Qt Reference Documentation

- Qt 4.8
- ALL VERSIONS

- A
- A
- A
- Print

# mainwindow.cpp Example File

demos/mainwindow/mainwindow.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
     ** Contact: http://www.qt-project.org/legal
     **
     ** This file is part of the demonstration applications of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:LGPL$
     ** Commercial License Usage
     ** Licensees holding valid commercial Qt licenses may use this file in
     ** accordance with the commercial license agreement provided with the
     ** Software or, alternatively, in accordance with the terms contained in
     ** a written agreement between you and Digia.  For licensing terms and
     ** conditions see http://qt.digia.com/licensing.  For further information
     ** use the contact form at http://qt.digia.com/contact-us.
     **
     ** GNU Lesser General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU Lesser
     ** General Public License version 2.1 as published by the Free Software
     ** Foundation and appearing in the file LICENSE.LGPL included in the
     ** packaging of this file.  Please review the following information to
     ** ensure the GNU Lesser General Public License version 2.1 requirements
     ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
     **
     ** In addition, as a special exception, Digia gives you certain additional
     ** rights.  These rights are described in the Digia Qt LGPL Exception
     ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
     **
     ** GNU General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU
     ** General Public License version 3.0 as published by the Free Software
     ** Foundation and appearing in the file LICENSE.GPL included in the
     ** packaging of this file.  Please review the following information to
     ** ensure the GNU General Public License version 3.0 requirements will be
     ** met: http://www.gnu.org/copyleft/gpl.html.
     **
     **
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #include "mainwindow.h"
     #include "colorswatch.h"
     #include "toolbar.h"

     #include <QAction>
     #include <QLayout>
     #include <QMenu>
     #include <QMenuBar>
     #include <QStatusBar>
     #include <QTextEdit>
     #include <QFile>
     #include <QDataStream>
     #include <QFileDialog>
     #include <QMessageBox>
     #include <QSignalMapper>
     #include <QApplication>
     #include <QPainter>
     #include <QMouseEvent>
     #include <QLineEdit>
     #include <QComboBox>
     #include <QLabel>
     #include <QPushButton>
     #include <qdebug.h>

     static const char * const message =
         "<p><b>Qt Main Window Demo</b></p>"

         "<p>This is a demonstration of the QMainWindow, QToolBar and "
         "QDockWidget classes.</p>"

         "<p>The tool bar and dock widgets can be dragged around and rearranged "
         "using the mouse or via the menu.</p>"

         "<p>Each dock widget contains a colored frame and a context "
         "(right-click) menu.</p>"

     #ifdef Q_WS_MAC
         "<p>On Mac OS X, the \"Black\" dock widget has been created as a "
         "<em>Drawer</em>, which is a special kind of QDockWidget.</p>"
     #endif
         ;

     Q_DECLARE_METATYPE(QDockWidget::DockWidgetFeatures)

     MainWindow::MainWindow(const QMap<QString, QSize> &customSizeHints,
                             QWidget *parent, Qt::WindowFlags flags)
         : QMainWindow(parent, flags)
     {
         setObjectName("MainWindow");
         setWindowTitle("Qt Main Window Demo");

         center = new QTextEdit(this);
         center->setReadOnly(true);
         center->setMinimumSize(400, 205);
         setCentralWidget(center);

         setupToolBar();
         setupMenuBar();
         setupDockWidgets(customSizeHints);

         statusBar()->showMessage(tr("Status Bar"));
     }

     void MainWindow::actionTriggered(QAction *action)
     {
         qDebug("action '%s' triggered", action->text().toLocal8Bit().data());
     }

     void MainWindow::setupToolBar()
     {
         for (int i = 0; i < 3; ++i) {
             ToolBar *tb = new ToolBar(QString::fromLatin1("Tool Bar %1").arg(i + 1), this);
             toolBars.append(tb);
             addToolBar(tb);
         }
     }

     void MainWindow::setupMenuBar()
     {
         QMenu *menu = menuBar()->addMenu(tr("&File"));

         QAction *action = menu->addAction(tr("Save layout..."));
         connect(action, SIGNAL(triggered()), this, SLOT(saveLayout()));

         action = menu->addAction(tr("Load layout..."));
         connect(action, SIGNAL(triggered()), this, SLOT(loadLayout()));

         action = menu->addAction(tr("Switch layout direction"));
         connect(action, SIGNAL(triggered()), this, SLOT(switchLayoutDirection()));

         menu->addSeparator();

         menu->addAction(tr("&Quit"), this, SLOT(close()));

         mainWindowMenu = menuBar()->addMenu(tr("Main window"));

         action = mainWindowMenu->addAction(tr("Animated docks"));
         action->setCheckable(true);
         action->setChecked(dockOptions() & AnimatedDocks);
         connect(action, SIGNAL(toggled(bool)), this, SLOT(setDockOptions()));

