DefinitionTileLayout
Where each part of a Flow tile goes (definition-picker-flow §DPD-7, §DPT-1).
In the namespace construct::ui. Declared in src/libs/libconstruct/construct/ui/DefinitionTileDelegate.hpp.
Detailed description
One pure function computes it, so paint() and a tooltip read the same geometry, and a test reads it with no pixels.