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# Font Displayer

This example program displays all characters of a font.

Header file:

    /****************************************************************************
    ** $Id: qt/fontdisplayer.h   3.2.1   edited May 13 09:08 $
    **
    ** Copyright (C) 1992-2000 Trolltech 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.
    **
    *****************************************************************************/

    #ifndef FontDisplayer_H
    #define FontDisplayer_H

    #include <qframe.h>
    #include <qmainwindow.h>

    class QSlider;

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

        QSize sizeHint() const;

    signals:
        void fontInformation(const QString&);

    public slots:
        void setRow(int);
        void chooseFont();

    protected:
        QSize cellSize() const;
        void paintEvent( QPaintEvent* );
    private:
        QFont tablefont;
        int row;
    };

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

    #endif

Implementation:

    /****************************************************************************
    ** $Id: qt/fontdisplayer.cpp   3.2.1   edited May 13 09:08 $
    **
    ** Copyright (C) 1992-2000 Trolltech 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 "fontdisplayer.h"
    #include <qapplication.h>
    #include <qslider.h>
    #include <qspinbox.h>
    #include <qpainter.h>
    #include <qtoolbar.h>
    #include <qstatusbar.h>
    #include <qlabel.h>
    #include <qpushbutton.h>
    #include <qfontdialog.h>
    #include <stdlib.h>

    FontRowTable::FontRowTable( QWidget* parent, const char* name ) :
        QFrame(parent,name)
    {
        setBackgroundMode(PaletteBase);
        setFrameStyle(Panel|Sunken);
        setMargin(8);
        setRow(0);
        tablefont = QApplication::font();
    }

    QSize FontRowTable::sizeHint() const
    {
        return 16*cellSize()+QSize(2,2)*(margin()+frameWidth());
    }

    QSize FontRowTable::cellSize() const
    {
        QFontMetrics fm = fontMetrics();
        return QSize( fm.maxWidth(), fm.lineSpacing()+1 );
    }

    void FontRowTable::paintEvent( QPaintEvent* e )
    {
        QFrame::paintEvent(e);
        QPainter p(this);
        p.setClipRegion(e->region());
        QRect r = e->rect();
        QFontMetrics fm = fontMetrics();
        int ml = frameWidth()+margin() + 1 + QMAX(0,-fm.minLeftBearing());
        int mt = frameWidth()+margin();
        QSize cell((width()-15-ml)/16,(height()-15-mt)/16);

        if ( !cell.width() || !cell.height() )
            return;

        int mini = r.left() / cell.width();
        int maxi = (r.right()+cell.width()-1) / cell.width();
        int minj = r.top() / cell.height();
        int maxj = (r.bottom()+cell.height()-1) / cell.height();

        int h = fm.height();

        QColor body(255,255,192);
        QColor negative(255,192,192);
        QColor positive(192,192,255);
        QColor rnegative(255,128,128);
        QColor rpositive(128,128,255);

        for (int j = minj; j<=maxj; j++) {
            for (int i = mini; i<=maxi; i++) {
                if ( i < 16 && j < 16 ) {
                    int x = i*cell.width();
                    int y = j*cell.height();

                    QChar ch = QChar(j*16+i,row);

                    if ( fm.inFont(ch) ) {
                        int w = fm.width(ch);
                        int l = fm.leftBearing(ch);
                        int r = fm.rightBearing(ch);

                        x += ml;
                        y += mt+h;

                        p.fillRect(x,y,w,-h,body);
                        if ( w ) {
                            if ( l ) {
                                p.fillRect(x+(l>0?0:l), y-h/2, abs(l),-h/2,
                                           l < 0 ? negative : positive);
                            }
                            if ( r ) {
                                p.fillRect(x+w-(r>0?r:0),y+2, abs(r),-h/2,
                                           r < 0 ? rnegative : rpositive);
                            }
                        }
                        QString s;
                        s += ch;
                        p.setPen(QPen(Qt::black));
                        p.drawText(x,y,s);
                    }
                }
            }
        }
    }

    void FontRowTable::setRow(int r)
    {
        row = r;

        QFontMetrics fm = fontMetrics();
        QString str;
        str.sprintf("mLB=%d mRB=%d mW=%d",
            fm.minLeftBearing(),
            fm.minRightBearing(),
            fm.maxWidth()
            );

        emit fontInformation(str);
        update();
    }

    void FontRowTable::chooseFont()
    {
        bool ok;
        QFont oldfont = tablefont;
        tablefont = QFontDialog::getFont(&ok, oldfont, this);

        if (ok)
            setFont(tablefont);
        else
            tablefont = oldfont;

    }

    FontDisplayer::FontDisplayer( QWidget* parent, const char* name ) :
        QMainWindow(parent,name)
    {
        FontRowTable* table = new FontRowTable(this);
        QToolBar* controls = new QToolBar(this);
        (void) new QLabel(tr("Row:"), controls);
        QSpinBox *row = new QSpinBox(0,255,1,controls);
        controls->addSeparator();
        QPushButton *fontbutton = new QPushButton(tr("Font..."), controls);

        connect(row,SIGNAL(valueChanged(int)),table,SLOT(setRow(int)));
        connect(fontbutton, SIGNAL(clicked()), table, SLOT(chooseFont()));
        connect(table,SIGNAL(fontInformation(const QString&)),
                statusBar(),SLOT(message(const QString&)));
        table->setRow(0);
        setCentralWidget(table);
    }

Main:

    /****************************************************************************
    ** $Id: qt/qfd.cpp   3.2.1   edited May 13 09:08 $
    **
    ** Copyright (C) 1992-2000 Trolltech 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 "fontdisplayer.h"

    #include <qapplication.h>
    #include <qslider.h>
    #include <qpainter.h>
    #include <qstatusbar.h>

    int main(int argc, char** argv)
    {
        QApplication app(argc,argv);

        FontDisplayer m;
        QSize sh = m.centralWidget()->sizeHint();
        m.resize(sh.width(),
                 sh.height()+3*m.statusBar()->height());
        app.setMainWidget(&m);
        m.setCaption("Qt Example - QFD");
        m.show();

        return app.exec();
    }

See also Examples.