10 Advanced Flutter Widgets for Building Complex User Interfaces

Rounding up the widgets that are helping take cross-platform app development to the next level.

Photo by Hal Gatewood on Unsplash

As a seasoned Flutter developer with over 4 years of experience developing hybrid applications, I have had the opportunity to work on deploying applications for multiple platforms, including Android, iOS, and the web, from a single codebase. During this time, I have come across several advanced Flutter widgets that have proven to be incredibly useful in designing cross-platform applications. In this article, I’m sharing few of the top advanced widgets that made my job so much easier.

Flutter

Flutter is a popular open-source framework for building cross-platform mobile applications. One of its key strengths is the large collection of customisable widgets that make it easy to create beautiful and functional user interfaces.

To know about setting it up, get started here.

Let us explore ten advanced Flutter widgets that can help you build complex and dynamic user interfaces.

1. AnimatedContainer

The AnimatedContainer widget is a convenient way to animate the properties of a container, such as its size, padding, and color. To use this widget, simply wrap it around another widget and specify the properties you want to animate. Here’s an example that animates the width of a container over 500 milliseconds:

AnimatedContainer(
  duration: Duration(milliseconds: 500),
  width: _width,
  child: Container(
    color: Colors.red,
  ),
);

2. Stack

The Stack widget is a powerful layout widget that allows you to stack widgets on top of each other. You can specify the alignment and position of each child widget within the stack, making it a great choice for creating layered user interfaces. Here’s an example that stacks two containers vertically and centers them within the parent stack:

Stack(
  alignment: Alignment.center,
  children: [
    Container(
      width: 100,
      height: 100,
      color: Colors.red,
    ),
    Container(
      width: 50,
      height: 50,
      color: Colors.blue,
    ),
  ],
);

3. Expanded

The Expanded widget is used to control the distribution of space within a Flex layout. You can use it to make one widget take up more space than the others within the same row or column. Here’s an example that creates a row with two Expanded widgets and a Text widget, where the first Expanded widget takes up 2 times more space than the other:

Row(
  children: [
    Expanded(
      flex: 2,
      child: Container(
        color: Colors.red,
      ),
    ),
    Expanded(
      child: Container(
        color: Colors.blue,
      ),
    ),
    Text("Hello World"),
  ],
);

4. AnimatedOpacity

The AnimatedOpacity widget is similar to the AnimatedContainer widget, but it animates the opacity of its child widget. You can use it to fade a widget in or out, for example, when navigating between screens or showing/hiding a menu. Here’s an example that fades in a Container over 500 milliseconds:

AnimatedOpacity(
  opacity: _opacity,
  duration: Duration(milliseconds: 500),
  child: Container(
    color: Colors.red,
  ),
);

5. Draggable

The Draggable widget is a powerful tool for creating drag-and-drop interactions in Flutter. You can use it to create widgets that can be dragged and dropped within a parent widget or even between different widgets. Here’s an example that creates a Draggable widget that can be dragged within a Container:

Draggable(
  child: Container(
    color: Colors.red,
  ),
  feedback: Container(
    color: Colors.red.withOpacity(0.5),
  ),
);

6. GestureDetector

The GestureDetector widget is used to detect gestures, such as taps, drags, and scaling, on its child widget. You can use it to create interactive widgets that respond to user input. Here’s an example that creates a GestureDetector that responds to taps and changes the background color of a Container:

GestureDetector(
  onTap: () {
    setState(() {
      _color = Colors.green;
    });
  },
  child: Container(
    color: _color,
  ),
);

7. Transform

The Transform widget allows you to apply transformations, such as rotations, translations, and scalings, to its child widget. You can use it to create complex animations and visual effects. Here’s an example that rotates a Container by 45 degrees:

Transform.rotate(
  angle: 45,
  child: Container(
    color: Colors.red,
  ),
);

8. Hero

The Hero widget is used to create smooth animations between two pages in Flutter. You can use it to create a shared element transition, where an element animates from one screen to another. Here’s an example that creates a Hero widget that animates a Container between two screens:

Hero(
  tag: "hero",
  child: Container(
    color: Colors.red,
  ),
);

9. ClipRRect

The ClipRRect widget is used to clip its child widget to a rounded rectangle. You can use it to create rounded corners, for example, on images or containers. Here’s an example that creates a ClipRRect widget that clips a Container to a rounded rectangle:

ClipRRect(
  borderRadius: BorderRadius.all(Radius.circular(10)),
  child: Container(
    color: Colors.red,
  ),
);

10. AnimatedSwitcher

The AnimatedSwitcher widget is used to switch between different widgets with an animation. You can use it to create dynamic and interactive user interfaces, for example, when switching between different screens or data. Here’s an example that creates an AnimatedSwitcher widget that switches between two Containers:

AnimatedSwitcher(
  duration: Duration(milliseconds: 500),
  child: _isRed ? Container(key: UniqueKey(), color: Colors.red) : Container(key: UniqueKey(), color: Colors.blue),
);

Conclusion

In conclusion, these ten advanced Flutter widgets can help you build complex and dynamic user interfaces with ease. By combining them with other Flutter widgets and tools, you can create beautiful, interactive, and performant mobile applications. Happy coding!

I hope this article helped you in brushing up on a few advanced Flutter widgets. Let me know your experiences and thoughts about the widgets listed. Have you used any of them in your projects? Did you face challenges or have tips to share? Which other advanced Flutter widgets do you think we should include in the list? Your feedback and experiences benefit the Flutter community. Share them in the comments below. Thank you! :)

My LinkedIn is open for connections and discussions.

Read more about Advanced Flutter and Declarative Programming —

Streaming Flutter Events With Mosquitto MQTT Broker

The Burger Analogy: For Imperative vs. Declarative Styles of Programming