Qt Toolkit - widgets/widgets.cpp example file

# Widgets Demo

This example creates a window with many Qt widgets and two custom example widgets; aclock and dclock. It also shows how to connect widget signals to internal slots.

    /****************************************************************************
    ** $Id: widgets.cpp,v 2.46 1998/07/08 13:22:45 aavit Exp $
    **
    ** Copyright (C) 1992-1998 Troll Tech AS.  All rights reserved.
    **
    ** This file is part of an example program for Qt.  This example
    ** program may be used, distributed and modified without limitation.
    **
    *****************************************************************************/

    #include <qdialog.h>
    #include <qmessagebox.h>
    #include <qpixmap.h>
    #include <qmovie.h>
    #include <qlayout.h>
    #include <qapplication.h>
    #include <qkeycode.h>

    // Standard Qt widgets

    #include <qmenubar.h>
    #include <qpopupmenu.h>
    #include <qbuttongroup.h>
    #include <qcheckbox.h>
    #include <qcombobox.h>
    #include <qframe.h>
    #include <qgroupbox.h>
    #include <qlabel.h>
    #include <qlcdnumber.h>
    #include <qmultilinedit.h>
    #include <qlineedit.h>
    #include <qlistbox.h>
    #include <qpushbutton.h>
    #include <qradiobutton.h>
    #include <qslider.h>
    #include <qtooltip.h>
    #include <qspinbox.h>

    // Some sample widgets

    #include "../aclock/aclock.h"
    #include "../dclock/dclock.h"

    #define MOVIEFILENAME "trolltech.gif"

    //
    // WidgetView contains lots of Qt widgets.
    //

    class WidgetView : public QWidget
    {
        Q_OBJECT
    public:
        WidgetView( QWidget *parent=0, const char *name=0 );

    public slots:
        void        setStatus(const char*);

    private slots:
        void        button1Clicked();
        void        checkBoxClicked( int );
        void        radioButtonClicked( int );
        void        sliderValueChanged( int );
        void        listBoxItemSelected( int );
        void        comboBoxItemActivated( int );
        void        edComboBoxItemActivated( const char * );
        void        lineEditTextChanged( const char * );
        void        movieStatus( int );
        void        movieUpdate( const QRect& );
        void        spinBoxValueChanged( const char * );

    private:
        bool        eventFilter( QObject *, QEvent * );
        QLabel     *msg;
        QCheckBox  *cb[3];
        QLabel     *movielabel;
        QMovie      movie;
    };

    //
    // Construct the WidgetView with buttons
    //

    WidgetView::WidgetView( QWidget *parent, const char *name )
        : QWidget( parent, name )
    {
        QColor col;

      // Set the window caption/title

        setCaption( "Qt Widgets Demo Application" );

      // Install an application-global event filter

        qApp->installEventFilter( this );

      // Create a layout to position the widgets

        QVBoxLayout *topLayout = new QVBoxLayout( this, 10 );

      // Create a grid layout to hold most of the widgets

        QGridLayout *grid = new QGridLayout( 6, 3 );
     // This layout will get all of the stretch
        topLayout->addLayout( grid, 10 );

      // Create a menubar
        QMenuBar *menubar = new QMenuBar( this );
        menubar->setSeparator( QMenuBar::InWindowsStyle );
      // Create an easter egg
        QToolTip::add( menubar, QRect( 0, 0, 2, 2 ), "easter egg" );

        QPopupMenu* popup;
        popup = new QPopupMenu;
        int id;
        id = popup->insertItem( "&New" );
        popup->setItemEnabled( id, FALSE );
        id = popup->insertItem( "&Open" );
        popup->setItemEnabled( id, FALSE );
        popup->insertSeparator();
        popup->insertItem( "&Quit", qApp, SLOT(quit()), CTRL+Key_Q );

        menubar->insertItem( "&File", popup );

        // Must tell the layout about a menubar in a widget
        topLayout->setMenuBar( menubar );

      // Create an analog and a digital clock

        AnalogClock  *aclock = new AnalogClock( this );
        DigitalClock *dclock = new DigitalClock( this );
        dclock->setMaximumWidth(200);
        grid->addWidget( aclock, 0, 2 );
        grid->addWidget( dclock, 1, 2 );

      // Give the dclock widget a blue palette

        col.setRgb( 0xaa, 0xbe, 0xff );
        dclock->setPalette( QPalette( col ) );

      // make tool tips for both of them

        QToolTip::add( aclock, "custom widget: analog clock" );
        QToolTip::add( dclock, "custom widget: digital clock" );

      // Create a push button.

