Check boxes

Check boxes consist of several toggle buttons that present a set of options to the user. The user can choose none, all, or any combination of the buttons. A CwRowColumn widget can be used to contain the buttons. When the row-column's radioBehavior resource is false, its default, more than one toggle button can be selected at a time.

The code that follows creates the toggle-button group shown on the right.

| shell rowColumn button buttonNames initialValues | shell := CwTopLevelShell createApplicationShell: 'shell' argBlock: [:w | w title: 'Check Box Example']. rowColumn := shell createRowColumn: 'group' argBlock: nil. rowColumn manageChild.

buttonNames := #('Item 1' 'Item 2' 'Item 3').

initialValues := (Array with: false with: true with: true).

1 to: buttonNames size

do: [:i |

button := rowColumn

createToggleButton: (buttonNames at: i)

"The state of each toggle button is set on creation according to the

corresponding value in the initialValues array. In this example, Item2

and Item3 are both selected, and this is indicated by an X."

argBlock: [:w | w set: (initialValues at: i)].

button

addCallback: XmNvalueChangedCallback

receiver: self

selector: #valueChanged:clientData:callData:

clientData: nil.

button manageChild].

shell realizeWidget.

The valueChanged callback used by the code is shown below. A message is written to the transcript whenever a button is selected or deselected.

valueChanged: widget clientData:clientData callData: callData

"A toggle button has changed state."

Transcript cr; show: widget labelString, ' has been '.

callData set

ifTrue: [Transcript show: 'selected.']

ifFalse: [Transcript show: 'deselected.'].