famo.us RenderPool. Work in progres...

RenderPool.js

define(function(require, exports, module) {
  var RenderNode = require('famous/core/RenderNode');
  var Modifier = require('famous/core/Modifier');
  var Surface = require('famous/core/Surface');

  function RenderPool() {
    this._node = new RenderNode();
    this._children = {};
    this._unusedChildren = [];
  }

  /** @const */
  RenderPool.SIZE_HIDDEN = [0.0001, 0.0001];
  RenderPool.OPACITY_HIDDEN = 1e-6;

  RenderPool.prototype.create = function create(id, modifierOptions, surfaceOptions) {
    var modifier;
    var surface;
    var child = this._children[id] || this._unusedChildren.pop();

    if (child) {
      modifier = child.get();
      surface = child._child.get();

      _updateModifier(modifier, modifierOptions);
      surface.setOptions(surfaceOptions);
      return child;
    }

    modifier = new Modifier(modifierOptions);
    surface = new Surface(surfaceOptions);

    child = this._node.add(modifier);
    child.add(surface);
    this._children[id] = child;

    return child;
  };

  RenderPool.prototype.get = function get(id) {
    return this._children[id];
  };

  RenderPool.prototype.remove = function remove(id) {
    var child = this._children[id];
    if (!child) return;

    delete this._children[id];

    child._object.sizeFrom(RenderPool.SIZE_HIDDEN);
    child._object.opacityFrom(RenderPool.OPACITY_HIDDEN);

    this._unusedChildren.push(child);
  };

  RenderPool.prototype.clear = function clear() {
    Object.keys(this._children).forEach(this.remove, this);
  };

  RenderPool.prototype.getSize = function getSize() {
    return this._node.getSize();
  };

  RenderPool.prototype.commit = function commit(context) {
    return this._node.commit(context);
  };

  RenderPool.prototype.render = function render() {
    return this._node.render();
  };

  function _updateModifier(modifier, options) {
    options = options || {};

    if (options.transform) modifier.transformFrom(options.transform);
    if (options.origin) modifier.originFrom(options.origin);

    if (options.size) modifier.sizeFrom(options.size);
    else modifier.sizeFrom(null);

    if (options.opacity !== undefined) modifier.opacityFrom(options.opacity);
    else modifier.opacityFrom(1);
  }

  module.exports = RenderPool;
});