Focus and text fields

When a text field is selected and accepting input, it is said to have “focus.” Generally, users shift focus to a text field by tapping, and developers shift focus to a text field programmatically by using the tools described in this recipe.

Managing focus is a fundamental tool for creating forms with an intuitive flow. For example, say you have a search screen with a text field. When the user navigates to the search screen, you can set the focus to the text field for the search term. This allows the user to start typing as soon as the screen is visible, without needing to manually tap the text field.

In this recipe, learn how to give the focus to a text field as soon as it’s visible, as well as how to give focus to a text field when a button is tapped.

Focus a text field as soon as it’s visible

To give focus to a text field as soon as it’s visible, use the autofocus property.

TextField(
  autofocus: true,
);

For more information on handling input and creating text fields, see the Forms section of the cookbook.

Focus a text field when a button is tapped

Rather than immediately shifting focus to a specific text field, you might need to give focus to a text field at a later point in time. In the real world, you might also need to give focus to a specific text field in response to an API call or a validation error. In this example, give focus to a text field after the user presses a button using the following steps:

  1. Create a FocusNode.
  2. Pass the FocusNode to a TextField.
  3. Give focus to the TextField when a button is tapped.

1. Create a FocusNode

First, create a FocusNode. Use the FocusNode to identify a specific TextField in Flutter’s “focus tree.” This allows you to give focus to the TextField in the next steps.

Since focus nodes are long-lived objects, manage the lifecycle using a State object. Use the following instructions to create a FocusNode instance inside the initState() method of a State class, and clean it up in the dispose() method:

// Define a custom Form widget.
class MyCustomForm extends StatefulWidget {
  @override
  _MyCustomFormState createState() => _MyCustomFormState();
}

// Define a corresponding State class.
// This class holds data related to the form.
class _MyCustomFormState extends State<MyCustomForm> {
  // Define the focus node. To manage the lifecycle, create the FocusNode in
  // the initState method, and clean it up in the dispose method.
  FocusNode myFocusNode;

  @override
  void initState() {
    super.initState();

    myFocusNode = FocusNode();
  }

  @override
  void dispose() {
    // Clean up the focus node when the Form is disposed.
    myFocusNode.dispose();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    // Fill this out in the next step.
  }
}

2. Pass the FocusNode to a TextField

Now that you have a FocusNode, pass it to a specific TextField in the build() method.

class _MyCustomFormState extends State<MyCustomForm> {
  // Code to create the Focus node...

  @override
  Widget build(BuildContext context) {
    return TextField(
      focusNode: myFocusNode,
    );
  }
}

3. Give focus to the TextField when a button is tapped

Finally, focus the text field when the user taps a floating action button. Use the requestFocus() method to perform this task.

FloatingActionButton(
  // When the button is pressed, give focus to the text field using
  // myFocusNode.
  onPressed: () => myFocusNode.requestFocus(),
);

Interactive example

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Text Field Focus',
      home: MyCustomForm(),
    );
  }
}

// Define a custom Form widget.
class MyCustomForm extends StatefulWidget {
  @override
  _MyCustomFormState createState() => _MyCustomFormState();
}

// Define a corresponding State class.
// This class holds data related to the form.
class _MyCustomFormState extends State<MyCustomForm> {
  // Define the focus node. To manage the lifecycle, create the FocusNode in
  // the initState method, and clean it up in the dispose method.
  FocusNode myFocusNode;

  @override
  void initState() {
    super.initState();

    myFocusNode = FocusNode();
  }

  @override
  void dispose() {
    // Clean up the focus node when the Form is disposed.
    myFocusNode.dispose();

    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Text Field Focus'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: [
            // The first text field is focused on as soon as the app starts.
            TextField(
              autofocus: true,
            ),
            // The second text field is focused on when a user taps the
            // FloatingActionButton.
            TextField(
              focusNode: myFocusNode,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        // When the button is pressed,
        // give focus to the text field using myFocusNode.
        onPressed: () => myFocusNode.requestFocus(),
        tooltip: 'Focus Second Text Field',
        child: Icon(Icons.edit),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}