qt--实现多文档编辑器

qt--实现多文档编辑器，实现对文件编辑复制，保存，效果图如下；

通过本例子可以学习到便器窗口的使用和处理数据保存的知识；

头文件editor.h

#ifndef EDITOR_H

#define EDITOR_H

#include 

class Editor : public QTextEdit

{

    Q_OBJECT

public:

    Editor(QWidget *parent = 0);

    void newFile();

    bool save();

    bool saveAs();

    QSize sizeHint() const;

    QAction *windowMenuAction() const { return action; }

    static Editor *open(QWidget *parent = 0);

    static Editor *openFile(const QString &fileName,

                            QWidget *parent = 0);

protected:

    void closeEvent(QCloseEvent *event);

private slots:

    void documentWasModified();

private:

    bool okToContinue();

    bool saveFile(const QString &fileName);

    void setCurrentFile(const QString &fileName);

    bool readFile(const QString &fileName);

    bool writeFile(const QString &fileName);

    QString strippedName(const QString &fullFileName);

    QString curFile;

    bool isUntitled;

    QAction *action;

};

#endif

源文件editor.cpp

#include

#include "editor.h"

#include

#include 

#include 

#include 

Editor::Editor(QWidget *parent)

    : QTextEdit(parent)

{

    action = new QAction(this);

    action->setCheckable(true);

    connect(action, SIGNAL(triggered()), this, SLOT(show()));

    connect(action, SIGNAL(triggered()), this, SLOT(setFocus()));

    isUntitled = true;

    connect(document(), SIGNAL(contentsChanged()),

            this, SLOT(documentWasModified()));

    setWindowIcon(QPixmap(":/images/document.png"));

    setWindowTitle("[*]");

    setAttribute(Qt::WA_DeleteOnClose);

}

void Editor::newFile()

{

    static int documentNumber = 1;

    curFile = tr("document%1.txt").arg(documentNumber);

    setWindowTitle(curFile + "[*]");

    action->setText(curFile);

    isUntitled = true;

    ++documentNumber;

}

bool Editor::save()

{

    if (isUntitled) {

        return saveAs();

    } else {

        return saveFile(curFile);

    }

}

bool Editor::saveAs()

{

    QString fileName =

            QFileDialog::getSaveFileName(this, tr("Save As"), curFile);

    if (fileName.isEmpty())

        return false;

    return saveFile(fileName);

}

QSize Editor::sizeHint() const

{

    return QSize(72 * fontMetrics().width('x'),

                 25 * fontMetrics().lineSpacing());

}

Editor *Editor::open(QWidget *parent)

{

    QString fileName =

            QFileDialog::getOpenFileName(parent, tr("Open"), ".");

    if (fileName.isEmpty())

        return 0;

    return openFile(fileName, parent);

}

Editor *Editor::openFile(const QString &fileName, QWidget *parent)

{

    Editor *editor = new Editor(parent);

    if (editor->readFile(fileName)) {

        editor->setCurrentFile(fileName);

        return editor;

    } else {

        delete editor;

        return 0;

    }

}

void Editor::closeEvent(QCloseEvent *event)

{

    if (okToContinue()) {

        event->accept();

    } else {

        event->ignore();

    }

}

void Editor::documentWasModified()

{

    setWindowModified(true);

}

bool Editor::okToContinue()

{

    if (document()->isModified()) {

        int r = QMessageBox::warning(this, tr("MDI Editor"),

                        tr("File %1 has been modified.\n"

                           "Do you want to save your changes?")

                        .arg(strippedName(curFile)),

                        QMessageBox::Yes | QMessageBox::No

                        | QMessageBox::Cancel);

        if (r == QMessageBox::Yes) {

            return save();

        } else if (r == QMessageBox::Cancel) {

            return false;

        }

    }

    return true;

}

bool Editor::saveFile(const QString &fileName)

{

    if (writeFile(fileName)) {

        setCurrentFile(fileName);

        return true;

    } else {

        return false;

    }

}

void Editor::setCurrentFile(const QString &fileName)

{

    curFile = fileName;

    isUntitled = false;

    action->setText(strippedName(curFile));

    document()->setModified(false);

    setWindowTitle(strippedName(curFile) + "[*]");

    setWindowModified(false);

}

bool Editor::readFile(const QString &fileName)

{

    QFile file(fileName);

    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {

        QMessageBox::warning(this, tr("MDI Editor"),

                             tr("Cannot read file %1:\n%2.")

