Qt实现编辑器

TextEdit::TextEdit(QWidget *parent)
    : QMainWindow(parent)
{    
    setToolButtonStyle(Qt::ToolButtonFollowStyle);
    setupFileActions();
    setupEditActions();
    setupTextActions();

    {
        QMenu *helpMenu = new QMenu(tr("Help"), this);
        menuBar()->addMenu(helpMenu);
        helpMenu->addAction(tr("About"), this, SLOT(about()));
        helpMenu->addAction(tr("About &Qt"), qApp, SLOT(aboutQt()));
    }

    textEdit = new QTextEdit(this);
    connect(textEdit, SIGNAL(currentCharFormatChanged(QTextCharFormat)),
            this, SLOT(currentCharFormatChanged(QTextCharFormat)));
    connect(textEdit, SIGNAL(cursorPositionChanged()),
            this, SLOT(cursorPositionChanged()));

    setCentralWidget(textEdit);
    textEdit->setFocus();
    setCurrentFileName(QString());

    QFont textFont("Helvetica");
    textFont.setStyleHint(QFont::SansSerif);
    textEdit->setFont(textFont);
    fontChanged(textEdit->font());
    colorChanged(textEdit->textColor());
    alignmentChanged(textEdit->alignment());

    connect(textEdit->document(), SIGNAL(modificationChanged(bool)),
            actionSave, SLOT(setEnabled(bool)));
    connect(textEdit->document(), SIGNAL(modificationChanged(bool)),
            this, SLOT(setWindowModified(bool)));
    connect(textEdit->document(), SIGNAL(undoAvailable(bool)),
            actionUndo, SLOT(setEnabled(bool)));
    connect(textEdit->document(), SIGNAL(redoAvailable(bool)),
            actionRedo, SLOT(setEnabled(bool)));

    setWindowModified(textEdit->document()->isModified());
    actionSave->setEnabled(textEdit->document()->isModified());
    actionUndo->setEnabled(textEdit->document()->isUndoAvailable());
    actionRedo->setEnabled(textEdit->document()->isRedoAvailable());

    connect(actionUndo, SIGNAL(triggered()), textEdit, SLOT(undo()));
    connect(actionRedo, SIGNAL(triggered()), textEdit, SLOT(redo()));

    actionCut->setEnabled(false);
    actionCopy->setEnabled(false);

    connect(actionCut, SIGNAL(triggered()), textEdit, SLOT(cut()));
    connect(actionCopy, SIGNAL(triggered()), textEdit, SLOT(copy()));
    connect(actionPaste, SIGNAL(triggered()), textEdit, SLOT(paste()));

    connect(textEdit, SIGNAL(copyAvailable(bool)), actionCut, SLOT(setEnabled(bool)));
    connect(textEdit, SIGNAL(copyAvailable(bool)), actionCopy, SLOT(setEnabled(bool)));

#ifndef QT_NO_CLIPBOARD
    connect(QApplication::clipboard(), SIGNAL(dataChanged()), this, SLOT(clipboardDataChanged()));
#endif

    QString initialFile = ":/example.html";
    const QStringList args = QCoreApplication::arguments();
    if (args.count() == 2)
        initialFile = args.at(1);

    if (!load(initialFile))
        fileNew();
}

void TextEdit::closeEvent(QCloseEvent *e)
{
    if (maybeSave())
        e->accept();
    else
        e->ignore();
}

void TextEdit::setupFileActions()
{
    QToolBar *tb = new QToolBar(this);
    tb->setWindowTitle(tr("File Actions"));
    addToolBar(tb);

    QMenu *menu = new QMenu(tr("&File"), this);
    menuBar()->addMenu(menu);

    QAction *a;

    QIcon newIcon = QIcon::fromTheme("document-new", QIcon(rsrcPath + "/filenew.png"));
    a = new QAction( newIcon, tr("&New"), this);
    a->setPriority(QAction::LowPriority);
    a->setShortcut(QKeySequence::New);
    connect(a, SIGNAL(triggered()), this, SLOT(fileNew()));
    tb->addAction(a);
    menu->addAction(a);

    a = new QAction(QIcon::fromTheme("document-open", QIcon(rsrcPath + "/fileopen.png")),
                    tr("&Open..."), this);
    a->setShortcut(QKeySequence::Open);
    connect(a, SIGNAL(triggered()), this, SLOT(fileOpen()));
    tb->addAction(a);
    menu->addAction(a);

    menu->addSeparator();

    actionSave = a = new QAction(QIcon::fromTheme("document-save", QIcon(rsrcPath + "/filesave.png")),
                                 tr("&Save"), this);
    a->setShortcut(QKeySequence::Save);
    connect(a, SIGNAL(triggered()), this, SLOT(fileSave()));
    a->setEnabled(false);
    tb->addAction(a);
    menu->addAction(a);

    a = new QAction(tr("Save &As..."), this);
    a->setPriority(QAction::LowPriority);
    connect(a, SIGNAL(triggered()), this, SLOT(fileSaveAs()));
    menu->addAction(a);
    menu->addSeparator();
}