         action = mainWindowMenu->addAction(tr("Allow nested docks"));
         action->setCheckable(true);
         action->setChecked(dockOptions() & AllowNestedDocks);
         connect(action, SIGNAL(toggled(bool)), this, SLOT(setDockOptions()));

         action = mainWindowMenu->addAction(tr("Allow tabbed docks"));
         action->setCheckable(true);
         action->setChecked(dockOptions() & AllowTabbedDocks);
         connect(action, SIGNAL(toggled(bool)), this, SLOT(setDockOptions()));

         action = mainWindowMenu->addAction(tr("Force tabbed docks"));
         action->setCheckable(true);
         action->setChecked(dockOptions() & ForceTabbedDocks);
         connect(action, SIGNAL(toggled(bool)), this, SLOT(setDockOptions()));

         action = mainWindowMenu->addAction(tr("Vertical tabs"));
         action->setCheckable(true);
         action->setChecked(dockOptions() & VerticalTabs);
         connect(action, SIGNAL(toggled(bool)), this, SLOT(setDockOptions()));

         QMenu *toolBarMenu = menuBar()->addMenu(tr("Tool bars"));
         for (int i = 0; i < toolBars.count(); ++i)
             toolBarMenu->addMenu(toolBars.at(i)->menu);

         dockWidgetMenu = menuBar()->addMenu(tr("&Dock Widgets"));
     }

     void MainWindow::setDockOptions()
     {
         DockOptions opts;
         QList<QAction*> actions = mainWindowMenu->actions();

         if (actions.at(0)->isChecked())
             opts |= AnimatedDocks;
         if (actions.at(1)->isChecked())
             opts |= AllowNestedDocks;
         if (actions.at(2)->isChecked())
             opts |= AllowTabbedDocks;
         if (actions.at(3)->isChecked())
             opts |= ForceTabbedDocks;
         if (actions.at(4)->isChecked())
             opts |= VerticalTabs;

         QMainWindow::setDockOptions(opts);
     }

     void MainWindow::saveLayout()
     {
         QString fileName
             = QFileDialog::getSaveFileName(this, tr("Save layout"));
         if (fileName.isEmpty())
             return;
         QFile file(fileName);
         if (!file.open(QFile::WriteOnly)) {
             QString msg = tr("Failed to open %1\n%2")
                             .arg(fileName)
                             .arg(file.errorString());
             QMessageBox::warning(this, tr("Error"), msg);
             return;
         }

         QByteArray geo_data = saveGeometry();
         QByteArray layout_data = saveState();

         bool ok = file.putChar((uchar)geo_data.size());
         if (ok)
             ok = file.write(geo_data) == geo_data.size();
         if (ok)
             ok = file.write(layout_data) == layout_data.size();

         if (!ok) {
             QString msg = tr("Error writing to %1\n%2")
                             .arg(fileName)
                             .arg(file.errorString());
             QMessageBox::warning(this, tr("Error"), msg);
             return;
         }
     }

     void MainWindow::loadLayout()
     {
         QString fileName
             = QFileDialog::getOpenFileName(this, tr("Load layout"));
         if (fileName.isEmpty())
             return;
         QFile file(fileName);
         if (!file.open(QFile::ReadOnly)) {
             QString msg = tr("Failed to open %1\n%2")
                             .arg(fileName)
                             .arg(file.errorString());
             QMessageBox::warning(this, tr("Error"), msg);
             return;
         }

         uchar geo_size;
         QByteArray geo_data;
         QByteArray layout_data;

         bool ok = file.getChar((char*)&geo_size);
         if (ok) {
             geo_data = file.read(geo_size);
             ok = geo_data.size() == geo_size;
         }
         if (ok) {
             layout_data = file.readAll();
             ok = layout_data.size() > 0;
         }

         if (ok)
             ok = restoreGeometry(geo_data);
         if (ok)
             ok = restoreState(layout_data);

         if (!ok) {
             QString msg = tr("Error reading %1")
                             .arg(fileName);
             QMessageBox::warning(this, tr("Error"), msg);
             return;
         }
     }

     QAction *addAction(QMenu *menu, const QString &text, QActionGroup *group, QSignalMapper *mapper,
                         int id)
     {
         bool first = group->actions().isEmpty();
         QAction *result = menu->addAction(text);
         result->setCheckable(true);
         result->setChecked(first);
         group->addAction(result);
         QObject::connect(result, SIGNAL(triggered()), mapper, SLOT(map()));
         mapper->setMapping(result, id);
         return result;
     }

     void MainWindow::setupDockWidgets(const QMap<QString, QSize> &customSizeHints)
     {
         qRegisterMetaType<QDockWidget::DockWidgetFeatures>();

         mapper = new QSignalMapper(this);
         connect(mapper, SIGNAL(mapped(int)), this, SLOT(setCorner(int)));

