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# *   (c) 2020 Carlo Pavan <carlopav@gmail.com>                             *
# *   (c) 2020 Eliud Cabrera Castillo <e.cabrera-castillo@tum.de>           *
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"""Modules that contain classes that define viewproviders for scripted objects.

These classes define viewproviders for the custom objects
defined in the `draftobjects` package.
They extend the basic viewprovider that is installed by default
with the creation of a base object defined in C++.

These classes are not normally used by themselves, but are used at creation
time by the make functions defined in the `draftmake` package.
These viewproviders are installed only when the graphical interface
is available; in console-only mode the viewproviders are not available
so the make functions ignore them.

Similar to the object classes, once a viewprovider class is assigned
to an object, and it is saved in a document, the object's viewprovider
will be rebuilt with the same class every time the document
is opened. In order to do this, the viewprovider module must exist
with the same name as when the object was saved.

For example, when creating a `Rectangle`, the object uses
the `draftviewproviders.view_rectangle.ViewProviderRectangle` class.
This class must exist when the document is opened again.

This means that, in general, these modules cannot be renamed or moved
without risking breaking previously saved files. They can be renamed
only if the old class can be migrated to point to a new class,
for example, by creating a reference to the new class named the same
as the older class.

::

    old_module.ViewProviderRectangle = new_module.ViewProviderRectangle
"""
## \defgroup draftviewproviders draftviewproviders
# \ingroup DRAFT
# \brief Classes that define viewproviders for the scripted objects.