Defining nested objects with the new API

[ahayzen-kdab]

Defining nested objects with the new API probably two types to consider

• Owned by C++/Qt
• Owned by Rust

Could have a separate type for owned by C++ ? So that Drop doesn't deconstruct it.

Can raw pointers, shared pointers, or unique pointers be used for any of these?

How do we know it's a QObject pointer and not a CXX type ?

Should we have QPointer and QOwnedPointer as the "magic" types ?

What types does QML expect/accept when it's a pointer?

Can we return a nested object from an invokable ? What does this mean ? Who has ownership ?

Ensure that one object would be able to call into another object by maybe borrowing (for the locks as rust/rust_mut don't lock? maybe they should now that we use a recursive_mutex?)

[ahayzen-kdab]

Do we even need owned by Rust initially ? Or would supporting Q_PROPERTY(AnotherObject* other READ other WRITE setOther NOTIFY otherChanged) via something like other: *mut crate::mod::qobject::AnotherObject be enough ? What does the Default impl look like in this case?

Can owned by Rust properties get away with just being UniquePtr/SharedPtr and then if you want to reach those in QML add some getters in the C++ to convert to a raw pointer?

[LeonMatthesKDAB]

Do we even need owned by Rust initially ? Or would supporting Q_PROPERTY(AnotherObject* other READ other WRITE setOther NOTIFY otherChanged) via something like other: *mut crate::mod::qobject::AnotherObject be enough ? What does the Default impl look like in this case?

Can owned by Rust properties get away with just being UniquePtr/SharedPtr and then if you want to reach those in QML add some getters in the C++ to convert to a raw pointer?

I think that would be enough for now.
Default would just set the ptr to nullptr 🤷 .