Add sourceEvent to custom events.

The drag behavior, zoom behavior and brush component now set a "sourceEvent"
property on their events, defined as the triggering mouse or touch event. The
d3.mouse and d3.touches helpers likewise use the source event, letting you query
the mouse or touch location when handling a custom event.

d3.v2.js

@@ -546,7 +546,7 @@ d3.ns = {
   }
 };
 d3.dispatch = function() {
-  var dispatch = new d3_dispatch(),
+  var dispatch = new d3_dispatch,
       i = -1,
       n = arguments.length;
   while (++i < n) dispatch[arguments[i]] = d3_dispatch_event(dispatch);
@@ -862,6 +862,49 @@ function d3_eventCancel() {
   d3.event.stopPropagation();
   d3.event.preventDefault();
 }
+
+function d3_eventSource() {
+  var e = d3.event, s;
+  while (s = e.sourceEvent) e = s;
+  return e;
+}
+
+// Like d3.dispatch, but for custom events abstracting native UI events. These
+// events have a target component (such as a brush), a target element (such as
+// the svg:g element containing the brush) and the standard arguments `d` (the
+// target element's data) and `i` (the selection index of the target element).
+function d3_eventDispatch(target) {
+  var dispatch = new d3_dispatch,
+      i = 0,
+      n = arguments.length;
+
+  while (++i < n) dispatch[arguments[i]] = d3_dispatch_event(dispatch);
+
+  // Creates a dispatch context for the specified `thiz` (typically, the target
+  // DOM element that received the source event) and `argumentz` (typically, the
+  // data `d` and index `i` of the target element). The returned function can be
+  // used to dispatch an event to any registered listeners; the function takes a
+  // single argument as input, being the event to dispatch. The event must have
+  // a "type" attribute which corresponds to a type registered in the
+  // constructor. This context will automatically populate the "sourceEvent" and
+  // "target" attributes of the event, as well as setting the `d3.event` global
+  // for the duration of the notification.
+  dispatch.of = function(thiz, argumentz) {
+    return function(e1) {
+      try {
+        var e0 =
+        e1.sourceEvent = d3.event;
+        e1.target = target;
+        d3.event = e1;
+        dispatch[e1.type].apply(thiz, argumentz);
+      } finally {
+        d3.event = e0;
+      }
+    };
+  };
+
+  return dispatch;
+}
 d3.interpolate = function(a, b) {
   var i = d3.interpolators.length, f;
   while (--i >= 0 && !(f = d3.interpolators[i](a, b)));
@@ -2461,7 +2504,7 @@ function d3_transformCombine(a, b, k) {
 
 var d3_transformDegrees = 180 / Math.PI;
 d3.mouse = function(container) {
-  return d3_mousePoint(container, d3.event);
+  return d3_mousePoint(container, d3_eventSource());
 };
 
 // https://bugs.webkit.org/show_bug.cgi?id=44083
@@ -2495,8 +2538,7 @@ function d3_mousePoint(container, e) {
   return [e.clientX - rect.left - container.clientLeft, e.clientY - rect.top - container.clientTop];
 };
 d3.touches = function(container, touches) {
-  if (arguments.length < 2) touches = d3.event.touches;
+  if (arguments.length < 2) touches = d3_eventSource().touches;
-
   return touches ? d3_array(touches).map(function(touch) {
     var point = d3_mousePoint(container, touch);
     point.identifier = touch.identifier;
@@ -4185,7 +4227,7 @@ function d3_svg_axisSubdivide(scale, ticks, m) {
   return subticks;
 }
 d3.svg.brush = function() {
-  var event = d3.dispatch("brushstart", "brush", "brushend"),
+  var event = d3_eventDispatch(brush, "brushstart", "brush", "brushend"),
       x, // x-scale, optional
       y, // y-scale, optional
       extent = [[0, 0], [0, 0]]; // [x0, y0], [x1, y1]
@@ -4293,24 +4335,12 @@ d3.svg.brush = function() {
     d3_svg_brushY = !/^(e|w)$/.test(resize) && y;
 
