flutter - How to change PopupMenuButton offset

Flutter - PopupMenuButton Offset

The PopupMenuButton class allows us to display a menu when pressed and calls onSelected when the menu is dismissed because an item was selected. The value passed to onSelected is the value of the selected menu item. The flutter developers can provide one of a child or an icon but not both. If developers provide an icon then PopupMenuButton behaves like an IconButton. If both child and icon are null, then a standard overflow icon is created depending on the platform.

The following flutter app development tutorial will demonstrate how to set or change the offset value of a PopupMenuButton widget. Here we used the PopupMenuButton class’s offset property to set or change the PupupMenuButton widget’s default offset value.

The PopupMenuButton class’s offset property value is an Offset instance that is the offset is applied relative to the initial position set by the position. If the flutter developers do not set the PopupMenuButton widget’s offset value, the offset default value is Offset.zero.

The Offset class represents an immutable 2D floating-point offset. The Offset(double dx, double dy) constructor creates an offset. The first argument sets dx, the horizontal component, and the second sets dy, the vertical component.

The Offset class dx property value is a Double instance that is the x component of the offset. And the dy property value is also a Double instance that is the y component of the offset. So we can set the PopupMenuButton widget’s offset by passing an Offset instance value to its offset property.

main.dart

import 'package:flutter/material.dart';

void main(){
  runApp(
    MaterialApp(
      theme: ThemeData(primarySwatch: Colors.indigo),
      home: Scaffold(
        appBar: AppBar(
          title: const Text("PopupMenuButton Offset"),
          actions: [
            PopupMenuButton(
              itemBuilder: (context) => [
                const PopupMenuItem(child: Text("First Item")),
                const PopupMenuItem(child: Text("Second Item")),
                const PopupMenuItem(child: Text("Third Item"))
              ],
              color: Colors.blueGrey.shade50,
              offset: const Offset(0, 56),
              shape: const RoundedRectangleBorder(
                  borderRadius: BorderRadius.only(
                      bottomLeft: Radius.circular(12)
                  )
              ),
            )
          ],
        ),
      ),
    ),
  );
}