refactor: Vector mixin

packages/entity/trait.js

@@ -1,6 +1,7 @@
 import * as I from 'immutable';
 
 import {Resource} from '@avocado/resource';
+import {Vector} from '@avocado/math';
 import {Property} from '@avocado/mixins';
 
 export class Trait {
@@ -95,3 +96,33 @@ export function simpleState(key, meta = {}) {
     return Property(key, meta)(Superclass);
   }
 }
+
+export function simpleStateVector(vector, x, y, meta = {}) {
+  return (Superclass) => {
+    meta.default = undefined;
+    meta.emit = meta.emit || function(...args) {
+      this.entity.emit(...args);
+    };
+    meta.get = meta.get || function() {
+      return [
+        this.state.get(x),
+        this.state.get(y),
+      ];
+    };
+    meta.set = meta.set || function(vector) {
+      if (meta.track && meta.emit) {
+        if (this.state.get(x) !== vector[0]) {
+          meta.emit.call(this, `${x}Changed`, this.state.get(x), vector[0]);
+        }
+        if (this.state.get(y) !== vector[1]) {
+          meta.emit.call(this, `${y}Changed`, this.state.get(y), vector[1]);
+        }
+      }
+      this.state = this.state.merge({
+        [x]: vector[0],
+        [y]: vector[1],
+      });
+    };
+    return Vector.Mixin(vector, x, y, meta)(Superclass);
+  };
+}

packages/entity/traits/positioned.js

@@ -1,12 +1,9 @@
 import {compose} from '@avocado/core';
 
-import {simpleState, Trait} from '../trait';
+import {simpleStateVector, Trait} from '../trait';
 
 const decorate = compose(
-  simpleState('x', {
-    track: true,
-  }),
-  simpleState('y', {
+  simpleStateVector('position', 'x', 'y', {
     track: true,
   }),
 );
@@ -20,42 +17,6 @@ class PositionedBase extends Trait {
     };
   }
 
-  get position() {
-    return [
-      this.state.get('x'),
-      this.state.get('y'),
-    ];
-  }
-
-  set position([x, y]) {
-    const positionChanged = x !== entity.x || y !== entity.y;
-    const lastPosition = entity.position;
-    this.entity.x = x;
-    this.entity.y = y;
-    if (positionChanged) {
-      this.entity.emit('positionChanged', lastPosition, entity.position);
-    }
-  }
-
-  listeners() {
-    return {
-      xChanged: (x, oldX) => {
-        this.entity.emit(
-          'positionChanged',
-          this.entity.position,
-          [oldX, this.entity.y]
-        );
-      },
-      yChanged: (y, oldY) => {
-        this.entity.emit(
-          'positionChanged',
-          this.entity.position,
-          [this.entity.x, oldY]
-        );
-      },
-    }
-  }
-
 }
 
 export class Positioned extends decorate(PositionedBase) {}

packages/math/vector/index.js

@@ -1,3 +1,4 @@
+export {VectorMixin as Mixin} from './mixin';
 
 export const SQRT_2_2 = Math.sqrt(2) / 2;
 

packages/math/vector/mixin.coffee

@@ -1,32 +0,0 @@
-import {Mixin, Property} from '@avocado/composition'
-import {Vector as Vector_} from '@avocado/math'
-import {setterName} from '@avocado/string'
-
-export VectorMixin = (
-  vector = 'vector', x = 'x', y = 'y', meta = {}
-) -> (Superclass) ->
-
-  setX = setterName x
-  setY = setterName y
-
-  Base = Mixin(Superclass).with(
-
-    Property x, meta[x] ? {}
-    Property y, meta[y] ? {}
-
-    Property vector, Object.assign {
-
-      set: (vector) ->
-
-        this[setX] vector[0]
-        this[setY] vector[1]
-
-        return
-
-      get: -> [@[x](), @[y]()]
-
-      eq: (l, r) -> Vector_.equals l, r
-
-    }, meta
-  )
-  class Vector extends Base

packages/math/vector/mixin.js

@@ -0,0 +1,64 @@
+import {compose} from '@avocado/core';
+import {Mixin, Property} from '@avocado/mixins'
+import {Vector} from '@avocado/math'
+
+export function VectorMixin(
+  vector = 'vector',
+  x = 'x',
+  y = 'y',
+  meta = {},
+) {
+  meta = {
+    default: [0, 0],
+    emit: function (...args) {
+      if (this.emit) {
+        this.emit(...args);
+      }
+    },
+    eq: function(l, r) {
+      return Vector.equals(l, r);
+    },
+    get: function() {
+      return [
+        this[x],
+        this[y],
+      ];
+    },
+    ...meta,
+  };
+  meta.set = meta.set || function(vector) {
+    if (meta.track && meta.emit) {
+      if (this[vector][0] !== vector[0]) {
+        meta.emit.call(this, `${x}Changed`, this[vector][0], vector[0]);
+      }
+      if (this[vector][1] !== vector[1]) {
+        meta.emit.call(this, `${y}Changed`, this[vector][1], vector[1]);
+      }
+    }
+    this[vector] = [vector[0], vector[1]];
+  }
+  const decorate = compose(
+    Property(vector, meta),
+  );
+  return (Superclass) => {
+    return class Vector extends decorate(Superclass) {
+
+      get [x]() {
+        return this[vector][0];
+      }
+
+      set [x](x) {
+        this[vector] = [x, this[vector][1]];
+      }
+
+      get [y]() {
+        return this[vector][1];
+      }
+
+      set [y](y) {
+        this[vector] = [this[vector][0], y];
+      }
+
+    }
+  };
+}