Asserts that the given context has a Scaffold ancestor.
Used by some material design widgets to make sure that they are only used in contexts where they can communicate with a Scaffold.
For example, the AppBar in some situations requires a Scaffold to do the right thing with scrolling.
To call this function, use the following pattern, typically in the
relevant Widget's build method:
assert(debugCheckHasScaffold(context));
Does nothing if asserts are disabled. Always returns true.
Source
bool debugCheckHasScaffold(BuildContext context) {
assert(() {
if (Scaffold.of(context) == null) {
Element element = context;
throw new FlutterError(
'No Scaffold widget found.\n'
'${context.widget.runtimeType} widgets require a Scaffold widget ancestor.\n'
'The specific widget that could not find a Scaffold ancestor was:\n'
' ${context.widget}\n'
'The ownership chain for the affected widget is:\n'
' ${element.debugGetCreatorChain(10)}'
);
}
return true;
});
return true;
}