Two

package.json

@@ -33,11 +33,11 @@
     "postpublish": "git push && git push --tags && cd ../d3.github.com && git pull && cp ../${npm_package_name}/dist/${npm_package_name}.js ${npm_package_name}.v${npm_package_version%%.*}.js && cp ../${npm_package_name}/dist/${npm_package_name}.min.js ${npm_package_name}.v${npm_package_version%%.*}.min.js && git add ${npm_package_name}.v${npm_package_version%%.*}.js ${npm_package_name}.v${npm_package_version%%.*}.min.js && git commit -m \"${npm_package_name} ${npm_package_version}\" && git push && cd - && zip -j dist/${npm_package_name}.zip -- LICENSE README.md dist/${npm_package_name}.js dist/${npm_package_name}.min.js"
   },
   "dependencies": {
-    "d3-dispatch": "1",
-    "d3-drag": "1",
-    "d3-interpolate": "1",
-    "d3-selection": "1",
-    "d3-transition": "1"
+    "d3-dispatch": "1 - 2",
+    "d3-drag": "2",
+    "d3-interpolate": "1 - 2",
+    "d3-selection": "2",
+    "d3-transition": "1 - 2"
   },
   "devDependencies": {
     "eslint": "6",

src/brush.js

@@ -1,7 +1,7 @@
 import {dispatch} from "d3-dispatch";
 import {dragDisable, dragEnable} from "d3-drag";
 import {interpolate} from "d3-interpolate";
-import {customEvent, event, touch, mouse, select} from "d3-selection";
+import {pointer, select} from "d3-selection";
 import {interrupt} from "d3-transition";
 import constant from "./constant.js";
 import BrushEvent from "./event.js";
@@ -12,6 +12,8 @@ var MODE_DRAG = {name: "drag"},
     MODE_HANDLE = {name: "handle"},
     MODE_CENTER = {name: "center"};
 
+const {abs, max, min} = Math;
+
 function number1(e) {
   return [+e[0], +e[1]];
 }
@@ -20,12 +22,6 @@ function number2(e) {
   return [number1(e[0]), number1(e[1])];
 }
 
-function toucher(identifier) {
-  return function(target) {
-    return touch(target, event.touches, identifier);
-  };
-}
-
 var X = {
   name: "x",
   handles: ["w", "e"].map(type),
@@ -109,7 +105,7 @@ function type(t) {
 }
 
 // Ignore right-click, since that should open the context menu.
-function defaultFilter() {
+function defaultFilter(event) {
   return !event.ctrlKey && !event.button;
 }
 
@@ -216,10 +212,10 @@ function brush(dim) {
   }
 
   brush.move = function(group, selection) {
-    if (group.selection) {
+    if (group.selection && group.selection() !== group) {
       group
-          .on("start.brush", function() { emitter(this, arguments).beforestart().start(); })
-          .on("interrupt.brush end.brush", function() { emitter(this, arguments).end(); })
+          .on("start.brush", function(event) { emitter(this, arguments).beforestart().start(event); })
+          .on("interrupt.brush end.brush", function(event) { emitter(this, arguments).end(event); })
           .tween("brush", function() {
             var that = this,
                 state = that.__brush,
@@ -302,28 +298,40 @@ function brush(dim) {
 
   Emitter.prototype = {
     beforestart: function() {
-      if (++this.active === 1) this.state.emitter = this, this.starting = true;
+      if (++this.active === 1) this.state.emitter = this, this.starting = true, this.dispatch = listeners.copy();
       return this;
     },
-    start: function() {
-      if (this.starting) this.starting = false, this.emit("start");
-      else this.emit("brush");
+    start: function(event) {
+      if (this.starting) this.starting = false, this.emit("start", event);
+      else this.emit("brush", event);
       return this;
     },
-    brush: function() {
-      this.emit("brush");
+    brush: function(event) {
+      this.emit("brush", event);
       return this;
     },
-    end: function() {
-      if (--this.active === 0) delete this.state.emitter, this.emit("end");
+    end: function(event) {
+      if (--this.active === 0) delete this.state.emitter, this.emit("end", event);
       return this;
     },
-    emit: function(type) {
-      customEvent(new BrushEvent(brush, type, dim.output(this.state.selection)), listeners.apply, listeners, [type, this.that, this.args]);
+    emit: function(type, event) {
+      var dispatch = this.dispatch,
+          d = select(this.that).datum();
+      dispatch.call(
+        type,
+        this.that,
+        new BrushEvent(type, {
+          sourceEvent: event,
+          target: brush,
+          selection: dim.output(this.state.selection),
+          dispatch
+        }),
+        d
+      );
     }
   };
 
