Listen to vrdisplayconnect/vrdisplaydisconnect to enter/exit VR when a headset is plugged/unplugged

t push -f dmarcos# Date:      Tue Jul 25 17:49:24 2017 -0700

Author: dmarcos

src/core/scene/a-scene.js

@@ -121,6 +121,12 @@ module.exports.AScene = registerElement('a-scene', {
 
         // Exit VR on `vrdisplaydeactivate` (e.g. taking off Rift headset).
         window.addEventListener('vrdisplaydeactivate', function () { self.exitVR(); });
+
+        // Enter VR on `vrdisplayconnect` (e.g. plugging on Rift headset).
+        window.addEventListener('vrdisplayconnect', function () { self.enterVR(); });
+
+        // Exit VR on `vrdisplaydisconnect` (e.g. unplugging Rift headset).
+        window.addEventListener('vrdisplaydisconnect', function () { self.exitVR(true); });
       },
       writable: window.debug
     },
@@ -247,7 +253,8 @@ module.exports.AScene = registerElement('a-scene', {
             throw new Error('Failed to enter VR mode (`requestPresent`).');
           }
         }
-      }
+      },
+      writable: window.debug
     },
      /**
      * Call `exitPresent` if WebVR or WebVR polyfill.
@@ -296,7 +303,8 @@ module.exports.AScene = registerElement('a-scene', {
             throw new Error('Failed to exit VR mode (`exitPresent`).');
           }
         }
-      }
+      },
+      writable: window.debug
     },
 
     /**

tests/core/scene/a-scene.test.js

@@ -60,6 +60,34 @@ suite('a-scene (without renderer)', function () {
     });
   });
 
+  suite.only('vrdisplayconnect', function () {
+    test('tells A-Frame about entering VR when the headset is connected', function (done) {
+      var event;
+      var sceneEl = this.el;
+      var enterVRStub = this.sinon.stub(sceneEl, 'enterVR');
+      event = new CustomEvent('vrdisplayconnect');
+      window.dispatchEvent(event);
+      process.nextTick(function () {
+        assert.ok(enterVRStub.called);
+        done();
+      });
+    });
+  });
+
+  suite.only('vrdisplaydisconnect', function () {
+    test('tells A-Frame about entering VR when the headset is connected', function (done) {
+      var event;
+      var sceneEl = this.el;
+      var exitVRStub = this.sinon.stub(sceneEl, 'exitVR');
+      event = new CustomEvent('vrdisplaydisconnect');
+      window.dispatchEvent(event);
+      process.nextTick(function () {
+        assert.ok(exitVRStub.calledWith(true));
+        done();
+      });
+    });
+  });
+
   suite('vrdisplaypresentchange', function () {
     test('tells A-Frame about entering VR if now presenting', function (done) {
       var event;