Added logout. Truncate username to 8 characters

interface/resources/qml/hifi/tablet/Tablet.qml

@@ -1,5 +1,6 @@
 import QtQuick 2.5
 import QtGraphicalEffects 1.0
+import QtQuick.Layouts 1.3
 
 import "../../styles-uit"
 import "../audio" as HifiAudio
@@ -116,20 +117,36 @@ Item {
             anchors.rightMargin: 30
             anchors.verticalCenter: parent.verticalCenter
 
-            RalewaySemiBold {
-                id: usernameText
-                text: Account.isLoggedIn() ? tabletRoot.username : qsTr("Log in")
-                anchors.verticalCenter: parent.verticalCenter
-                horizontalAlignment: Text.AlignRight
-                anchors.right: parent.right
-                font.pixelSize: 20
-                color: "#afafaf"
+            ColumnLayout {
+                anchors.fill: parent
+
+                RalewaySemiBold {
+                    text: Account.isLoggedIn() ? qsTr("Log out") : qsTr("Log in")
+                    horizontalAlignment: Text.AlignRight
+                    anchors.right: parent.right
+                    font.pixelSize: 20
+                    color: "#afafaf"
+                }
+
+                RalewaySemiBold {
+                    visible: Account.isLoggedIn()
+                    height: Account.isLoggedIn() ? parent.height/2 - parent.spacing/2 : 0
+                    text: Account.isLoggedIn() ? "[" + tabletRoot.usernameShort + "]" : ""
+                    horizontalAlignment: Text.AlignRight
+                    anchors.right: parent.right
+                    font.pixelSize: 20
+                    color: "#afafaf"
+                }
             }
+
             MouseArea {
                 anchors.fill: parent
-                enabled: !Account.isLoggedIn()
                 onClicked: {
-                    DialogsManager.showLoginDialog()
+                    if (!Account.isLoggedIn()) {
+                        DialogsManager.showLoginDialog()
+                    } else {
+                        Account.logOut()
+                    }
                 }
             }
         }

interface/resources/qml/hifi/tablet/TabletRoot.qml

@@ -8,6 +8,7 @@ Item {
     id: tabletRoot
     objectName: "tabletRoot"
     property string username: "Unknown user"
+    property string usernameShort: "Unknown user"
     property var rootMenu;
     property var openModal: null;
     property var openMessage: null;
@@ -157,6 +158,11 @@ Item {
 
     function setUsername(newUsername) {
         username = newUsername;
+        usernameShort = newUsername.substring(0, 8);
+
+        if (newUsername.length > 8) {
+            usernameShort = usernameShort + "..."
+        }
     }
 
     ListModel {

interface/src/scripting/AccountScriptingInterface.cpp

@@ -31,6 +31,11 @@ bool AccountScriptingInterface::checkAndSignalForAccessToken() {
     return accountManager->checkAndSignalForAccessToken();
 }
 
+void AccountScriptingInterface::logOut() {
+    auto accountManager = DependencyManager::get<AccountManager>();
+    return accountManager->logout();
+}
+
 QString AccountScriptingInterface::getUsername() {
     auto accountManager = DependencyManager::get<AccountManager>();
     if (accountManager->isLoggedIn()) {

interface/src/scripting/AccountScriptingInterface.h

@@ -50,6 +50,7 @@ public slots:
      */
     bool isLoggedIn();
     bool checkAndSignalForAccessToken();
+    void logOut();
 };
 
 #endif // hifi_AccountScriptingInterface_h