Allow opening another window

CMakeLists.txt

@@ -175,7 +175,8 @@ set(REQUIRED_ICONS
     system-file-manager
     document-save
     view-media-lyrics
-    image-resize-symbolic)
+    image-resize-symbolic
+    window-new)
 
 # find c++utilities
 set(CONFIGURATION_PACKAGE_SUFFIX

gui/mainwindow.cpp

@@ -114,6 +114,7 @@ MainWindow::MainWindow(QWidget *parent)
 
     // connect signals and slots, install event filter
     //  menu: application
+    connect(m_ui->actionNew_window, &QAction::triggered, this, &MainWindow::showNewWindow);
     connect(m_ui->actionSettings, &QAction::triggered, this, &MainWindow::showSettingsDlg);
     connect(m_ui->actionOpen_MusicBrainz_search, &QAction::triggered, this, &MainWindow::toggleDbQueryWidget);
     connect(m_ui->lockLayout, &QAction::triggered, this, &MainWindow::toggleLayoutLocked);
@@ -378,6 +379,17 @@ void MainWindow::showAboutDlg()
     }
 }
 
+
+/*!
+ * \brief MainWindow::showNewWindow
+ */
+void MainWindow::showNewWindow()
+{
+    auto *const newWindow = new MainWindow;
+    newWindow->setAttribute(Qt::WA_DeleteOnClose);
+    newWindow->show();
+}
+
 /*!
  * \brief Shows the settings dialog (modal).
  */

gui/mainwindow.h

@@ -69,6 +69,7 @@ private Q_SLOTS:
     void handleCurrentPathChanged(const QString &newPath);
 
     // settings
+    void showNewWindow();
     void showSettingsDlg();
     void applySettingsFromDialog();
 

gui/mainwindow.ui

@@ -46,7 +46,7 @@
      <x>0</x>
      <y>0</y>
      <width>1225</width>
-     <height>26</height>
+     <height>30</height>
     </rect>
    </property>
    <widget class="QMenu" name="menuFile">
@@ -82,6 +82,7 @@
     <property name="title">
      <string>A&amp;pplication</string>
     </property>
+    <addaction name="actionNew_window"/>
     <addaction name="actionSettings"/>
     <addaction name="actionOpen_MusicBrainz_search"/>
     <addaction name="lockLayout"/>
@@ -363,6 +364,14 @@
     <string>&amp;Lock layout</string>
    </property>
   </action>
+  <action name="actionNew_window">
+   <property name="icon">
+    <iconset theme="window-new"/>
+   </property>
+   <property name="text">
+    <string>New window</string>
+   </property>
+  </action>
  </widget>
  <customwidgets>
   <customwidget>