                             .arg(file.fileName())

                             .arg(file.errorString()));

        return false;

    }

    QTextStream in(&file);

   // QApplication::setOverrideCursor(Qt::WaitCursor);

    setPlainText(in.readAll());

 //   QApplication::restoreOverrideCursor();

    return true;

}

bool Editor::writeFile(const QString &fileName)

{

    QFile file(fileName);

    if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {

        QMessageBox::warning(this, tr("MDI Editor"),

                             tr("Cannot write file %1:\n%2.")

                             .arg(file.fileName())

                             .arg(file.errorString()));

        return false;

    }

    QTextStream out(&file);

  //  QApplication::setOverrideCursor(Qt::WaitCursor);

    out << toPlainText();

 //   QApplication::restoreOverrideCursor();

    return true;

}

QString Editor::strippedName(const QString &fullFileName)

{

    return QFileInfo(fullFileName).fileName();

}

头文件mainwindow.h

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include 

namespace Ui {

class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

public:

    explicit MainWindow(QWidget *parent = 0);

    ~MainWindow();

private:

    Ui::MainWindow *ui;

};

#endif // MAINWINDOW_H

源文件 mainwindow.cpp #include

#include

#include "editor.h"

#include "mainwindow.h"

#include 

#include

#include 

#include 

#include 

#include 

#include

#include

#include 

MainWindow::MainWindow()

{

    mdiArea = new QMdiArea;

    setCentralWidget(mdiArea);

    connect(mdiArea, SIGNAL(subWindowActivated(QMdiSubWindow*)),

            this, SLOT(updateActions()));

    createActions();

    createMenus();

    createToolBars();

    createStatusBar();

    setWindowIcon(QPixmap(":/images/icon.png"));

    setWindowTitle(tr("MDI Editor"));

    QTimer::singleShot(0, this, SLOT(loadFiles()));

}

void MainWindow::loadFiles()

{

    QStringList args = QApplication::arguments();

    args.removeFirst();

    if (!args.isEmpty()) {

        foreach (QString arg, args)

            openFile(arg);

        mdiArea->cascadeSubWindows();

    } else {

        newFile();

    }

    mdiArea->activateNextSubWindow();

}

void MainWindow::newFile()

{

    Editor *editor = new Editor;

    editor->newFile();

    addEditor(editor);

}

void MainWindow::openFile(const QString &fileName)

{

    Editor *editor = Editor::openFile(fileName, this);

    if (editor)

        addEditor(editor);

}

void MainWindow::closeEvent(QCloseEvent *event)

{

    mdiArea->closeAllSubWindows();

    if (!mdiArea->subWindowList().isEmpty()) {

        event->ignore();

    } else {

        event->accept();

    }

}

void MainWindow::open()

{

    Editor *editor = Editor::open(this);

    if (editor)

        addEditor(editor);

}

void MainWindow::save()

{

    if (activeEditor())

        activeEditor()->save();

}

void MainWindow::saveAs()

{

    if (activeEditor())

        activeEditor()->saveAs();

}

void MainWindow::cut()

{

    if (activeEditor())

        activeEditor()->cut();

}

void MainWindow::copy()

{

    if (activeEditor())

        activeEditor()->copy();

}

void MainWindow::paste()

{

    if (activeEditor())

        activeEditor()->paste();

}

void MainWindow::about()

{

    QMessageBox::about(this, tr("About MDI Editor"),

            tr("
Editor 1.1
"

               "
Copyright © 2007 Software Inc."