        QPushButton *pb;
        pb = new QPushButton( this, "button1" );    // create button 1
        pb->setText( "Push button 1" );
        pb->setFixedHeight( pb->sizeHint().height() );
        grid->addWidget( pb, 0, 0, AlignVCenter );
        connect( pb, SIGNAL(clicked()), SLOT(button1Clicked()) );
        QToolTip::add( pb, "push button 1" );
        QPixmap pm;
        bool pix = pm.load("qt.bmp");               // load pixmap for button 2
        if ( !pix ) {
            QMessageBox::information( 0, "Qt Widgets Example",
                                      "Could not load the file \"qt.bmp\", which\n"
                                      "contains an icon used...\n\n"
                                      "The text \"line 42\" will be substituted.",
                                      QMessageBox::Ok + QMessageBox::Default );
        }

        // Create a label containing a QMovie

        movielabel = new QLabel( this, "label0" );
        movie = QMovie( MOVIEFILENAME );
        movie.connectStatus(this, SLOT(movieStatus(int)));
        movie.connectUpdate(this, SLOT(movieUpdate(const QRect&)));
        movielabel->setFrameStyle( QFrame::Box | QFrame::Plain );
        movielabel->setMovie( movie );
        movielabel->setMargin( 0 );
        movielabel->setFixedSize( 128+movielabel->frameWidth()*2,
                                  64+movielabel->frameWidth()*2 );
        grid->addWidget( movielabel, 0, 1, AlignCenter );
        QToolTip::add( movielabel, "movie" );

      // Create a group of check boxes

        QButtonGroup *bg = new QButtonGroup( this, "checkGroup" );
        bg->setTitle( "Check Boxes" );
        grid->addWidget( bg, 1, 0 );

      // Create a layout for the check boxes
        QVBoxLayout *vbox = new QVBoxLayout(bg, 10);

        vbox->addSpacing( bg->fontMetrics().height() );

        cb[0] = new QCheckBox( bg );
        cb[0]->setText( "Read" );
        vbox->addWidget( cb[0] );
        cb[0]->setMinimumSize( cb[0]->sizeHint() );
        cb[1] = new QCheckBox( bg );
        cb[1]->setText( "Write" );
        vbox->addWidget( cb[1] );
        cb[1]->setMinimumSize( cb[1]->sizeHint() );
        cb[2] = new QCheckBox( bg );
        cb[2]->setText( "Execute" );
        cb[2]->setMinimumSize( cb[2]->sizeHint() );
        vbox->addWidget( cb[2] );
        bg->setMinimumSize( bg->childrenRect().size() );
        vbox->activate();

        connect( bg, SIGNAL(clicked(int)), SLOT(checkBoxClicked(int)) );

        QToolTip::add( cb[0], "check box 1" );
        QToolTip::add( cb[1], "check box 2" );
        QToolTip::add( cb[2], "check box 3" );

      // Create a group of radio buttons

        QRadioButton *rb;
        bg = new QButtonGroup( this, "radioGroup" );
        bg->setTitle( "Radio buttons" );

        grid->addWidget( bg, 1, 1 );

      // Create a layout for the radio buttons
        vbox = new QVBoxLayout(bg, 10);

        vbox->addSpacing( bg->fontMetrics().height() );
        rb = new QRadioButton( bg );
        rb->setText( "&AM" );
        rb->setChecked( TRUE );
        vbox->addWidget(rb);
        rb->setMinimumSize( rb->sizeHint() );
        QToolTip::add( rb, "radio button 1" );
        rb = new QRadioButton( bg );
        rb->setText( "&FM" );
        vbox->addWidget(rb);
        rb->setMinimumSize( rb->sizeHint() );
        QToolTip::add( rb, "radio button 2" );
        rb = new QRadioButton( bg );
        rb->setText( "&Short Wave" );
        vbox->addWidget(rb);
        rb->setMinimumSize( rb->sizeHint() );
        vbox->activate();

        connect( bg, SIGNAL(clicked(int)), SLOT(radioButtonClicked(int)) );
        QToolTip::add( rb, "radio button 3" );

      // Create a list box

        QListBox *lb = new QListBox( this, "listBox" );
        for ( int i=0; i<100; i++ ) {               // fill list box
            QString str;
            str.sprintf( "line %d", i );
            if ( i == 42 && pix )
                lb->insertItem( pm );
            else
                lb->insertItem( str );
        }
        grid->addMultiCellWidget( lb, 2, 4, 0, 0 );
        connect( lb, SIGNAL(selected(int)), SLOT(listBoxItemSelected(int)) );
        QToolTip::add( lb, "list box" );

        vbox = new QVBoxLayout(8);
        grid->addLayout( vbox, 2, 1 );

