Warning if webcam access is refused

Fix #41

lib/Vroom/I18N/en.pm

@@ -149,6 +149,9 @@ our %Lexicon = (
   "NO_WEBRTC_SUPPORT"                    => "Sorry, but the video conference will not work because your web browser doesn't have the " .
                                             "required functionnalities. We recommand you download one of the following browsers " .
                                             "which support the latest web technologies required to use VROOM",
+  "NO_WEBCAM"                            => "Cannot access your webcam",
+  "CANT_ACCESS_WEBCAM"                   => "We couldn't access your webcam. Please check it's connected, powered on, and that you've ".
+                                            "allowed the browser to access it, then reload this page",
   "HOME"                                 => "Home",
   "HELP"                                 => "Help",
   "ABOUT"                                => "About",

lib/Vroom/I18N/fr.pm

@@ -160,6 +160,9 @@ our %Lexicon = (
                                                    "ne dispose pas des fonctions nécessaires. Nous recommandons de télécharger " .
                                                    "un des navigateurs suivants, qui supportent les dernières technologies nécessaires " .
                                                    "à l'utilisation de VROOM",
+    "NO_WEBCAM"                                 => "Impossible d'accéder à votre webcam",
+    "CANT_ACCESS_WEBCAM"                        => "Nous n'avons pas pu accéder à votre webcam, vérifiez qu'elle soit bien connectée, allumée, et que ".
+                                                   "vous avez autorisé le navigateur à y accéder, puis raffraichissez cette page",
     "HOME"                                      => "Accueil",
     "HELP"                                      => "Aide",
     "ABOUT"                                     => "À propos",

public/js/vroom.js

@@ -895,10 +895,16 @@ function initVroom(room) {
     addVideo(video,peer);
   });
 
+  // We share our screen
   webrtc.on('localScreenAdded', function(video){
     addVideo(video);
   });
 
+  // error opening the webcam stream
+  webrtc.on('localMediaError', function(){
+    $('#noWebcam').modal('show');
+  });
+
   // Handle video stream removed: someone leaved the room
   // TODO: don't trigger on local screen unshare
   webrtc.on('videoRemoved', function(video,peer){

templates/default/join.html.ep

@@ -285,6 +285,22 @@
         </div>
       </div>
     </div>
+    <div class="modal fade" role="dialog" id="noWebcam" aria-labelledby="noWebcam" aria-hidden="true">
+      <div class="modal-dialog modal-lg">
+        <div class="modal-content">
+          <div class="modal-header">
+            <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
+            <h4 class="modal-title" id="noWebcamTitle"><%=l 'NO_WEBCAM' %></h4>
+          </div>
+          <div class="modal-body">
+            <p><%=l 'CANT_ACCESS_WEBCAM' %></p>
+            <center>
+              <img src="/img/webcam.png" alt="Webcam"/>
+            </center>
+          </div>
+        </div>
+      </div>
+    </div>
     <div class="frame">
       <div id="chatMenu" class="nav-collapse collapse">
         <div id="chatHistory" class="form-control">