mainwindow.cpp Example File

mainwindows/mdi/mainwindow.cpp
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#include <QtWidgets> #include "mainwindow.h" #include "mdichild.h" MainWindow::MainWindow() : mdiArea(new QMdiArea) { mdiArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded); mdiArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded); setCentralWidget(mdiArea); connect(mdiArea, &QMdiArea::subWindowActivated, this, &MainWindow::updateMenus); createActions(); createStatusBar(); updateMenus(); readSettings(); setWindowTitle(tr("MDI")); setUnifiedTitleAndToolBarOnMac(true); } void MainWindow::closeEvent(QCloseEvent *event) { mdiArea->closeAllSubWindows(); if (mdiArea->currentSubWindow()) { event->ignore(); } else { writeSettings(); event->accept(); } } void MainWindow::newFile() { MdiChild *child = createMdiChild(); child->newFile(); child->show(); } void MainWindow::open() { const QString fileName = QFileDialog::getOpenFileName(this); if (!fileName.isEmpty()) openFile(fileName); } bool MainWindow::openFile(const QString &fileName) { if (QMdiSubWindow *existing = findMdiChild(fileName)) { mdiArea->setActiveSubWindow(existing); return true; } const bool succeeded = loadFile(fileName); if (succeeded) statusBar()->showMessage(tr("File loaded"), 2000); return succeeded; } bool MainWindow::loadFile(const QString &fileName) { MdiChild *child = createMdiChild(); const bool succeeded = child->loadFile(fileName); if (succeeded) child->show(); else child->close(); MainWindow::prependToRecentFiles(fileName); return succeeded; } static inline QString recentFilesKey() { return QStringLiteral("recentFileList"); } static inline QString fileKey() { return QStringLiteral("file"); } static QStringList readRecentFiles(QSettings &settings) { QStringList result; const int count = settings.beginReadArray(recentFilesKey()); for (int i = 0; i < count; ++i) { settings.setArrayIndex(i); result.append(settings.value(fileKey()).toString()); } settings.endArray(); return result; } static void writeRecentFiles(const QStringList &files, QSettings &settings) { const int count = files.size(); settings.beginWriteArray(recentFilesKey()); for (int i = 0; i < count; ++i) { settings.setArrayIndex(i); settings.setValue(fileKey(), files.at(i)); } settings.endArray(); } bool MainWindow::hasRecentFiles() { QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName()); const int count = settings.beginReadArray(recentFilesKey()); settings.endArray(); return count > 0; } void MainWindow::prependToRecentFiles(const QString &fileName) { QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName()); const QStringList oldRecentFiles = readRecentFiles(settings); QStringList recentFiles = oldRecentFiles; recentFiles.removeAll(fileName); recentFiles.prepend(fileName); if (oldRecentFiles != recentFiles) writeRecentFiles(recentFiles, settings); setRecentFilesVisible(!recentFiles.isEmpty()); } void MainWindow::setRecentFilesVisible(bool visible) { recentFileSubMenuAct->setVisible(visible); recentFileSeparator->setVisible(visible); } void MainWindow::updateRecentFileActions() { QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName()); const QStringList recentFiles = readRecentFiles(settings); const int count = qMin(int(MaxRecentFiles), recentFiles.size()); int i = 0; for ( ; i < count; ++i) { const QString fileName = QFileInfo(recentFiles.at(i)).fileName(); recentFileActs[i]->setText(tr("&%1 %2").arg(i + 1).arg(fileName)); recentFileActs[i]->setData(recentFiles.at(i)); recentFileActs[i]->setVisible(true); } for ( ; i < MaxRecentFiles; ++i) recentFileActs[i]->setVisible(false); } void MainWindow::openRecentFile() { if (const QAction *action = qobject_cast<const QAction *>(sender())) openFile(action->data().toString()); } void MainWindow::save() { if (activeMdiChild() && activeMdiChild()->save()) statusBar()->showMessage(tr("File saved"), 2000); } void MainWindow::saveAs() { MdiChild *child = activeMdiChild(); if (child && child->saveAs()) { statusBar()->showMessage(tr("File saved"), 2000); MainWindow::prependToRecentFiles(child->currentFile()); } } #ifndef QT_NO_CLIPBOARD void MainWindow::cut() { if (activeMdiChild()) activeMdiChild()->cut(); } void MainWindow::copy() { if (activeMdiChild()) activeMdiChild()->copy(); } void MainWindow::paste() { if (activeMdiChild()) activeMdiChild()->paste(); } #endif void MainWindow::about() { QMessageBox::about(this, tr("About MDI"), tr("The <b>MDI</b> example demonstrates how to write multiple " "document interface applications using Qt.")); } void MainWindow::updateMenus() { bool hasMdiChild = (activeMdiChild() != 0); saveAct->setEnabled(hasMdiChild); saveAsAct->setEnabled(hasMdiChild); #ifndef QT_NO_CLIPBOARD pasteAct->setEnabled(hasMdiChild); #endif closeAct->setEnabled(hasMdiChild); closeAllAct->setEnabled(hasMdiChild); tileAct->setEnabled(hasMdiChild); cascadeAct->setEnabled(hasMdiChild); nextAct->setEnabled(hasMdiChild); previousAct->setEnabled(hasMdiChild); windowMenuSeparatorAct->setVisible(hasMdiChild); #ifndef QT_NO_CLIPBOARD bool hasSelection = (activeMdiChild() && activeMdiChild()->textCursor().hasSelection()); cutAct->setEnabled(hasSelection); copyAct->setEnabled(hasSelection); #endif } void MainWindow::updateWindowMenu() { windowMenu->clear(); windowMenu->addAction(closeAct); windowMenu->addAction(closeAllAct); windowMenu->addSeparator(); windowMenu->addAction(tileAct); windowMenu->addAction(cascadeAct); windowMenu->addSeparator(); windowMenu->addAction(nextAct); windowMenu->addAction(previousAct); windowMenu->addAction(windowMenuSeparatorAct); QList<QMdiSubWindow *> windows = mdiArea->subWindowList(); windowMenuSeparatorAct->setVisible(!windows.isEmpty()); for (int i = 0; i < windows.size(); ++i) { QMdiSubWindow *mdiSubWindow = windows.at(i); MdiChild *child = qobject_cast<MdiChild *>(mdiSubWindow->widget()); QString text; if (i < 9) { text = tr("&%1 %2").arg(i + 1) .arg(child->userFriendlyCurrentFile()); } else { text = tr("%1 %2").arg(i + 1) .arg(child->userFriendlyCurrentFile()); } QAction *action = windowMenu->addAction(text, mdiSubWindow, [this, mdiSubWindow]() { mdiArea->setActiveSubWindow(mdiSubWindow); }); action->setCheckable(true); action ->setChecked(child == activeMdiChild()); } } MdiChild *MainWindow::createMdiChild() { MdiChild *child = new MdiChild; mdiArea->addSubWindow(child); #ifndef QT_NO_CLIPBOARD connect(child, &QTextEdit::copyAvailable, cutAct, &QAction::setEnabled); connect(child, &QTextEdit::copyAvailable, copyAct, &QAction::setEnabled); #endif return child; } void MainWindow::createActions() { QMenu *fileMenu = menuBar()->addMenu(tr("&File")); QToolBar *fileToolBar = addToolBar(tr("File")); const QIcon newIcon = QIcon::fromTheme("document-new", QIcon(":/images/new.png")); newAct = new