Also improves the SNR and consistency of the menu item text. For
instance, a position is rarely useful, while relative sizes can be.
Also removes some unnecessary repitition, such as "Graphic Rectangle"
when "Rectangle" communicates the necessary information.
Set up a new lineage for SCH_ITEMS to get back to the SCHEMATIC
they live on: Items will all be parented to the SCH_SCREEN that
they are added to, and each SCH_SCREEN will point back to the
SCHEMATIC that it is part of. Note that this hierarchy is not
the same as the actual schematic hierarchy, which continues to
be managed through SCH_SHEETs and SCH_SHEET_PATHS.
Texts were drawn with a minimal line thickness = GetDefaultPenWidth().
The default pen width can be to large for small texts.
So the actual text thickness is now always clamped.
This change completely removes the LIB_ALIAS design pattern an replaces
it by allowing LIB_PART objects to inherit from other LIB_PART objects.
The initial implementation only allows for single inheritance and only
supports the mandatory fields in the derived part because that is all
that the current symbol library file format will support. Once the new
file format is implemented and saving to the old file format is deprecated,
more complex inheritance will be added. The LIB_ALIAS information saved
in the document files was move into the LIB_PART object. This change
impacts virtually every part of the schematic and symbol library editor
code so this commit message is woefully incomplete.
REMOVE: Removed the symbol aliases concept from the schematic and symbol
editors and the symbol viewer.
NEW: Replace the symbol alias concept with simple inheritance that allows
a library symbol to be derived from another library symbol.
Note that since the markup might exist for other reasons, it has
to be turned on with a preference setting. (It goes through a set
of bitflags so the same architecture can be used for other markup
structures that we might want to support in the future.)
Note also that this is more about engineering nomenclature than
visual formatting. In that respect it's more similar to overbar
than italic or bold.