,
BorderLayout.CENTER
);
52
frame.pack();
// set internal frame to size of contents
53
54
theDesktop.add(frame);
// attach internal frame
frame.setVisible(
true
);
// show internal frame
55
56
}
57
}
58
);
59
}
// end DesktopFrame constructor
60
}
// end class DesktopFrame
61
62
// class to display an ImageIcon on a panel
63
class
MyJPanel
extends
JPanel
64
{
65
private
static final
SecureRandom generator =
new
SecureRandom();
66
private final
ImageIcon picture;
// image to be displayed
67
private
final static
String[] images = {
"yellowflowers.png"
,
68
"purpleflowers.png"
,
"redflowers.png"
,
"redflowers2.png"
,
69
"lavenderflowers.png"
};
70
71
// load image
72
public
MyJPanel()
73
{
74
int
randomNumber = generator.nextInt(images.length);
75
picture =
new
ImageIcon(images[randomNumber]);
// set icon
76
}
77
78
// display imageIcon on panel
79
@Override
80
public
void
paintComponent(Graphics g)
81
{
82
super
.paintComponent(g);
83
picture.paintIcon(
this
, g,
0
,
0
);
// display icon
84
}
85
86
// return image dimensions
87
public
Dimension getPreferredSize()
88
{
89
return
new
Dimension(picture.getIconWidth(),
picture.getIconHeight());
90
91
}
92
}
// end class MyJPanel
Fig. 22.11
|
Multiple-document interface. (Part 2 of 2.)
