This adds support for inheritance to the existing experimental
implementation in tests/manual/layoutbuilder/experimental
and gets rid of the tight coupling and qobject_casts in the
setter implementations. Plan is to use this (minus "bindings"
via *::Id / id()) for utils/layoutbuilder.{h,cpp} later.
The "binding" support via id() is still experimental, and in
its current version not really useful. A possible idea would
be to re-use the Tasking::Storage idea, but it's not quite
clear how to expose that "long distance" (i.e. across multiple,
unrelated top-level builders). However, this is not used in
in current uses of the "old" layoutbuilder, so this is not
blocking anything.
Some notes:
The *Interface hierarchy is not strictly needed, it could directly
act on things in the QObject hierarchy but would then need #includes
of all "buildable" classes, which can be avoided in the current
implementation. Besides, the indirection allows us to tweak and/or
add functionailty to the Qt classes in the indirecting code, that
does not necessarily have to match 1:1 to the underlyings Qt classes.
The std::function based callbacks are quite fat and not functionally
needed and could be dropped by "inlining" the relevant bits from
typical std::function implementations. However, these invariably seem
to end up calling functions through pointers to (ABI-compatible, but)
different types, which is for /user/ code formally undefined behavior
according to C++11 §5.2.10/6. To avoid a discussion whether doing
the same ourselves is tolerable or not, this uses std::function
and pays the price of the overhead.
Change-Id: I6d40c1bd48cf065fcf211eaff8d9a2298bca20eb
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>