QAction(newIcon, tr("&New"), this); newAct->setShortcuts(QKeySequence::New); newAct->setStatusTip(tr("Create a new file")); connect(newAct, &QAction::triggered, this, &MainWindow::newFile); fileMenu->addAction(newAct); fileToolBar->addAction(newAct); const QIcon openIcon = QIcon::fromTheme("document-open", QIcon(":/images/open.png")); QAction *openAct = new QAction(openIcon, tr("&Open..."), this); openAct->setShortcuts(QKeySequence::Open); openAct->setStatusTip(tr("Open an existing file")); connect(openAct, &QAction::triggered, this, &MainWindow::open); fileMenu->addAction(openAct); fileToolBar->addAction(openAct); const QIcon saveIcon = QIcon::fromTheme("document-save", QIcon(":/images/save.png")); saveAct = new QAction(saveIcon, tr("&Save"), this); saveAct->setShortcuts(QKeySequence::Save); saveAct->setStatusTip(tr("Save the document to disk")); connect(saveAct, &QAction::triggered, this, &MainWindow::save); fileToolBar->addAction(saveAct); const QIcon saveAsIcon = QIcon::fromTheme("document-save-as"); saveAsAct = new QAction(saveAsIcon, tr("Save &As..."), this); saveAsAct->setShortcuts(QKeySequence::SaveAs); saveAsAct->setStatusTip(tr("Save the document under a new name")); connect(saveAsAct, &QAction::triggered, this, &MainWindow::saveAs); fileMenu->addAction(saveAsAct); fileMenu->addSeparator(); QMenu *recentMenu = fileMenu->addMenu(tr("Recent...")); connect(recentMenu, &QMenu::aboutToShow, this, &MainWindow::updateRecentFileActions); recentFileSubMenuAct = recentMenu->menuAction(); for (int i = 0; i < MaxRecentFiles; ++i) { recentFileActs[i] = recentMenu->addAction(QString(), this, &MainWindow::openRecentFile); recentFileActs[i]->setVisible(false); } recentFileSeparator = fileMenu->addSeparator(); setRecentFilesVisible(MainWindow::hasRecentFiles()); fileMenu->addAction(tr("Switch layout direction"), this, &MainWindow::switchLayoutDirection); fileMenu->addSeparator(); const QIcon exitIcon = QIcon::fromTheme("application-exit"); QAction *exitAct = fileMenu->addAction(exitIcon, tr("E&xit"), qApp, &QApplication::closeAllWindows); exitAct->setShortcuts(QKeySequence::Quit); exitAct->setStatusTip(tr("Exit the application")); fileMenu->addAction(exitAct); #ifndef QT_NO_CLIPBOARD QMenu *editMenu = menuBar()->addMenu(tr("&Edit")); QToolBar *editToolBar = addToolBar(tr("Edit")); const QIcon cutIcon = QIcon::fromTheme("edit-cut", QIcon(":/images/cut.png")); cutAct = new QAction(cutIcon, tr("Cu&t"), this); cutAct->setShortcuts(QKeySequence::Cut); cutAct->setStatusTip(tr("Cut the current selection's contents to the " "clipboard")); connect(cutAct, &QAction::triggered, this, &MainWindow::cut); editMenu->addAction(cutAct); editToolBar->addAction(cutAct); const QIcon copyIcon = QIcon::fromTheme("edit-copy", QIcon(":/images/copy.png")); copyAct = new QAction(copyIcon, tr("&Copy"), this); copyAct->setShortcuts(QKeySequence::Copy); copyAct->setStatusTip(tr("Copy the current selection's contents to the " "clipboard")); connect(copyAct, &QAction::triggered, this, &MainWindow::copy); editMenu->addAction(copyAct); editToolBar->addAction(copyAct); const QIcon pasteIcon = QIcon::fromTheme("edit-paste", QIcon(":/images/paste.png")); pasteAct = new QAction(pasteIcon, tr("&Paste"), this); pasteAct->setShortcuts(QKeySequence::Paste); pasteAct->setStatusTip(tr("Paste the clipboard's contents into the current " "selection")); connect(pasteAct, &QAction::triggered, this, &MainWindow::paste); editMenu->addAction(pasteAct); editToolBar->addAction(pasteAct); #endif windowMenu = menuBar()->addMenu(tr("&Window")); connect(windowMenu, &QMenu::aboutToShow, this, &MainWindow::updateWindowMenu); closeAct = new QAction(tr("Cl&ose"), this); closeAct->setStatusTip(tr("Close the active window")); connect(closeAct, &QAction::triggered, mdiArea, &QMdiArea::closeActiveSubWindow); closeAllAct = new QAction(tr("Close &All"), this); closeAllAct->setStatusTip(tr("Close all the windows")); connect(closeAllAct, &QAction::triggered, mdiArea, &QMdiArea::closeAllSubWindows); tileAct = new QAction(tr("&Tile"), this); tileAct->setStatusTip(tr("Tile the windows")); connect(tileAct, &QAction::triggered, mdiArea, &QMdiArea::tileSubWindows); cascadeAct = new QAction(tr("&Cascade"), this); cascadeAct->setStatusTip(tr("Cascade the windows")); connect(cascadeAct, &QAction::triggered, mdiArea, &QMdiArea::cascadeSubWindows); nextAct = new QAction(tr("Ne&xt"), this); nextAct->setShortcuts(QKeySequence::NextChild); nextAct->setStatusTip(tr("Move the focus to the next window")); connect(nextAct, &QAction::triggered, mdiArea, &QMdiArea::activateNextSubWindow); previousAct = new QAction(tr("Pre&vious"), this); previousAct->setShortcuts(QKeySequence::PreviousChild); previousAct->setStatusTip(tr("Move the focus to the previous " "window")); connect(previousAct, &QAction::triggered, mdiArea, &QMdiArea::activatePreviousSubWindow); windowMenuSeparatorAct = new QAction(this); windowMenuSeparatorAct->setSeparator(true); updateWindowMenu(); menuBar()->addSeparator(); QMenu *helpMenu = menuBar()->addMenu(tr("&Help")); QAction *aboutAct = helpMenu->addAction(tr("&About"), this, &MainWindow::about); aboutAct->setStatusTip(tr("Show the application's About box")); QAction *aboutQtAct = helpMenu->addAction(tr("About &Qt"), qApp, &QApplication::aboutQt); aboutQtAct->setStatusTip(tr("Show the Qt library's About box")); } void MainWindow::createStatusBar() { statusBar()->showMessage(tr("Ready")); } void MainWindow::readSettings() { QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName()); const QByteArray geometry = settings.value("geometry", QByteArray()).toByteArray(); if (geometry.isEmpty()) { const QRect availableGeometry = QApplication::desktop()->availableGeometry(this); resize(availableGeometry.width() / 3, availableGeometry.height() / 2); move((availableGeometry.width() - width()) / 2, (availableGeometry.height() - height()) / 2); } else { restoreGeometry(geometry); } } void MainWindow::writeSettings() { QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName()); settings.setValue("geometry", saveGeometry()); } MdiChild *MainWindow::activeMdiChild() const { if (QMdiSubWindow *activeSubWindow = mdiArea->activeSubWindow()) return qobject_cast<MdiChild *>(activeSubWindow->widget()); return 0; } QMdiSubWindow *MainWindow::findMdiChild(const QString &fileName) const { QString canonicalFilePath = QFileInfo(fileName).canonicalFilePath(); foreach (QMdiSubWindow *window, mdiArea->subWindowList()) { MdiChild *mdiChild = qobject_cast<MdiChild *>(window->widget()); if (mdiChild->currentFile() == canonicalFilePath) return window; } return 0; } void MainWindow::switchLayoutDirection() { if (layoutDirection() == Qt::LeftToRight) QGuiApplication::setLayoutDirection(Qt::RightToLeft); else QGuiApplication::setLayoutDirection(Qt::LeftToRight); }