               "
MDI Editor is a small application that demonstrates "

               "QMdiArea."));

}

void MainWindow::updateActions()

{

    bool hasEditor = (activeEditor() != 0);

    bool hasSelection = activeEditor()

                        && activeEditor()->textCursor().hasSelection();

    saveAction->setEnabled(hasEditor);

    saveAsAction->setEnabled(hasEditor);

    cutAction->setEnabled(hasSelection);

    copyAction->setEnabled(hasSelection);

    pasteAction->setEnabled(hasEditor);

    closeAction->setEnabled(hasEditor);

    closeAllAction->setEnabled(hasEditor);

    tileAction->setEnabled(hasEditor);

    cascadeAction->setEnabled(hasEditor);

    nextAction->setEnabled(hasEditor);

    previousAction->setEnabled(hasEditor);

    separatorAction->setVisible(hasEditor);

    if (activeEditor())

        activeEditor()->windowMenuAction()->setChecked(true);

}

void MainWindow::createActions()

{

    newAction = new QAction(tr("&New"), this);

    newAction->setIcon(QIcon(":/images/new.png"));

    newAction->setShortcut(QKeySequence::New);

    newAction->setStatusTip(tr("Create a new file"));

    connect(newAction, SIGNAL(triggered()), this, SLOT(newFile()));

    openAction = new QAction(tr("&Open..."), this);

    openAction->setIcon(QIcon(":/images/open.png"));

    openAction->setShortcut(QKeySequence::Open);

    openAction->setStatusTip(tr("Open an existing file"));

    connect(openAction, SIGNAL(triggered()), this, SLOT(open()));

    saveAction = new QAction(tr("&Save"), this);

    saveAction->setIcon(QIcon(":/images/save.png"));

    saveAction->setShortcut(QKeySequence::Save);

    saveAction->setStatusTip(tr("Save the file to disk"));

    connect(saveAction, SIGNAL(triggered()), this, SLOT(save()));

    saveAsAction = new QAction(tr("Save &As..."), this);

    saveAsAction->setStatusTip(tr("Save the file under a new name"));

    connect(saveAsAction, SIGNAL(triggered()), this, SLOT(saveAs()));

    exitAction = new QAction(tr("E&xit"), this);

    exitAction->setShortcut(tr("Ctrl+Q"));

    exitAction->setStatusTip(tr("Exit the application"));

    connect(exitAction, SIGNAL(triggered()), this, SLOT(close()));

    cutAction = new QAction(tr("Cu&t"), this);

    cutAction->setIcon(QIcon(":/images/cut.png"));

    cutAction->setShortcut(QKeySequence::Cut);

    cutAction->setStatusTip(tr("Cut the current selection to the "

                               "clipboard"));

    connect(cutAction, SIGNAL(triggered()), this, SLOT(cut()));

    copyAction = new QAction(tr("&Copy"), this);

    copyAction->setIcon(QIcon(":/images/copy.png"));

    copyAction->setShortcut(QKeySequence::Copy);

    copyAction->setStatusTip(tr("Copy the current selection to the "

                                "clipboard"));

    connect(copyAction, SIGNAL(triggered()), this, SLOT(copy()));

    pasteAction = new QAction(tr("&Paste"), this);

    pasteAction->setIcon(QIcon(":/images/paste.png"));

    pasteAction->setShortcut(QKeySequence::Paste);

    pasteAction->setStatusTip(tr("Paste the clipboard's contents at "

                                 "the cursor position"));

    connect(pasteAction, SIGNAL(triggered()), this, SLOT(paste()));

    closeAction = new QAction(tr("Cl&ose"), this);

    closeAction->setShortcut(QKeySequence::Close);

    closeAction->setStatusTip(tr("Close the active window"));

    connect(closeAction, SIGNAL(triggered()),

            mdiArea, SLOT(closeActiveSubWindow()));

    closeAllAction = new QAction(tr("Close &All"), this);

    closeAllAction->setStatusTip(tr("Close all the windows"));

    connect(closeAllAction, SIGNAL(triggered()), this, SLOT(close()));

    tileAction = new QAction(tr("&Tile"), this);

    tileAction->setStatusTip(tr("Tile the windows"));

    connect(tileAction, SIGNAL(triggered()),

            mdiArea, SLOT(tileSubWindows()));

    cascadeAction = new QAction(tr("&Cascade"), this);

    cascadeAction->setStatusTip(tr("Cascade the windows"));

