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    41 

    42 #include <QtGui>

    43 #include <math.h>

    44 

    45 #include "window.h"

    46 

    47 Window::Window(QWidget *parent)

    48     : QWidget(parent)

    49 {

    50     text = QString("Support for text rendering and layout in Qt 4 has been "

    51                    "redesigned around a system that allows textual content to "

    52                    "be represented in a more flexible way than was possible "

    53                    "with Qt 3. Qt 4 also provides a more convenient "

    54                    "programming interface for editing documents. These "

    55                    "improvements are made available through a reimplementation "

    56                    "of the existing text rendering engine, and the "

    57                    "introduction of several new classes. "

    58                    "See the relevant module overview for a detailed discussion "

    59                    "of this framework. The following sections provide a brief "

    60                    "overview of the main concepts behind Scribe.");

    61 

    62     setWindowTitle(tr("Plain Text Layout"));

    63 }

    64 

    65 void Window::paintEvent(QPaintEvent *event)

    66 {

    67 //! [0]

    68     QTextLayout textLayout(text, font);

    69     qreal margin = 10;

    70     qreal radius = qMin(width()/2.0, height()/2.0) - margin;

    71     QFontMetrics fm(font);

    72 

    73     qreal lineHeight = fm.height();

    74     qreal y = 0;

    75 

    76     textLayout.beginLayout();

    77 

    78     while (1) {

    79         // create a new line 

    80         QTextLine line = textLayout.createLine();

    81         if (!line.isValid())

    82             break;

    83 

    84         qreal x1 = qMax(0.0, pow(pow(radius,2)-pow(radius-y,2), 0.5));

    85         qreal x2 = qMax(0.0, pow(pow(radius,2)-pow(radius-(y+lineHeight),2), 0.5));

    86         qreal x = qMax(x1, x2) + margin;

    87         qreal lineWidth = (width() - margin) - x;

    88 

    89         line.setLineWidth(lineWidth);

    90         line.setPosition(QPointF(x, margin+y));

    91         y += line.height();

    92     }

    93 

    94     textLayout.endLayout();

    95 

    96     QPainter painter;

    97     painter.begin(this);

    98     painter.setRenderHint(QPainter::Antialiasing);

    99     painter.fillRect(rect(), Qt::white);

   100     painter.setBrush(QBrush(Qt::black));

   101     painter.setPen(QPen(Qt::black));

   102     textLayout.draw(&painter, QPoint(0,0));

   103 

   104     painter.setBrush(QBrush(QColor("#a6ce39")));

   105     painter.setPen(QPen(Qt::black));

   106     painter.drawEllipse(QRectF(-radius, margin, 2*radius, 2*radius));

   107     painter.end();

   108 //! [0]

   109 }