feat: spawner

packages/entity/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@avocado/entity",
-  "version": "1.0.9",
+  "version": "1.0.10",
   "main": "index.js",
   "author": "cha0s",
   "license": "MIT",
@@ -15,6 +15,7 @@
     "debug": "^3.1.0",
     "immutable": "4.0.0-rc.12",
     "lodash.mapvalues": "4.6.0",
+    "lodash.merge": "4.6.1",
     "lodash.without": "4.4.0"
   }
 }

packages/entity/traits/spawner.trait.js

@@ -0,0 +1,86 @@
+import merge from 'lodash.merge';
+
+import {compose} from '@avocado/core';
+import {Vector} from '@avocado/math';
+
+import {StateProperty, Trait} from '../trait';
+import {Entity} from '..';
+
+const decorate = compose(
+  StateProperty('isSpawning', {
+    track: true,
+  }),
+  StateProperty('maxSpawns'),
+);
+
+export class Spawner extends decorate(Trait) {
+
+  static defaultParams() {
+    return {
+      spawns: {},
+    };
+  }
+
+  static defaultState() {
+    return {
+      isSpawning: true,
+      maxSpawns: Infinity,
+    };
+  }
+
+  initialize() {
+    this.children = [];
+    this.spawnJSONs = this.params.get('spawns').toJS();
+  }
+
+  listeners() {
+    return {
+
+      dying: () => {
+        this.isSpawning = false;
+      },
+
+    };
+  }
+
+  methods() {
+    return {
+
+      killAllChildren: () => {
+        for (let i = 0; i < this.children.length; i++) {
+          const child = this.children[i];
+          // Try kill...
+          if (child.is('alive')) {
+            child.die();
+          }
+          else {
+            child.destroy();
+          }
+        }
+      },
+
+      spawn: (key, json = {}) => {
+        if (!this.entity.is('listed')) {
+          return;
+        }
+        if (this.maxSpawns < this.children.length) {
+          return;
+        }
+        const spawnJSON = this.spawnJSONs[key];
+        if (!spawnJSON) {
+          return;
+        }
+        const spawn = new Entity().fromJSON(merge(spawnJSON, json));
+        this.children.push(spawn);
+        spawn.on('destroy', () => {
+          const index = this.children.indexOf(spawn);
+          this.children.splice(index, 1);
+        })
+        const list = this.entity.list;
+        list.addEntity(spawn);
+      },
+
+    };
+  }
+
+}