change theme switch

add fab icon for share screen pdf , camera change and change theme dark/light

src/lib/VueJanus.vue

@@ -4,7 +4,7 @@
         <PdfShare v-if="sharePdf" :username="username"  :opaque-id="opaqueId" :room="room" :janus-init="janusInit" ></PdfShare>
         <v-dialog
                 v-model="mozillaAlert"
-                max-width="290"
+                max-width="600"
         >
             <v-card>
                 <v-card-title class="headline">Share whole screen or a window?</v-card-title>
@@ -17,9 +17,10 @@
                     <v-btn @click="shareScreenStart('window')">Share a window</v-btn>
                 </v-card-actions>
             </v-card>
-        </v-dialog><v-dialog
+        </v-dialog>
+        <v-dialog
                 v-model="chromeAlert"
-                max-width="290"
+                max-width="600"
         >
             <v-card>
                 <v-card-title class="headline">Chrome Extension Error</v-card-title>
@@ -82,6 +83,7 @@
                 </v-card-actions>
             </v-card>
         </v-dialog>
+
         <v-row>
             <v-col cols="12" md="2">
                     <video ref="ownstream" class="rounded centered" id="myvideo" width="100%" height="100%" autoplay
@@ -139,9 +141,9 @@
             </v-btn>
             <v-btn
                     fab
-                    dark
+                    :dark="!screenShareStarted"
                     small
-                    @click="screenShare"
+                    @click="screenShareSwitch"
             >
                 <v-icon>mdi-monitor-screenshot</v-icon>
             </v-btn>
@@ -179,6 +181,7 @@
                 audioDevices: [],
                 deviceSelectDialog: false,
                 noVid: false,
+                fab: true,
                 shareScreenId: null,
                 remoteStreams: [],
                 screenShareStarted: false
@@ -238,6 +241,13 @@
             onlocalstreamScreen (stream) {
                 this.$refs.ownstreamscreen.srcObject = stream
             },
+            screenShareSwitch () {
+              if(this.screenShareStarted) {
+                  this.screenShareStop()
+              } else {
+                  this.screenShare()
+              }
+            },
             shareScreenStart (capture) {
                 this.capture = capture
                 this.janusInit.attach(