Making the window be centralized

main.cpp

 #include "functions.h"
 #include <cassert>
 #include <QDebug>
+#include <QDesktopWidget>
 
 void testSort() {
     QString a = "AAA" , b = "BBB" , c = "CCC";
     srand(time(NULL));
     QApplication a(argc, argv);
     MainWindow w;
+
+    QDesktopWidget desktop;
+
+    int screenWidth, screenHeight;
+
+    screenWidth = desktop.screenGeometry().width();
+    screenHeight = desktop.screenGeometry().height();
+    w.move( ( screenWidth - w.width() )/2, ( screenHeight- w.height() ) /2);
     w.show();
 
 

mainwindow.cpp

 #include <QtCore/qmath.h>
 #include <QMessageBox>
 #include "functions.h"
+#include <QDesktopWidget>
 
 MainWindow::MainWindow(QWidget *parent) :
     QMainWindow(parent),
 
     window = new secondwindow;
 
+    QDesktopWidget desktop;
+
+
+    window->move( ( desktop.screenGeometry().width() - window->width() )/2,
+                 ( desktop.screenGeometry().height()- window->height() ) /2);
+
+
     // We need to know whenever the second window is closed to show the
     // main window, or to hide when the second one is showed
     connect(window, SIGNAL(cerrado(bool)), this, SLOT(mostrar(bool)));
 
         // Create the new window and connecting it again with the signal
         window = new secondwindow;
+
+        QDesktopWidget desktop;
+
+
+        window->move( ( desktop.screenGeometry().width() - window->width() )/2,
+                     ( desktop.screenGeometry().height()- window->height() ) /2);
+
+
         connect(window, SIGNAL(cerrado(bool)), this, SLOT(mostrar(bool)));
     }
     else hide();
     //notify when it was closed so we can shor the main-window
     window->setLayout(layout);
     mostrar(false);
+
+    QDesktopWidget desktop;
+
+
+    window->move( ( desktop.screenGeometry().width() - window->width() )/2,
+                 ( desktop.screenGeometry().height()- window->height() ) /2);
+
     window->show();
 }
 
     //and show the new one. The new-window has a signal that
     //notify when it was closed so we can shor the main-window
     window->setLayout(layout);
+    mostrar(false);
     window->show();
 }
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