c++ - Make QDialog modal to operating system -

is possible if qdialog instance exec()uted, entire operating system blocked until user closes dialog? in following minimal example dialog blocks parent widget not os elements outside of qt application.

rootwindow.h

#ifndef rootwindow_h #define rootwindow_h  #include <qapplication> #include <qmainwindow> #include <qtdebug> #include <qdialog> #include <qpushbutton> #include <qmessagebox> #include <qboxlayout>  class rootwindow : public qmainwindow {     q_object  private:      qwidget *widgetcentral;     qboxlayout *layoutmain;     qpushbutton *button;     qdialog *dialog;  public:      rootwindow(qwidget *parent = 0, qt::windowflags flags = 0);     ~rootwindow();  private slots:      void slotclicked(); };  #endif // rootwindow_h 

rootwindow.cpp

#include "rootwindow.h"  rootwindow::rootwindow(qwidget *parent, qt::windowflags flags): qmainwindow(parent, flags) {     setcentralwidget( widgetcentral = new qwidget );     widgetcentral->setlayout( layoutmain = new qboxlayout(qboxlayout::lefttoright) );     layoutmain->addwidget(button = new qpushbutton("click me"));      dialog = new qdialog(this);     dialog->setmodal(true);     dialog->setwindowmodality(qt::applicationmodal);      connect(button, &qpushbutton::clicked, this, &rootwindow::slotclicked); }  rootwindow::~rootwindow() {  }  void rootwindow::slotclicked() {     int = dialog->exec();     qdebug() << "dialog result: " << i; } 

main.cpp

#include "rootwindow.h"  int main(int argc, char *argv[]) {     qapplication a(argc, argv);      rootwindow w;     w.show();      return a.exec(); } 

short answer: can't. there may way using native api, doubt it.

however, there way can archive similar behavior: show frameless fullscreen window opacity of 1% - window invisible user, block mouse input. show normal dialog on top of window.

please note approach merely workaround , not work multiple desktops. in addition that, applications (like task-manager) still stay on top of window. keyboard shortcust alt+tab, windows-key , others still work normally. , more...

and last not least: if could, shouldn't. blocking whole computer bad behavior application. showing normal, application modal dialog should enough! if user doesn't want pay attention program, should not force him!