application: Add a Starting() slot to Application

Add a slot that is invoked when the main application loop starts. This
can be used to perform setup tasks after the initialization has
occurred. Initial use is to hide a splash.

src/core/application.cpp

@@ -252,6 +252,10 @@ void Application::MoveToThread(QObject* object, QThread* thread) {
 
 void Application::AddError(const QString& message) { emit ErrorAdded(message); }
 
+void Application::Starting() {
+  qLog(Debug) << "Application starting";
+}
+
 QString Application::language_without_region() const {
   const int underscore = language_name_.indexOf('_');
   if (underscore != -1) {

src/core/application.h

@@ -114,6 +114,7 @@ class Application : public QObject {
   void MoveToThread(QObject* object, QThread* thread);
 
  public slots:
+  void Starting();
   void AddError(const QString& message);
   void ReloadSettings();
   void OpenSettingsDialogAtPage(SettingsDialog::Page page);

src/main.cpp

@@ -460,6 +460,10 @@ int main(int argc, char* argv[]) {
   QObject::connect(&a, SIGNAL(messageReceived(QString)), &w,
                    SLOT(CommandlineOptionsReceived(QString)));
 
+  // Use a queued connection so the invokation occurs after the application
+  // loop starts.
+  QMetaObject::invokeMethod(&app, "Starting", Qt::QueuedConnection);
+
   int ret = a.exec();
 
   return ret;