This comes with a factory function that re-directs to the backend and a
run member function to replace
sixtyfps_runtime_run_component_with_gl_renderer. For now it's all still
hidden in the generated run() method.
Typically their emission requires an evaluation context parameter.
Similar to properties, provide a public emitter function that takes care
of the context.
This also required two fixes in the compiler, in order to make the
following (as part of the test case) work:
signal foo;
foo => { ... }
(1) Register declared signals before attempting to implement the
connection handlers.
(2) When looking up the signal property, not only look in the base
type but also in the current type.
This is relatively straight-forward via a pass in the compiler to
collect the resources to embed and then use include_bytes! (once per
resource).
What's really annoying is that the rust resource enum can't store a
&'static [u8] because cbindgen doesn't represent that, probably because
the slice representation isn't guaranteed to stay as it is. So instead
this, for now, uses raw pointers.
The Image's source property used to be a string. Now it is a Resource
enum, which can either be None or an absolute file path to the image on
disk. This also replaces the internal Image type.
The compiler internally resolves the img bang expression to a resource
reference, which shall remain just an absolute path. For now the target
generator passes that through, but in the future the target generator
may choose a target specific way of embedding the data and thus
generating a different Resource type in the final code (through
compile_expression in the cpp and rust generator).
The C++ binding is a bit messy as cbindgen doesn't really support
exporting enums that can be constructed on the C++ side. So instead we
use cbindgen to merely export the type internally and only use the tag
from it then. The public API is then a custom Resource type that is
meant to be binary compatible.
