How to detect when a TextField is focused

In Flutter, a TextField is a commonly used widget for accepting user input. Sometimes, you might want to know when a TextField is in focus so that you can perform specific actions or update the UI accordingly. In this article, we will discuss how to detect when a TextField is focused using Flutter.

Using the FocusNode class

Flutter provides the FocusNode class, which represents a node in the focus hierarchy. We can use this class to detect when a TextField is focused. Here's how:

1. Create a FocusNode object in your widget's state:

FocusNode _focusNode = FocusNode();

2. Assign the focusNode property of the TextField widget to the _focusNode object:

TextField(
  focusNode: _focusNode,
  // other properties
)

3. Add a listener to the _focusNode object to detect focus changes:

_focusNode.addListener(() {
  if (_focusNode.hasFocus) {
    // TextField is focused
    // Perform actions or update the UI
  } else {
    // TextField lost focus
    // Perform actions or update the UI
  }
});

By adding a listener to the _focusNode object, we can detect when the TextField gains or loses focus. Inside the listener, you can perform specific actions or update the UI as needed.

Summary

Detecting when a TextField is focused is essential for building interactive and responsive user interfaces in Flutter. By using the FocusNode class, we can easily listen for focus changes and perform actions accordingly. With this knowledge, you can now enhance your Flutter apps by responding to TextField focus events.