#include <QApplication>
#include <QtGui>
#include <QMainWindow>

class QAction;
class QActionGroup;
class QLabel;
class QMenu;

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow();

protected:
    void contextMenuEvent(QContextMenuEvent *event);

private slots:
    void newFile();
    void open();
    void save();
    void print();
    void undo();
    void redo();
    void cut();
    void copy();
    void paste();
    void bold();
    void italic();
    void leftAlign();
    void rightAlign();
    void justify();
    void center();
    void setLineSpacing();
    void setParagraphSpacing();
    void about();
    void aboutQt();

private:
    void createActions();
    void createMenus();

    QMenu *fileMenu;
    QMenu *editMenu;
    QMenu *formatMenu;
    QMenu *helpMenu;
    QActionGroup *alignmentGroup;
    QAction *newAct;
    QAction *openAct;
    QAction *saveAct;
    QAction *printAct;
    QAction *exitAct;
    QAction *undoAct;
    QAction *redoAct;
    QAction *cutAct;
    QAction *copyAct;
    QAction *pasteAct;
    QAction *boldAct;
    QAction *italicAct;
    QAction *leftAlignAct;
    QAction *rightAlignAct;
    QAction *justifyAct;
    QAction *centerAct;
    QAction *setLineSpacingAct;
    QAction *setParagraphSpacingAct;
    QAction *aboutAct;
    QAction *aboutQtAct;
    QLabel *infoLabel;
};

MainWindow::MainWindow()
{
    QWidget *w = new QWidget;
    setCentralWidget(w);

    QWidget *topFiller = new QWidget;
    topFiller->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

    infoLabel = new QLabel(tr("<i>Choose a menu option, or right-click to "
                              "invoke a context menu</i>"));
    infoLabel->setFrameStyle(QFrame::StyledPanel | QFrame::Sunken);
    infoLabel->setAlignment(Qt::AlignCenter);

    QWidget *bottomFiller = new QWidget;
    bottomFiller->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

    QVBoxLayout *vbox = new QVBoxLayout;
    vbox->setMargin(5);
    vbox->addWidget(topFiller);
    vbox->addWidget(infoLabel);
    vbox->addWidget(bottomFiller);
    w->setLayout(vbox);

    createActions();
    createMenus();

    statusBar()->showMessage(tr("A context menu is available by right-clicking"));

    setWindowTitle(tr("Menus"));
    setMinimumSize(160, 160);
    resize(480, 320);
}

void MainWindow::contextMenuEvent(QContextMenuEvent *event)
{
    QMenu menu(this);
    menu.addAction(cutAct);
    menu.addAction(copyAct);
    menu.addAction(pasteAct);
    menu.exec(event->globalPos());
}

void MainWindow::newFile()
{
    infoLabel->setText(tr("Invoked <b>File|New</b>"));
}

void MainWindow::open()
{
    infoLabel->setText(tr("Invoked <b>File|Open</b>"));
}

void MainWindow::save()
{
    infoLabel->setText(tr("Invoked <b>File|Save</b>"));
}

void MainWindow::print()
{
    infoLabel->setText(tr("Invoked <b>File|Print</b>"));
}

void MainWindow::undo()
{
    infoLabel->setText(tr("Invoked <b>Edit|Undo</b>"));
}

void MainWindow::redo()
{
    infoLabel->setText(tr("Invoked <b>Edit|Redo</b>"));
}

void MainWindow::cut()
{
    infoLabel->setText(tr("Invoked <b>Edit|Cut</b>"));
}

void MainWindow::copy()
{
    infoLabel->setText(tr("Invoked <b>Edit|Copy</b>"));
}

void MainWindow::paste()
{
    infoLabel->setText(tr("Invoked <b>Edit|Paste</b>"));
}

void MainWindow::bold()
{
    infoLabel->setText(tr("Invoked <b>Edit|Format|Bold</b>"));
}

void MainWindow::italic()
{
    infoLabel->setText(tr("Invoked <b>Edit|Format|Italic</b>"));
}

void MainWindow::leftAlign()
{
    infoLabel->setText(tr("Invoked <b>Edit|Format|Left Align</b>"));
}

void MainWindow::rightAlign()
{
    infoLabel->setText(tr("Invoked <b>Edit|Format|Right Align</b>"));
}

void MainWindow::justify()
{
    infoLabel->setText(tr("Invoked <b>Edit|Format|Justify</b>"));
}

