How to write a text around a circle using QPainter class? - qt

Question

The question is simple ! I want something like this. Either using QPainter class or using Qt Graphics Framework:

Answer 1

There are several ways to do this using a QPainterPath specified here.
Here is the second example from that page:
#include <QtGui>
#include <cmath>
class Widget : public QWidget
{
public:
Widget ()
: QWidget() { }
private:
void paintEvent ( QPaintEvent *)
{
QString hw("hello world");
int drawWidth = width() / 100;
QPainter painter(this);
QPen pen = painter.pen();
pen.setWidth(drawWidth);
pen.setColor(Qt::darkGreen);
painter.setPen(pen);
QPainterPath path(QPointF(0.0, 0.0));
QPointF c1(width()*0.2,height()*0.8);
QPointF c2(width()*0.8,height()*0.2);
path.cubicTo(c1,c2,QPointF(width(),height()));
//draw the bezier curve
painter.drawPath(path);
//Make the painter ready to draw chars
QFont font = painter.font();
font.setPixelSize(drawWidth*2);
painter.setFont(font);
pen.setColor(Qt::red);
painter.setPen(pen);
qreal percentIncrease = (qreal) 1/(hw.size()+1);
qreal percent = 0;
for ( int i = 0; i < hw.size(); i++ ) {
percent += percentIncrease;
QPointF point = path.pointAtPercent(percent);
qreal angle = path.angleAtPercent(percent); // Clockwise is negative
painter.save();
// Move the virtual origin to the point on the curve
painter.translate(point);
// Rotate to match the angle of the curve
// Clockwise is positive so we negate the angle from above
painter.rotate(-angle);
// Draw a line width above the origin to move the text above the line
// and let Qt do the transformations
painter.drawText(QPoint(0, -pen.width()),QString(hw[i]));
painter.restore();
}
}
};
int main(int argc, char **argv)
{
QApplication app(argc, argv);
Widget widget;
widget.show();
return app.exec();
}