git.r.bdr.sh - rbdr/serpentity/blob - lib/serpentity/node_collection.js

   1 'use strict';
   2
   3 /*
   4  * Node Collections contain nodes, in order to keep the lists of nodes
   5  * that belong to each type.
   6  *
   7  * It has a type which is the class name of the node, and an array of
   8  * instances of that class.
   9  */
  10
  11 const NodeCollection = class NodeCollection {
  12
  13   constructor(config) {
  14
  15     this.nodes = [];
  16     this.type = null;
  17
  18     Object.assign(this, config);
  19   }
  20
  21   /*
  22    * Creates a node for an entity if it matches, and adds it to the
  23    * node list.
  24    *
  25    * Returns true if added, false otherwise.
  26    */
  27   add(entity) {
  28
  29     if (this.type.matches(entity) && !this._entityExists(entity)) {
  30
  31       const node = new this.type({});
  32       const types = this.type.types;
  33       const typeNames = Object.keys(types);
  34
  35       node.entity = entity;
  36
  37       for (const typeName of typeNames) {
  38         node[typeName] = entity.getComponent(types[typeName]);
  39       }
  40
  41       this.nodes.push(node);
  42
  43       return true;
  44     }
  45
  46     return false;
  47   }
  48
  49   /*
  50    * Removes an entity by removing its related node from the list of nodes
  51    *
  52    * returns true if it was removed, false otherwise.
  53    */
  54   remove(entity) {
  55
  56     let foundIndex = -1;
  57
  58     const found = this.nodes.some((node, i) => {
  59
  60       if (node.entity === entity) {
  61         foundIndex = i;
  62         return true;
  63       }
  64     });
  65
  66     if (found) {
  67       this.nodes.splice(foundIndex, 1);
  68     }
  69
  70     return found;
  71   }
  72
  73   /*
  74    * Checks whether we already have nodes for this entity.
  75    */
  76   _entityExists(entity) {
  77
  78     let found = false;
  79
  80     for (const node of this.nodes) {
  81       if (node.entity === entity) {
  82         found = true;
  83       }
  84     }
  85
  86     return found;
  87   }
  88 };
  89
  90 module.exports = NodeCollection;