void MainWindow::center()
{
    infoLabel->setText(tr("Invoked <b>Edit|Format|Center</b>"));
}

void MainWindow::setLineSpacing()
{
    infoLabel->setText(tr("Invoked <b>Edit|Format|Set Line Spacing</b>"));
}

void MainWindow::setParagraphSpacing()
{
    infoLabel->setText(tr("Invoked <b>Edit|Format|Set Paragraph Spacing</b>"));
}

void MainWindow::about()
{
    infoLabel->setText(tr("Invoked <b>Help|About</b>"));
    QMessageBox::about(this, tr("About Menu"),
            tr("The <b>Menu</b> example shows how to create "
               "menu-bar menus and context menus."));
}

void MainWindow::aboutQt()
{
    infoLabel->setText(tr("Invoked <b>Help|About Qt</b>"));
}

void MainWindow::createActions()
{
    newAct = new QAction(tr("&New"), this);
    newAct->setShortcut(tr("Ctrl+N"));
    newAct->setStatusTip(tr("Create a new file"));
    connect(newAct, SIGNAL(triggered()), this, SLOT(newFile()));

    openAct = new QAction(tr("&Open..."), this);
    openAct->setShortcut(tr("Ctrl+O"));
    openAct->setStatusTip(tr("Open an existing file"));
    connect(openAct, SIGNAL(triggered()), this, SLOT(open()));

    saveAct = new QAction(tr("&Save"), this);
    saveAct->setShortcut(tr("Ctrl+S"));
    saveAct->setStatusTip(tr("Save the document to disk"));
    connect(saveAct, SIGNAL(triggered()), this, SLOT(save()));

    printAct = new QAction(tr("&Print..."), this);
    printAct->setShortcut(tr("Ctrl+P"));
    printAct->setStatusTip(tr("Print the document"));
    connect(printAct, SIGNAL(triggered()), this, SLOT(print()));

    exitAct = new QAction(tr("E&xit"), this);
    exitAct->setShortcut(tr("Ctrl+Q"));
    exitAct->setStatusTip(tr("Exit the application"));
    connect(exitAct, SIGNAL(triggered()), this, SLOT(close()));

    undoAct = new QAction(tr("&Undo"), this);
    undoAct->setShortcut(tr("Ctrl+Z"));
    undoAct->setStatusTip(tr("Undo the last operation"));
    connect(undoAct, SIGNAL(triggered()), this, SLOT(undo()));

    redoAct = new QAction(tr("&Redo"), this);
    redoAct->setShortcut(tr("Ctrl+Y"));
    redoAct->setStatusTip(tr("Redo the last operation"));
    connect(redoAct, SIGNAL(triggered()), this, SLOT(redo()));

    cutAct = new QAction(tr("Cu&t"), this);
    cutAct->setShortcut(tr("Ctrl+X"));
    cutAct->setStatusTip(tr("Cut the current selection's contents to the "
                            "clipboard"));
    connect(cutAct, SIGNAL(triggered()), this, SLOT(cut()));

    copyAct = new QAction(tr("&Copy"), this);
    copyAct->setShortcut(tr("Ctrl+C"));
    copyAct->setStatusTip(tr("Copy the current selection's contents to the "
                             "clipboard"));
    connect(copyAct, SIGNAL(triggered()), this, SLOT(copy()));

    pasteAct = new QAction(tr("&Paste"), this);
    pasteAct->setShortcut(tr("Ctrl+V"));
    pasteAct->setStatusTip(tr("Paste the clipboard's contents into the current "
                              "selection"));
    connect(pasteAct, SIGNAL(triggered()), this, SLOT(paste()));

    boldAct = new QAction(tr("&Bold"), this);
    boldAct->setCheckable(true);
    boldAct->setShortcut(tr("Ctrl+B"));
    boldAct->setStatusTip(tr("Make the text bold"));
    connect(boldAct, SIGNAL(triggered()), this, SLOT(bold()));

    QFont boldFont = boldAct->font();
    boldFont.setBold(true);
    boldAct->setFont(boldFont);

    italicAct = new QAction(tr("&Italic"), this);
    italicAct->setCheckable(true);
    italicAct->setShortcut(tr("Ctrl+I"));
    italicAct->setStatusTip(tr("Make the text italic"));
    connect(italicAct, SIGNAL(triggered()), this, SLOT(italic()));

