PositionedDirectional class

A widget that controls where a child of a Stack is positioned without committing to a specific TextDirection.

The ambient Directionality is used to determine whether start is to the left or to the right.

A PositionedDirectional widget must be a descendant of a Stack, and the path from the PositionedDirectional widget to its enclosing Stack must contain only StatelessWidgets or StatefulWidgets (not other kinds of widgets, like RenderObjectWidgets).

If a widget is wrapped in a PositionedDirectional, then it is a positioned widget in its Stack. If the top property is non-null, the top edge of this child/ will be positioned top layout units from the top of the stack widget. The start, bottom, and end properties work analogously.

If both the top and bottom properties are non-null, then the child will be forced to have exactly the height required to satisfy both constraints. Similarly, setting the start and end properties to non-null values will force the child to have a particular width. Alternatively the width and height properties can be used to give the dimensions, with one corresponding position property (e.g. top and height).

See also:

• Positioned, which specifies the widget's position visually.
• Positioned.directional, which also specifies the widget's horizontal position using start and end but has an explicit TextDirection.
• AnimatedPositionedDirectional, which automatically transitions the child's position over a given duration whenever the given position changes.