Flutter showmenu position

Positioning the ShowMenu in Flutter:

In Flutter, the `showMenu` method is used to display a popup menu when a user interacts with certain UI elements. The `showMenu` method allows you to specify the position of the menu relative to the UI element.

Basic Syntax:

    
      showMenu(
        context: context,
        position: RelativeRect.fromLTRB(left, top, right, bottom),
        items: [...],
      );
    
  

Explanation:

• context: The build context of the current widget.
• position: Defines the position of the menu relative to the UI element. It is defined using `RelativeRect.fromLTRB(left, top, right, bottom)` where the parameters specify the distances from the left, top, right, and bottom edges of the element.
• items: The list of `PopupMenuEntry` items that define the menu. These can be `ListTile`, `PopupMenuItem`, or `PopupMenuDivider` widgets.

Examples:

Example 1 – Showing Menu Below a Button:

    
      ElevatedButton(
        onPressed: () {
          final RenderBox box = context.findRenderObject();
          final menuHeight = 100; // Height of the menu

          showMenu(
            context: context,
            position: RelativeRect.fromLTRB(
              0,
              box.size.height,
              0,
              box.size.height + menuHeight,
            ),
            items: [
              PopupMenuItem(
                child: Text('Menu Item 1'),
                value: 1,
              ),
              PopupMenuItem(
                child: Text('Menu Item 2'),
                value: 2,
              ),
              // additional menu items...
            ],
          );
        },
        child: Text('Show Menu'),
      );
    
  

In this example, when the button is pressed, the `showMenu` method is called. The menu is positioned below the button by adding the height of the button to the top and bottom values of `RelativeRect.fromLTRB()`.

Example 2 – Showing Menu Above a TextField:

    
      TextField(
        onTap: () {
          final RenderBox box = context.findRenderObject();
          final menuHeight = 150; // Height of the menu

          showMenu(
            context: context,
            position: RelativeRect.fromLTRB(
              0,
              -(box.size.height + menuHeight),
              0,
              -box.size.height,
            ),
            items: [
              PopupMenuItem(
                child: Text('Copy'),
                value: 'copy',
              ),
              PopupMenuItem(
                child: Text('Paste'),
                value: 'paste',
              ),
              // additional menu items...
            ],
          );
        },
        decoration: InputDecoration(
          labelText: 'Text Field',
        ),
      );
    
  

In this example, when the user taps on the text field, the `showMenu` method is called. The menu is positioned above the text field by subtracting the height of the text field and the menu from the top and bottom values of `RelativeRect.fromLTRB()`.