     // Notify listeners.
-    d3_svg_brushDispatch = dispatcher(this, arguments);
+    d3_svg_brushEvent = event.of(this, arguments);
-    d3_svg_brushDispatch("brushstart");
+    d3_svg_brushEvent({type: "brushstart"});
     d3_svg_brushMove();
     d3_eventCancel();
   }
 
-  function dispatcher(that, argumentz) {
-    return function(type) {
-      var e = d3.event;
-      try {
-        d3.event = {type: type, target: brush};
-        event[type].apply(that, argumentz);
-      } finally {
-        d3.event = e;
-      }
-    };
-  }
-
   brush.x = function(z) {
     if (!arguments.length) return x;
     x = z;
@@ -4385,7 +4415,7 @@ d3.svg.brush = function() {
 };
 
 var d3_svg_brush,
-    d3_svg_brushDispatch,
+    d3_svg_brushEvent,
     d3_svg_brushTarget,
     d3_svg_brushX,
     d3_svg_brushY,
@@ -4484,7 +4514,7 @@ function d3_svg_brushMove() {
     // Final redraw and notify listeners.
     if (moved) {
       d3_svg_brushRedraw(g, d3_svg_brushExtent);
-      d3_svg_brushDispatch("brush");
+      d3_svg_brushEvent({type: "brush"});
     }
   }
 }
@@ -4537,9 +4567,9 @@ function d3_svg_brushUp() {
     d3_svg_brushMove();
     d3.select(d3_svg_brushTarget).style("pointer-events", "all").selectAll(".resize").style("display", d3_svg_brush.empty() ? "none" : null);
     d3.select("body").style("cursor", null);
-    d3_svg_brushDispatch("brushend");
+    d3_svg_brushEvent({type: "brushend"});
     d3_svg_brush =
-    d3_svg_brushDispatch =
+    d3_svg_brushEvent =
     d3_svg_brushTarget =
     d3_svg_brushX =
     d3_svg_brushY =
@@ -4566,7 +4596,7 @@ d3.behavior = {};
 // TODO Track touch points by identifier.
 
 d3.behavior.drag = function() {
-  var event = d3.dispatch("drag", "dragstart", "dragend"),
+  var event = d3_eventDispatch(drag, "drag", "dragstart", "dragend"),
       origin = null;
 
   function drag() {
@@ -4584,13 +4614,11 @@ d3.behavior.drag = function() {
 
   // snapshot the local context for subsequent dispatch
   function start() {
-    d3_behavior_dragEvent = event;
     d3_behavior_dragEventTarget = d3.event.target;
-    d3_behavior_dragTarget = this;
+    d3_behavior_dragEvent = event.of(d3_behavior_dragTarget = this, arguments);
-    d3_behavior_dragArguments = arguments;
     d3_behavior_dragOrigin = d3_behavior_dragPoint();
     if (origin) {
-      d3_behavior_dragOffset = origin.apply(d3_behavior_dragTarget, d3_behavior_dragArguments);
+      d3_behavior_dragOffset = origin.apply(d3_behavior_dragTarget, arguments);
       d3_behavior_dragOffset = [d3_behavior_dragOffset.x - d3_behavior_dragOrigin[0], d3_behavior_dragOffset.y - d3_behavior_dragOrigin[1]];
     } else {
       d3_behavior_dragOffset = [0, 0];
@@ -4600,7 +4628,7 @@ d3.behavior.drag = function() {
 
   function mousedown() {
     start.apply(this, arguments);
-    d3_behavior_dragDispatch("dragstart");
+    d3_behavior_dragEvent({type: "dragstart"});
   }
 
   drag.origin = function(x) {
@@ -4615,40 +4643,14 @@ d3.behavior.drag = function() {
 var d3_behavior_dragEvent,
     d3_behavior_dragEventTarget,
     d3_behavior_dragTarget,
-    d3_behavior_dragArguments,
     d3_behavior_dragOffset,
     d3_behavior_dragOrigin,
     d3_behavior_dragMoved;
 
