isRetainedBySource

Whether the originating image store still retains this pixel version for future placements, including offscreen placements. Once false, it stays false; copyArgb, dimensions and pixels remain valid for existing consumers.

Renderers may discard a cached raster when this is false and the resource is absent from their installed frame. A frame can still reference a retired resource, so this property must not suppress its rendering. Implementations tracking retirement must make changes visible across threads. The default is true for providers without retirement tracking.