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#include <QtGui>

#include <math.h>

#include "window.h"

Window::Window(QWidget *parent)

    : QWidget(parent)

{

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

                   "redesigned around a system that allows textual content to "

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

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

                   "programming interface for editing documents. These "

                   "improvements are made available through a reimplementation "

                   "of the existing text rendering engine, and the "

                   "introduction of several new classes. "

                   "See the relevant module overview for a detailed discussion "

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

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

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

}

void Window::paintEvent(QPaintEvent *event)

{

//! [0]

    QTextLayout textLayout(text, font);

    qreal margin = 10;

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

    QFontMetrics fm(font);

    qreal lineHeight = fm.height();

    qreal y = 0;

    textLayout.beginLayout();

    while (1) {

        // create a new line 

        QTextLine line = textLayout.createLine();

        if (!line.isValid())

            break;

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

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

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

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

        line.setLineWidth(lineWidth);

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

        y += line.height();

    }

    textLayout.endLayout();

    QPainter painter;

    painter.begin(this);

    painter.setRenderHint(QPainter::Antialiasing);

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

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

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

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

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

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

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

    painter.end();

//! [0]

}