Class text item can
represent a text_item<-value_set
or do completion on the basis of their associated text_item<-type.
In both cases, visualisation by means of a combo box
provides useful feedback to the user as well as a commonly found user
interface style.
text_item<-style
combo_box is automatically selected after text_item->value_set
or
text_item->type
with a suitable type. It may be switched afterwards.
A text item showing as a combo-box both supports completion and
opening the combo-box.
Style stepper shows a small up/down arrow at the right
of the text-entry-field. Pressing this field invokes text_item->increment
and
text_item->decrement,
holding the mouse-button down repeats this message. This style is used
by class int_item.
Applications may use it to implement -for example- an ordinal scale.
The text_item<->type
slot describes the value-type represented by the text_item. When a value
is displayed, it is translated into a string using
object<-print_name.
After editing, it is translated into a PCE
object of the specified type using type<-check.
Slot text_item<-type
is set by text_item->default,
where it is deduced from the initial value. When the value is an
integer, the type is int. Otherwise the type describes the
class the selection belongs to.
If the type can generate a value_set (see type<-value_set
and
text_item<->value_set,
the text_item->style
will automatically be changed to
combo_box.
EXAMPLE
?- new(P, picture),
send(P, display, new(B, box(100,100))),
send(new(D, dialog), below, P),
send(D, append,
text_item(size, B?size,
message(B, size, @arg1))),
send(P, open).
- See also
- - type
<-check
- object<-print_name
