Tip:
  Before moving to the next section,
  change CrossAxisAlignment.start to another value.

Flexible widget

Compares itself against other flex
properties before determining what fraction of the
total remaining space each Flexible widget receives.

Determines whether a Flexible widget
fills all of its extra space.

Example: Changing fit properties

The following example demonstrates the fit property,
  which can have one of two values:

The widget’s preferred size is used. (Default)

Forces the widget to fill all of its extra space.

In this example, change the fit properties to
  make the Flexible widgets fill the extra space.

1. Click the Run button.

2. Change both fit values to FlexFit.tight,
         and run again.

Example: Testing flex values