Fix crash cause when Menu::instance() is before offscreen ui startup

interface/src/Application.cpp

@@ -767,6 +767,7 @@ void Application::initializeUi() {
     AddressBarDialog::registerType();
     LoginDialog::registerType();
     MessageDialog::registerType();
+    VrMenu::registerType();
 
     auto offscreenUi = DependencyManager::get<OffscreenUi>();
     offscreenUi->create(_glWidget->context()->contextHandle());
@@ -775,6 +776,8 @@ void Application::initializeUi() {
     offscreenUi->setBaseUrl(QUrl::fromLocalFile(PathUtils::resourcesPath() + "/qml/"));
     offscreenUi->load("Root.qml");
     offscreenUi->load("RootMenu.qml");
+    VrMenu::load();
+    VrMenu::executeQueuedLambdas();
     offscreenUi->setMouseTranslator([this](const QPointF& p){
         if (OculusManager::isConnected()) {
             glm::vec2 pos = _applicationOverlay.screenToOverlay(toGlm(p));

interface/src/Menu.cpp

@@ -975,7 +975,9 @@ bool Menu::menuItemExists(const QString& menu, const QString& menuitem) {
 
 
 MenuWrapper::MenuWrapper(QMenu* menu) : _realMenu(menu) {
-    VrMenu::instance()->addMenu(menu);
+    VrMenu::executeOrQueue([=](VrMenu* vrMenu) {
+        vrMenu->addMenu(menu);
+    });
     _backMap[menu] = this;
 }
 
@@ -997,18 +999,24 @@ void MenuWrapper::addSeparator() {
 
 void MenuWrapper::addAction(QAction* action) {
     _realMenu->addAction(action);
-    VrMenu::instance()->addAction(_realMenu, action);
+    VrMenu::executeOrQueue([=](VrMenu* vrMenu) {
+        vrMenu->addAction(_realMenu, action);
+    });
 }
 
 QAction* MenuWrapper::addAction(const QString& menuName) {
     QAction* action = _realMenu->addAction(menuName);
-    VrMenu::instance()->addAction(_realMenu, action);
+    VrMenu::executeOrQueue([=](VrMenu* vrMenu) {
+        vrMenu->addAction(_realMenu, action);
+    });
     return action;
 }
 
 QAction* MenuWrapper::addAction(const QString& menuName, const QObject* receiver, const char* member, const QKeySequence& shortcut) {
     QAction* action = _realMenu->addAction(menuName, receiver, member, shortcut);
-    VrMenu::instance()->addAction(_realMenu, action);
+    VrMenu::executeOrQueue([=](VrMenu* vrMenu) {
+        vrMenu->addAction(_realMenu, action);
+    });
     return action;
 }
 
@@ -1018,7 +1026,9 @@ void MenuWrapper::removeAction(QAction* action) {
 
 void MenuWrapper::insertAction(QAction* before, QAction* action) {
     _realMenu->insertAction(before, action);
-    VrMenu::instance()->insertAction(before, action);
+    VrMenu::executeOrQueue([=](VrMenu* vrMenu) {
+        vrMenu->insertAction(before, action);
+    });
 }
 
 QHash<QMenu*, MenuWrapper*> MenuWrapper::_backMap;

libraries/ui/src/VrMenu.cpp

@@ -42,7 +42,7 @@ private:
         qmlObject->setUserData(USER_DATA_ID, this);
         qmlObject->setObjectName(uuid.toString());
         // Make sure we can find it again in the future
-        Q_ASSERT(VrMenu::instance()->findMenuObject(uuid.toString()));
+        Q_ASSERT(VrMenu::_instance->findMenuObject(uuid.toString()));
     }
 };
 
@@ -57,14 +57,25 @@ HIFI_QML_DEF_LAMBDA(VrMenu, [&](QQmlContext* context, QObject* newItem) {
 });
 
 VrMenu* VrMenu::_instance{ nullptr };
+static QQueue<std::function<void(VrMenu*)>> queuedLambdas;
 
-VrMenu* VrMenu::instance() {
-    if (!_instance) {
-        VrMenu::registerType();
-        VrMenu::load();
-        Q_ASSERT(_instance);
+void VrMenu::executeOrQueue(std::function<void(VrMenu*)> f) {
+    if (_instance) {
+        foreach(std::function<void(VrMenu*)> priorLambda, queuedLambdas) {
+            priorLambda(_instance);
+        }
+        f(_instance);
+    } else {
+        queuedLambdas.push_back(f);
     }
-    return _instance;
+}
+
+void VrMenu::executeQueuedLambdas() {
+    Q_ASSERT(_instance);
+    foreach(std::function<void(VrMenu*)> f, queuedLambdas) {
+        f(_instance);
+    }
+    queuedLambdas.clear();
 }
 
 VrMenu::VrMenu(QQuickItem* parent) : QQuickItem(parent) {
@@ -72,6 +83,7 @@ VrMenu::VrMenu(QQuickItem* parent) : QQuickItem(parent) {
     this->setEnabled(false);
 }
 
+
 // QML helper functions
 QObject* addMenu(QObject* parent, const QString& text) {
     // FIXME add more checking here to ensure no name conflicts

libraries/ui/src/VrMenu.h

@@ -26,7 +26,8 @@ class VrMenu : public QQuickItem {
     HIFI_QML_DECL_LAMBDA
 
 public:
-    static VrMenu* instance();
+    static void executeOrQueue(std::function<void(VrMenu*)> f);
+    static void executeQueuedLambdas();
     VrMenu(QQuickItem* parent = nullptr);
     void addMenu(QMenu* menu);
     void addAction(QMenu* parent, QAction* action);