OverlayEntry Explained | Flutter for Web Developers

What’s OverlayEntry?

The OverlayEntry class in Flutter is a powerful tool that allows developers to create overlays, which are widgets that float above other widgets. This class is particularly useful for displaying temporary content, such as dialogs, menus, or tooltips. Key methods include ‘insert’, which adds the overlay to the widget tree, and ‘remove’, which removes it.

Check the official documentation for more.

OverlayEntry explained for Web Developers

From a web developer’s perspective, the OverlayEntry class can be compared to modal dialogs or popups in web frameworks like React or Angular. Just as these frameworks allow developers to create components that can overlay other content, Flutter’s OverlayEntry provides a similar capability. However, while web APIs often rely on DOM manipulation, Flutter’s approach is more widget-centric, allowing for a more seamless integration with the widget tree.

Example Code

Here is an example of how to use OverlayEntry:

OverlayEntry overlayEntry = OverlayEntry(
  builder: (context) => Positioned(
    top: 100.0,
    left: 100.0,
    child: Material(
      child: Container(
        width: 200.0,
        height: 100.0,
        color: Colors.blue,
        child: Center(child: Text('Overlay Entry')),
      ),
    ),
  ),
);

// To insert the overlay
Overlay.of(context).insert(overlayEntry);

// To remove the overlay
overlayEntry.remove();

OverlayEntry Remarks

In conclusion, the OverlayEntry class is a valuable asset for Flutter developers looking to create dynamic and interactive user interfaces. By understanding how to effectively use overlays, developers can enhance the user experience in their applications.