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.
The dialog was using a LIB_ALIAS from library cache to show the symbol to the canvas without making a local copy.
Unfortunately, the library viewer is doing the same thing.
Now the GAL is used in Eeschema, a link to the VIEW used by the GAL canvas is stored in this class.
When The selector symbol dialog is used to choose a symbol to display in the Library viewer,
a race condition between the Library viewer GAL canvas and the dtor dialog that destroyed this link in the same instancied class.
Now, the SYMBOL_PREVIEW_WIDGET used in the dialog works on a local copy of the symbol to display.
Wayne Stambaugh
jean-pierre charras
Jeff Young