-  function started() {
+  function started(event) {
     if (touchending && !event.touches) return;
     if (!filter.apply(this, arguments)) return;
 
@@ -345,17 +353,25 @@ function brush(dim) {
         shifting = signX && signY && keys && event.shiftKey,
         lockX,
         lockY,
-        pointer = event.touches ? toucher(event.changedTouches[0].identifier) : mouse,
-        point0 = pointer(that),
-        point = point0,
-        emit = emitter(that, arguments, true).beforestart();
+        points = Array.from(event.touches || [event], t => {
+          const i = t.identifier;
+          t = pointer(t, that);
+          t.point0 = t.slice();
+          t.identifier = i;
+          return t;
+        });
 
     if (type === "overlay") {
       if (selection) moving = true;
-      state.selection = selection = [
-        [w0 = dim === Y ? W : point0[0], n0 = dim === X ? N : point0[1]],
-        [e0 = dim === Y ? E : w0, s0 = dim === X ? S : n0]
-      ];
+      const pts = [points[0], points[1] || points[0]];
+      state.selection = selection = [[
+          w0 = dim === Y ? W : min(pts[0][0], pts[1][0]),
+          n0 = dim === X ? N : min(pts[0][1], pts[1][1])
+        ], [
+          e0 = dim === Y ? E : max(pts[0][0], pts[1][0]),
+          s0 = dim === X ? S : max(pts[0][1], pts[1][1])
+        ]];
+      if (points.length > 1) move();
     } else {
       w0 = selection[0][0];
       n0 = selection[0][1];
@@ -374,6 +390,9 @@ function brush(dim) {
     var overlay = group.selectAll(".overlay")
         .attr("cursor", cursors[type]);
 
+    interrupt(that);
+    var emit = emitter(that, arguments, true).beforestart();
+
     if (event.touches) {
       emit.moved = moved;
       emit.ended = ended;
@@ -388,24 +407,30 @@ function brush(dim) {
       dragDisable(event.view);
     }
 
-    nopropagation();
-    interrupt(that);
     redraw.call(that);
     emit.start();
 
-    function moved() {
-      var point1 = pointer(that);
-      if (shifting && !lockX && !lockY) {
-        if (Math.abs(point1[0] - point[0]) > Math.abs(point1[1] - point[1])) lockY = true;
-        else lockX = true;
+    function moved(event) {
+      for (const p of event.changedTouches || [event]) {
+        for (const d of points)
+          if (d.identifier === p.identifier) d.cur = pointer(p, that);
       }
-      point = point1;
+      if (shifting && !lockX && !lockY && points.length === 1) {
+        const point = points[0];
+        if (abs(point.cur[0] - point[0]) > abs(point.cur[1] - point[1]))
+          lockY = true;
+        else
+          lockX = true;
+      }
+      for (const point of points)
+        if (point.cur) point[0] = point.cur[0], point[1] = point.cur[1];
       moving = true;
-      noevent();
-      move();
+      noevent(event);
+      move(event);
     }
 
-    function move() {
+    function move(event) {
+      const point = points[0], point0 = point.point0;
       var t;
 
