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1 : dpvc 4772 loadMacros('Parser.pl','contextString.pl');
2 :    
3 :     sub _parserRadioButtons_init {}; # don't reload this file
4 :    
5 : gage 4997 =head1 DESCRIPTION
6 :    
7 : dpvc 4772 ####################################################################
8 :     #
9 :     # This file implements a radio button group object that is compatible
10 :     # with Value objects, and in particular, with the MultiPart object.
11 :     #
12 :     # To create a RadioButtons object, use
13 :     #
14 :     # $radio = RadioButtons([choices,...],correct,options);
15 :     #
16 :     # where "choices" are the strings for the items in the radio buttons,
17 :     # "correct" is the choice that is the correct answer for the group,
18 :     # and options are chosen from among:
19 :     #
20 :     # labels => [label1,...] Specifies the text to be used
21 :     # as the student answer for each
22 :     # entry in the radio group.
23 :     # This can also be set to the string
24 :     # "ABC" to get lettered labels or
25 :     # "123" to get numbered labels.
26 :     # The default is to use a few words
27 :     # from the text string for each button.
28 :     #
29 :     # separator => string text to put between the radio
30 :     # buttons.
31 :     # Default: $BR
32 :     #
33 :     # checked => choice the text or index (starting at zero)
34 :     # of the button to be checked
35 :     # Default: none checked
36 :     #
37 :     # maxLabelSize => n the approximate largest size that should
38 :     # be used for the answer strings to be
39 :     # generated by the radio buttons (if
40 :     # the choice strings are too long, they
41 :     # will be trimmed and "..." inserted)
42 :     # Default: 25
43 :     #
44 : dpvc 4773 # uncheckable => 0 or 1 determines whether the radio buttons can
45 :     # or "shift" be unchecked (requires JavaScript).
46 :     # To uncheck, click a second time; when
47 :     # set to "shift", unchecking requires the
48 :     # shift key to be pressed.
49 :     # Default: 0
50 : dpvc 4772 #
51 : dpvc 4773 #
52 : dpvc 4772 # To insert the radio buttons into the problem text, use
53 :     #
54 :     # BEGIN_TEXT
55 :     # \{$radio->buttons\}
56 :     # END_TEXT
57 :     #
58 :     # and then
59 :     #
60 :     # ANS($radio->cmp);
61 :     #
62 :     # to get the answer checker for the radion buttons.
63 :     #
64 :     # You can use the RadioButtons object in MultiPart objects. This is
65 :     # the reason for the RadioButton's ans_rule method (since that is what
66 :     # MultiPart calls to get answer rules).
67 :     #
68 :    
69 : gage 4997 =cut
70 :    
71 : dpvc 4772 sub RadioButtons {parserRadioButtons->new(@_)}
72 :    
73 :     #
74 :     # The package that implements RadioButtons
75 :     #
76 :     package parserRadioButtons;
77 :     our @ISA = qw(Value::String);
78 :    
79 : dpvc 4773 my $jsPrinted = 0; # true when the JavaScript has been printed
80 : dpvc 4772
81 : dpvc 4773
82 : dpvc 4772 #
83 :     # Create a new RadioButtons object
84 :     #
85 :     sub new {
86 :     my $self = shift; my $class = ref($self) || $self;
87 : dpvc 5073 my $context = (Value::isContext($_[0]) ? shift : $self->context);
88 : dpvc 4772 my $choices = shift; my $value = shift;
89 :     my %options;
90 :     main::set_default_options(\%options,
91 :     labels => [],
92 :     separator => $main::BR,
93 :     checked => undef,
94 :     maxLabelSize => 25,
95 : dpvc 4773 uncheckable => 0,
96 : dpvc 4772 @_,
97 :     );
98 :     $options{labels} = [1..scalar(@$choices)] if $options{labels} eq "123";
99 :     $options{labels} = [@main::ALPHABET[0..scalar(@$choices)-1]] if $options{labels} eq "ABC";
100 :     my $self = bless {%options, choices=>$choices}, $class; # temporary to so we can call our methods
101 :     Value::Error("A RadioButton's first argument should be a list of button labels")
102 :     unless ref($choices) eq 'ARRAY';
103 :     Value::Error("A RadioButton's second argument should be the correct button choice")
104 :     unless defined($value) && $value ne "";
105 : dpvc 5370 my $context = Parser::Context->getCopy("String");
106 : dpvc 4772 my %choiceHash = $self->choiceHash(1);
107 :     $context->strings->add(map {$_=>{}} (keys %choiceHash));
108 :     $value = $self->correctChoice($value);
109 : dpvc 5073 $self = bless $context->Package("String")->new($context,$value)->with(
110 :     isValue => 1, choices => $choices, %options), $class;
111 : dpvc 4773 $self->JavaScript if $self->{uncheckable};
112 : dpvc 4772 return $self;
113 :     }
114 :    
115 :     #
116 :     # Locate the label of the correct answer
117 :     # The answer can be given as an index, as the full answer
118 :     # or as the label itself.
