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<H2><A NAME="sec:4.1"><SPAN class="sec-nr">4.1</SPAN> <SPAN class="sec-title">An
example</SPAN></A></H2>
<P>Before diving into the complexities we will illustrate normal usage
through an example. The following Prolog predicate creates a dialog for
entering information on an employee. The result, running on Windows-NT,
is shown in <A class="fig" href="sec-4.1.html#fig:employee">figure 8</A>.
<PRE class="code">
ask_employee :-
new(Dialog, dialog('Define employee')),
send_list(Dialog, append,
[ new(N1, text_item(first_name)),
new(N2, text_item(family_name)),
new(S, new(S, menu(sex))),
new(A, int_item(age, low := 18, high := 65)),
new(D, menu(department, cycle)),
button(cancel, message(Dialog, destroy)),
button(enter, and(message(@prolog,
assert_employee,
N1?selection,
N2?selection,
S?selection,
A?selection,
D?selection),
message(Dialog, destroy)))
]),
send_list(S, append, [male, female]),
send_list(D, append, [research, development, marketing]),
send(Dialog, default_button, enter),
send(Dialog, open).
assert_employee(FirstName, FamilyName, Sex, Age, Depth) :-
format('Adding ~w ~w ~w, age ~w, working at ~w~n',
[ Sex, FirstName, FamilyName, Age, Depth]).</PRE>
<P>This example shows the layout capabilities of <A class="" href="summary.html#class:dialog">dialog</A>
and its <A class="" href="summary.html#class:dialog_item">dialog_item</A>
objects. Simply appending items will place items vertically and group
buttons in rows. Labels are properly aligned. The <B>enter</B> button
defines a call-back on the predicate <A NAME="idx:assertemployee5:118"></A><SPAN class="pred-ext">assert_employee/5</SPAN>
using the values from the various controllers. <A class="sec" href="exeobjects.html">Section
10.2</A> explains the use of <A class="" href="summary.html#class:message">message</A>
objects in detail.
<P><A NAME="fig:employee"></A>
<CENTER>
<IMG SRC="employee.gif">
</CENTER>
<TABLE ALIGN=center WIDTH="75%"><TR><TD>
<B>Figure 8 : </B>Enter employee</TABLE>
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