Flutter TypeAhead

A TypeAhead (autocomplete) widget for Flutter, where you can show suggestions to users as they type

Features

• Shows suggestions in an floating box with the same width as your TextField
• Allows controlling all aspects: suggestions, loading, errors, empty, animation, decoration, layout, etc.
• Comes in both Material and Cupertino widget flavors

For installation, see installation instructions.

Usage

You can import the package with:

import 'package:flutter_typeahead/flutter_typeahead.dart';

The package comes in both Material and Cupertino widget flavors. All parameters identical, the only changes are the visual defaults.

Basic

TypeAheadField<City>(
  suggestionsCallback: (search) => CityService.of(context).find(search),
  builder: (context, controller, focusNode) {
    return TextField(
      controller: controller,
      focusNode: focusNode,
      autofocus: true,
      decoration: InputDecoration(
        border: OutlineInputBorder(),
        labelText: 'City',
      )
    );
  },
  itemBuilder: (context, city) {
    return ListTile(
      title: Text(city.name),
      subtitle: Text(city.country),
    );
  },
  onSelected: (city) {
    Navigator.of(context).push<void>(
      MaterialPageRoute(
        builder: (context) => CityPage(city: city),
      ),
    );
  },
)

Customizing the layout

By default, TypeAhead uses a ListView to render the items created by itemBuilder.
You may specify a custom layout via the listBuilder property.

For example, to use a GridView:

TypeAheadField(
  // ...
  listBuilder: (context, children) => GridView.count(
    controller: scrollContoller,
    crossAxisCount: 2,
    crossAxisSpacing: 8,
    mainAxisSpacing: 8,
    shrinkWrap: true,
    reverse: SuggestionsController.of<City>(context).effectiveDirection ==
        VerticalDirection.up,
    children: children,
  ),
);

Note: To inherit the correct ScrollController, please do not set primary to false. The suggestions box will automatically provide an ambient PrimaryScrollController.

Customizing the TextField

The TypeAheadField will use a simple default TextField builder, if none is provided. To customize your TextField, you can use the builder property.

You may also use a TextFormField or any other widget that connects to a TextEditingController and FocusNode.

TypeAheadField(
  // ...
  builder: (context, controller, focusNode) {
    return TextField(
      controller: controller,
      focusNode: focusNode,
      obscureText: true,
      decoration: InputDecoration(
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(8),
        ),
        labelText: 'Password',
      ),
    );
  },
);

It is crucial that you use the provided controller and focusNode properties, as they are required for the suggestions box to function.

Customizing the suggestions box

The TypeAheadField will use a simple default decoration builder. To customize the suggestions box, you can create your own decoration builder. You may also specify offsets and constraints to position the suggestions box.

TypeAheadField(
  // ...
  decorationBuilder: (context, child) {
    return Material(
      type: MaterialType.card,
      elevation: 4,
      borderRadius: BorderRadius.circular(8),
      child: child,
    );
  },
  offset: Offset(0, 12),
  constraints: BoxConstraints(maxHeight: 500),
);

Customizing the loading, error and empty message

You can use the loadingBuilder, errorBuilder and emptyBuilder to customize their corresponding widgets.

For example:

TypeAheadField(
  // ...
  loadingBuilder: (context) => const Text('Loading...'),
  errorBuilder: (context, error) => const Text('Error!'),
  emptyBuilder: (context) => const Text('No items found!'),
);

By default, the suggestions box will maintain the old suggestions while new suggestions are being retrieved. To show a circular progress indicator during retrieval instead, set keepSuggestionsOnLoading to false.

Hiding the suggestions box

You may want to hide the suggestions box when it is in certain states. You can do so with the following parameters:

• hideOnLoading: Hide the suggestions box while suggestions are being retrieved. This ignores the loadingBuilder.
• hideOnEmpty: Hide the suggestions box when there are no suggestions. This ignores the emptyBuilder.
• hideOnError: Hide the suggestions box when there is an error retrieving suggestions. This ignores the errorBuilder.
• hideOnSelect: Hide the suggestions box when a suggestion is selected. True by default.
• hideOnUnfocus: Hide the suggestions box when the TextField loses focus. True by default.
• hideWithKeyboard: Hide the suggestions box when the keyboard is hidden. True by default.

You can also very generally hide the suggestions box by returning null from the suggestionsCallback. This is different from returning an empty list, which will show the empty widget.

Customizing the animation

Animation duration can be customized using the animationDuration parameter. You may also specify a custom animation using the transitionBuilder parameter.

For example:

TypeAheadField(
  // ...
  transitionBuilder: (context, animation, child) {
    return FadeTransition(
      opacity: CurvedAnimation(
        parent: animation,
        curve: Curves.fastOutSlowIn
      ),
      child: child,
    ),
  },
);

To disable animatons, return the child directly.

Customizing the debounce duration

The suggestions box does not fire for each character the user types. Instead, we wait until the user is idle for a duration of time, and then call the suggestionsCallback. The duration defaults to 300 milliseconds``, but can be configured using the debounceDuration` parameter.

Customizing the direction

By default, the list grows towards the bottom. However, you can use the direction to specify either VerticalDirection.down or VerticalDirection.up.

