Dropdown Flutter

DropdownFlutter designed to enhance your Flutter application, offers highly customizable dropdowns with advanced features including list data search, network search, and multiple-selection.

Features

Lots of properties to use and customize dropdown widget as per your need. Also usable under Form widget for required validation.

• Dropdown Flutter using constructor DropdownFlutter().
• Dropdown Flutter with search field using named constructor DropdownFlutter.search().
• Dropdown Flutter with search request field using named constructor DropdownFlutter.searchRequest().
• Multi select Dropdown Flutter using named constructor DropdownFlutter.multiSelect().
• Multi select Dropdown Flutter with search field using named constructor DropdownFlutter.multiSelectSearch().
• Multi select Dropdown Flutter with search request field using named constructor DropdownFlutter.multiSelectSearchRequest().

Preview

---

Getting started

1. Add the latest version of package to your pubspec.yaml (and run flutter pub get):

dependencies:
  dropdown_flutter: 1.0.1

2. Import the package and use it in your Flutter App.

import 'package:dropdown_flutter/custom_dropdown.dart';

---

Example usage

1. Dropdown Flutter

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<String> _list = [
    'Developer',
    'Designer',
    'Consultant',
    'Student',
  ];

class SimpleDropdown extends StatelessWidget {
  const SimpleDropdown({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return DropdownFlutter<String>(
      hintText: 'Select job role',
      items: _list,
      initialItem: _list[0],
      onChanged: (value) {
        log('changing value to: $value');
      },
    );
  }
}

2. Dropdown Flutter with custom type model

Let's start with the type of object we are going to work with:

class Job {
  final String name;
  final IconData icon;
  const Job(this.name, this.icon);

  @override
  String toString() {
    return name;
  }
}

Whenever you are going to work with custom type model T, your model must override the default toString() method and return the property inside that you want to display as list item otherwise the dropdown list item would show Instance of [model name].

Now the widget:

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<Job> _list = [
    Job('Developer', Icons.developer_mode),
    Job('Designer', Icons.design_services),
    Job('Consultant', Icons.account_balance),
    Job('Student', Icons.school),
  ];

class SimpleDropdown extends StatelessWidget {
  const SimpleDropdown({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return DropdownFlutter<Job>(
      hintText: 'Select job role',
      items: _list,
      onChanged: (value) {
        log('changing value to: $value');
      },
    );
  }
}

3. Dropdown Flutter with multiple selection

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<Job> _list = [
    Job('Developer', Icons.developer_mode),
    Job('Designer', Icons.design_services),
    Job('Consultant', Icons.account_balance),
    Job('Student', Icons.school),
  ];

class MultiSelectDropDown extends StatelessWidget {
  const MultiSelectDropDown({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return DropdownFlutter<Job>.multiSelect(
        items: _jobItems,
        initialItems: _jobItems.take(1).toList(),
        onListChanged: (value) {
          log('changing value to: $value');
        },
      );
  }
}

4. Dropdown Flutter with search: A Dropdown Flutter with the possibility to filter the items.

First, let's enhance our Job model with more functionality:

class Job with DropdownFlutterListFilter {
  final String name;
  final IconData icon;
  const Job(this.name, this.icon);

  @override
  String toString() {
    return name;
  }

  @override
  bool filter(String query) {
    return name.toLowerCase().contains(query.toLowerCase());
  }
}

If the filter on the object is more complex, you can add the DropdownFlutterListFilter mixin to it, which gives you access to the filter(query) method, and by this the items of the list will be filtered.

Now the widgets:

SearchDropdown

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<Job> _list = [
    Job('Developer', Icons.developer_mode),
    Job('Designer', Icons.design_services),
    Job('Consultant', Icons.account_balance),
    Job('Student', Icons.school),
  ];

class SearchDropdown extends StatelessWidget {
  const SearchDropdown({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return DropdownFlutter<Job>.search(
      hintText: 'Select job role',
      items: _list,
      excludeSelected: false,
      onChanged: (value) {
        log('changing value to: $value');
      },
    );
  }
}

MultiSelectSearchDropdown

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<Job> _list = [
    Job('Developer', Icons.developer_mode),
    Job('Designer', Icons.design_services),
    Job('Consultant', Icons.account_balance),
    Job('Student', Icons.school),
  ];

class MultiSelectSearchDropdown extends StatelessWidget {
  const SearchDropdown({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return DropdownFlutter<Job>.multiSelectSearch(
      hintText: 'Select job role',
      items: _list,
      onListChanged: (value) {
        log('changing value to: $value');
      },
    );
  }
}