    connect(cascadeAction, SIGNAL(triggered()),

            mdiArea, SLOT(cascadeSubWindows()));

    nextAction = new QAction(tr("Ne&xt"), this);

    nextAction->setShortcut(QKeySequence::NextChild);

    nextAction->setStatusTip(tr("Move the focus to the next window"));

    connect(nextAction, SIGNAL(triggered()),

            mdiArea, SLOT(activateNextSubWindow()));

    previousAction = new QAction(tr("Pre&vious"), this);

    previousAction->setShortcut(QKeySequence::PreviousChild);

    previousAction->setStatusTip(tr("Move the focus to the previous "

                                    "window"));

    connect(previousAction, SIGNAL(triggered()),

            mdiArea, SLOT(activatePreviousSubWindow()));

    separatorAction = new QAction(this);

    separatorAction->setSeparator(true);

    aboutAction = new QAction(tr("&About"), this);

    aboutAction->setStatusTip(tr("Show the application's About box"));

    connect(aboutAction, SIGNAL(triggered()), this, SLOT(about()));

    aboutQtAction = new QAction(tr("About &Qt"), this);

    aboutQtAction->setStatusTip(tr("Show the Qt library's About box"));

    connect(aboutQtAction, SIGNAL(triggered()), qApp, SLOT(aboutQt()));

    windowActionGroup = new QActionGroup(this);

}

void MainWindow::createMenus()

{

    fileMenu = menuBar()->addMenu(tr("&File"));

    fileMenu->addAction(newAction);

    fileMenu->addAction(openAction);

    fileMenu->addAction(saveAction);

    fileMenu->addAction(saveAsAction);

    fileMenu->addSeparator();

    fileMenu->addAction(exitAction);

    editMenu = menuBar()->addMenu(tr("&Edit"));

    editMenu->addAction(cutAction);

    editMenu->addAction(copyAction);

    editMenu->addAction(pasteAction);

    windowMenu = menuBar()->addMenu(tr("&Window"));

    windowMenu->addAction(closeAction);

    windowMenu->addAction(closeAllAction);

    windowMenu->addSeparator();

    windowMenu->addAction(tileAction);

    windowMenu->addAction(cascadeAction);

    windowMenu->addSeparator();

    windowMenu->addAction(nextAction);

    windowMenu->addAction(previousAction);

    windowMenu->addAction(separatorAction);

    menuBar()->addSeparator();

    helpMenu = menuBar()->addMenu(tr("&Help"));

    helpMenu->addAction(aboutAction);

    helpMenu->addAction(aboutQtAction);

}

void MainWindow::createToolBars()

{

    fileToolBar = addToolBar(tr("File"));

    fileToolBar->addAction(newAction);

    fileToolBar->addAction(openAction);

    fileToolBar->addAction(saveAction);

    editToolBar = addToolBar(tr("Edit"));

    editToolBar->addAction(cutAction);

    editToolBar->addAction(copyAction);

    editToolBar->addAction(pasteAction);

}

void MainWindow::createStatusBar()

{

    readyLabel = new QLabel(tr(" Ready"));

    this->statusBar()->addWidget(readyLabel, 1);

}

void MainWindow::addEditor(Editor *editor)

{

    connect(editor, SIGNAL(copyAvailable(bool)),

            cutAction, SLOT(setEnabled(bool)));

    connect(editor, SIGNAL(copyAvailable(bool)),

            copyAction, SLOT(setEnabled(bool)));

    QMdiSubWindow *subWindow = mdiArea->addSubWindow(editor);

    windowMenu->addAction(editor->windowMenuAction());

    windowActionGroup->addAction(editor->windowMenuAction());

    subWindow->show();

}

Editor *MainWindow::activeEditor()

{

    QMdiSubWindow *subWindow = mdiArea->activeSubWindow();

    if (subWindow)

        return qobject_cast<Editor *>(subWindow->widget());

    return 0;

}

main头文件

#include

#include "mainwindow.h"

int main(int argc, char *argv[])

{

    QApplication app(argc, argv);

    MainWindow mainWin;

    mainWin.show();

    return app.exec();

}