Added an AbstractDialog class and using it as base for a NewItemDialog class (no new item functionality yet).

mainwindow.h

@@ -3,10 +3,11 @@
 
 #include <QMainWindow>
 
-QT_BEGIN_NAMESPACE
-
+class NewItemDialog;
 class QAbstractItemModel;
 
+QT_BEGIN_NAMESPACE
+
 namespace Ui {
 class MainWindow;
 }
@@ -37,6 +38,9 @@ class MainWindow : public QMainWindow {
 
   void on_pushButton_clicked();
 
+  /// slots for menu actions
+  void openNewItemDialog();
+
  private:
   Ui::MainWindow* ui;
 
@@ -63,10 +67,14 @@ class MainWindow : public QMainWindow {
   unique_ptr<QAction> m_deleteItemAct;
   unique_ptr<QAction> m_findItemAct;
 
+  /// Dialogs
+  unique_ptr<NewItemDialog> m_newItemDialog;
+
   /// Setup functions
   void createActions();
   void createFileActions();
   void createEditActions();
   void createHelpMenu();
+  void createGuiDialogs();
 };
 #endif  // MAINWINDOW_H