1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
package Jcd; // -- Listing-4 -- Display.java // 1
// 2
import java.util.*; // 3
import java.awt.*; // 4
import java.awt.event.*; // 5
import Jcd.SmartDrive; // 6
import Jcd.Monitor; // 7
// 8
class Display extends Panel implements Observer {
// 10
// Independent status display thread. // 11
// 12
private TextField trackField = new TextField(2);
private TextField indexField = new TextField(8);
private TextField timeField = new TextField(22);
// 16
private SmartDrive cdPlayer; // 17
private String prevText = ""; // 18
// 19
public Display(SmartDrive drive) // 20
{ // 21
setLayout(
new FlowLayout(FlowLayout.LEFT,5,5));// 22
indexField.setEditable(false); // 23
timeField.setEditable(false); // 24
// 25
cdPlayer = drive; // 26
add(trackField); // 27
add(indexField); // 28
add(timeField); // 29
// 30
trackField.addFocusListener(
new TrackFocusLost()); // 31
trackField.addKeyListener(
new TrackKeyPress()); // 32
// 33
cdPlayer.monitor.addObserver(this); // 34
} // 35
// 36
public void update(Observable obj, Object arg) {
Monitor mon = (Monitor) obj; // 38
if (mon.status != Drive.STATUS_INVALID) {
int time = ( // 40
mon.trackEndAddress[mon.currentTrack] -
mon.currentAddress) /
Drive.FRAMES_PER_SECOND; // 41
String newTrackText =
Integer.toString(mon.currentTrack); // 42
// Prevent excessive updates - so that
// the user can edit the field. // 43
if (prevText.compareTo(newTrackText) != 0) {
trackField.setText(newTrackText); // 45
prevText = newTrackText; // 46
} // 47
indexField.setText("Index: " + // 48
mon.currentIndex);
timeField.setText("Trk Rem: " + // 49
time/60 + " min " +
time%60 + " sec");
} // 50
} // 51
// 52
private class TrackFocusLost // 53
extends FocusAdapter { // 54
// removes text entered on focus out.
public void focusLost(FocusEvent e) { // 55
trackField.setText(prevText);
}
} // 56
// 57
private class TrackKeyPress extends KeyAdapter {
// 59
public void keyPressed(KeyEvent e) // 60
{ // 61
if (e.getKeyChar() == '\n') { // 62
try { // 63
cdPlayer.play( // 64
Integer.parseInt(trackField.getText()));
} // 65
catch (NumberFormatException nx) { // 66
System.out.println(
"Invalid track number: " + nx); // 67
} // 68
catch (DriveException dx) { // 69
System.out.println("Exception: " + dx);
} // 71
} // 72
} // 73
} // 74
// 75
} // 76
|