-function d3_behavior_dragDispatch(type) {
-  var p = d3_behavior_dragPoint(),
-      o = d3.event,
-      e = d3.event = {type: type};
-
-  if (p) {
-    e.x = p[0] + d3_behavior_dragOffset[0];
-    e.y = p[1] + d3_behavior_dragOffset[1];
-    e.dx = p[0] - d3_behavior_dragOrigin[0];
-    e.dy = p[1] - d3_behavior_dragOrigin[1];
-    d3_behavior_dragMoved |= e.dx | e.dy;
-    d3_behavior_dragOrigin = p;
-  }
-
-  try {
-    d3_behavior_dragEvent[type].apply(d3_behavior_dragTarget, d3_behavior_dragArguments);
-  } finally {
-    d3.event = o;
-  }
-
-  o.stopPropagation();
-}
-
 function d3_behavior_dragPoint() {
   var p = d3_behavior_dragTarget.parentNode,
       t = d3.event.changedTouches;
-  return p && (t
+  return t ? d3.touches(p, t)[0] : d3.mouse(p);
-      ? d3.touches(p, t)[0]
-      : d3.mouse(p));
 }
 
 function d3_behavior_dragMove() {
@@ -4658,13 +4660,26 @@ function d3_behavior_dragMove() {
   // O NOES! The drag element was removed from the DOM.
   if (!parent) return d3_behavior_dragUp();
 
-  d3_behavior_dragDispatch("drag");
+  var p = d3_behavior_dragPoint(),
+      dx = p[0] - d3_behavior_dragOrigin[0],
+      dy = p[1] - d3_behavior_dragOrigin[1];
+
+  d3_behavior_dragMoved |= dx | dy;
+  d3_behavior_dragOrigin = p;
   d3_eventCancel();
+
+  d3_behavior_dragEvent({
+    type: "drag",
+    x: p[0] + d3_behavior_dragOffset[0],
+    y: p[1] + d3_behavior_dragOffset[1],
+    dx: dx,
+    dy: dy
+  });
 }
 
 function d3_behavior_dragUp() {
   if (!d3_behavior_dragTarget) return;
-  d3_behavior_dragDispatch("dragend");
+  d3_behavior_dragEvent({type: "dragend"});
 
   // If the node was moved, prevent the mouseup from propagating.
   // Also prevent the subsequent click from propagating (e.g., for anchors).
@@ -4676,7 +4691,6 @@ function d3_behavior_dragUp() {
   d3_behavior_dragEvent =
   d3_behavior_dragEventTarget =
   d3_behavior_dragTarget =
-  d3_behavior_dragArguments =
   d3_behavior_dragOffset =
   d3_behavior_dragOrigin = null;
 }
@@ -4693,7 +4707,7 @@ d3.behavior.zoom = function() {
       scale = 1,
       scale0, // scale when we started touching
       scaleExtent = d3_behavior_zoomInfinity,
-      event = d3.dispatch("zoom"),
+      event = d3_eventDispatch(zoom, "zoom"),
       x0,
       x1,
       y0,
@@ -4762,20 +4776,17 @@ d3.behavior.zoom = function() {
     translate[1] += p[1] - l[1];
   }
 
-  function dispatch(argumentz) {
+  function dispatch(event) {
-    var o = d3.event; // events can by reentrant (e.g., focus);
-    d3.event = {scale: scale, translate: translate, target: zoom};
     if (x1) x1.domain(x0.range().map(function(x) { return (x - translate[0]) / scale; }).map(x0.invert));
     if (y1) y1.domain(y0.range().map(function(y) { return (y - translate[1]) / scale; }).map(y0.invert));
-    try { event.zoom.apply(zoom, argumentz); }
+    d3.event.preventDefault();
-    finally { d3.event = o; }
+    event({type: "zoom", scale: scale, translate: translate});
-    o.preventDefault();
   }
 
