fix #78; non-passive event listeners

src/drag.js

@@ -1,7 +1,7 @@
 import {dispatch} from "d3-dispatch";
 import {select, pointer} from "d3-selection";
 import nodrag, {yesdrag} from "./nodrag.js";
-import noevent, {nopropagation} from "./noevent.js";
+import noevent, {nonpassive, nonpassivecapture, nopropagation} from "./noevent.js";
 import constant from "./constant.js";
 import DragEvent from "./event.js";
 
@@ -41,7 +41,7 @@ export default function() {
         .on("mousedown.drag", mousedowned)
       .filter(touchable)
         .on("touchstart.drag", touchstarted)
-        .on("touchmove.drag", touchmoved)
+        .on("touchmove.drag", touchmoved, nonpassive)
         .on("touchend.drag touchcancel.drag", touchended)
         .style("touch-action", "none")
         .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");
@@ -51,7 +51,9 @@ export default function() {
     if (touchending || !filter.call(this, event, d)) return;
     var gesture = beforestart(this, container.call(this, event, d), event, d, "mouse");
     if (!gesture) return;
-    select(event.view).on("mousemove.drag", mousemoved, true).on("mouseup.drag", mouseupped, true);
+    select(event.view)
+      .on("mousemove.drag", mousemoved, nonpassivecapture)
+      .on("mouseup.drag", mouseupped, nonpassivecapture);
     nodrag(event.view);
     nopropagation(event);
     mousemoving = false;

src/nodrag.js

@@ -1,11 +1,11 @@
 import {select} from "d3-selection";
-import noevent from "./noevent.js";
+import noevent, {nonpassivecapture} from "./noevent.js";
 
 export default function(view) {
   var root = view.document.documentElement,
-      selection = select(view).on("dragstart.drag", noevent, true);
+      selection = select(view).on("dragstart.drag", noevent, nonpassivecapture);
   if ("onselectstart" in root) {
-    selection.on("selectstart.drag", noevent, true);
+    selection.on("selectstart.drag", noevent, nonpassivecapture);
   } else {
     root.__noselect = root.style.MozUserSelect;
     root.style.MozUserSelect = "none";
@@ -16,7 +16,7 @@ export function yesdrag(view, noclick) {
   var root = view.document.documentElement,
       selection = select(view).on("dragstart.drag", null);
   if (noclick) {
-    selection.on("click.drag", noevent, true);
+    selection.on("click.drag", noevent, nonpassivecapture);
     setTimeout(function() { selection.on("click.drag", null); }, 0);
   }
   if ("onselectstart" in root) {

src/noevent.js

@@ -1,3 +1,8 @@
+// These are typically used in conjunction with noevent to ensure that we can
+// preventDefault on the event.
+export const nonpassive = {passive: false};
+export const nonpassivecapture = {capture: true, passive: false};
+
 export function nopropagation(event) {
   event.stopImmediatePropagation();
 }