C++
virtual void heartbeat() = 0;
Description
Called periodically by the plotting framework during AcPlPlotEngine::beginGenerateGraphics() and AcPlPlotEngine::endGenerateGraphics() to allow the plot progress dialog implementation to be responsive to user input messages while regenerating the drawing for the plot. For example, progress dialogs running the same thread as the main AutoCAD window may want to have a message pump in their implementation of this method to pump user interface messages sent to their dialog implementation during the regeneration process.