From 2deb730f221277ac421f632caf70f5394c5a6d94 Mon Sep 17 00:00:00 2001
From: Daniel Freedman <dfreedm@google.com>
Date: Mon, 4 Nov 2013 15:21:54 -0800
Subject: [PATCH] Tunnel source event preventDefault to PointerEvents

- Only way to disable some default actions
- Related to #103
---
 src/dispatcher.js |  7 +++++++
 src/mouse.js      |  6 ++++++
 src/touch.js      | 10 ++++++++++
 3 files changed, 23 insertions(+)

diff --git a/src/dispatcher.js b/src/dispatcher.js
index 7d11d239..04da312a 100644
--- a/src/dispatcher.js
+++ b/src/dispatcher.js
@@ -223,6 +223,7 @@
         inEvent.relatedTarget = null;
       }
       var e = new PointerEvent(inType, inEvent);
+      e.preventDefault = inEvent.preventDefault;
       this.targets.set(e, this.targets.get(inEvent) || inEvent.target);
       return e;
     },
@@ -244,6 +245,12 @@
         p = CLONE_PROPS[i];
         eventCopy[p] = inEvent[p] || CLONE_DEFAULTS[i];
       }
+      // keep the semantics of preventDefault
+      if (inEvent.preventDefault) {
+        eventCopy.preventDefault = function() {
+          inEvent.preventDefault();
+        };
+      }
       return eventCopy;
     },
     getTarget: function(inEvent) {
diff --git a/src/mouse.js b/src/mouse.js
index e7138b7e..040d247e 100644
--- a/src/mouse.js
+++ b/src/mouse.js
@@ -42,6 +42,12 @@
     },
     prepareEvent: function(inEvent) {
       var e = dispatcher.cloneEvent(inEvent);
+      // forward mouse preventDefault
+      var pd = e.preventDefault;
+      e.preventDefault = function() {
+        inEvent.preventDefault();
+        pd();
+      };
       e.pointerId = this.POINTER_ID;
       e.isPrimary = true;
       e.pointerType = this.POINTER_TYPE;
diff --git a/src/touch.js b/src/touch.js
index 24768ac3..8d461927 100644
--- a/src/touch.js
+++ b/src/touch.js
@@ -154,6 +154,16 @@
     processTouches: function(inEvent, inFunction) {
       var tl = inEvent.changedTouches;
       var pointers = touchMap(tl, this.touchToPointer, this);
+      // forward touch preventDefaults
+      pointers.forEach(function(p) {
+        var pd = p.preventDefault;
+        p.preventDefault = function() {
+          this.scrolling = false;
+          this.firstXY = null;
+          inEvent.preventDefault();
+          pd();
+        };
+      }, this);
       pointers.forEach(inFunction, this);
     },
     // For single axis scrollers, determines whether the element should emit