   function mousedown() {
     var moved = 0,
         that = this,
-        argumentz = arguments,
+        event_ = event.of(that, arguments),
         target = d3.event.target,
         w = d3.select(window).on("mousemove.zoom", mousemove).on("mouseup.zoom", mouseup),
         l = location(d3.mouse(that));
@@ -4786,7 +4797,7 @@ d3.behavior.zoom = function() {
     function mousemove() {
       moved = 1;
       translateTo(d3.mouse(that), l);
-      dispatch(argumentz);
+      dispatch(event_);
     }
 
     function mouseup() {
@@ -4804,7 +4815,7 @@ d3.behavior.zoom = function() {
     if (!translate0) translate0 = location(d3.mouse(this));
     scaleTo(Math.pow(2, d3_behavior_zoomDelta() * .002) * scale);
     translateTo(d3.mouse(this), translate0);
-    dispatch(arguments);
+    dispatch(event.of(this, arguments));
   }
 
   function mousemove() {
@@ -4815,7 +4826,7 @@ d3.behavior.zoom = function() {
     var p = d3.mouse(this), l = location(p);
     scaleTo(d3.event.shiftKey ? scale / 2 : scale * 2);
     translateTo(p, l);
-    dispatch(arguments);
+    dispatch(event.of(this, arguments));
   }
 
   function touchstart() {
@@ -4831,7 +4842,7 @@ d3.behavior.zoom = function() {
       var p = touches[0], l = location(touches[0]);
       scaleTo(scale * 2);
       translateTo(p, l);
-      dispatch(arguments);
+      dispatch(event.of(this, arguments));
     }
     touchtime = now;
   }
@@ -4847,7 +4858,7 @@ d3.behavior.zoom = function() {
       scaleTo(d3.event.scale * scale0);
     }
     translateTo(p0, l0);
-    dispatch(arguments);
+    dispatch(event.of(this, arguments));
   }
 
   return d3.rebind(zoom, event, "on");
@@ -5386,7 +5397,6 @@ function d3_layout_forceDragOut(d) {
 }
 
 function d3_layout_forceDragEnd() {
-  d3_layout_forceDrag();
   d3_layout_forceDragNode.fixed &= 1;
   d3_layout_forceDragForce = d3_layout_forceDragNode = null;
 }

src/behavior/drag.js

@@ -1,7 +1,7 @@
 // TODO Track touch points by identifier.
 
 d3.behavior.drag = function() {
-  var event = d3.dispatch("drag", "dragstart", "dragend"),
+  var event = d3_eventDispatch(drag, "drag", "dragstart", "dragend"),
       origin = null;
 
   function drag() {
@@ -19,13 +19,11 @@ d3.behavior.drag = function() {
 
   // snapshot the local context for subsequent dispatch
   function start() {
-    d3_behavior_dragEvent = event;
     d3_behavior_dragEventTarget = d3.event.target;
-    d3_behavior_dragTarget = this;
+    d3_behavior_dragEvent = event.of(d3_behavior_dragTarget = this, arguments);
-    d3_behavior_dragArguments = arguments;
     d3_behavior_dragOrigin = d3_behavior_dragPoint();
     if (origin) {
-      d3_behavior_dragOffset = origin.apply(d3_behavior_dragTarget, d3_behavior_dragArguments);
+      d3_behavior_dragOffset = origin.apply(d3_behavior_dragTarget, arguments);
       d3_behavior_dragOffset = [d3_behavior_dragOffset.x - d3_behavior_dragOrigin[0], d3_behavior_dragOffset.y - d3_behavior_dragOrigin[1]];
     } else {
       d3_behavior_dragOffset = [0, 0];
@@ -35,7 +33,7 @@ d3.behavior.drag = function() {
 
   function mousedown() {
     start.apply(this, arguments);
-    d3_behavior_dragDispatch("dragstart");
+    d3_behavior_dragEvent({type: "dragstart"});
   }
 
   drag.origin = function(x) {
@@ -50,40 +48,14 @@ d3.behavior.drag = function() {
 var d3_behavior_dragEvent,
     d3_behavior_dragEventTarget,
     d3_behavior_dragTarget,
-    d3_behavior_dragArguments,
     d3_behavior_dragOffset,
     d3_behavior_dragOrigin,
     d3_behavior_dragMoved;
 
