Home | All Classes | Main Classes | Annotated | Grouped Classes | Functions |

# A Complete Application Window

This example program looks like a complete modern application. It has a menu bar, it has a tool bar, it has a status bar and works like a simple text editor.

There is a walkthrough of this example.

Header file:

    /****************************************************************************
    ** $Id: qt/application.h   3.3.8   edited Jan 11 14:37 $
    **
    ** Copyright (C) 1992-2007 Trolltech ASA.  All rights reserved.
    **
    ** This file is part of an example program for TQt.  This example
    ** program may be used, distributed and modified without limitation.
    **
    *****************************************************************************/

    #ifndef APPLICATION_H
    #define APPLICATION_H

    #include <ntqmainwindow.h>

    class TQTextEdit;

    class ApplicationWindow: public TQMainWindow
    {
        TQ_OBJECT

    public:
        ApplicationWindow();
        ~ApplicationWindow();

    protected:
        void closeEvent( TQCloseEvent* );

    private slots:
        void newDoc();
        void choose();
        void load( const TQString &fileName );
        void save();
        void saveAs();
        void print();

        void about();
        void aboutTQt();

    private:
        TQPrinter *printer;
        TQTextEdit *e;
        TQString filename;
    };

    #endif

Implementation:

    /****************************************************************************
    ** $Id: qt/application.cpp   3.3.8   edited Jan 11 14:37 $
    **
    ** Copyright (C) 1992-2007 Trolltech ASA.  All rights reserved.
    **
    ** This file is part of an example program for TQt.  This example
    ** program may be used, distributed and modified without limitation.
    **
    *****************************************************************************/

    #include "application.h"

    #include <ntqimage.h>
    #include <ntqpixmap.h>
    #include <ntqtoolbar.h>
    #include <ntqtoolbutton.h>
    #include <ntqpopupmenu.h>
    #include <ntqmenubar.h>
    #include <ntqtextedit.h>
    #include <ntqfile.h>
    #include <ntqfiledialog.h>
    #include <ntqstatusbar.h>
    #include <ntqmessagebox.h>
    #include <ntqprinter.h>
    #include <ntqapplication.h>
    #include <ntqaccel.h>
    #include <ntqtextstream.h>
    #include <ntqpainter.h>
    #include <ntqpaintdevicemetrics.h>
    #include <ntqwhatsthis.h>
    #include <ntqsimplerichtext.h>

    #include "filesave.xpm"
    #include "fileopen.xpm"
    #include "fileprint.xpm"

    ApplicationWindow::ApplicationWindow()
        : TQMainWindow( 0, "example application main window", WDestructiveClose | WGroupLeader )
    {
        printer = new TQPrinter( TQPrinter::HighResolution );
        TQPixmap openIcon, saveIcon, printIcon;

        TQToolBar * fileTools = new TQToolBar( this, "file operations" );
        fileTools->setLabel( "File Operations" );

        openIcon = TQPixmap( fileopen );
        TQToolButton * fileOpen
            = new TQToolButton( openIcon, "Open File", TQString::null,
                               this, SLOT(choose()), fileTools, "open file" );

        saveIcon = TQPixmap( filesave );
        TQToolButton * fileSave
            = new TQToolButton( saveIcon, "Save File", TQString::null,
                               this, SLOT(save()), fileTools, "save file" );

        printIcon = TQPixmap( fileprint );
        TQToolButton * filePrint
            = new TQToolButton( printIcon, "Print File", TQString::null,
                               this, SLOT(print()), fileTools, "print file" );

        (void)TQWhatsThis::whatsThisButton( fileTools );

        const char * fileOpenText = "<p><img source=\"fileopen\"> "
                     "Click this button to open a <em>new file</em>.<br>"
                     "You can also select the <b>Open</b> command "
                     "from the <b>File</b> menu.</p>";

        TQWhatsThis::add( fileOpen, fileOpenText );

        TQMimeSourceFactory::defaultFactory()->setPixmap( "document-open", openIcon );

        const char * fileSaveText = "<p>Click this button to save the file you "
                     "are editing. You will be prompted for a file name.\n"
                     "You can also select the <b>Save</b> command "
                     "from the <b>File</b> menu.</p>";

        TQWhatsThis::add( fileSave, fileSaveText );

        const char * filePrintText = "Click this button to print the file you "
                     "are editing.\n"
                     "You can also select the Print command "
                     "from the File menu.";

        TQWhatsThis::add( filePrint, filePrintText );

        TQPopupMenu * file = new TQPopupMenu( this );
        menuBar()->insertItem( "&File", file );

        file->insertItem( "&New", this, SLOT(newDoc()), CTRL+Key_N );

        int id;
        id = file->insertItem( openIcon, "&Open...",
                               this, SLOT(choose()), CTRL+Key_O );
        file->setWhatsThis( id, fileOpenText );

        id = file->insertItem( saveIcon, "&Save",
                               this, SLOT(save()), CTRL+Key_S );
        file->setWhatsThis( id, fileSaveText );

        id = file->insertItem( "Save &As...", this, SLOT(saveAs()) );
        file->setWhatsThis( id, fileSaveText );

        file->insertSeparator();

        id = file->insertItem( printIcon, "&Print...",
                               this, SLOT(print()), CTRL+Key_P );
        file->setWhatsThis( id, filePrintText );

        file->insertSeparator();

        file->insertItem( "&Close", this, SLOT(close()), CTRL+Key_W );

        file->insertItem( "&Quit", tqApp, SLOT( closeAllWindows() ), CTRL+Key_Q );

        menuBar()->insertSeparator();

