Is there a way to add a notch above the center icon in BottomNavigationBar(Flutter)? Something like in this image:

FITFLOP

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01-10-2024

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Adding a Notch to Your Flutter BottomNavigationBar

Flutter's BottomNavigationBar is a versatile widget for creating navigation bars at the bottom of your app. However, sometimes you might want to add a visual element to the center icon, such as a notch or a visual highlight, to draw attention to it. Here's how you can achieve this:

The Problem:

Let's say you want to create a BottomNavigationBar where the center icon has a notch above it, similar to the image provided. The default BottomNavigationBar doesn't offer this feature directly.

Original Code:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _selectedIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('BottomNavigationBar with Notch'),
      ),
      body: Center(
        child: Text('You have pushed the button $_selectedIndex times.'),
      ),
      bottomNavigationBar: BottomNavigationBar(
        items: const <BottomNavigationBarItem>[
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            label: 'Home',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.search),
            label: 'Search',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.person),
            label: 'Profile',
          ),
        ],
        currentIndex: _selectedIndex,
        selectedItemColor: Colors.amber[800],
        onTap: (index) {
          setState(() {
            _selectedIndex = index;
          });
        },
      ),
    );
  }
}

Solution:

To add the notch, we need to use a combination of Stack and Positioned widgets. The Stack widget allows us to layer widgets on top of each other, while Positioned lets us control the position and size of each widget within the stack.

Here's the modified code:

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _selectedIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('BottomNavigationBar with Notch'),
      ),
      body: Center(
        child: Text('You have pushed the button $_selectedIndex times.'),
      ),
      bottomNavigationBar: BottomNavigationBar(
        items: const <BottomNavigationBarItem>[
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            label: 'Home',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.search),
            label: 'Search',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.person),
            label: 'Profile',
          ),
        ],
        currentIndex: _selectedIndex,
        selectedItemColor: Colors.amber[800],
        onTap: (index) {
          setState(() {
            _selectedIndex = index;
          });
        },
      ),
    );
  }
}

Explanation:

1. Stack: We wrap the BottomNavigationBar in a Stack widget. This allows us to place the notch above the navigation bar.

2. Positioned: We add a Positioned widget inside the Stack, placing it above the center icon of the BottomNavigationBar. The top property controls the vertical position of the notch.

3. Container: We use a Container as the visual representation of the notch. Here, we've used a solid color for simplicity. You can customize the shape, color, and size of the notch as needed.

Further Customization:

• You can adjust the top and height properties of the Positioned widget to fine-tune the notch's position.
• Customize the Container's appearance with different colors, borders, and shapes.
• Explore using other widgets like CustomPaint to create more complex notch designs.

Key Takeaways:

• Flutter's Stack and Positioned widgets provide a flexible way to layer and position elements within your UI.
• By carefully choosing the position and size of the Positioned widget, you can achieve various creative effects, such as adding notches or other elements.
• With some basic customization, you can create a visually appealing and unique BottomNavigationBar with a notch to highlight the center icon.

This example provides a starting point for creating a notched BottomNavigationBar. You can further customize it to fit your specific needs and app design. Remember to experiment with different properties and widgets to create a visually appealing and user-friendly navigation bar.