ConstructStagedMutationTask

The base for a mutation whose work must stay off the GUI thread.

In the namespace construct::opal. Declared in src/libs/libconstruct/construct/opal/ConstructMutationTask.hpp.

Detailed description

Use it only for work that takes long enough to stall the interface — a bounds measurement, say. The step runs on the plan thread and reaches the document through StepDocument, one GUI call at a time: read what the work needs in one call, compute off the GUI thread, then write the result in another. Everything else derives from ConstructMutationTask, whose step runs in one GUI call.