    QFont italicFont = italicAct->font();
    italicFont.setItalic(true);
    italicAct->setFont(italicFont);

    leftAlignAct = new QAction(tr("&Left Align"), this);
    leftAlignAct->setCheckable(true);
    leftAlignAct->setShortcut(tr("Ctrl+L"));
    leftAlignAct->setStatusTip(tr("Left align the selected text"));
    connect(leftAlignAct, SIGNAL(triggered()), this, SLOT(leftAlign()));

    rightAlignAct = new QAction(tr("&Right Align"), this);
    rightAlignAct->setCheckable(true);
    rightAlignAct->setShortcut(tr("Ctrl+R"));
    rightAlignAct->setStatusTip(tr("Right align the selected text"));
    connect(rightAlignAct, SIGNAL(triggered()), this, SLOT(rightAlign()));

    justifyAct = new QAction(tr("&Justify"), this);
    justifyAct->setCheckable(true);
    justifyAct->setShortcut(tr("Ctrl+J"));
    justifyAct->setStatusTip(tr("Justify the selected text"));
    connect(justifyAct, SIGNAL(triggered()), this, SLOT(justify()));

    centerAct = new QAction(tr("&Center"), this);
    centerAct->setCheckable(true);
    centerAct->setShortcut(tr("Ctrl+E"));
    centerAct->setStatusTip(tr("Center the selected text"));
    connect(centerAct, SIGNAL(triggered()), this, SLOT(center()));

    alignmentGroup = new QActionGroup(this);
    alignmentGroup->addAction(leftAlignAct);
    alignmentGroup->addAction(rightAlignAct);
    alignmentGroup->addAction(justifyAct);
    alignmentGroup->addAction(centerAct);
    leftAlignAct->setChecked(true);

    setLineSpacingAct = new QAction(tr("Set &Line Spacing..."), this);
    setLineSpacingAct->setStatusTip(tr("Change the gap between the lines of a "
                                       "paragraph"));
    connect(setLineSpacingAct, SIGNAL(triggered()), this, SLOT(setLineSpacing()));

    setParagraphSpacingAct = new QAction(tr("Set &Paragraph Spacing..."), this);
    setLineSpacingAct->setStatusTip(tr("Change the gap between paragraphs"));
    connect(setParagraphSpacingAct, SIGNAL(triggered()),
            this, SLOT(setParagraphSpacing()));

    aboutAct = new QAction(tr("&About"), this);
    aboutAct->setStatusTip(tr("Show the application's About box"));
    connect(aboutAct, SIGNAL(triggered()), this, SLOT(about()));

    aboutQtAct = new QAction(tr("About &Qt"), this);
    aboutQtAct->setStatusTip(tr("Show the Qt library's About box"));
    connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt()));
    connect(aboutQtAct, SIGNAL(triggered()), this, SLOT(aboutQt()));
}

void MainWindow::createMenus()
{
    fileMenu = menuBar()->addMenu(tr("&File"));
    fileMenu->addAction(newAct);
    fileMenu->addAction(openAct);
    fileMenu->addAction(saveAct);
    fileMenu->addAction(printAct);
    fileMenu->addSeparator();
    fileMenu->addAction(exitAct);

    editMenu = menuBar()->addMenu(tr("&Edit"));
    editMenu->addAction(undoAct);
    editMenu->addAction(redoAct);
    editMenu->addSeparator();
    editMenu->addAction(cutAct);
    editMenu->addAction(copyAct);
    editMenu->addAction(pasteAct);
    editMenu->addSeparator();

    formatMenu = editMenu->addMenu(tr("&Format"));
    formatMenu->addAction(boldAct);
    formatMenu->addAction(italicAct);
    formatMenu->addSeparator()->setText(tr("Alignment"));
    formatMenu->addAction(leftAlignAct);
    formatMenu->addAction(rightAlignAct);
    formatMenu->addAction(justifyAct);
    formatMenu->addAction(centerAct);
    formatMenu->addSeparator();
    formatMenu->addAction(setLineSpacingAct);
    formatMenu->addAction(setParagraphSpacingAct);

    helpMenu = menuBar()->addMenu(tr("&Help"));
    helpMenu->addAction(aboutAct);
    helpMenu->addAction(aboutQtAct);
}

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow window;
    window.show();
    return app.exec();
}