       dx = point[0] - point0[0];
@@ -414,20 +439,25 @@ function brush(dim) {
       switch (mode) {
         case MODE_SPACE:
         case MODE_DRAG: {
-          if (signX) dx = Math.max(W - w0, Math.min(E - e0, dx)), w1 = w0 + dx, e1 = e0 + dx;
-          if (signY) dy = Math.max(N - n0, Math.min(S - s0, dy)), n1 = n0 + dy, s1 = s0 + dy;
+          if (signX) dx = max(W - w0, min(E - e0, dx)), w1 = w0 + dx, e1 = e0 + dx;
+          if (signY) dy = max(N - n0, min(S - s0, dy)), n1 = n0 + dy, s1 = s0 + dy;
           break;
         }
         case MODE_HANDLE: {
-          if (signX < 0) dx = Math.max(W - w0, Math.min(E - w0, dx)), w1 = w0 + dx, e1 = e0;
-          else if (signX > 0) dx = Math.max(W - e0, Math.min(E - e0, dx)), w1 = w0, e1 = e0 + dx;
-          if (signY < 0) dy = Math.max(N - n0, Math.min(S - n0, dy)), n1 = n0 + dy, s1 = s0;
-          else if (signY > 0) dy = Math.max(N - s0, Math.min(S - s0, dy)), n1 = n0, s1 = s0 + dy;
+          if (points[1]) {
+            if (signX) w1 = max(W, min(E, points[0][0])), e1 = max(W, min(E, points[1][0])), signX = 1;
+            if (signY) n1 = max(N, min(S, points[0][1])), s1 = max(N, min(S, points[1][1])), signY = 1;
+          } else {
+            if (signX < 0) dx = max(W - w0, min(E - w0, dx)), w1 = w0 + dx, e1 = e0;
+            else if (signX > 0) dx = max(W - e0, min(E - e0, dx)), w1 = w0, e1 = e0 + dx;
+            if (signY < 0) dy = max(N - n0, min(S - n0, dy)), n1 = n0 + dy, s1 = s0;
+            else if (signY > 0) dy = max(N - s0, min(S - s0, dy)), n1 = n0, s1 = s0 + dy;
+          }
           break;
         }
         case MODE_CENTER: {
-          if (signX) w1 = Math.max(W, Math.min(E, w0 - dx * signX)), e1 = Math.max(W, Math.min(E, e0 + dx * signX));
-          if (signY) n1 = Math.max(N, Math.min(S, n0 - dy * signY)), s1 = Math.max(N, Math.min(S, s0 + dy * signY));
+          if (signX) w1 = max(W, min(E, w0 - dx * signX)), e1 = max(W, min(E, e0 + dx * signX));
+          if (signY) n1 = max(N, min(S, n0 - dy * signY)), s1 = max(N, min(S, s0 + dy * signY));
           break;
         }
       }
@@ -456,12 +486,12 @@ function brush(dim) {
           || selection[1][1] !== s1) {
         state.selection = [[w1, n1], [e1, s1]];
         redraw.call(that);
-        emit.brush();
+        emit.brush(event);
       }
     }
 
-    function ended() {
-      nopropagation();
+    function ended(event) {
+      nopropagation(event);
       if (event.touches) {
         if (event.touches.length) return;
         if (touchending) clearTimeout(touchending);
@@ -474,10 +504,10 @@ function brush(dim) {
       overlay.attr("cursor", cursors.overlay);
       if (state.selection) selection = state.selection; // May be set by brush.move (on start)!
       if (empty(selection)) state.selection = null, redraw.call(that);
-      emit.end();
+      emit.end(event);
     }
 
-    function keydowned() {
+    function keydowned(event) {
       switch (event.keyCode) {
         case 16: { // SHIFT
           shifting = signX && signY;
@@ -504,10 +534,10 @@ function brush(dim) {
         }
         default: return;
       }
-      noevent();
+      noevent(event);
     }
 
-    function keyupped() {
+    function keyupped(event) {
       switch (event.keyCode) {
         case 16: { // SHIFT
           if (shifting) {
@@ -543,16 +573,16 @@ function brush(dim) {
         }
         default: return;
       }
-      noevent();
+      noevent(event);
     }
   }
 
-  function touchmoved() {
-    emitter(this, arguments).moved();
+  function touchmoved(event) {
+    emitter(this, arguments).moved(event);
   }
 
-  function touchended() {
-    emitter(this, arguments).ended();
+  function touchended(event) {
+    emitter(this, arguments).ended(event);
   }
 
   function initialize() {

src/constant.js

@@ -1,5 +1 @@
-export default function(x) {
-  return function() {
-    return x;
-  };
-}
+export default x => () => x;

src/event.js

@@ -1,5 +1,19 @@
-export default function(target, type, selection) {
-  this.target = target;
-  this.type = type;
-  this.selection = selection;
+export default function BrushEvent(type, {
+  sourceEvent,
+  target,
+  selection,
+  dispatch
+}) {
+  Object.defineProperties(this, {
+    type: {value: type, enumerable: true, configurable: true},
+    sourceEvent: {value: sourceEvent, enumerable: true, configurable: true},
+    target: {value: target, enumerable: true, configurable: true},
+    selection: {value: selection, enumerable: true, configurable: true},
+    _: {value: dispatch}
+  });
 }
+
+BrushEvent.prototype.on = function() {
+  var value = this._.on.apply(this._, arguments);
+  return value === this._ ? this : value;
+};

src/noevent.js

@@ -1,10 +1,8 @@
-import {event} from "d3-selection";
-
-export function nopropagation() {
+export function nopropagation(event) {
   event.stopImmediatePropagation();
 }
 
-export default function() {
+export default function(event) {
   event.preventDefault();
   event.stopImmediatePropagation();
 }