Snow Widget Reference

Common properties

These properties are available on every widget, unless stated otherwise.
Name Type Description Examples Notes
id symbol Binds a lexical variable to the current widget locally to the widget body. 
(frame (:id foo)
  (print foo))
 For containers only.
layout-manager
  • one of :default, :mig, :border, :box, :flow
  • a list whose car is one of the above and whose cdr are additional arguments
  • a native Java layout manager.
 Sets the policy for laying out the component's children. 
(panel (:layout-manager '(:box :y))
  (label :text "First Line")
  (label :text "Second Line"))
 For containers only.
layout string Constraints used to control how the component is to be laid out in its container. The possible values and their meaning depend on the layout manager of the container. 
(panel ()
  (label :layout "grow, wrap"
         :text "hello")
  (label :text "world"))
enabled-p boolean Controls whether the widget is enabled (able to receive user input).

size complex Sets the size of the widget. 
(frame (:size #C(800 600)))
 The size is represented as a complex number whose real part is the Width and imaginary part is the Height.

Widgets

Here's a summary of the widgets (GUI components) currently available in Snow. The "C" column indicates whether the widget is a container. You can follow the hyperlink on a widget's name to read about its properties.
Name Description C Backend Examples Notes
Swing
button A button with text on it.
Y 
(button :text "Ok!")
check-box A checkbox with optional text.
Y 
(check-box :text "Enabled")
frame A top-level window. Y Y 
(frame (:title "A frame" :on-close :exit)
  (label :text "push")
  (button :text "this!"))
label Read-only text.
Y 
(label :text "Hello")
list-widget Displays a list of strings.
Y 
(list-widget :model (make-cons-list-model '("foo" "bar" "baz")))
 Not named list to avoid clashing with the commonly used function by the same name in the COMMON-LISP package.
panel A generic container for other components. Y Y 
(panel ()
  (label :text "push")
  (button :text "this!"))
scroll A container for a single child, providing scrollbar support. Y Y 
(scroll ()
  (text-area :text "very, very, ..., long text"))
text-area Allows the user to enter multiple lines of text.
Y 
(text-area :text "type something here")
text-field Allows the user to enter a single line of text.
Y 
(text-field :text "type something here")
tree Displays hierarchical data in the form of a tree with expandable/collapsible nodes.
Y 
(tree :model (make-cons-tree-model '("foo" ("bar" "baz"))))

Widget-specific properties

button

:text
Sets the text displayed on the button
:on-action
Sets a callback to be invoked when the button is activated (e.g. by a mouse click or using the keyboard)