Add qr code to wallet secret and qr scanner at join page

js/controllers/join.js

@@ -1,9 +1,104 @@
 'use strict';
 
 angular.module('copayApp.controllers').controller('JoinController',
-  function($scope, $rootScope, walletFactory, controllerUtils, Passphrase, notification) {
+  function($scope, $rootScope, $timeout, walletFactory, controllerUtils, Passphrase, notification) {
     $scope.loading = false;
-    
+
+   // QR code Scanner
+    var cameraInput;
+    var video;
+    var canvas;
+    var $video;
+    var context;
+    var localMediaStream;
+
+    var _scan = function(evt) {
+      if (localMediaStream) {
+        context.drawImage(video, 0, 0, 300, 225);
+
+        try {
+          qrcode.decode();
+        } catch (e) {
+          //qrcodeError(e);
+        }
+      }
+
+      $timeout(_scan, 500);
+    };
+
+    var _successCallback = function(stream) {
+      video.src = (window.URL && window.URL.createObjectURL(stream)) || stream;
+      localMediaStream = stream;
+      video.play();
+      $timeout(_scan, 1000);
+    };
+
+    var _scanStop = function() {
+      $scope.showScanner = false;
+      if (!$scope.isMobile) {
+        if (localMediaStream && localMediaStream.stop) localMediaStream.stop();
+        localMediaStream = null;
+        video.src = '';
+      }
+    };
+
+    var _videoError = function(err) {
+      _scanStop();
+    };
+
+    qrcode.callback = function(data) {
+      _scanStop();
+
+      $scope.$apply(function() {
+        $scope.connectionId = data;
+      });
+    };
+
+    $scope.cancelScanner = function() {
+      _scanStop();
+    };
+
+    $scope.openScanner = function() {
+      if (window.cordova) return $scope.scannerIntent();
+
+      $scope.showScanner = true;
+
+      // Wait a moment until the canvas shows
+      $timeout(function() {
+        canvas = document.getElementById('qr-canvas');
+        context = canvas.getContext('2d');
+
+        if ($scope.isMobile) {
+          cameraInput = document.getElementById('qrcode-camera');
+          cameraInput.addEventListener('change', _scan, false);
+        } else {
+          video = document.getElementById('qrcode-scanner-video');
+          $video = angular.element(video);
+          canvas.width = 300;
+          canvas.height = 225;
+          context.clearRect(0, 0, 300, 225);
+
+          navigator.getUserMedia({
+            video: true
+          }, _successCallback, _videoError);
+        }
+      }, 500);
+    };
+
+    $scope.scannerIntent = function() {
+      cordova.plugins.barcodeScanner.scan(
+        function onSuccess(result) {
+          if (result.cancelled) return;
+
+          $scope.connectionId = result.text;
+          $rootScope.$digest();
+        },
+        function onError(error) {
+          alert('Scanning error');
+        });
+    }
+
+
     $scope.join = function(form) {
       if (form && form.$invalid) {
         notification.error('Error', 'Please enter the required fields');