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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
|
</R>Purpose<!R>
The Cdk Itemlist widget allows the user to select a value from a list. This
widget is very much like a 1 line scrolling list.
</R>Construction Options<!R>
A itemlist widget is defined using the following syntax. The variable
</B>$itemlistObject<!B> contains the reference to the itemlist object.
$itemlistObject = new Cdk::Itemlist ( options );
The options are defined in the following table.
</U>Option Default Value Type Purpose<!U>
Label Required Scalar The label of the itemlist field.
List Required Array Ref The list of items to choose from.
Default 0 Scalar The default choice.
Xpos Center Scalar This is the position of the window on the X axis.
Ypos Center Scalar This is the position of the window on the Y axis.
Lpos Left Scalar This is the position of the label in the window.
Box True Scalar This boolean states whether the dialog box will have a box drawn around it.
Shadow False Scalar This boolean states whether the dialog box will have a shadow on the box.
</R>Available Methods<!R>
</B>activate<!B>
Activation of an object means to make the object available for use. The
following example demonstrates how to activate a itemlist widget.
$returnValue = $itemlistObject->activate ();
The variable </B>$returnValue<!B> contains a scalar value which represents the
integer value of the corresponding item from the list.
</B>inject<!B>
This function injects a single character into the widget. The following
examples demonstrates how to call the inject method.
<C></B>$itemlistObject->inject ( options );
The options are defined in the following table.
</U>Option Default Value Type Purpose<!U>
Shadow Required Scalar The character to inject into the widget.
If you are injecting a special character into the widget, then you can
use a pre-defined value to represent the key.
<C><#UL><#HL(12)><#TT><#HL(15)><#UR>
<C><#VL></U>Key <#VL>Key Value <!U><#VL>
<C><#VL>Left Arrow <#VL>KEY_LEFT <#VL>
<C><#VL>Right Arrow <#VL>KEY_RIGHT <#VL>
<C><#VL>Up Arrow <#VL>KEY_UP <#VL>
<C><#VL>Down Arrow <#VL>KEY_DOWN <#VL>
<C><#VL>Delete <#VL>KEY_DELETE <#VL>
<C><#VL>Backspace <#VL>KEY_BACKSPACE <#VL>
<C><#VL>Page Up <#VL>KEY_PPAGE <#VL>
<C><#VL>Page Down <#VL>KEY_NPAGE <#VL>
<C><#VL>Home <#VL>KEY_HOME <#VL>
<C><#VL>End <#VL>KEY_END <#VL>
<C><#VL>Escape <#VL>KEY_ESC <#VL>
<C><#LL><#HL(12)><#BT><#HL(15)><#LR>
</B>set<!B>
Sets or resets certain attributes or features of the widget. The following
demonstrates how to call the set method from the itemlist field.
$itemlistObject->set ( options );
The options are defined in the following table.
</U>Option Default Value Type Purpose<!U>
List Required Arry Ref The list of items to choose from.
Default 0 Scalar The default choice.
Box True Scalar Changes the current value of the box flag.
</B>bind<!B>
The bind method binds keys to events. The binding is specific to the individual
objects. The following example demonstrates how to call the bind method.
$itemlistObject->bind ( options );
The options are defined in the following table.
</U>Option Default Value Type Purpose<!U>
Key Required Scalar This is the character to bind the event to.
Function Required Scalar This is the name of the callback function.
</B>preProcess<!B>
The </B>preProcess<!B> function sets a process to be run before the key entered
is processed. If this function returns a value of 0, then the key injected
into the widget will not be processed; otherwise the character will be
processed as normal. The following example demonstrates how to call the
preProcess method.
<C></B>$itemlistObject->preProcess ( options );
The options are defined in the following table.
</U>Option Default Value Type Purpose<!U>
Function Required Scalar This is the name of the
callback function.
To create a pre-process callback the following code segment demonstrates
how to do it properly.
<C></B>$itemlistObject->preProcess ('Function' => sub { callback (@_); });
Notice that the array </B>@_<!B> is passed into the function called
</B>callback<!B>. This is done because when the callback process is
called the key which was pressed is passed into the perl subroutine.
Since we nest the call-back function inside an anonymous subroutine,
we need to pass the array </B>@_<!B> to the call-back function. If
the key given to the call-back function is a non alphanumeric key
then a predefined value will be given to the function. The following
table describes the values passed into the function.
<C><#UL><#HL(12)><#TT><#HL(15)><#UR>
<C><#VL></U>Key <#VL>Key Value <!U><#VL>
<C><#VL>Left Arrow <#VL>KEY_LEFT <#VL>
<C><#VL>Right Arrow <#VL>KEY_RIGHT <#VL>
<C><#VL>Up Arrow <#VL>KEY_UP <#VL>
<C><#VL>Down Arrow <#VL>KEY_DOWN <#VL>
<C><#VL>Delete <#VL>KEY_DELETE <#VL>
<C><#VL>Backspace <#VL>KEY_BACKSPACE <#VL>
<C><#VL>Page Up <#VL>KEY_PPAGE <#VL>
<C><#VL>Page Down <#VL>KEY_NPAGE <#VL>
<C><#VL>Home <#VL>KEY_HOME <#VL>
<C><#VL>End <#VL>KEY_END <#VL>
<C><#VL>Escape <#VL>KEY_ESC <#VL>
<C><#LL><#HL(12)><#BT><#HL(15)><#LR>
If the pre-process function returns a value of 0 the key hit will
not be injected into the widget. This allows the programmer to
selectively pick which characters will or will not get injected
into the widget.