      // Create a slider

        QSlider *sb = new QSlider( 0, 300, 1, 100, QSlider::Horizontal,
                                   this, "Slider" );
        sb->setTickmarks( QSlider::Below );
        sb->setTickInterval( 10 );
        sb->setFocusPolicy( QWidget::TabFocus );
        sb->setFixedHeight(sb->sizeHint().height());
        vbox->addWidget( sb );

        connect( sb, SIGNAL(valueChanged(int)), SLOT(sliderValueChanged(int)) );
        QToolTip::add( sb, "slider" );

      // Create a combo box

        QComboBox *combo = new QComboBox( FALSE, this, "comboBox" );
        combo->insertItem( "darkBlue" );
        combo->insertItem( "darkRed" );
        combo->insertItem( "darkGreen" );
        combo->insertItem( "blue" );
        combo->insertItem( "red" );
        combo->setFixedHeight(combo->sizeHint().height());
        vbox->addWidget( combo );
        connect( combo, SIGNAL(activated(int)), SLOT(comboBoxItemActivated(int)) );
        QToolTip::add( combo, "read-only combo box" );

      // Create an editable combo box

        QComboBox *edCombo = new QComboBox( TRUE, this, "edComboBox" );
        edCombo->insertItem( "Permutable" );
        edCombo->insertItem( "Malleable" );
        edCombo->insertItem( "Adaptable" );
        edCombo->insertItem( "Alterable" );
        edCombo->insertItem( "Inconstant" );
        edCombo->setFixedHeight(edCombo->sizeHint().height());
        vbox->addWidget( edCombo );
        connect( edCombo, SIGNAL(activated(const char *)),
                 SLOT(edComboBoxItemActivated(const char *)) );
        QToolTip::add( edCombo, "editable combo box" );

        edCombo->setAutoCompletion( TRUE );

        vbox->addStretch( 1 );

        vbox = new QVBoxLayout(8);
        grid->addLayout( vbox, 2, 2 );

      // Create a spin box

        QSpinBox *spin = new QSpinBox( 0, 10, 1, this, "spin" );
        spin->setSuffix(" mm");
        spin->setSpecialValueText( "Auto" );
        spin->setMinimumSize( spin->sizeHint() );
        connect( spin, SIGNAL( valueChanged(const char*) ),
                 SLOT( spinBoxValueChanged(const char*) ) );
        QToolTip::add( spin, "spin box" );
        vbox->addWidget( spin );

        vbox->addStretch( 1 );

      // Create a multi line edit

        QMultiLineEdit *mle = new QMultiLineEdit( this, "multiLineEdit" );

        grid->addMultiCellWidget( mle, 3, 3, 1, 2 );
        mle->setMinimumHeight(mle->fontMetrics().height()*3);
        mle->setText("This is a QMultiLineEdit widget,\n"
                     "useful for small multi-line\n"
                     "input fields.");
        QToolTip::add( mle, "multi line editor" );

      // Create a single line edit

        QLineEdit *le = new QLineEdit( this, "lineEdit" );
        grid->addMultiCellWidget( le, 4, 4, 1, 2 );
        le->setFixedHeight(le->sizeHint().height());
        connect( le, SIGNAL(textChanged(const char *)),
                     SLOT(lineEditTextChanged(const char *)) );
        QToolTip::add( le, "single line editor" );

      // Create a horizontal line (sort of QFrame) above the message line

        QFrame *separator = new QFrame( this, "separatorLine" );
        separator->setFrameStyle( QFrame::HLine | QFrame::Sunken );
        separator->setFixedHeight( separator->sizeHint().height() );
        grid->addMultiCellWidget( separator, 5, 5, 0, 2 );
        QToolTip::add( separator, "tool tips on a separator! wow!" );

        grid->setRowStretch(0,0);
        grid->setRowStretch(1,0);
        grid->setRowStretch(2,0);
        grid->setRowStretch(3,1);
        grid->setRowStretch(4,1);
        grid->setRowStretch(5,0);

        grid->setColStretch(0,1);
        grid->setColStretch(1,1);
        grid->setColStretch(2,1);

      // Create an label and a message in a plain widget
      // The message is updated when buttons are clicked etc.

