import “../arrays/map”; import “../core/subclass”; import “../event/dispatch”; import “../event/timer”; import “../interpolate/ease”; import “../selection/selection”;

function d3_transition(groups, id) {

d3_subclass(groups, d3_transitionPrototype);

groups.id = id; // Note: read-only!

return groups;

}

var d3_transitionPrototype = [],

d3_transitionId = 0,
d3_transitionInheritId,
d3_transitionInherit;

d3_transitionPrototype.call = d3_selectionPrototype.call; d3_transitionPrototype.empty = d3_selectionPrototype.empty; d3_transitionPrototype.node = d3_selectionPrototype.node; d3_transitionPrototype.size = d3_selectionPrototype.size;

d3.transition = function(selection) {

return arguments.length
    ? (d3_transitionInheritId ? selection.transition() : selection)
    : d3_selectionRoot.transition();

};

d3.transition.prototype = d3_transitionPrototype;

import “select”; import “selectAll”; import “filter”; import “attr”; import “style”; import “text”; import “remove”; import “ease”; import “delay”; import “duration”; import “each”; import “subtransition”; import “tween”;

function d3_transitionNode(node, i, id, inherit) {

var lock = node.__transition__ || (node.__transition__ = {active: 0, count: 0}),
    transition = lock[id];

if (!transition) {
  var time = inherit.time;

  transition = lock[id] = {
    tween: new d3_Map,
    time: time,
    ease: inherit.ease,
    delay: inherit.delay,
    duration: inherit.duration
  };

  ++lock.count;

  d3.timer(function(elapsed) {
    var d = node.__data__,
        ease = transition.ease,
        delay = transition.delay,
        duration = transition.duration,
        tweened = [];

    return delay <= elapsed
        ? start(elapsed)
        : d3.timer(start, delay, time), 1;

    function start(elapsed) {
      if (lock.active > id) return stop();
      lock.active = id;
      transition.event && transition.event.start.call(node, d, i);

      transition.tween.forEach(function(key, value) {
        if (value = value.call(node, d, i)) {
          tweened.push(value);
        }
      });

      if (!tick(elapsed)) d3.timer(tick, 0, time);
      return 1;
    }

    function tick(elapsed) {
      if (lock.active !== id) return stop();

      var t = (elapsed - delay) / duration,
          e = ease(t),
          n = tweened.length;

      while (n > 0) {
        tweened[--n].call(node, e);
      }

      if (t >= 1) {
        stop();
        transition.event && transition.event.end.call(node, d, i);
        return 1;
      }
    }

    function stop() {
      if (--lock.count) delete lock[id];
      else delete node.__transition__;
      return 1;
    }
  }, 0, time);

  return transition;
}

}