TwoDimensionalViewportParentData class

Parent data structure used by RenderTwoDimensionalViewport.

The parent data primarily describes where a child is in the viewport. The layoutOffset must be set by subclasses of RenderTwoDimensionalViewport, during RenderTwoDimensionalViewport.layoutChildSequence which represents the position of the child in the viewport.

The paintOffset is computed by RenderTwoDimensionalViewport after RenderTwoDimensionalViewport.layoutChildSequence. If subclasses of RenderTwoDimensionalViewport override the paint method, the paintOffset should be used to position the child in the viewport in order to account for a reversed AxisDirection in one or both dimensions.

Mixed in types




hashCode int
The hash code for this object.
no setterinherited
isVisible bool
Whether or not the child is actually visible within the viewport.
no setter
keepAlive bool
Whether to keep the child alive even when it is no longer visible.
getter/setter pairinherited
keptAlive bool
Whether the widget is currently being kept alive, i.e. has keepAlive set to true and is offscreen.
no setteroverride
layoutOffset Offset?
The offset at which to paint the child in the parent's coordinate system.
getter/setter pair
paintOffset Offset?
The position of the child relative to the bounds and AxisDirection of the viewport.
getter/setter pair
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
vicinity ChildVicinity
The logical positioning of children in two dimensions.
getter/setter pair


detach() → void
Called when the RenderObject is removed from the tree.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
toString() String
A string representation of this object.


operator ==(Object other) bool
The equality operator.