-function d3_behavior_dragDispatch(type) {
-  var p = d3_behavior_dragPoint(),
-      o = d3.event,
-      e = d3.event = {type: type};
-
-  if (p) {
-    e.x = p[0] + d3_behavior_dragOffset[0];
-    e.y = p[1] + d3_behavior_dragOffset[1];
-    e.dx = p[0] - d3_behavior_dragOrigin[0];
-    e.dy = p[1] - d3_behavior_dragOrigin[1];
-    d3_behavior_dragMoved |= e.dx | e.dy;
-    d3_behavior_dragOrigin = p;
-  }
-
-  try {
-    d3_behavior_dragEvent[type].apply(d3_behavior_dragTarget, d3_behavior_dragArguments);
-  } finally {
-    d3.event = o;
-  }
-
-  o.stopPropagation();
-}
-
 function d3_behavior_dragPoint() {
   var p = d3_behavior_dragTarget.parentNode,
       t = d3.event.changedTouches;
-  return p && (t
+  return t ? d3.touches(p, t)[0] : d3.mouse(p);
-      ? d3.touches(p, t)[0]
-      : d3.mouse(p));
 }
 
 function d3_behavior_dragMove() {
@@ -93,13 +65,26 @@ function d3_behavior_dragMove() {
   // O NOES! The drag element was removed from the DOM.
   if (!parent) return d3_behavior_dragUp();
 
-  d3_behavior_dragDispatch("drag");
+  var p = d3_behavior_dragPoint(),
+      dx = p[0] - d3_behavior_dragOrigin[0],
+      dy = p[1] - d3_behavior_dragOrigin[1];
+
+  d3_behavior_dragMoved |= dx | dy;
+  d3_behavior_dragOrigin = p;
   d3_eventCancel();
+
+  d3_behavior_dragEvent({
+    type: "drag",
+    x: p[0] + d3_behavior_dragOffset[0],
+    y: p[1] + d3_behavior_dragOffset[1],
+    dx: dx,
+    dy: dy
+  });
 }
 
 function d3_behavior_dragUp() {
   if (!d3_behavior_dragTarget) return;
-  d3_behavior_dragDispatch("dragend");
+  d3_behavior_dragEvent({type: "dragend"});
 
   // If the node was moved, prevent the mouseup from propagating.
   // Also prevent the subsequent click from propagating (e.g., for anchors).
@@ -111,7 +96,6 @@ function d3_behavior_dragUp() {
   d3_behavior_dragEvent =
   d3_behavior_dragEventTarget =
   d3_behavior_dragTarget =
-  d3_behavior_dragArguments =
   d3_behavior_dragOffset =
   d3_behavior_dragOrigin = null;
 }

src/behavior/zoom.js

@@ -4,7 +4,7 @@ d3.behavior.zoom = function() {
       scale = 1,
       scale0, // scale when we started touching
       scaleExtent = d3_behavior_zoomInfinity,
-      event = d3.dispatch("zoom"),
+      event = d3_eventDispatch(zoom, "zoom"),
       x0,
       x1,
       y0,
@@ -73,20 +73,17 @@ d3.behavior.zoom = function() {
     translate[1] += p[1] - l[1];
   }
 
