five-bells-visualization/public/bower_components/polymer/src/lib/array-observe.html

Tool to visualize Five Bells payments

<!--
@license
Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-->
<link rel="import" href="debounce.html">

<script>

(function() {

  var callbacks = new WeakMap();
  
  function observe(array, cb) {
    if (Array.observe) {
      var ncb = function(changes) {
        changes = changes.filter(function(o) { return o.type == 'splice'; });
        if (changes.length) {
          cb(changes);
        }
      };
      callbacks.set(cb, ncb);
      Array.observe(array, ncb);
    } else {
      if (!array.__polymerObservable) {
        makeObservable(array);
      }
      callbacks.get(array).push(cb);
    }
  }

  function unobserve(array, cb) {
    if (Array.observe) {
      var ncb = callbacks.get(cb);
      callbacks.delete(cb);
      Array.unobserve(array, ncb);
    } else {
      var cbs = callbacks.get(array);
      var idx = cbs.indexOf(cb);
      if (idx >= 0) {
        cbs.splice(idx, 1);
      }
    }
  }

  function makeObservable(array) {
    var splices = [];
    var debounce;
    var orig = {
      push: array.push,
      pop: array.pop,
      splice: array.splice,
      shift: array.shift,
      unshift: array.unshift,
      sort: array.sort
    };
    var addSplice = function(index, added, removed) {
      splices.push({
        index: index,
        addedCount: added,
        removed: removed,
        object: array,
        type: 'splice'
      });
    };
    callbacks.set(array, []);
    array.push = function() {
      debounce = Polymer.Debounce(debounce, fin);
      addSplice(array.length, 1, []);
      return orig.push.apply(this, arguments);
    };
    array.pop = function() {
      debounce = Polymer.Debounce(debounce, fin);
      addSplice(array.length - 1, 0, array.slice(-1));
      return orig.pop.apply(this, arguments);
    };
    array.splice = function(start, deleteCount) {
      debounce = Polymer.Debounce(debounce, fin);
      addSplice(start, arguments.length - 2, array.slice(start, start + deleteCount));
      return orig.splice.apply(this, arguments);
    };
    array.shift = function() {
      debounce = Polymer.Debounce(debounce, fin);
      addSplice(0, 0, [array[0]]);
      return orig.shift.apply(this, arguments);
    };
    array.unshift = function() {
      debounce = Polymer.Debounce(debounce, fin);
      addSplice(0, 1, []);
      return orig.unshift.apply(this, arguments);
    };
    array.sort = function() {
      debounce = Polymer.Debounce(debounce, fin);
      console.warn('[ArrayObserve]: sort not observable');
      return orig.sort.apply(this, arguments);
    };
    var fin = function() {
      var cbs = callbacks.get(array);
      for (var i=0; i<cbs.length; i++) {
        cbs[i](splices);
      }
      splices = [];
    };
    array.__polymerObservable = true;
  }

  Polymer.ArrayObserve = {
    observe: observe,
    unobserve: unobserve
  };
  
})();

</script>