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ExtendableDropdown

A Versatile Flutter Package for Dynamic, Generic Dropdown Menus (v1.0.4)

Introducing ExtendableDropdown, a production-ready Flutter package that empowers you to create dynamic and expandable multiple dropdown menus with full support for generic data types.

🚀 Key Features

• Generic Type Support: Handle any data type (T) with full type safety. No longer restricted to strings!
• Dynamic Slot Management: Add or remove dropdown slots on the fly with a simple, intuitive UI.
• Dismissible Interaction: Swipe-to-dismiss functionality for removing selections with item return logic.
• labelBuilder API: Complete control over how your custom objects are rendered as text in the dropdown.
• Configurable UI Fragments: Pass your own Widgets for the Add Button and custom callbacks for message handling.
• Fully Mutable-Safe: Built with immutability in mind, following Flutter's best practices for widget design.

📦 Installation

Add extendable_dropdown as a dependency in your pubspec.yaml file:

dependencies:
  extendable_dropdown: ^1.0.4

Import the package in your Flutter code:

import 'package:extendable_dropdown/extendable_dropdown.dart';

🛠 Usage

Simple Usage (Strings)

List<String> cities = ['Colombo', 'Kandy', 'Galle', 'Jaffna'];

ExtendableDropdown<String>(
  list: cities,
  onSendListChanged: (selectedItems) {
    print('Selected cities: $selectedItems');
  },
)

Advanced Usage (Custom Objects & UI)

You can use any custom model and fully override the UI.

ExtendableDropdown<Location>(
  list: myLocationList,
  onSendListChanged: (selected) => print(selected),
  labelBuilder: (location) => location.name,
  // Completely custom add button
  addButton: ElevatedButton.icon(
    onPressed: null, // Logic is handled internally
    icon: Icon(Icons.add),
    label: Text("Add Location"),
  ),
  // Custom notification logic
  onMessage: (context, message) {
    MyCustomToast.show(message);
  },
)

🎨 Professional Customization

ExtendableDropdown comes with a wide range of styling options:

Property	Description	Default
list	The initial list of items to choose from.	Required
onSendListChanged	Callback triggered when the selection changes.	Required
labelBuilder	Function to map generic items to strings.	item.toString()
addButton	Widget: Custom widget for the add button.	Styled default button
onMessage	Callback: Handle custom alerts/notifications.	Default SnackBar
dismissibleBackgroundColor	Color shown when swiping to delete.	Colors.red
selectedIcon	Icon shown for a selected slot.	Icons.radio_button_checked
nonSelectedIcon	Icon shown for an empty slot.	Icons.location_on_outlined
dropdownBorderRadius	Border radius of the dropdown container.	10.0

Check out the [example](file:///Users/mymac/Documents/MyProjects/extendable_dropdown/example/lib/main.dart) folder for a full implementation!

🚧 Roadmap

• [x] Generic data type support (Completed)
• [x] Improved state management and immutability (Completed)
• [ ] Searchable dropdown options
• [ ] Multi-select within a single dropdown slot
• [ ] Custom animation support for slot addition

🤝 Contributing

We welcome your feedback and contributions! Please feel free to open issues or submit pull requests.

📄 License

This project is licensed under the MIT License - see the [LICENSE](file:///Users/mymac/Documents/MyProjects/extendable_dropdown/LICENSE) file for details.

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Made with ❤️ by Chanuka Ranathunga