SearchableDropdownPlus<C extends BlocBase<S>, S> class

A single-select searchable dropdown that integrates with any BLoC/Cubit.

Type Parameters

  • C — your Cubit/Bloc type, e.g. WorkerCubit
  • S — the state type emitted by C, e.g. WorkerState

Key Features

  • Real-time search via onSearch
  • Offline caching: falls back to client-side filtering when no internet
  • Controlled-mode support via selectedValue (useful for QR scan, form reset, etc.)
  • Full visual customisation via dropdownTheme or preset themeStyle
  • Custom item & selected-value builders

Basic Usage

SearchableDropdownPlus<WorkerCubit, WorkerState>(
  cubit: workerCubit,
  hintText: 'Search worker…',
  onSearch: workerCubit.search,
  onStateChange: (state, updateList, updateLoading) {
    if (state is WorkersLoaded) {
      updateList(state.workers
          .map((w) => DropdownItem(value: w, label: w.name))
          .toList());
      updateLoading(false);
    } else if (state is WorkersLoading) {
      updateLoading(true);
    }
  },
  onSelectionChanged: (item) => setState(() => _selected = item.value),
)

Controlled Mode (e.g. QR scan)

SearchableDropdownPlus(
  key: ValueKey(qrScanKey), // increment key to force re-sync
  selectedValue: scannedItem,
  ...
)
Inheritance

Constructors

SearchableDropdownPlus({required C cubit, required void onSearch(String query), required void onStateChange(S state, void updateList(List<DropdownItem>), void updateLoading(bool)), required String hintText, Key? key, DropdownItem? selectedValue, void onSelectionChanged(DropdownItem item)?, String? searchHint, String? noResultsText, String? loadingText, bool needInitialFetch = false, DropdownPlusTheme? dropdownTheme, DropdownPlusThemeStyle? themeStyle, Widget itemBuilder(DropdownItem item, bool isSelected)?, Widget selectedValueBuilder(DropdownItem selectedItem)?, Future<bool> checkInternetConnection()?, Duration debounceDuration = Duration.zero, bool enabled = true, bool autofocusSearch = false, DropdownEmptyBuilder? emptyBuilder, DropdownLoadingBuilder? loadingBuilder, Object? error, VoidCallback? onRetry, DropdownErrorBuilder? errorBuilder, String? semanticsLabel, int minSearchLength = 0, VoidCallback? onLoadMore, bool hasMore = false, bool isLoadingMore = false, FocusNode? focusNode, DropdownMenuController? menuController})
const

Properties

autofocusSearch → bool
Focus the search field when the panel opens.
final
checkInternetConnection → Future<bool> Function()?
Optional async function returning true when the device is online. When null, the widget always performs remote search (no offline fallback).
final
cubit → C
The BLoC/Cubit instance that drives this dropdown.
final
debounceDuration → Duration
Debounce delay before onSearch is invoked. Default: no debounce.
final
Visual customisation. When null, themeStyle is used if set.
final
emptyBuilder → DropdownEmptyBuilder?
Custom empty-state UI when there are no results.
final
enabled → bool
When false, the dropdown cannot be opened or searched.
final
error → Object?
Optional error to display in the panel (controlled mode).
final
errorBuilder → DropdownErrorBuilder?
Custom error UI. Receives onRetry for retry actions.
final
focusNode → FocusNode?
Optional focus node for the trigger button.
final
hashCode → int
The hash code for this object.
no setterinherited
hasMore → bool
Whether more items can be loaded via onLoadMore.
final
hintText → String
Placeholder text shown when no item is selected.
final
isLoadingMore → bool
Shows a loading footer while the next page loads.
final
itemBuilder → Widget Function(DropdownItem item, bool isSelected)?
Override the item row rendering.
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
loadingBuilder → DropdownEmptyBuilder?
Custom loading UI while items are loading.
final
loadingText → String?
Message shown while the cubit is loading.
final
Optional menu controller for programmatic open/close.
final
minSearchLength → int
Minimum query length before onSearch is invoked (empty query always fires).
final
needInitialFetch → bool
If true, onSearch is called with an empty string on widget mount.
final
noResultsText → String?
Message shown when the search returns no results.
final
onLoadMore → VoidCallback?
Called when the user scrolls near the bottom of the item list.
final
onRetry → VoidCallback?
Called when the user taps retry in the default error UI.
final
onSearch → void Function(String query)
Called whenever the user types in the search box.
final
onSelectionChanged → void Function(DropdownItem item)?
Called when the user picks an item. Not called for programmatic updates via selectedValue.
final
onStateChange → void Function(S state, void updateList(List<DropdownItem>), void updateLoading(bool))
Maps incoming BLoC/Cubit states to list updates.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
searchHint → String?
Hint text shown inside the search input. Defaults to 'Search…'.
final
selectedValue → DropdownItem?
Pre-selected item (controlled mode). When provided, the parent owns the selection state.
final
selectedValueBuilder → Widget Function(DropdownItem selectedItem)?
Override how the selected value is displayed in the trigger button.
final
semanticsLabel → String?
Semantics label for the trigger button.
final
themeStyle → DropdownPlusThemeStyle?
Preset theme style. Ignored when dropdownTheme is non-null. Use for out-of-the-box looks: DropdownPlusThemeStyle.minimal, DropdownPlusThemeStyle.dark, etc.
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<SearchableDropdownPlus<C, S>>
Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String
A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String
Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String
Returns a one-line detailed description of the object.
inherited
toStringShort() → String
A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited