[proposal]hooks

[hookex]

@brianzinn
Do you think we need to add some other hooks?

For example:

useClick

useClick(onClick: Function<event>): [ref]

https://github.com/hookex/bviz/blob/master/src/hooks.ts

useHover

useHover(over: Function<event>, out: Function<event>): [ref, isHovering]

https://github.com/hookex/bviz/blob/master/src/hooks.ts

...

[brianzinn]

Most definitely - great use of action manager and very useful! The only thing I don't know is if we should be returning a method to de-register before the mesh disposes (like useBeforeRender hook does). Hopefully babylonjs takes care of that automatically when the mesh is removed from the scene.

[brianzinn]

When the mesh is disposed (which happens when it is removed) the action manager is disposed:
https://github.com/BabylonJS/Babylon.js/blob/master/src/Meshes/abstractMesh.ts#L1603

So, under normal conditions likely wouldn't need this. One issue may arise when referencing a mesh in parent hierarchy (like a forwardRef), as it will keep registering actions if the effect is re-created. Does this look right?

useEffect(() => {
        if (ref.current) {
            // what you have now...
            const registeredAction: Nullable<IAction> = mesh.actionManager.registerAction(
               // ...
            );

            return () => {
                // called when component is unmounted?
                mesh.actionManager!.unregisterAction(registeredAction!)
            }
        }
    }, [ref.current])
}

[brianzinn]

Also, I will add it separately, but it needs a guard clause - can check the metadata. GUI have a different hover:

onPointerEnterObservable.add(() => { /* ... */ }

If you make a PR I will accept with or without those extra changes. Thanks Hooke!

[hookex]

Thanks for your remind. I will add this code.
Over the next few days, I will integrate my application with spring and event hooks, then submit PR.