        QHBoxLayout *hbox = new QHBoxLayout();
        topLayout->addLayout( hbox );
        QLabel *msgLabel = new QLabel( this, "msgLabel" );
        msgLabel->setText( "Message:" );
        msgLabel->setAlignment( AlignHCenter|AlignVCenter );
        msgLabel->setFixedSize( msgLabel->sizeHint() );
        hbox->addWidget( msgLabel );
        QToolTip::add( msgLabel, "label 1" );

        msg = new QLabel( this, "message" );
        msg->setFrameStyle( QFrame::Panel | QFrame::Sunken );
        msg->setAlignment( AlignCenter );
        msg->setFont( QFont("times",12,QFont::Bold) );
        msg->setText( "Message" );
        msg->setFixedHeight( msg->sizeHint().height() );
        msg->setText( "" );
        hbox->addWidget( msg, 5 );
        QToolTip::add( msg, "label 2" );

        topLayout->activate();
    }

    void WidgetView::setStatus(const char* text)
    {
        msg->setText(text);
    }

    void WidgetView::button1Clicked()
    {
        msg->setText( "The first push button was clicked" );
    }

    void WidgetView::movieUpdate( const QRect& )
    {
        // Uncomment this to test animated icons on your window manager
        //setIcon( movie.framePixmap() );
    }

    void WidgetView::movieStatus( int s )
    {
        switch ( s ) {
          case QMovie::SourceEmpty:
            movielabel->setText("Could not load\n" MOVIEFILENAME );
            movielabel->setAlignment( AlignCenter );
            movielabel->setBackgroundColor( backgroundColor() );
          break;
          default:
            if ( movielabel->movie() )              // for flicker-free animation:
                movielabel->setBackgroundMode( NoBackground );
        }
    }

    void WidgetView::checkBoxClicked( int id )
    {
        QString str;
        str.sprintf( "Check box %d clicked : ", id );
        QString chk = "---";
        if ( cb[0]->isChecked() )
            chk[0] = 'r';
        if ( cb[1]->isChecked() )
            chk[1] = 'w';
        if ( cb[2]->isChecked() )
            chk[2] = 'x';
        str += chk;
        msg->setText( str );
    }

    void WidgetView::edComboBoxItemActivated( const char * text)
    {
        QString str;
        str.sprintf( "Editable Combo Box set to %s", text );
        msg->setText( str );
    }

    void WidgetView::radioButtonClicked( int id )
    {
        QString str;
        str.sprintf( "Radio button #%d clicked", id );
        msg->setText( str );
    }

    void WidgetView::listBoxItemSelected( int index )
    {
        QString str;
        str.sprintf( "List box item %d selected", index );
        msg->setText( str );
    }

    void WidgetView::sliderValueChanged( int value )
    {
        QString str;
        str.sprintf( "Movie set to %d%% of normal speed", value );
        msg->setText( str );
        movie.setSpeed( value );
    }

    void WidgetView::comboBoxItemActivated( int index )
    {
        QString str;
        str.sprintf( "Combo box item %d activated", index );
        msg->setText( str );
        switch ( index ) {
        default:
        case 0:
            QApplication::setWinStyleHighlightColor( darkBlue );
            break;
        case 1:
            QApplication::setWinStyleHighlightColor( darkRed );
            break;
        case 2:
            QApplication::setWinStyleHighlightColor( darkGreen );
            break;
        case 3:
            QApplication::setWinStyleHighlightColor( blue );
            break;
        case 4:
            QApplication::setWinStyleHighlightColor( red );
            break;
        }
    }

    void WidgetView::lineEditTextChanged( const char *newText )
    {
        QString str( "Line edit text: ");
        str += newText;
        msg->setText( str );
    }

    void WidgetView::spinBoxValueChanged( const char * valueText )
    {
        QString str( "Spin box value: " );
        str += valueText;
        msg->setText( str );
    }

    //
    // All application events are passed throught this event filter.
    // We're using it to display some information about a clicked
    // widget (right mouse button + CTRL).
    //

    bool WidgetView::eventFilter( QObject *obj, QEvent *event )
    {
        static bool identify_now = TRUE;
        if ( event->type() == Event_MouseButtonPress && identify_now ) {
            QMouseEvent *e = (QMouseEvent*)event;
            if ( e->button() == RightButton && (e->state() & ControlButton) != 0 ){
                QString str = "The clicked widget is a\n";
                str += obj->className();
                str += "\nThe widget's name is\n";
                if ( obj->name() )
                    str += obj->name();
                else
                    str += "<no name>";
                identify_now = FALSE;               // don't do it in message box
                QMessageBox::message( "Identify Widget", str, 0, (QWidget*)obj );
                identify_now = TRUE;                // allow it again
            }
        }
        return FALSE;                               // don't eat event
    }

    //
    // Include the meta-object code for classes in this file
    //

    #include "widgets.moc"

    //
    // Create and display our WidgetView.
    //

    int main( int argc, char **argv )
    {
        QApplication::setColorSpec( QApplication::CustomColor );
        QApplication a( argc, argv );
        WidgetView w;
        a.setMainWidget( &w );
        w.show();
        return a.exec();
    }