The </B>postProcess<!B> function sets a process to be run before the key entered
is processed. If this function returns a value of 0, then the key injected
into the widget will not be processed; otherwise the character will be
processed as normal. The following example demonstrates how to call the
postProcess method.
<C></B>$itemlistObject->postProcess ( options );
The options are defined in the following table.
</U>Option Default Value Type Purpose<!U>
Function Required Scalar This is the name of the
callback function.
To create a post-process callback the following code segment demonstrates
how to do it properly.
<C></B>$itemlistObject->postProcess ('Function' => sub { callback (@_); });
Notice that the array </B>@_<!B> is passed into the function called
</B>callback<!B>. This is done because when the callback process is
called the key which was pressed is passed into the perl subroutine.
Since we nest the call-back function inside an anonymous subroutine,
we need to pass the array </B>@_<!B> to the call-back function. If
the key given to the call-back function is a non alphanumeric key
then a predefined value will be given to the function. The following
table describes the values passed into the function.
<C><#UL><#HL(12)><#TT><#HL(15)><#UR>
<C><#VL></U>Key <#VL>Key Value <!U><#VL>
<C><#VL>Left Arrow <#VL>KEY_LEFT <#VL>
<C><#VL>Right Arrow <#VL>KEY_RIGHT <#VL>
<C><#VL>Up Arrow <#VL>KEY_UP <#VL>
<C><#VL>Down Arrow <#VL>KEY_DOWN <#VL>
<C><#VL>Delete <#VL>KEY_DELETE <#VL>
<C><#VL>Backspace <#VL>KEY_BACKSPACE <#VL>
<C><#VL>Page Up <#VL>KEY_PPAGE <#VL>
<C><#VL>Page Down <#VL>KEY_NPAGE <#VL>
<C><#VL>Home <#VL>KEY_HOME <#VL>
<C><#VL>End <#VL>KEY_END <#VL>
<C><#VL>Escape <#VL>KEY_ESC <#VL>
<C><#LL><#HL(12)><#BT><#HL(15)><#LR>
</B>draw<!B>
This method draws the object on the screen. The following example demonstrates
how to call the draw method.
$itemlistObject->draw ( options );
The options are defined in the following table.
</U>Option Default Value Type Purpose<!U>
Box True Scalar Draws the window with a box around it.
</B>erase<!B>
This method removes the object from the screen. This does </B/U>NOT<!B!U>
destroy the object. The following example demonstrates how to call the erase
method.
$itemlistObject->erase ();
</B>raise<!B>
The raise method raises the widget to the top of the screen. This means if there
were any widgets obscuring part of the view, raising the object would bring the
complete object into view. The following example demonstrates how to call the
raise method.
$itemlistObject->raise();
</B>lower<!B>
The lower method lowers the object so it doesn't obscure the view of any other
objects. The following example demonstrates how to call the lower method.
$itemlistObject->lower();
</B>register<!B>
The register method registers the object to the default screen. This does </R>NOT<!R>
have to be called since the objects are registered automatically. This method
should be called if the </B>unregister<!B> method was called. The following
example demonstrates how to call the register method.
$itemlistObject->register();
</B>unregister<!B>
The unregister method should be called when a widget, which is part of the
default screen, needs to be taken away temporarily. This does not delete or free
the object, it just unmaps it from any future screen refreshes. The object can
be registered by calling the </B>register<!B> method. The following example
demonstrates how to call the unregister method.
$itemlistObject->unregister();
</B>getwin<!B>
This method returns a pointer to the window of the object. Not much use for this
yet. It will be useful in the future when the drawing methods are added. The
following example demonstrates how to call the getwin method.
$itemlistObject->getwin();
</R>Default Key Bindings<!R>
</U>Key Action<!U>
Up Arrow Displays the next item in the list.
Right Arrow Displays the next item in the list.
Space Displays the next item in the list.
+ Displays the next item in the list.
n Displays the next item in the list.
Down Arrow Displays the previous item in the list.
Left Arrow Displays the previous item in the list.
- Displays the previous item in the list.
p Displays the previous item in the list.
d Sets the list to the default choice.
D Sets the list to the default choice.
0 Sets the list to the first choice in the list.
$ Sets the list to the last choice in the list.
Return Returns the current information in the field and exits the widget.
Tab Returns the current information in the field and exits the widget.
CTRL-N Returns the current information in the field and exits the widget.
CTRL-R Refreshes the screen.
</R>Tips & Tricks<!R>
None.
</R>Physical Restrictions<!R>
</U>Restriction Value<!U>
Maximum number of items. 500
</R>Example Use Of The Widget<!R>
#!/usr/local/bin/perl
#
# Load in the Cdk Extension.
#
use Cdk;
Cdk::init();
# Create a new itemlist object.
@list = qw (January Feburary March April May June July August September November December);
$month = new Cdk::Itemlist ( 'Label' => "Pick a month: ", 'List' => \@list);
# Activate the object.
$choice = $month->activate();
# Exit Cdk.
Cdk::end();
# Print out the results.
print "\n\n\n\n";
print "You selected: <$choice>\n";
<C><#HL(70)>
<C>Document Created: June, 1995
<C>Document Revised: November, 1995
<C>Document Revised: March, 2012
|