The suggestions list will automatically reverse in case it is flipped. To turn off this behavior, set autoFlipDirection to false.

Controlling the suggestions box

You may manually control many aspects of the suggestions box by using the SuggestionsController class.

It grants access to the following:

• the current suggestions
• the current loading state
• the current error
• the open/closed state
• the desired and effective direction
• the stream of selected suggestions
• the callback to trigger a resize

When building a widget inside of the suggestions box, you can access the controller via SuggestionsController.of(context).

Controlling the focus

Focus plays an important role in the suggestions box. It is used to determine when to show and hide the suggestions box. However, in certain situations you may want to control the suggestions box independently of the focus.

Options to do so are as follows:

On the TypeAheadField:

• showOnFocus (default: true): Show the suggestions box when the TextField gains focus.
• hideOnUnfocus (default: true): Hide the suggestions box when the TextField loses focus.

On the SuggestionsController:

• open(gainFocus: false): Show the suggestions box without focusing it.
• close(retainFocus: true): Hide the suggestions box without unfocusing it.

Customizing everything

To create your own version of the TypeAhead widget, that is neither Material nor Cupertino, you can use the RawTypeAheadField widget.

You must then specify the following parameters:

• builder (to build the TextField)
• loadingBuilder (to build the loading widget)
• errorBuilder (to build the error widget)
• emptyBuilder (to build the empty widget)
• itemBuilder (to build the suggestions)

As well as all the usual parameters, such as suggestionsCallback, onSelected, etc.

The decorationBuilder can be used to inject required wrappers like Material or DefaultTextStyle. For more information, see the source code of the TypeAheadField widget.

FAQ

My suggestions arent changing when I type

You have most likely forgotten to pass the controller and focus node to the TextField in the builder property. This is required for the suggestions box to function. Here is an example:

TypeAheadField(
  // ...
  controller: myTextEditingController, // your custom controller, or null
  builder: (context, controller, focusNode) {
    return TextField(
      controller: controller, // note how the controller is passed
      focusNode: focusNode,
      // ...
    );
  },
);

My suggestions are not updating when I click on the TextField

The TypeAhead field caches the suggestions to avoid unnecessary calls to the suggestionsCallback. If you want to force the suggestions to update, you can use the SuggestionsController to force a refresh.

mySuggestionsController.refresh();

Migrations

From 4.x to 5.x

Since version 5.x, the package is based on Dart 3 (null-safety enforced). To use this package, please upgrade your Flutter SDK.

Additionally, various changes have been made to the API surface to make the package more flexible and customizable. The following changes have been made:

• SuggestionsBoxDecoration has been removed. You can now directly wrap the SuggestionsBox with any widget you wish via the decorationBuilder property.
• TextFieldConfiguration has been removed. You can now directly build your own custom TextField via the builder property. Note that you must use the provided controller and focusNode properties, as they are required for the suggestions box to function.
• SuggestionsBoxController has been renamed to SuggestionsController.
• CupertinoSuggestionsBoxController has been merged into SuggestionsController.
• SuggestionsController now holds the full state of the suggestions box, meaning suggestions, loading and error state. It will also send notifications when state changes occur.
• SuggestionsController now offers streams for when a suggestion is selected.
• SuggestionsBox should now automatically resize in all situations. Manual resize calls are no longer required.
• TypeAheadFormField has been removed. You can use the builder property to build your own TextFormField.
• Various parameters have been renamed to be shorter and more concise. Notable changes include:
  • suggestionsBoxController -> suggestionsController
  • layoutArchitecture -> listBuilder
  • noItemsFoundBuilder-> emptyBuilder
  • onSuggestionSelected -> onSelected
  • suggestionsBoxVerticalOffset -> offset (now also includes horizontal offset)
  • hideSuggestionsOnKeyboardHide -> hideWithKeyboard
  • keepSuggestionsOnSuggestionSelected -> hideOnSelect (inverted)
  • keepSuggestionsOnLoading-> retainOnLoading
• Some parameters have been removed:
  • intercepting: This is now always true, since it doesnt interfere on mobile platforms and generally has no downsides.
  • onSuggestionsBoxToggle: You can subscribe to the SuggestionsController to get notified when the suggestions box is toggled.
  • ignoreAccessibleNavigation: The new Overlay code no longer requires to act differently when accessibility is enabled.
  • minCharsForSuggestions: You can return an empty list from suggestionsCallback instead.
  • animationStart: You can use the animation in the builder and map it to customise this.
  • autoFlipListDirection: This is now always true. You can use the list builder to disable this behavior.
  • getImmediateSuggestions: You can use the debounceDuration to achieve the same effect.

From 2.x to 3.x

Since version 3.x, the package is based on Dart 2.12 (null-safety). Flutter now also features the inbuilt Autocomplete widget, which has similar behavior to this package.

For more information

Visit the API Documentation.

Team

AbdulRahman AlHamali	S McDowall	Kenneth Liang	clragon

Thank you

This project is the result of the collective effort of contributors who participated effectively by submitting pull requests, reporting issues, and answering questions. Thank you for your proactiveness, and we hope flutter_typeahead made your lifes at least a little easier!

If you would like to contribute, please read the Contribution Guidelines.