69 lines
2.1 KiB
Dart
69 lines
2.1 KiB
Dart
|
import 'package:flutter/widgets.dart';
|
||
|
|
import 'package:imagini/bloc/bloc-prov.dart';
|
||
|
|
|
||
|
|
/// A Flutter [Widget] that merges multiple [BlocProvider] widgets into one widget tree.
|
||
|
|
///
|
||
|
|
/// [BlocProviderTree] improves the readability and eliminates the need
|
||
|
|
/// to nest multiple [BlocProviders].
|
||
|
|
///
|
||
|
|
/// By using [BlocProviderTree] we can go from:
|
||
|
|
///
|
||
|
|
/// ```dart
|
||
|
|
/// BlocProvider<BlocA>(
|
||
|
|
/// bloc: BlocA(),
|
||
|
|
/// child: BlocProvider<BlocB>(
|
||
|
|
/// bloc: BlocB(),
|
||
|
|
/// child: BlocProvider<BlocC>(
|
||
|
|
/// value: BlocC(),
|
||
|
|
/// child: ChildA(),
|
||
|
|
/// )
|
||
|
|
/// )
|
||
|
|
/// )
|
||
|
|
/// ```
|
||
|
|
///
|
||
|
|
/// to:
|
||
|
|
///
|
||
|
|
/// ```dart
|
||
|
|
/// BlocProviderTree(
|
||
|
|
/// blocProviders: [
|
||
|
|
/// BlocProvider<BlocA>(bloc: BlocA()),
|
||
|
|
/// BlocProvider<BlocB>(bloc: BlocB()),
|
||
|
|
/// BlocProvider<BlocC>(bloc: BlocC()),
|
||
|
|
/// ],
|
||
|
|
/// child: ChildA(),
|
||
|
|
/// )
|
||
|
|
/// ```
|
||
|
|
///
|
||
|
|
/// [BlocProviderTree] converts the [BlocProvider] list
|
||
|
|
/// into a tree of nested [BlocProvider] widgets.
|
||
|
|
/// As a result, the only advantage of using [BlocProviderTree] is improved
|
||
|
|
/// readability due to the reduction in nesting and boilerplate.
|
||
|
|
class BlocProviderTree extends StatelessWidget {
|
||
|
|
/// The [BlocProvider] list which is converted into a tree of [BlocProvider] widgets.
|
||
|
|
/// The tree of [BlocProvider] widgets is created in order meaning the first [BlocProvider]
|
||
|
|
/// will be the top-most [BlocProvider] and the last [BlocProvider] will be a direct ancestor
|
||
|
|
/// of the `child` [Widget].
|
||
|
|
final List<BlocProvider> blocProviders;
|
||
|
|
|
||
|
|
/// The [Widget] and its descendants which will have access to every [Bloc] provided by `blocProviders`.
|
||
|
|
/// This [Widget] will be a direct descendent of the last [BlocProvider] in `blocProviders`.
|
||
|
|
final Widget child;
|
||
|
|
|
||
|
|
const BlocProviderTree({
|
||
|
|
Key key,
|
||
|
|
@required this.blocProviders,
|
||
|
|
@required this.child,
|
||
|
|
}) : assert(blocProviders != null),
|
||
|
|
assert(child != null),
|
||
|
|
super(key: key);
|
||
|
|
|
||
|
|
@override
|
||
|
|
Widget build(BuildContext context) {
|
||
|
|
Widget tree = child;
|
||
|
|
for (final blocProvider in blocProviders.reversed) {
|
||
|
|
tree = blocProvider.copyWith(tree);
|
||
|
|
}
|
||
|
|
return tree;
|
||
|
|
}
|
||
|
|
}
|