Instead of determining the focus item through item tree traversal and
pointer comparison and storing the intermediate indices in the
components in the tree, remember the focus item by a pair of
VWeak<ComponentVTable, Dyn> and item_index: usize.
This speeds up determining the focus item as well as delivering events,
which can now be done directly after retrieving an ItemRef with
get_item_ref.
This also fixes the duplicate line edit focus in the 7gui cells
test case.
This is in preparation for allowing the run-time / items to clone VRc's
of the component.
ComponentVTable functions like visit_children_item contine to take a
ComponentRefPin as "self" parameter type, as a VRc would not be
supported by rust right now. That means the implementation then uses
self_weak to obtain a strong self-reference.
The setup code is used to place an initial set_focus_item call, for
example. In preparation for future changes, this needs to happen *after*
self_weak has been set up. For C++ this means placing the code into the
create() function, where there's no (implicit) this pointer, so we need
to use self in some places.
All call sites of dynamic_component::instantiate move the result into a VRc<ErasedComponentBox>,
so might as well do this in that function.
Also added a self_weak for future use.
Move the layout constraint tracker into the window where we can apply
the constraints right before drawing, instead of doing that from within
the event loop. This allows to remove the component parameter from the
run function.
Component's get_item_ref has a life time attached to it, and in the
interpreter we're having two vtable implementations, one for
ErasedComponentBox and another generated one. The approach with
as_pin_ref to transfer the lifetime to a reference to the trait object
for the other vtable isn't working because as_pin_ref consumes the VRef
and then takes the address of a temporary on the stack.
Short of a cleaner solution, this patch circumvents the second vtable
indirection and calls our extern "C" function directly.
Last commit broke for structures containing models, because models are not PartialEq.
So we need to implement PartialEq for ModelHandle. Which means a struct needs to
be created
This will allow the online editor to load imports from URL asynchroniously later
Since currently the compiler is only working on a single thread, and that we
never await on a future that could block, it is allowed to use the spin_on executor
Separate out the padding and spacing parameter handling. A separate data
holds these and the code generation is also split out into
helper functions in the C++ and Rust generator. This will allow re-use in the future.
