ExpansionPanelList.radio constructor

const ExpansionPanelList.radio({Key key, List<ExpansionPanelRadio> children: const [], ExpansionPanelCallback expansionCallback, Duration animationDuration: kThemeAnimationDuration, Object initialOpenPanelValue })

Creates a radio expansion panel list widget.

This widget allows for at most one panel in the list to be open. The expansion panel callback is triggered when an expansion panel expand/collapse button is pushed. The children and animationDuration arguments must not be null. The children objects must be instances of ExpansionPanelRadio.

Implementation 

const ExpansionPanelList.radio({
  Key key,
  List<ExpansionPanelRadio> children = const <ExpansionPanelRadio>[],
  this.expansionCallback,
  this.animationDuration = kThemeAnimationDuration,
  this.initialOpenPanelValue,
}) : children = children, // ignore: prefer_initializing_formals
     assert(children != null),
     assert(animationDuration != null),
     _allowOnlyOnePanelOpen = true,
     super(key: key);