A widget that controls the placement of a child in a grid.
The placementData this widget associates with the child is interpreted by the grid's GridDelegate in its GridDelegate.getChildPlacement function. During layout, the grid calls the delegate's GridDelegate.getChildPlacement function for each child, passing the placementData associated with that child as context. The return value of GridDelegate.getChildPlacement is then used to determine the size and position of that child within the grid.
A GridPlacementData widget must be a descendant of a GridRenderObjectWidget, and the path from the GridPlacementData widget to its enclosing GridRenderObjectWidget must contain only StatelessWidgets or StatefulWidgets (not other kinds of widgets, like RenderObjectWidgets).
- Inheritance
- Object
- Widget
- ProxyWidget
- ParentDataWidget<GridRenderObjectWidget>
- GridPlacementData
Constructors
- GridPlacementData({Key key, @required DataType placementData, @required Widget child })
-
Creates a widget that controls placement of a child in a grid.
Properties
- placementData → DataType
-
Opaque data passed to the getChildPlacement method of the grid's GridDelegate.
read-only - child → Widget
-
The widget below this widget in the tree.
read-only, inherited - hashCode → int
-
Get a hash code for this object.
read-only, inherited - key → Key
-
Controls how one widget replaces another widget in the tree.
read-only, inherited - runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
Operators
-
operator ==(
other) → bool -
The equality operator.
inherited
Methods
-
applyParentData(
RenderObject renderObject) → void -
Write the data from this widget into the given render object's parent data.
-
debugFillDescription(
List<String> description) → void -
Add additional information to the given description for use by
toString. -
createElement(
) → ParentDataElement<GridRenderObjectWidget> -
Inflates this configuration to a concrete instance.
inherited -
debugDescribeInvalidAncestorChain(
{String description, String ownershipChain, bool foundValidAncestor, Iterable<Widget> badAncestors }) → String -
Subclasses should override this to describe the requirements for using the ParentDataWidget subclass. It is called when debugIsValidAncestor() returned false for an ancestor, or when there are extraneous ParentDataWidgets in the ancestor chain.
inherited -
debugIsValidAncestor(
RenderObjectWidget ancestor) → bool -
Subclasses should override this method to return true if the given ancestor is a RenderObjectWidget that wraps a RenderObject that can handle the kind of ParentData widget that the ParentDataWidget subclass handles.
inherited -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed.
inherited -
toString(
) → String -
Returns a string representation of this object.
inherited -
toStringShort(
) → String -
A short, textual description of this widget.
inherited