Flutter - FloatingActionButton

Last Updated : 17 Mar, 2025

A FloatingActionButton is a circular icon button that hovers over content to promote a primary action in the application. Floating action buttons are most commonly used in the Scaffold.floatingActionButton field.

Constructor

FloatingActionButton FloatingActionButton({
    Key? key,
    Widget? child,
    String? tooltip,
    Color? foregroundColor,
    Color? backgroundColor,
    Color? focusColor,
    Color? hoverColor,
    Color? splashColor,
    Object? heroTag = const _DefaultHeroTag(),
    double? elevation,
    double? focusElevation,
    double? hoverElevation,
    double? highlightElevation,
    double? disabledElevation,
    required void Function()? onPressed,
    MouseCursor? mouseCursor,
    bool mini = false,
    ShapeBorder? shape,
    Clip clipBehavior = Clip.none,
    FocusNode? focusNode,
    bool autofocus = false,
    MaterialTapTargetSize? materialTapTargetSize,
    bool isExtended = false,
    bool? enableFeedback,
})

Properties

Property

Description

autofocus

This property takes a boolean value as an object (final) to decide whether the button will be selected on the initial focus.

backgroundColor

Background color of FloatingActionButton.

child

The widget below this widget in the tree.

disabledElevation

With a double value as the object this property decides the location of the button on the z-coordinate when the button is disabled.

elevation

Again this property takes in a double as the object. And it controls the location on the z-coordinate on which the button will be placed.

focusColor

This property decided the color to be filled in the button at the time of input focus. It takes in Color class as the object.

focusNode

It provides an optional focus node to use as the focus node for this widget.

foregroundColor

It controls the default color of the text and icon inside the button.

heroTag

This is to add a hero tag to one of the widgets in the button

highlightElevation

This property controls the location of the z-axis on which to place the button while the user interacts with it.

hoverColor

This property holds the Color class as the object. It controls the color to be painted in the button at the event of hover.

hoverElevation

This property takes in a double value as the parameter to decide the height of the button on the z-axis on which the button should be place t the time of hover.

isExtended

This property takes in a boolean value as the object. If it is set to true then the button becomes an extended floating action button.

materialTapTargetSize

This property is there to control the tap target size of the button.

mini

It controls the size of the button.

mouseCursor

This property takes in MouseCursor property as the object. It controls the cursor for the mouse pointer when it interacts with the button.

onPressed

The callback that is called when the button is tapped or otherwise activated.

splashColor

Splash color of FloatingActionButton.

shape

the shape of the FloatingActionButton.

floatingActionButtonLocation

Responsible for determining where the floatingActionButton should go.

Example of FloatingActionButton in Flutter

main.dart

Dart 
import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'FAB',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
      debugShowCheckedModeBanner: false,
    );
  }
}

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

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          "FloatingActionButton",
        ),
        backgroundColor: Colors.green,
        foregroundColor: Colors.white,
      ),
      
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text("Floating action button pressed this many times"),
            Text(
              "$i",
              textScaleFactor: 3,
            )
          ],
        ),
      ),
      
      floatingActionButtonLocation: FloatingActionButtonLocation.endFloat,
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        backgroundColor: Colors.green,
        foregroundColor: Colors.white,
        onPressed: () {
          setState(() {
            i++;
          });
        },
      ),
    );
  }
}

Output:

If the properties are defined as below:

floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        backgroundColor: Colors.green,
        foregroundColor: Colors.white,
        onPressed: () {
          setState(() {
            i++;
          });
        },
      ),

The following design changes can be observed:

centerdocked


If the properties are defined as below:

floatingActionButtonLocation: FloatingActionButtonLocation.endDocked,
floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        backgroundColor: Colors.green,
        foregroundColor: Colors.white,
        onPressed: () {
          setState(() {
            i++;
          });
        },
      ),

The following design changes can be observed:

endDockedFAB


If the properties are defined as below:

floatingActionButtonLocation: FloatingActionButtonLocation.startDocked,
floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        backgroundColor: Colors.green,
        foregroundColor: Colors.white,
        onPressed: () {
          setState(() {
            i++;
          });
        },
      ),

The following design changes can be observed:

startDockedFAB

Final Output:

Complete code is available on Click here to access it.

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Article Tags:
Flutter
Flutter
Flutter-Widgets

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