Snow Widget Reference

Common properties

These properties are available on every widget, unless stated otherwise.

`id`

Type: symbol
Description: This pseudo-property has several uses:

if a lexical variable with the same name as the id exists, it will be assigned the widget.
if the widget is a container, a lexical variable with the same name as the id will be bound to the widget around the body of the container.
if a Java backing bean is used (as the value of *backing-bean*), and it has a property with the same name as the id, it will be injected the widget through the setter method of that property. The name of the id symbol will be translated from lisp-hyphenated-convention to javaCamelCasedConvention.

Examples:

(frame (:id foo) foo)
==> #<javax.swing.JFrame ...frame.toString()... {identityHashCode}>

(let (bar)
  (label :id bar)
  bar)
==> #<javax.swing.JLabel ...label.toString()... {identityHashCode}>

`layout-manager`

Type: a member of the following set of values:

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.

Description: Sets the policy for laying out the component's children. For containers only. If not specified, defaults to :default - which is the same as :mig, i.e., MiGLayout is used.
Examples:

(panel (:layout-manager '(:box :y))
  (label :text "First Line")
  (label :text "Second Line"))

`layout`

Type: string
Description: 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.
Examples:

(panel ()
  (label :layout "grow, wrap" :text "hello")
  (label :text "world"))

`enabled-p`

Type: boolean
Description: Controls whether the widget is enabled (able to receive user input).

`size`

Type: complex
Description: Sets the size of the widget. The size is represented as a complex number whose real part is the Width and imaginary part is the Height.
Example:

(frame (:size #C(800 600)))

`label`

Type: a label widget.
Description: Connects a label to this widget. Typically, clicking on the label will bring focus on the widget.
Examples:

(let (lbl)
  (label :id lbl :text "User Name: ")
  (text-field :label lbl))

Or, shorter, using an inline label:

(text-field :label (label :text "User Name: "))

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	Examples	Notes
`button`	A button with text on it.		(button :text "Ok!")
`check-box`	A checkbox with optional text.		(check-box :text "Enabled")
`frame`	A top-level window.	Y	(frame (:title "A frame" :on-close :exit) (label :text "push") (button :text "this!"))
`label`	Read-only text.		(label :text "Hello")
`list-widget`	Displays a list of strings.		(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	(panel () (label :text "push") (button :text "this!"))
`scroll`	A container for a single child, providing scrollbar support.	Y	(scroll () (text-area :text "very, very, ..., long text"))
`text-area`	Allows the user to enter multiple lines of text.		(text-area :text "type something here")
`text-field`	Allows the user to enter a single line of text.		(text-field :text "type something here")
`tree`	Displays hierarchical data in the form of a tree with expandable/collapsible nodes.		(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)