Improve components with a declarative API

[erickzanardo]

What could be improved

Flame already favors composability, Components can have children, their children can have their own and so on.

To put Flame more in line with Flutter APIs, we could a children attribute on all components in order to allow a more declarative way of developing composable components, for example:

add(
  PositionComponent(
    children: [
       SpriteComponent(sprite: playerSprite),
       KeyboardController(),
       ....
    ],
  ),
);

Why should this be improved

It will allow better declarative programming and bring Flame even closer to the "Flutter way"

Any risks?

Idk how complicated this would be to implement, on a naive idea, I think that just by receiving a list o Component on the constructor and adding then all on the component default onLoad will me enough, but we need to test and check if this will bring any issues with the Flame lifecycle.

More information

[erickzanardo]

cc @felangel @alestiago

[spydon]

Interesting idea! I think it could be pretty nice.

[alestiago]

I'm in love with this.

Question here is: If children can be specified, what happens when children are also added via the onLoad? How will the children be ordered?

[st-pasha]

If children can be specified, what happens when children are also added via the onLoad? How will the children be ordered?

The ones in the constructor come first, those from onLoad after.