NewMainWindow prototype - close, minimize

.. very basic, no icons. Just to be able to close
   gracefully. Need to get same level of functionality
   on windows and macOS.

src/Gui/NewMainWindow.cpp

@@ -11,6 +11,8 @@ constexpr double gl_minheight = 700;
 constexpr double gl_toolbarheight = 46;
 constexpr double gl_searchwidth = 350;
 constexpr double gl_searchheight = 26;
+constexpr double gl_quitheight = 26;
+constexpr double gl_quitwidth = 26;
 
 NewMainWindow::NewMainWindow(QApplication *app) : QMainWindow(NULL), app(app)
 {
@@ -50,7 +52,13 @@ NewMainWindow::setupToolbar()
     searchbox->setFixedHeight(gl_searchheight * dpiXFactor);
     searchbox->setFrame(QFrame::NoFrame);
     searchbox->setStyleSheet("background: white; border-radius: 7px;");
-    searchbox->setPlaceholderText(tr("search or /expression... "));
+    searchbox->setPlaceholderText(tr("                    Search or type a command "));
+
+    // spacer to balance the minimize and close buttons
+    QWidget *balanceSpacer = new QWidget(this);
+    balanceSpacer->setFixedSize(gl_quitwidth*dpiXFactor * 2, gl_quitheight*dpiYFactor);
+    balanceSpacer->setVisible(true);
+    balanceSpacer->setAutoFillBackground(false);
 
     QWidget *leftSpacer = new QWidget(this);
     leftSpacer->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Preferred);
@@ -62,10 +70,31 @@ NewMainWindow::setupToolbar()
     rightSpacer->setVisible(true);
     rightSpacer->setAutoFillBackground(false);
 
+    toolbar->addWidget(balanceSpacer);
     toolbar->addWidget(leftSpacer);
     toolbar->addWidget(searchbox);
     toolbar->addWidget(rightSpacer);
 
+    // and close push buttons on the right
+    minimisebutton = new QPushButton(this);
+    minimisebutton->setFlat(true);
+    minimisebutton->setFixedSize(gl_quitwidth * dpiXFactor, gl_quitheight *dpiXFactor);
+    minimisebutton->setStyleSheet("background: lightGray; color: white;");
+    minimisebutton->setText("_"); // fix with icon later
+    toolbar->addWidget(minimisebutton);
+
+    // and close push buttons on the right
+    quitbutton = new QPushButton(this);
+    quitbutton->setFlat(true);
+    quitbutton->setFixedSize(gl_quitwidth * dpiXFactor, gl_quitheight *dpiXFactor);
+    quitbutton->setStyleSheet("background: lightGray; color: white;");
+    quitbutton->setText("X"); // fix with icon later
+    toolbar->addWidget(quitbutton);
+
+    // connect up
+    connect(quitbutton, SIGNAL(clicked()), this, SLOT(close()));
+    connect(minimisebutton, SIGNAL(clicked()), this, SLOT(minimizeWindow()));
+
     toolbar->show();
 }
 
@@ -113,3 +142,9 @@ void
 NewMainWindow::mouseMoveEvent(QMouseEvent *event) {
     move(event->globalX()-clickPos.x(),event->globalY()-clickPos.y());
 }
+
+void
+NewMainWindow::minimizeWindow()
+{
+    setWindowState(Qt::WindowMinimized);
+}

src/Gui/NewMainWindow.h

@@ -2,9 +2,12 @@
 #include <QToolBar>
 #include <QVBoxLayout>
 #include <QLineEdit>
+#include <QPushButton>
 
 class NewMainWindow : public QMainWindow
 {
+    Q_OBJECT
+
     public:
         NewMainWindow(QApplication *app);
 
@@ -24,6 +27,9 @@ class NewMainWindow : public QMainWindow
         // set initial geometry, screen etc
         void initialPosition();
 
+    public slots:
+        void minimizeWindow();
+
     private:
         QApplication *app;
 
@@ -31,6 +37,7 @@ class NewMainWindow : public QMainWindow
         QVBoxLayout *layout;
         QToolBar *toolbar;
         QLineEdit *searchbox;
+        QPushButton *quitbutton, *minimisebutton;
 
         QPoint clickPos;
 };