5. Dropdown Flutter with search request: A Dropdown Flutter with a search request to load the items.

Let's use a personalized object for the items:

class Pair {
  final String text;
  final IconData icon;
  const Pair(this.text, this.icon);

  @override
  String toString() {
    return text;
  }
}

Now the widgets:

SearchRequestDropdown

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<Pair> _list = [
    Pair('Developer', Icons.developer_board),
    Pair('Designer', Icons.deblur_sharp),
    Pair('Consultant', Icons.money_off),
    Pair('Student', Icons.edit),
  ];

class SearchRequestDropdown extends StatelessWidget {
  const SearchRequestDropdown({Key? key}) : super(key: key);

  // This should be a call to the api or service or similar
  Future<List<Pair>> _getFakeRequestData(String query) async {
    return await Future.delayed(const Duration(seconds: 1), () {
      return _list.where((e) {
        return e.text.toLowerCase().contains(query.toLowerCase());
      }).toList();
    });
  }

  @override
  Widget build(BuildContext context) {
    return DropdownFlutter<Pair>.searchRequest(
      futureRequest: _getFakeRequestData,
      hintText: 'Search job role',
      items: _list,
      onChanged: (value) {
        log('changing value to: $value');
      },
    );
  }
}

MultiSelectSearchRequestDropdown

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<Pair> _list = [
    Pair('Developer', Icons.developer_board),
    Pair('Designer', Icons.deblur_sharp),
    Pair('Consultant', Icons.money_off),
    Pair('Student', Icons.edit),
  ];

class MultiSelectSearchRequestDropdown extends StatelessWidget {
  const MultiSelectSearchRequestDropdown({Key? key}) : super(key: key);

  // This should be a call to the api or service or similar
  Future<List<Pair>> _getFakeRequestData(String query) async {
    return await Future.delayed(const Duration(seconds: 1), () {
      return _list.where((e) {
        return e.text.toLowerCase().contains(query.toLowerCase());
      }).toList();
    });
  }

  @override
  Widget build(BuildContext context) {
    return DropdownFlutter<Pair>.multiSelectSearchRequest(
      futureRequest: _getFakeRequestData,
      hintText: 'Search job role',
      onListChanged: (value) {
        log('changing value to: $value');
      },
    );
  }
}

6. Dropdown Flutter with validation: A Dropdown Flutter with validation.

ValidationDropdown

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<String> _list = [
    'Developer',
    'Designer',
    'Consultant',
    'Student',
  ];

class ValidationDropdown extends StatelessWidget {
  ValidationDropdown({Key? key}) : super(key: key);

  final _formKey = GlobalKey<FormState>();

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          DropdownFlutter<String>(
            hintText: 'Select job role',
            items: _list,
            onChanged: (value) {
              log('changing value to: $value');
            },
            // Run validation on item selected
            validateOnChange: true,
            // Function to validate if the current selected item is valid or not
            validator: (value) => value == null ? "Must not be null" : null,
          ),
          const SizedBox(height: 16),
          SizedBox(
            width: double.infinity,
            child: ElevatedButton(
              onPressed: () {
                if (!_formKey.currentState!.validate()) return;
              },
              child: const Text(
                'Submit',
                style: TextStyle(fontWeight: FontWeight.w600),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

MultiSelectValidationDropdown

import 'package:dropdown_flutter/custom_dropdown.dart';
import 'package:flutter/material.dart';
import 'dart:developer';

const List<String> _list = [
    'Developer',
    'Designer',
    'Consultant',
    'Student',
  ];

class MultiSelectValidationDropdown extends StatelessWidget {
  MultiSelectValidationDropdown({Key? key}) : super(key: key);

  final _formKey = GlobalKey<FormState>();

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          DropdownFlutter<String>.multiSelect(
            hintText: 'Select job role',
            items: _list,
            onListChanged: (value) {
              log('changing value to: $value');
            },
            listValidator: (value) => value.isEmpty ? "Must not be null" : null,
          ),
          const SizedBox(height: 16),
          SizedBox(
            width: double.infinity,
            child: ElevatedButton(
              onPressed: () {
                if (!_formKey.currentState!.validate()) return;
              },
              child: const Text(
                'Submit',
                style: TextStyle(fontWeight: FontWeight.w600),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

Customization

For a complete customization of the package, go to the example.

Issues & Feedback

Please file an issue to send feedback or report a bug. Thank you!