         QMenu *corner_menu = dockWidgetMenu->addMenu(tr("Top left corner"));
         QActionGroup *group = new QActionGroup(this);
         group->setExclusive(true);
         ::addAction(corner_menu, tr("Top dock area"), group, mapper, 0);
         ::addAction(corner_menu, tr("Left dock area"), group, mapper, 1);

         corner_menu = dockWidgetMenu->addMenu(tr("Top right corner"));
         group = new QActionGroup(this);
         group->setExclusive(true);
         ::addAction(corner_menu, tr("Top dock area"), group, mapper, 2);
         ::addAction(corner_menu, tr("Right dock area"), group, mapper, 3);

         corner_menu = dockWidgetMenu->addMenu(tr("Bottom left corner"));
         group = new QActionGroup(this);
         group->setExclusive(true);
         ::addAction(corner_menu, tr("Bottom dock area"), group, mapper, 4);
         ::addAction(corner_menu, tr("Left dock area"), group, mapper, 5);

         corner_menu = dockWidgetMenu->addMenu(tr("Bottom right corner"));
         group = new QActionGroup(this);
         group->setExclusive(true);
         ::addAction(corner_menu, tr("Bottom dock area"), group, mapper, 6);
         ::addAction(corner_menu, tr("Right dock area"), group, mapper, 7);

         dockWidgetMenu->addSeparator();

         static const struct Set {
             const char * name;
             uint flags;
             Qt::DockWidgetArea area;
         } sets [] = {
     #ifndef Q_WS_MAC
             { "Black", 0, Qt::LeftDockWidgetArea },
     #else
             { "Black", Qt::Drawer, Qt::LeftDockWidgetArea },
     #endif
             { "White", 0, Qt::RightDockWidgetArea },
             { "Red", 0, Qt::TopDockWidgetArea },
             { "Green", 0, Qt::TopDockWidgetArea },
             { "Blue", 0, Qt::BottomDockWidgetArea },
             { "Yellow", 0, Qt::BottomDockWidgetArea }
         };
         const int setCount = sizeof(sets) / sizeof(Set);

         for (int i = 0; i < setCount; ++i) {
             ColorSwatch *swatch = new ColorSwatch(tr(sets[i].name), this, Qt::WindowFlags(sets[i].flags));
             if (i%2)
                 swatch->setWindowIcon(QIcon(QPixmap(":/res/qt.png")));
             if (qstrcmp(sets[i].name, "Blue") == 0) {
                 BlueTitleBar *titlebar = new BlueTitleBar(swatch);
                 swatch->setTitleBarWidget(titlebar);
                 connect(swatch, SIGNAL(topLevelChanged(bool)), titlebar, SLOT(updateMask()));
                 connect(swatch, SIGNAL(featuresChanged(QDockWidget::DockWidgetFeatures)), titlebar, SLOT(updateMask()), Qt::QueuedConnection);

     #ifdef Q_WS_QWS
                 QPalette pal = palette();
                 pal.setBrush(backgroundRole(), QColor(0,0,0,0));
                 swatch->setPalette(pal);
     #endif
             }

             QString name = QString::fromLatin1(sets[i].name);
             if (customSizeHints.contains(name))
                 swatch->setCustomSizeHint(customSizeHints.value(name));

             addDockWidget(sets[i].area, swatch);
             dockWidgetMenu->addMenu(swatch->menu);
         }

         createDockWidgetAction = new QAction(tr("Add dock widget..."), this);
         connect(createDockWidgetAction, SIGNAL(triggered()), this, SLOT(createDockWidget()));
         destroyDockWidgetMenu = new QMenu(tr("Destroy dock widget"), this);
         destroyDockWidgetMenu->setEnabled(false);
         connect(destroyDockWidgetMenu, SIGNAL(triggered(QAction*)), this, SLOT(destroyDockWidget(QAction*)));

         dockWidgetMenu->addSeparator();
         dockWidgetMenu->addAction(createDockWidgetAction);
         dockWidgetMenu->addMenu(destroyDockWidgetMenu);
     }

