Remove QtkWidget dependency on MainWindow.

src/app/qtkmainwindow.cpp

@@ -25,6 +25,7 @@ MainWindow::MainWindow(QWidget * parent) : QMainWindow(parent)
   // Initialize static container for all active QtkWidgets
   auto qtkWidgets = findChildren<Qtk::QtkWidget *>();
   for (auto & qtkWidget : qtkWidgets) {
+    qtkWidget->setMainWindow(this);
     // NOTE: Set a temporary scene for the widget to use for initialization.
     // This should be replaced by loading a scene, or creating a new (unsaved)
     // scene when Qtk is opened.

src/designer-plugins/qtkwidget.cpp

@@ -7,16 +7,14 @@
 ##############################################################################*/
 
 #include <QKeyEvent>
-#include <QMimeData>
-#include <QVBoxLayout>
 #include <QMainWindow>
+#include <QMimeData>
 
 #include "qtk/input.h"
 #include "qtk/scene.h"
 #include "qtk/shape.h"
 
 #include "debugconsole.h"
-#include "app/qtkmainwindow.h"
 #include "qtkwidget.h"
 
 using namespace Qtk;
@@ -85,8 +83,10 @@ void QtkWidget::initializeGL()
   connect(this, SIGNAL(frameSwapped()), this, SLOT(update()));
 
   // Add the debug console widget to the window and set its hidden state.
-  MainWindow::getMainWindow()->addDockWidget(
+  if (mMainWindow != nullptr) {
-      Qt::DockWidgetArea::BottomDockWidgetArea, mConsole);
+    mMainWindow->addDockWidget(Qt::DockWidgetArea::BottomDockWidgetArea,
+                               mConsole);
+  }
   mConsole->setHidden(!mConsoleActive);
 
   // Initialize OpenGL debug context

src/designer-plugins/qtkwidget.h

@@ -119,6 +119,11 @@ namespace Qtk
        */
       void setScene(Qtk::Scene * scene);
 
+      /**
+       * @param window The QMainWindow that owns this QtkWidget.
+       */
+      void setMainWindow(QMainWindow * window) { mMainWindow = window; }
+
       /*************************************************************************
        * Public Members
        ************************************************************************/
@@ -218,6 +223,7 @@ namespace Qtk
       Qtk::Scene * mScene;
       Qtk::DebugConsole * mConsole;
       bool mConsoleActive = true;
+      QMainWindow * mMainWindow = Q_NULLPTR;
   };
 
   /**