blob: 509217933f24e6e9a3b2b4af245f04045b058546 (
plain)
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
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Blacksmith, Inc.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/
package net.wotonomy.ui.swing.components;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.event.KeyEvent;
import javax.swing.JTextField;
/**
* SmartTextField is an abstract class for that allows the text field to
* intelligently analyze the user's input in real-time. As the user enters
* keystrokes, the generated string is analyzed to determine if the new string
* is valid based on the criteria of the concrete classes that extend this
* class. An invalid keystroke is rejected and not displayed in the text field.
* This class can be extended to to create smart text fields that only accept
* integers or floating points number or alphabetic strings of maximum length.
* These are several examples.
*
* @author rob@straylight.princeton.com
* @author $Author: cgruber $
* @version $Revision: 904 $
*/
public abstract class SmartTextField extends JTextField {
/*******************************
* CONSTANTS
*******************************/
private static final int BACKSPACE = 8;
private static final int DELETE = 127;
private static final int SPACE = 32;
private static final int DASH = 45;
private static final int UNDERSCORE = 95;
private static final int PERIOD = 46;
private static final int PASTE = 22; // Ctl-V
/*******************************
* PUBLIC METHODS
*******************************/
/**
* This method processes a key event. This event is generated by input from the
* keyboard when this text field has the focus. This method is called for every
* key that is pressed and released on the keyboard. This includes modifier keys
* like the shift and alt keys. This class looks at the key and determines if
* the key is valid input given the restrictions of the concrete sub-classes.
* <BR>
* <BR>
* Example - A smart text field only allows alphabetic characters. If the key
* pressed is a "2" then this method will determine that the key is invalid and
* "consume" the key event. <BR>
* <BR>
* Note - Every printable character has a "TYPED" key event. Currentlt under
* Java 1.2.1 this does not happen. Bug 4186905 relating this bug has been fixed
* and is awaiting release.
*
* @param e A key event generated by a keyboard action.
*/
public void processKeyEvent(KeyEvent e) {
String currentText = "";
String testString = "";
char newChar = e.getKeyChar();
int currentLength = 0;
int selectionStart = 0;
int selectionEnd = 0;
int endOfHead = 0;
int startOfTail = 0;
boolean backspace = false;
boolean delete = false;
boolean paste = false;
boolean insertionPoint = false;
boolean selectionAtStart = false;
boolean selectionAtEnd = false;
backspace = (newChar == BACKSPACE);
delete = (newChar == DELETE);
paste = (newChar == PASTE);
if ((e.getKeyCode() == KeyEvent.VK_UNDEFINED) || ((backspace) || (delete) || (paste))) // A "key-typed" event
{
if (isValidCharacter(newChar)) {
if ((isPrintableCharacter(newChar)) || (backspace) || (delete) || (paste)) {
// Analyze the current contents of the field
currentText = getText();
currentLength = currentText.length();
selectionStart = getSelectionStart();
selectionEnd = getSelectionEnd();
insertionPoint = (selectionStart == selectionEnd);
selectionAtStart = (selectionStart == 0);
selectionAtEnd = (selectionEnd >= currentLength);
if (selectionEnd > currentLength) {
setSelectionEnd(currentLength);
}
// Generate new string
if (selectionStart > 0) // Create head of test string
{
endOfHead = selectionStart;
if (insertionPoint && backspace) {
endOfHead -= 1;
}
testString += currentText.substring(0, endOfHead);
}
if (!(backspace || delete || paste)) // Add the new character
{
testString += newChar;
}
if (paste) // Add the string from the clipboard
{
Transferable data = getToolkit().getSystemClipboard().getContents(this);
if (data != null) {
try {
String clipString = (String) data.getTransferData(DataFlavor.stringFlavor);
testString += clipString;
} catch (java.io.IOException ioe) {
// Do nothing
} catch (UnsupportedFlavorException ufe) {
// Do nothing
}
}
}
if (selectionEnd < currentLength) // Add the tail of the string
{
startOfTail = selectionEnd;
if (insertionPoint && delete) {
startOfTail += 1;
}
testString += currentText.substring(startOfTail);
}
}
if (testString.compareTo("") != 0) // Null string is OK
{
if (!(isValidString(testString))) {
e.consume();
}
}
} else {
e.consume();
}
}
super.processKeyEvent(e);
postProcessing();
}
/*******************************
* PROTECTED METHODS
*******************************/
/**
* Default constructor for this class. The initial text of the smart text field
* can be specified as well as the size (in characters) of the text field.
*
* @param text The initial string that is displayed in the text field.
* @param columns THe width of the text field in characters.
*/
protected SmartTextField(String text, int columns) {
super(text, columns);
}
/**
* Returns whether a character is valid for this text field. As the user types
* from the keyboard, this method is called to determine if the character is a
* valid character based in the restrictions of the subclass.
*
* @param aChar A character to perform the validity test with.
* @return True if the character is valid for this subclassed text field. <BR>
* False is the character is not valid.
*/
abstract protected boolean isValidCharacter(char aChar);
/**
* Returns whether a string is valid for this text field. As the user types from
* the keyboard, this method is called to determine if the new string in the
* text field is valid based upon the restriction of the subclass. This is done
* after the character has been determined to be valid since there can be
* restrictions placed on the text string as a whole, such a maximum length or
* date format.
*
* @param aString The string to perform the validity check with.
* @return True if the string is valid for this subclassed text field. <BR>
* False if the character is not valud.
*/
abstract protected boolean isValidString(String aString);
/**
* This method is used by the any subclass that need to complete any processing
* of the text string in the text field after all the requirement checks have
* been performed.
*/
abstract protected void postProcessing();
/*******************************
* PRIVATE METHODS
*******************************/
private boolean isPrintableCharacter(char inputChar) {
if ((inputChar >= ' ') && (inputChar <= '~')) {
return true;
}
return false;
}
}
|
