Explain the working principle of the constraints system for a widget and how it is applied.

In Flutter, the constraints system determines the size a widget can have during rendering. Each widget receives a set of constraints from its parent — the minimum and maximum width and height within which it must be placed.

How it works:

• The parent passes constraints to the child widget.
• The child widget chooses a size that satisfies these constraints.
• Then, the parent positions the child widget with the chosen size.

For example, if the parent sets constraints from 0 to 100 for width and height, the child widget cannot go beyond these limits.

This allows flexible management of widget sizes and placement, ensuring interface adaptability.

Example:

Container(
  constraints: BoxConstraints(
    minWidth: 50,
    maxWidth: 100,
    minHeight: 50,
    maxHeight: 100,
  ),
  child: Text('Limited widget'),
)