Abandon the previous behavior of always creating a new copy of the
buffered symbol which required a re-parenting of every derived symbol
to prevent accidentally orphaning a derived symbol parent symbol
pointers.
This change required something that should have been done a long time
ago by adding an assignment operator to LIB_PART. The assignment
operator makes it possible to create a single copy of the symbol to
buffer which gets updated rather than deleting the last copy and
replacing it with a new copy.
Add a clear method to the MULTIVECTOR class so that existing LIB_PART
object draw items can be removed before assigning the draw items from
the part being assigned.
Fixes#3672https://gitlab.com/kicad/code/kicad/issues/3672
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.
Jeff Young
Wayne Stambaugh
jean-pierre charras
Maciej Suminski