// Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies). // SPDX-License-Identifier: BSD-3-Clause #include #include #include #include #include #include #include #include class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(); public slots: void handleMessage(const QString& message); signals: void needToShow(); private: QMdiArea *workspace; }; MainWindow::MainWindow() { workspace = new QMdiArea(this); setCentralWidget(workspace); } void MainWindow::handleMessage(const QString& message) { enum Action { Nothing, Open, Print } action; action = Nothing; QString filename = message; if (message.toLower().startsWith("/print ")) { filename = filename.mid(7); action = Print; } else if (!message.isEmpty()) { action = Open; } if (action == Nothing) { emit needToShow(); return; } QFile file(filename); QString contents; if (file.open(QIODevice::ReadOnly)) contents = file.readAll(); else contents = "[[Error: Could not load file " + filename + "]]"; QTextEdit *view = new QTextEdit; view->setPlainText(contents); switch(action) { case Print: { QPrinter printer; view->print(&printer); delete view; } break; case Open: { workspace->addSubWindow(view); view->setWindowTitle(message); view->show(); emit needToShow(); } break; default: break; }; } #include "main.moc" int main(int argc, char **argv) { QtSingleApplication instance("File loader QtSingleApplication example", argc, argv); QString message; for (int a = 1; a < argc; ++a) { message += argv[a]; if (a < argc-1) message += " "; } if (instance.sendMessage(message)) return 0; MainWindow mw; mw.handleMessage(message); mw.show(); QObject::connect(&instance, SIGNAL(messageReceived(const QString&)), &mw, SLOT(handleMessage(const QString&))); instance.setActivationWindow(&mw, false); QObject::connect(&mw, SIGNAL(needToShow()), &instance, SLOT(activateWindow())); return instance.exec(); }