119 :     #
120 :     sub correctChoice {
121 :     my $self = shift; my $value = shift;
122 :     my $index = $self->Index($value);
123 :     foreach my $i (0..scalar(@{$self->{choices}})-1) {
124 :     my $label = $self->{labels}[$i]; my $choice = $self->{choices}[$i];
125 :     $label = $self->makeLabel($choice) unless defined $label;
126 :     return $label if $label eq $value || $index == $i || $choice eq $value;
127 :     }
128 :     Value::Error("The correct answer should be one of the button choices");
129 :     }
130 :    
131 :     #
132 :     # Create the hash of label => answer pairs to be used for the
133 :     # ans_radio_buttons() routine
134 :     #
135 :     sub choiceHash {
136 :     my $self = shift; my $noChecked = shift;
137 :     my @radio = ();
138 :     my $index = $self->Index($self->{checked});
139 :     my $checked = $self->{checked}; $checked = "" unless defined $checked;
140 :     if ($noChecked) {$checked = ""; $index = -1}
141 :     foreach my $i (0..scalar(@{$self->{choices}})-1) {
142 :     my $label = $self->{labels}[$i]; my $choice = $self->{choices}[$i];
143 :     $label = $self->makeLabel($choice) unless defined $label;
144 :     $label = "%$label" if $label eq $checked || $index == $i || $choice eq $checked;
145 :     push(@radio, $label,$choice);
146 :     }
147 :     return @radio;
148 :     }
149 :    
150 :     #
151 :     # Create a label for the answer, either using the labels
152 :     # provided by the user, or by creating one from the answer
153 :     # string (restrict its length so that the results table
154 :     # will not be overflowed).
155 :     #
156 :     sub makeLabel {
157 :     my $self = shift; my $choice = shift;
158 :     return $choice if length($choice) < $self->{maxLabelSize};
159 :     my @words = split(/\b/,$choice);
160 :     my ($s,$e) = ('','');
161 :     do {$s .= shift(@words); $e = pop(@words) . $e}
162 :     while length($s) + length($e) + 15 < $self->{maxLabelSize} && scalar(@words);
163 :     return $s . " ... " . $e;
164 :     }
165 :    
166 :     #
167 :     # Get a numeric index (-1 if not defined or not a number)
168 :     #
169 :     sub Index {
170 :     my $self = shift; my $index = shift;
171 :     return -1 unless defined $index && $index =~ m/^\d$/;
172 :     return $index;
173 :     }
174 :    
175 :     #
176 : dpvc 4773 # Print the JavaScript needed for uncheckable radio buttons
177 :     #
178 :     sub JavaScript {
179 :     return if $main::displayMode eq 'TeX';
180 :     return if $jsPrinted;
181 :     main::TEXT(
182 :     "\n<script>\n" .
183 :     "if (window.ww == null) {var ww = {}}\n" .
184 :     "if (ww.RadioButtons == null) {ww.RadioButtons = {}}\n" .
185 :     "if (ww.RadioButtons.selected == null) {ww.RadioButtons.selected = {}}\n" .
186 :     "ww.RadioButtons.Toggle = function (obj,event,shift) {\n" .
187 :     " if (!event) {event = window.event}\n" .
188 :     " if (shift && !event.shiftKey) {\n" .
189 :     " this.selected[obj.name] = obj\n" .
190 :     " return\n" .
191 :     " }\n" .
192 :     " var selected = this.selected[obj.name]\n" .
193 :     " if (selected && selected == obj) {\n".
194 :     " this.selected[obj.name] = null\n" .
195 :     " obj.checked = false\n" .
196 :     " } else {\n" .
197 :     " this.selected[obj.name] = obj\n".
198 :     " }\n" .
199 :     "}\n".
200 :     "</script>\n"
201 :     );
202 :     $jsSPrinted = 1;
203 :     }
204 :    
205 :     sub makeUncheckable {
206 :     my $self = shift;
207 :     my $shift = ($self->{uncheckable} =~ m/shift/i ? ",1" : "");
208 :     my $onclick = "onclick=\"ww.RadioButtons.Toggle(this,event$shift)\"";
209 :     my @radio = @_;
210 :     foreach (@radio) {$_ =~ s/<INPUT/<INPUT $onclick/i}
211 :     return @radio;
212 :     }
213 :    
214 :     #
215 : dpvc 4772 # Create the radio-buttons text
216 :     #
217 :     sub buttons {
218 :     my $self = shift;
219 :     my @radio = main::ans_radio_buttons($self->choiceHash);
220 : dpvc 4773 @radio = $self->makeUncheckable(@radio) if $self->{uncheckable};
221 : dpvc 4772 (wantarray) ? @radio : join($self->{separator}, @radio);
222 :     }
223 :     sub named_buttons {
224 :     my $self = shift; my $name = shift;
225 :     my @radio = NAMED_ANS_RADIO_BUTTONS($name,$self->choiceHash);
226 : dpvc 4773 @radio = $self->makeUncheckable(@radio) if $self->{uncheckable};
227 : dpvc 4772 #
228 :     # Taken from PGbasicmacros.pl
229 :     # It is wrong to have \item in the radio buttons and to add itemize here,
230 :     # but that is the way PGbasicmacros.pl does it.
231 :     #
232 :     if ($displayMode eq 'TeX') {
233 :     $radio[0] = "\n\\begin{itemize}\n" . $radio[0];
234 :     $radio[$#radio_buttons] .= "\n\\end{itemize}\n";
235 :     }
236 :     (wantarray) ? @radio: join($self->{separator}, @radio);
237 :     }
238 :    
239 :     sub ans_rule {shift->buttons(@_)}
240 :     sub named_ans_rule {shift->named_buttons(@_)}
241 :    
242 :     1;

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