How to have togglebutton take the whole space in a container?

Solution 1:

To get the full width ToggleButtons you can use LayoutBuilder.

LayoutBuilder(
  builder: (context, constraints) => ToggleButtons(
    constraints: BoxConstraints.expand(width: constraints.maxWidth/2),
    ....
    Your CODE
    ....
  )
);

This will dynamically expand your ToggleButtons to full width.