bevy_property 0.3.0

Dynamically interact with struct fields using their names
Documentation
use crate::{
    property_serde::{DynamicPropertiesDeserializer, DynamicPropertiesSerializer, Serializable},
    DeserializeProperty, Properties, Property, PropertyIter, PropertyType, PropertyTypeRegistry,
};
use bevy_utils::HashMap;
use serde::de::DeserializeSeed;
use std::{any::Any, borrow::Cow, fmt};

pub struct DynamicProperties {
    pub type_name: String,
    pub props: Vec<Box<dyn Property>>,
    pub prop_names: Vec<Cow<'static, str>>,
    pub prop_indices: HashMap<Cow<'static, str>, usize>,
    pub property_type: PropertyType,
}

impl fmt::Debug for DynamicProperties {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        let props = self
            .props
            .iter()
            .map(|p| p.as_ref() as *const dyn Property)
            .collect::<Vec<_>>();

        f.debug_struct("DynamicProperties")
            .field("type_name", &self.type_name)
            .field("props", &props)
            .field("prop_names", &self.prop_names)
            .field("prop_indices", &self.prop_indices)
            .field("property_type", &self.property_type)
            .finish()
    }
}

impl DynamicProperties {
    pub fn map() -> Self {
        DynamicProperties {
            type_name: std::any::type_name::<Self>().to_string(),
            props: Default::default(),
            prop_names: Default::default(),
            prop_indices: Default::default(),
            property_type: PropertyType::Map,
        }
    }

    pub fn seq() -> Self {
        DynamicProperties {
            type_name: std::any::type_name::<Self>().to_string(),
            props: Default::default(),
            prop_names: Default::default(),
            prop_indices: Default::default(),
            property_type: PropertyType::Seq,
        }
    }

    pub fn push(&mut self, prop: Box<dyn Property>, name: Option<&str>) {
        // TODO: validate map / seq operations
        self.props.push(prop);
        if let Some(name) = name {
            let cow_name: Cow<'static, str> = Cow::Owned(name.to_string()); // moo
            self.prop_names.push(cow_name.clone());
            self.prop_indices.insert(cow_name, self.props.len() - 1);
        }
    }

    pub fn set<T: Property>(&mut self, name: &str, prop: T) {
        // TODO: validate map / seq operations
        if let Some(index) = self.prop_indices.get(name) {
            self.props[*index] = Box::new(prop);
        } else {
            self.push(Box::new(prop), Some(name));
        }
    }

    pub fn set_box(&mut self, name: &str, prop: Box<dyn Property>) {
        // TODO: validate map / seq operations
        if let Some(index) = self.prop_indices.get(name) {
            self.props[*index] = prop;
        } else {
            self.push(prop, Some(name));
        }
    }
}

impl Properties for DynamicProperties {
    #[inline]
    fn prop(&self, name: &str) -> Option<&dyn Property> {
        if let Some(index) = self.prop_indices.get(name) {
            Some(&*self.props[*index])
        } else {
            None
        }
    }

    #[inline]
    fn prop_mut(&mut self, name: &str) -> Option<&mut dyn Property> {
        if let Some(index) = self.prop_indices.get(name) {
            Some(&mut *self.props[*index])
        } else {
            None
        }
    }

    #[inline]
    fn prop_with_index(&self, index: usize) -> Option<&dyn Property> {
        self.props.get(index).map(|prop| &**prop)
    }

    #[inline]
    fn prop_with_index_mut(&mut self, index: usize) -> Option<&mut dyn Property> {
        self.props.get_mut(index).map(|prop| &mut **prop)
    }

    #[inline]
    fn prop_name(&self, index: usize) -> Option<&str> {
        match self.property_type {
            PropertyType::Seq => None,
            PropertyType::Map => self.prop_names.get(index).map(|name| name.as_ref()),
            _ => panic!("DynamicProperties cannot be Value types"),
        }
    }

    #[inline]
    fn prop_len(&self) -> usize {
        self.props.len()
    }

    fn iter_props(&self) -> PropertyIter {
        PropertyIter {
            props: self,
            index: 0,
        }
    }
}

impl Property for DynamicProperties {
    #[inline]
    fn type_name(&self) -> &str {
        &self.type_name
    }

    #[inline]
    fn any(&self) -> &dyn Any {
        self
    }

    #[inline]
    fn any_mut(&mut self) -> &mut dyn Any {
        self
    }

    #[inline]
    fn clone_prop(&self) -> Box<dyn Property> {
        Box::new(self.to_dynamic())
    }

    #[inline]
    fn set(&mut self, value: &dyn Property) {
        if let Some(properties) = value.as_properties() {
            *self = properties.to_dynamic();
        } else {
            panic!("attempted to apply non-Properties type to Properties type");
        }
    }

    #[inline]
    fn apply(&mut self, value: &dyn Property) {
        if let Some(properties) = value.as_properties() {
            if properties.property_type() != self.property_type {
                panic!(
                    "Properties type mismatch. This type is {:?} but the applied type is {:?}",
                    self.property_type,
                    properties.property_type()
                );
            }
            match self.property_type {
                PropertyType::Map => {
                    for (i, prop) in properties.iter_props().enumerate() {
                        let name = properties.prop_name(i).unwrap();
                        if let Some(p) = self.prop_mut(name) {
                            p.apply(prop);
                        }
                    }
                }
                PropertyType::Seq => {
                    for (i, prop) in properties.iter_props().enumerate() {
                        if let Some(p) = self.prop_with_index_mut(i) {
                            p.apply(prop);
                        }
                    }
                }
                _ => panic!("DynamicProperties cannot be Value types"),
            }
        } else {
            panic!("attempted to apply non-Properties type to Properties type");
        }
    }

    fn as_properties(&self) -> Option<&dyn Properties> {
        Some(self)
    }

    fn serializable<'a>(&'a self, registry: &'a PropertyTypeRegistry) -> Serializable<'a> {
        Serializable::Owned(Box::new(DynamicPropertiesSerializer::new(self, registry)))
    }

    fn property_type(&self) -> PropertyType {
        self.property_type
    }
}

impl DeserializeProperty for DynamicProperties {
    fn deserialize(
        deserializer: &mut dyn erased_serde::Deserializer,
        property_type_registry: &PropertyTypeRegistry,
    ) -> Result<Box<dyn Property>, erased_serde::Error> {
        let dynamic_properties_deserializer =
            DynamicPropertiesDeserializer::new(property_type_registry);
        let dynamic_properties: DynamicProperties =
            dynamic_properties_deserializer.deserialize(deserializer)?;
        Ok(Box::new(dynamic_properties))
    }
}