fyrox-impl 1.0.1

// Copyright (c) 2019-present Dmitry Stepanov and Fyrox Engine contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

//! A wrapper for node pool record that allows to define custom visit method to have full
//! control over instantiation process at deserialization.

use crate::{
    core::{
        pool::PayloadContainer,
        reflect::prelude::*,
        uuid::Uuid,
        visitor::{Visit, VisitResult, Visitor},
    },
    engine::SerializationContext,
    scene::node::Node,
};
use fyrox_core::visitor::error::VisitError;

/// A wrapper for node pool record that allows to define custom visit method to have full
/// control over instantiation process at deserialization.
#[derive(Debug, Clone, Default, Reflect)]
pub struct NodeContainer(Option<Node>);

fn read_node(name: &str, visitor: &mut Visitor) -> Result<Node, VisitError> {
    let mut region = visitor.enter_region(name)?;

    let mut id = Uuid::default();
    id.visit("TypeUuid", &mut region)?;

    let serialization_context = region
        .blackboard
        .get::<SerializationContext>()
        .expect("Visitor environment must contain serialization context!");

    let mut node = serialization_context
        .node_constructors
        .try_create(&id)
        .ok_or_else(|| VisitError::User(format!("Unknown node type uuid {id}!")))?;

    node.visit("NodeData", &mut region)?;

    Ok(node)
}

fn write_node(name: &str, node: &mut Node, visitor: &mut Visitor) -> VisitResult {
    let mut region = visitor.enter_region(name)?;

    let mut id = node.id();
    id.visit("TypeUuid", &mut region)?;

    node.visit("NodeData", &mut region)?;

    Ok(())
}

impl Visit for NodeContainer {
    fn visit(&mut self, name: &str, visitor: &mut Visitor) -> VisitResult {
        let mut region = visitor.enter_region(name)?;

        let mut is_some = u8::from(self.is_some());
        is_some.visit("IsSome", &mut region)?;

        if is_some != 0 {
            if region.is_reading() {
                *self = NodeContainer(Some(read_node("Data", &mut region)?));
            } else {
                write_node("Data", self.0.as_mut().unwrap(), &mut region)?;
            }
        }

        Ok(())
    }
}

impl PayloadContainer for NodeContainer {
    type Element = Node;

    fn new_empty() -> Self {
        Self(None)
    }

    fn new(element: Self::Element) -> Self {
        Self(Some(element))
    }

    fn is_some(&self) -> bool {
        self.0.is_some()
    }

    fn as_ref(&self) -> Option<&Self::Element> {
        self.0.as_ref()
    }

    fn as_mut(&mut self) -> Option<&mut Self::Element> {
        self.0.as_mut()
    }

    fn replace(&mut self, element: Self::Element) -> Option<Self::Element> {
        self.0.replace(element)
    }

    fn take(&mut self) -> Option<Self::Element> {
        self.0.take()
    }
}