        TQPopupMenu * help = new TQPopupMenu( this );
        menuBar()->insertItem( "&Help", help );

        help->insertItem( "&About", this, SLOT(about()), Key_F1 );
        help->insertItem( "About &TQt", this, SLOT(aboutTQt()) );
        help->insertSeparator();
        help->insertItem( "What's &This", this, SLOT(whatsThis()), SHIFT+Key_F1 );

        e = new TQTextEdit( this, "editor" );
        e->setFocus();
        setCentralWidget( e );
        statusBar()->message( "Ready", 2000 );

        resize( 450, 600 );
    }

    ApplicationWindow::~ApplicationWindow()
    {
        delete printer;
    }

    void ApplicationWindow::newDoc()
    {
        ApplicationWindow *ed = new ApplicationWindow;
        ed->setCaption("TQt Example - Application");
        ed->show();
    }

    void ApplicationWindow::choose()
    {
        TQString fn = TQFileDialog::getOpenFileName( TQString::null, TQString::null,
                                                   this);
        if ( !fn.isEmpty() )
            load( fn );
        else
            statusBar()->message( "Loading aborted", 2000 );
    }

    void ApplicationWindow::load( const TQString &fileName )
    {
        TQFile f( fileName );
        if ( !f.open( IO_ReadOnly ) )
            return;

        TQTextStream ts( &f );
        e->setText( ts.read() );
        e->setModified( FALSE );
        setCaption( fileName );
        statusBar()->message( "Loaded document " + fileName, 2000 );
    }

    void ApplicationWindow::save()
    {
        if ( filename.isEmpty() ) {
            saveAs();
            return;
        }

        TQString text = e->text();
        TQFile f( filename );
        if ( !f.open( IO_WriteOnly ) ) {
            statusBar()->message( TQString("Could not write to %1").arg(filename),
                                  2000 );
            return;
        }

        TQTextStream t( &f );
        t << text;
        f.close();

        e->setModified( FALSE );

        setCaption( filename );

        statusBar()->message( TQString( "File %1 saved" ).arg( filename ), 2000 );
    }

    void ApplicationWindow::saveAs()
    {
        TQString fn = TQFileDialog::getSaveFileName( TQString::null, TQString::null,
                                                   this );
        if ( !fn.isEmpty() ) {
            filename = fn;
            save();
        } else {
            statusBar()->message( "Saving aborted", 2000 );
        }
    }

    void ApplicationWindow::print()
    {
        printer->setFullPage( TRUE );
        if ( printer->setup(this) ) {               // printer dialog
            statusBar()->message( "Printing..." );
            TQPainter p;
            if( !p.begin( printer ) ) {               // paint on printer
                statusBar()->message( "Printing aborted", 2000 );
                return;
            }

            TQPaintDeviceMetrics metrics( p.device() );
            int dpiy = metrics.logicalDpiY();
            int margin = (int) ( (2/2.54)*dpiy ); // 2 cm margins
            TQRect view( margin, margin, metrics.width() - 2*margin, metrics.height() - 2*margin );
            TQSimpleRichText richText( TQStyleSheet::convertFromPlainText(e->text()),
                                      TQFont(),
                                      e->context(),
                                      e->styleSheet(),
                                      e->mimeSourceFactory(),
                                      view.height() );
            richText.setWidth( &p, view.width() );
            int page = 1;
            do {
                richText.draw( &p, margin, margin, view, colorGroup() );
                view.moveBy( 0, view.height() );
                p.translate( 0 , -view.height() );
                p.drawText( view.right() - p.fontMetrics().width( TQString::number( page ) ),
                            view.bottom() + p.fontMetrics().ascent() + 5, TQString::number( page ) );
                if ( view.top() - margin >= richText.height() )
                    break;
                printer->newPage();
                page++;
            } while (TRUE);

            statusBar()->message( "Printing completed", 2000 );
        } else {
            statusBar()->message( "Printing aborted", 2000 );
        }
    }

    void ApplicationWindow::closeEvent( TQCloseEvent* ce )
    {
        if ( !e->isModified() ) {
            ce->accept();
            return;
        }

        switch( TQMessageBox::information( this, "TQt Application Example",
                                          "Do you want to save the changes"
                                          " to the document?",
                                          "Yes", "No", "Cancel",
                                          0, 1 ) ) {
        case 0:
            save();
            ce->accept();
            break;
        case 1:
            ce->accept();
            break;
        case 2:
        default: // just for sanity
            ce->ignore();
            break;
        }
    }

    void ApplicationWindow::about()
    {
        TQMessageBox::about( this, "TQt Application Example",
                            "This example demonstrates simple use of "
                            "TQMainWindow,\nTQMenuBar and TQToolBar.");
    }

    void ApplicationWindow::aboutTQt()
    {
        TQMessageBox::aboutTQt( this, "TQt Application Example" );
    }

Main:

    /****************************************************************************
    ** $Id: qt/main.cpp   3.3.8   edited Jan 11 14:37 $
    **
    ** Copyright (C) 1992-2007 Trolltech ASA.  All rights reserved.
    **
    ** This file is part of an example program for TQt.  This example
    ** program may be used, distributed and modified without limitation.
    **
    *****************************************************************************/

    #include <ntqapplication.h>
    #include "application.h"

    int main( int argc, char ** argv ) {
        TQApplication a( argc, argv );
        ApplicationWindow *mw = new ApplicationWindow();
        mw->setCaption( "TQt Example - Application" );
        mw->show();
        a.connect( &a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()) );
        return a.exec();
    }

See also Examples.