Validation graphs have been plugged into the codebase (by Paul) and thus #33 can be considered closed.
There are many things however that require attention.

Important architectural notes

geometry_dialog widget used to be where the old GooCanvas validation graphs had been stored.
Having geometry_dialog as this multi-purpose container led to a somewhat convoluted mixture of validation graph related code and code which has nothing to do with validation graphs.
geometry_dialog needs a refactor (at least a wipe of validation graph related things).

Something to look into

I do prefer however, in on_validation_graph_checkbutton_toggled() that he molecule index is determinded from the model combobox
having graphic_info_t variables to store the values of molecule selections is a hang-over from the GtkOptionmenu days.

Tasks

• Find and remove the old enum for representing graph types. It might get confused with the new enum which would be really bad.
• Remove dynamic-menus.{cc,hh}
• De-duplicate src/validation-graph-widget.{cc,h}}, src/validation-graphs.{cc,hh} vs src/validation-graphs/
• Delete the old class from src/validation-graphs/validation-graphs.hh
• Inspect what's going on with EMSCRIPTEN and *_min_max_t
• Inspect unresolved todos at graphics-info-graphs.cc
• Remove old code from graphics-info-graphs.cc
• Cleanup / refactor geometry_dialog:
  • graphics-info.h likely stores a lot of old unused code (look at // ------------- validation: -------------------)
  • Separate-out useful stuff and delete geometry-graphs.{cc,hh}
• Remove the old dialog used for validation graphs (it likely has been left behind)
  • Some traces of the dialog have been removed already
• Make sure that update_validation_graphs() looks good