     void MainWindow::setCorner(int id)
     {
         switch (id) {
             case 0:
                 QMainWindow::setCorner(Qt::TopLeftCorner, Qt::TopDockWidgetArea);
                 break;
             case 1:
                 QMainWindow::setCorner(Qt::TopLeftCorner, Qt::LeftDockWidgetArea);
                 break;
             case 2:
                 QMainWindow::setCorner(Qt::TopRightCorner, Qt::TopDockWidgetArea);
                 break;
             case 3:
                 QMainWindow::setCorner(Qt::TopRightCorner, Qt::RightDockWidgetArea);
                 break;
             case 4:
                 QMainWindow::setCorner(Qt::BottomLeftCorner, Qt::BottomDockWidgetArea);
                 break;
             case 5:
                 QMainWindow::setCorner(Qt::BottomLeftCorner, Qt::LeftDockWidgetArea);
                 break;
             case 6:
                 QMainWindow::setCorner(Qt::BottomRightCorner, Qt::BottomDockWidgetArea);
                 break;
             case 7:
                 QMainWindow::setCorner(Qt::BottomRightCorner, Qt::RightDockWidgetArea);
                 break;
         }
     }

     void MainWindow::showEvent(QShowEvent *event)
     {
         QMainWindow::showEvent(event);
     }

     void MainWindow::switchLayoutDirection()
     {
         if (layoutDirection() == Qt::LeftToRight)
             qApp->setLayoutDirection(Qt::RightToLeft);
         else
             qApp->setLayoutDirection(Qt::LeftToRight);
     }

     class CreateDockWidgetDialog : public QDialog
     {
     public:
         CreateDockWidgetDialog(QWidget *parent = 0);

         QString objectName() const;
         Qt::DockWidgetArea location() const;

     private:
         QLineEdit *m_objectName;
         QComboBox *m_location;
     };

     CreateDockWidgetDialog::CreateDockWidgetDialog(QWidget *parent)
         : QDialog(parent)
     {
         QGridLayout *layout = new QGridLayout(this);

         layout->addWidget(new QLabel(tr("Object name:")), 0, 0);
         m_objectName = new QLineEdit;
         layout->addWidget(m_objectName, 0, 1);

         layout->addWidget(new QLabel(tr("Location:")), 1, 0);
         m_location = new QComboBox;
         m_location->setEditable(false);
         m_location->addItem(tr("Top"));
         m_location->addItem(tr("Left"));
         m_location->addItem(tr("Right"));
         m_location->addItem(tr("Bottom"));
         m_location->addItem(tr("Restore"));
         layout->addWidget(m_location, 1, 1);

         QHBoxLayout *buttonLayout = new QHBoxLayout;
         layout->addLayout(buttonLayout, 2, 0, 1, 2);
         buttonLayout->addStretch();

         QPushButton *cancelButton = new QPushButton(tr("Cancel"));
         connect(cancelButton, SIGNAL(clicked()), this, SLOT(reject()));
         buttonLayout->addWidget(cancelButton);
         QPushButton *okButton = new QPushButton(tr("Ok"));
         connect(okButton, SIGNAL(clicked()), this, SLOT(accept()));
         buttonLayout->addWidget(okButton);

         okButton->setDefault(true);
     }

     QString CreateDockWidgetDialog::objectName() const
     {
         return m_objectName->text();
     }

     Qt::DockWidgetArea CreateDockWidgetDialog::location() const
     {
         switch (m_location->currentIndex()) {
             case 0: return Qt::TopDockWidgetArea;
             case 1: return Qt::LeftDockWidgetArea;
             case 2: return Qt::RightDockWidgetArea;
             case 3: return Qt::BottomDockWidgetArea;
             default:
                 break;
         }
         return Qt::NoDockWidgetArea;
     }

     void MainWindow::createDockWidget()
     {
         CreateDockWidgetDialog dialog(this);
         int ret = dialog.exec();
         if (ret == QDialog::Rejected)
             return;

         QDockWidget *dw = new QDockWidget;
         dw->setObjectName(dialog.objectName());
         dw->setWindowTitle(dialog.objectName());
         dw->setWidget(new QTextEdit);

         Qt::DockWidgetArea area = dialog.location();
         switch (area) {
             case Qt::LeftDockWidgetArea:
             case Qt::RightDockWidgetArea:
             case Qt::TopDockWidgetArea:
             case Qt::BottomDockWidgetArea:
                 addDockWidget(area, dw);
                 break;
             default:
                 if (!restoreDockWidget(dw)) {
                     QMessageBox::warning(this, QString(), tr("Failed to restore dock widget"));
                     delete dw;
                     return;
                 }
                 break;
         }

         extraDockWidgets.append(dw);
         destroyDockWidgetMenu->setEnabled(true);
         destroyDockWidgetMenu->addAction(new QAction(dialog.objectName(), this));
     }

     void MainWindow::destroyDockWidget(QAction *action)
     {
         int index = destroyDockWidgetMenu->actions().indexOf(action);
         delete extraDockWidgets.takeAt(index);
         destroyDockWidgetMenu->removeAction(action);
         action->deleteLater();

         if (destroyDockWidgetMenu->isEmpty())
             destroyDockWidgetMenu->setEnabled(false);
     }