TreeRowExtentDelegate typedef

TreeRowExtentDelegate = SpanExtentDelegate

Delegate passed to TreeSpanExtent.calculateExtent from the RenderTreeViewport during layout.

Provides access to metrics from the TreeView that a TreeRowExtent may need to calculate its extent.

Extents will not be computed for every frame unless the delegate has been updated. Otherwise, after the extents are computed during the first layout pass, they are cached and reused in subsequent frames.

Implementation

typedef TreeRowExtentDelegate = SpanExtentDelegate;