Add option to turn device orientation control on by default.

doc/json-config-parameters.md

@@ -63,6 +63,13 @@ not supported by the user's device. The user will be given the option to click
 a link and visit this URL if Pannellum fails to work.
 
 
+### `orientationOnByDefault` (boolean)
+
+If set to `true`, device orientation control will be used when the panorama is
+loaded, if the device supports it. If false, device orientation control needs
+to be activated by pressing a button. Defaults to `false`.
+
+
 ### `showZoomCtrl` (boolean)
 
 If set to `false`, the zoom controls will not be displayed. Defaults to `true`.

src/js/pannellum.js

@@ -192,13 +192,10 @@ if (document.fullscreenEnabled || document.mozFullScreenEnabled || document.webk
 // Device orientation toggle
 controls.orientation = document.createElement('div');
 controls.orientation.addEventListener('click', function(e) {
-    if (orientation) {
+    if (orientation)
         stopOrientation();
-    } else {
-        orientation = true;
-        window.addEventListener('deviceorientation', orientationListener);
-        controls.orientation.classList.add('pnlm-orientation-button-active');
-    }
+    else
+        startOrientation();
 });
 controls.orientation.addEventListener('mousedown', function(e) {e.stopPropagation();});
 controls.orientation.addEventListener('touchstart', function(e) {e.stopPropagation();});
@@ -1820,6 +1817,12 @@ function processOptions() {
                     controls.zoom.style.display = 'none';
                     controls.fullscreen.style.display = 'none';
                 }
+                break;
+
+            case 'orientationOnByDefault':
+                if (config[key])
+                    startOrientation();
+                break;
         }
       }
     }
@@ -2043,6 +2046,16 @@ function stopOrientation() {
 }
 
 /**
+ * Start using device orientation.
+ * @private
+ */
+function startOrientation() {
+    orientation = true;
+    window.addEventListener('deviceorientation', orientationListener);
+    controls.orientation.classList.add('pnlm-orientation-button-active');
+}
+
+/**
  * Escapes HTML string (to mitigate possible DOM XSS attacks).
  * @private
  * @param {string} s - String to escape