From 69872c99d27cc063dc88bc2a9ead3f64359778a2 Mon Sep 17 00:00:00 2001
From: Paul Spencer <paul@pagameba.com>
Date: Sat, 7 Sep 2013 21:48:49 -0400
Subject: [PATCH] Detect iOS compass heading

iOS webkit does not provide an absolute alpha, instead it provides
webkitCompassHeading.
---
 src/ol/deviceorientation.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/ol/deviceorientation.js b/src/ol/deviceorientation.js
index 3b86d5bba4..c10584091a 100644
--- a/src/ol/deviceorientation.js
+++ b/src/ol/deviceorientation.js
@@ -122,6 +122,9 @@ ol.DeviceOrientation.prototype.orientationChange_ = function(browserEvent) {
     // event.absolute is undefined in iOS.
     if (goog.isBoolean(event.absolute) && event.absolute) {
       this.set(ol.DeviceOrientationProperty.HEADING, alpha);
+    } else if (goog.isDefAndNotNull(event.webkitCompassHeading)) {
+      var heading = goog.math.toRadians(event.webkitCompassHeading);
+      this.set(ol.DeviceOrientationProperty.HEADING, heading);
     }
   }
   if (goog.isDefAndNotNull(event.beta)) {