added drag events to MouseConstraint, closes #45

src/constraint/MouseConstraint.js

@@ -40,8 +40,7 @@ var MouseConstraint = {};
  var defaults = {
  type: 'mouseConstraint',
  mouse: mouse,
- dragBody: null,
- dragPoint: null,
+ body: null,
  constraint: constraint,
  collisionFilter: {
  category: 0x0001,
@@ -70,31 +69,36 @@ var MouseConstraint = {};
  */
  MouseConstraint.update = function(mouseConstraint, bodies) {
  var mouse = mouseConstraint.mouse,
- constraint = mouseConstraint.constraint;
+ constraint = mouseConstraint.constraint,
+ body = mouseConstraint.body;
 
  if (mouse.button === 0) {
  if (!constraint.bodyB) {
  for (var i = 0; i < bodies.length; i++) {
- var body = bodies[i];
+ body = bodies[i];
  if (Bounds.contains(body.bounds, mouse.position) 
  && Vertices.contains(body.vertices, mouse.position)
  && Detector.canCollide(body.collisionFilter, mouseConstraint.collisionFilter)) {
+
  constraint.pointA = mouse.position;
- constraint.bodyB = body;
+ constraint.bodyB = mouseConstraint.body = body;
  constraint.pointB = { x: mouse.position.x - body.position.x, y: mouse.position.y - body.position.y };
  constraint.angleB = body.angle;
+
  Sleeping.set(body, false);
+ Events.trigger(mouseConstraint, 'startdrag', { mouse: mouse, body: body });
  }
  }
+ } else {
+ Sleeping.set(constraint.bodyB, false);
+ constraint.pointA = mouse.position;
  }
  } else {
- constraint.bodyB = null;
+ constraint.bodyB = mouseConstraint.body = null;
  constraint.pointB = null;
- }
 
- if (constraint.bodyB) {
- Sleeping.set(constraint.bodyB, false);
- constraint.pointA = mouse.position;
+ if (body)
+ Events.trigger(mouseConstraint, 'enddrag', { mouse: mouse, body: body });
  }
  };
 
@@ -157,6 +161,28 @@ var MouseConstraint = {};
  * @param {} event.name The name of the event
  */
 
+ /**
+ * Fired when the user starts dragging a body
+ *
+ * @event startdrag
+ * @param {} event An event object
+ * @param {mouse} event.mouse The engine's mouse instance
+ * @param {body} event.body The body being dragged
+ * @param {} event.source The source object of the event
+ * @param {} event.name The name of the event
+ */
+
+ /**
+ * Fired when the user ends dragging a body
+ *
+ * @event enddrag
+ * @param {} event An event object
+ * @param {mouse} event.mouse The engine's mouse instance
+ * @param {body} event.body The body that has stopped being dragged
+ * @param {} event.source The source object of the event
+ * @param {} event.name The name of the event
+ */
+
  /*
  *
  * Properties Documentation
@@ -182,15 +208,7 @@ var MouseConstraint = {};
  /**
  * The `Body` that is currently being moved by the user, or `null` if no body.
  *
- * @property dragBody
- * @type body
- * @default null
- */
-
- /**
- * The `Vector` offset at which the drag started relative to the `dragBody`, if any.
- *
- * @property dragPoint
+ * @property body
  * @type body
  * @default null
  */