-  function dispatch(argumentz) {
+  function dispatch(event) {
-    var o = d3.event; // events can by reentrant (e.g., focus);
-    d3.event = {scale: scale, translate: translate, target: zoom};
     if (x1) x1.domain(x0.range().map(function(x) { return (x - translate[0]) / scale; }).map(x0.invert));
     if (y1) y1.domain(y0.range().map(function(y) { return (y - translate[1]) / scale; }).map(y0.invert));
-    try { event.zoom.apply(zoom, argumentz); }
+    d3.event.preventDefault();
-    finally { d3.event = o; }
+    event({type: "zoom", scale: scale, translate: translate});
-    o.preventDefault();
   }
 
   function mousedown() {
     var moved = 0,
         that = this,
-        argumentz = arguments,
+        event_ = event.of(that, arguments),
         target = d3.event.target,
         w = d3.select(window).on("mousemove.zoom", mousemove).on("mouseup.zoom", mouseup),
         l = location(d3.mouse(that));
@@ -97,7 +94,7 @@ d3.behavior.zoom = function() {
     function mousemove() {
       moved = 1;
       translateTo(d3.mouse(that), l);
-      dispatch(argumentz);
+      dispatch(event_);
     }
 
     function mouseup() {
@@ -115,7 +112,7 @@ d3.behavior.zoom = function() {
     if (!translate0) translate0 = location(d3.mouse(this));
     scaleTo(Math.pow(2, d3_behavior_zoomDelta() * .002) * scale);
     translateTo(d3.mouse(this), translate0);
-    dispatch(arguments);
+    dispatch(event.of(this, arguments));
   }
 
   function mousemove() {
@@ -126,7 +123,7 @@ d3.behavior.zoom = function() {
     var p = d3.mouse(this), l = location(p);
     scaleTo(d3.event.shiftKey ? scale / 2 : scale * 2);
     translateTo(p, l);
-    dispatch(arguments);
+    dispatch(event.of(this, arguments));
   }
 
   function touchstart() {
@@ -142,7 +139,7 @@ d3.behavior.zoom = function() {
       var p = touches[0], l = location(touches[0]);
       scaleTo(scale * 2);
       translateTo(p, l);
-      dispatch(arguments);
+      dispatch(event.of(this, arguments));
     }
     touchtime = now;
   }
@@ -158,7 +155,7 @@ d3.behavior.zoom = function() {
       scaleTo(d3.event.scale * scale0);
     }
     translateTo(p0, l0);
-    dispatch(arguments);
+    dispatch(event.of(this, arguments));
   }
 
   return d3.rebind(zoom, event, "on");

src/core/dispatch.js

@@ -1,5 +1,5 @@
 d3.dispatch = function() {
-  var dispatch = new d3_dispatch(),
+  var dispatch = new d3_dispatch,
       i = -1,
       n = arguments.length;
   while (++i < n) dispatch[arguments[i]] = d3_dispatch_event(dispatch);

src/core/event.js

@@ -4,3 +4,46 @@ function d3_eventCancel() {
   d3.event.stopPropagation();
   d3.event.preventDefault();
 }
+
+function d3_eventSource() {
+  var e = d3.event, s;
+  while (s = e.sourceEvent) e = s;
+  return e;
+}
+
+// Like d3.dispatch, but for custom events abstracting native UI events. These
+// events have a target component (such as a brush), a target element (such as
+// the svg:g element containing the brush) and the standard arguments `d` (the
+// target element's data) and `i` (the selection index of the target element).
+function d3_eventDispatch(target) {
+  var dispatch = new d3_dispatch,
+      i = 0,
+      n = arguments.length;
+
+  while (++i < n) dispatch[arguments[i]] = d3_dispatch_event(dispatch);
+
+  // Creates a dispatch context for the specified `thiz` (typically, the target
+  // DOM element that received the source event) and `argumentz` (typically, the
+  // data `d` and index `i` of the target element). The returned function can be
+  // used to dispatch an event to any registered listeners; the function takes a
+  // single argument as input, being the event to dispatch. The event must have
+  // a "type" attribute which corresponds to a type registered in the
+  // constructor. This context will automatically populate the "sourceEvent" and
+  // "target" attributes of the event, as well as setting the `d3.event` global
+  // for the duration of the notification.
+  dispatch.of = function(thiz, argumentz) {
+    return function(e1) {
+      try {
+        var e0 =
+        e1.sourceEvent = d3.event;
+        e1.target = target;
+        d3.event = e1;
+        dispatch[e1.type].apply(thiz, argumentz);
+      } finally {
+        d3.event = e0;
+      }
+    };
+  };
+
+  return dispatch;
+}

