Previously it was in the `gui_selectplane` module but we prefer to place it in its own module so that the files are as small as possible.
2020 February
These files define the "GuiCommands", that is, classes called in a graphical way through either buttons, menu entries, or context actions. They don't define the graphical interfaces themselves, they just setup tools that connect with FreeCAD's C++ code.
These tools should be split from the big DraftTools.py module.
The classes defined here internally use the GUI-less functions
defined in Draft.py, or in the newer modules under draftobjects/.
These tools are loaded by InitGui.py, and thus require the graphical
interface to exist.
Those commands that require a "task panel" call the respective module
and class in drafttaskpanels/. The task panel interfaces themselves
are defined inside the Resources/ui/ files created with QtCreator.
For more information see the thread: [Discussion] Splitting Draft tools into their own modules