playcanvas/build/playcanvas/src/framework/asset/asset-reference.js

PlayCanvas WebGL game engine

class AssetReference {
		constructor(propertyName, parent, registry, callbacks, scope){
				this._evtLoadById = null;
				this._evtUnloadById = null;
				this._evtAddById = null;
				this._evtRemoveById = null;
				this._evtLoadByUrl = null;
				this._evtAddByUrl = null;
				this._evtRemoveByUrl = null;
				this.propertyName = propertyName;
				this.parent = parent;
				this._scope = scope;
				this._registry = registry;
				this.id = null;
				this.url = null;
				this.asset = null;
				this._onAssetLoad = callbacks.load;
				this._onAssetAdd = callbacks.add;
				this._onAssetRemove = callbacks.remove;
				this._onAssetUnload = callbacks.unload;
		}
		set id(value) {
				if (this.url) throw Error('Can\'t set id and url');
				this._unbind();
				this._id = value;
				this.asset = this._registry.get(this._id);
				this._bind();
		}
		get id() {
				return this._id;
		}
		set url(value) {
				if (this.id) throw Error('Can\'t set id and url');
				this._unbind();
				this._url = value;
				this.asset = this._registry.getByUrl(this._url);
				this._bind();
		}
		get url() {
				return this._url;
		}
		_bind() {
				if (this.id) {
						if (this._onAssetLoad) this._evtLoadById = this._registry.on(`load:${this.id}`, this._onLoad, this);
						if (this._onAssetAdd) this._evtAddById = this._registry.once(`add:${this.id}`, this._onAdd, this);
						if (this._onAssetRemove) this._evtRemoveById = this._registry.on(`remove:${this.id}`, this._onRemove, this);
						if (this._onAssetUnload) this._evtUnloadById = this._registry.on(`unload:${this.id}`, this._onUnload, this);
				}
				if (this.url) {
						if (this._onAssetLoad) this._evtLoadByUrl = this._registry.on(`load:url:${this.url}`, this._onLoad, this);
						if (this._onAssetAdd) this._evtAddByUrl = this._registry.once(`add:url:${this.url}`, this._onAdd, this);
						if (this._onAssetRemove) this._evtRemoveByUrl = this._registry.on(`remove:url:${this.url}`, this._onRemove, this);
				}
		}
		_unbind() {
				if (this.id) {
						this._evtLoadById?.off();
						this._evtLoadById = null;
						this._evtAddById?.off();
						this._evtAddById = null;
						this._evtRemoveById?.off();
						this._evtRemoveById = null;
						this._evtUnloadById?.off();
						this._evtUnloadById = null;
				}
				if (this.url) {
						this._evtLoadByUrl?.off();
						this._evtLoadByUrl = null;
						this._evtAddByUrl?.off();
						this._evtAddByUrl = null;
						this._evtRemoveByUrl?.off();
						this._evtRemoveByUrl = null;
				}
		}
		_onLoad(asset) {
				this._onAssetLoad.call(this._scope, this.propertyName, this.parent, asset);
		}
		_onAdd(asset) {
				this.asset = asset;
				this._onAssetAdd.call(this._scope, this.propertyName, this.parent, asset);
		}
		_onRemove(asset) {
				this._onAssetRemove.call(this._scope, this.propertyName, this.parent, asset);
				this.asset = null;
		}
		_onUnload(asset) {
				this._onAssetUnload.call(this._scope, this.propertyName, this.parent, asset);
		}
}

export { AssetReference };