src/core/mouse.js

@@ -1,5 +1,5 @@
 d3.mouse = function(container) {
-  return d3_mousePoint(container, d3.event);
+  return d3_mousePoint(container, d3_eventSource());
 };
 
 // https://bugs.webkit.org/show_bug.cgi?id=44083

src/core/touches.js

@@ -1,6 +1,5 @@
 d3.touches = function(container, touches) {
-  if (arguments.length < 2) touches = d3.event.touches;
+  if (arguments.length < 2) touches = d3_eventSource().touches;
-
   return touches ? d3_array(touches).map(function(touch) {
     var point = d3_mousePoint(container, touch);
     point.identifier = touch.identifier;

src/layout/force.js

@@ -289,7 +289,6 @@ function d3_layout_forceDragOut(d) {
 }
 
 function d3_layout_forceDragEnd() {
-  d3_layout_forceDrag();
   d3_layout_forceDragNode.fixed &= 1;
   d3_layout_forceDragForce = d3_layout_forceDragNode = null;
 }

src/svg/brush.js

@@ -1,5 +1,5 @@
 d3.svg.brush = function() {
-  var event = d3.dispatch("brushstart", "brush", "brushend"),
+  var event = d3_eventDispatch(brush, "brushstart", "brush", "brushend"),
       x, // x-scale, optional
       y, // y-scale, optional
       extent = [[0, 0], [0, 0]]; // [x0, y0], [x1, y1]
@@ -107,24 +107,12 @@ d3.svg.brush = function() {
     d3_svg_brushY = !/^(e|w)$/.test(resize) && y;
 
     // Notify listeners.
-    d3_svg_brushDispatch = dispatcher(this, arguments);
+    d3_svg_brushEvent = event.of(this, arguments);
-    d3_svg_brushDispatch("brushstart");
+    d3_svg_brushEvent({type: "brushstart"});
     d3_svg_brushMove();
     d3_eventCancel();
   }
 
-  function dispatcher(that, argumentz) {
-    return function(type) {
-      var e = d3.event;
-      try {
-        d3.event = {type: type, target: brush};
-        event[type].apply(that, argumentz);
-      } finally {
-        d3.event = e;
-      }
-    };
-  }
-
   brush.x = function(z) {
     if (!arguments.length) return x;
     x = z;
@@ -199,7 +187,7 @@ d3.svg.brush = function() {
 };
 
 var d3_svg_brush,
-    d3_svg_brushDispatch,
+    d3_svg_brushEvent,
     d3_svg_brushTarget,
     d3_svg_brushX,
     d3_svg_brushY,
@@ -298,7 +286,7 @@ function d3_svg_brushMove() {
     // Final redraw and notify listeners.
     if (moved) {
       d3_svg_brushRedraw(g, d3_svg_brushExtent);
-      d3_svg_brushDispatch("brush");
+      d3_svg_brushEvent({type: "brush"});
     }
   }
 }
@@ -351,9 +339,9 @@ function d3_svg_brushUp() {
     d3_svg_brushMove();
     d3.select(d3_svg_brushTarget).style("pointer-events", "all").selectAll(".resize").style("display", d3_svg_brush.empty() ? "none" : null);
     d3.select("body").style("cursor", null);
-    d3_svg_brushDispatch("brushend");
+    d3_svg_brushEvent({type: "brushend"});
     d3_svg_brush =
-    d3_svg_brushDispatch =
+    d3_svg_brushEvent =
     d3_svg_brushTarget =
     d3_svg_brushX =
     d3_svg_brushY =