ExpansionPanelCallback typedef Null safety

ExpansionPanelCallback = void Function(int panelIndex, bool isExpanded)

Signature for the callback that's called when an ExpansionPanel is expanded or collapsed.

The position of the panel within an ExpansionPanelList is given by panelIndex.

Implementation

typedef ExpansionPanelCallback = void Function(int panelIndex, bool isExpanded);