renderarea.cpp Example File
painting/basicdrawing/renderarea.cpp
#include <QtGui>
#include "renderarea.h"
RenderArea::RenderArea(QWidget *parent)
: QWidget(parent)
{
shape = Polygon;
antialiased = false;
transformed = false;
pixmap.load(":/images/qt-logo.png");
setBackgroundRole(QPalette::Base);
setAutoFillBackground(true);
}
QSize RenderArea::minimumSizeHint() const
{
return QSize(100, 100);
}
QSize RenderArea::sizeHint() const
{
return QSize(400, 200);
}
void RenderArea::setShape(Shape shape)
{
this->shape = shape;
update();
}
void RenderArea::setPen(const QPen &pen)
{
this->pen = pen;
update();
}
void RenderArea::setBrush(const QBrush &brush)
{
this->brush = brush;
update();
}
void RenderArea::setAntialiased(bool antialiased)
{
this->antialiased = antialiased;
update();
}
void RenderArea::setTransformed(bool transformed)
{
this->transformed = transformed;
update();
}
void RenderArea::paintEvent(QPaintEvent * )
{
static const QPoint points[4] = {
QPoint(10, 80),
QPoint(20, 10),
QPoint(80, 30),
QPoint(90, 70)
};
QRect rect(10, 20, 80, 60);
QPainterPath path;
path.moveTo(20, 80);
path.lineTo(20, 30);
path.cubicTo(80, 0, 50, 50, 80, 80);
int startAngle = 20 * 16;
int arcLength = 120 * 16;
QPainter painter(this);
painter.setPen(pen);
painter.setBrush(brush);
if (antialiased)
painter.setRenderHint(QPainter::Antialiasing, true);
for (int x = 0; x < width(); x += 100) {
for (int y = 0; y < height(); y += 100) {
painter.save();
painter.translate(x, y);
if (transformed) {
painter.translate(50, 50);
painter.rotate(60.0);
painter.scale(0.6, 0.9);
painter.translate(-50, -50);
}
switch (shape) {
case Line:
painter.drawLine(rect.bottomLeft(), rect.topRight());
break;
case Points:
painter.drawPoints(points, 4);
break;
case Polyline:
painter.drawPolyline(points, 4);
break;
case Polygon:
painter.drawPolygon(points, 4);
break;
case Rect:
painter.drawRect(rect);
break;
case RoundedRect:
painter.drawRoundedRect(rect, 25, 25, Qt::RelativeSize);
break;
case Ellipse:
painter.drawEllipse(rect);
break;
case Arc:
painter.drawArc(rect, startAngle, arcLength);
break;
case Chord:
painter.drawChord(rect, startAngle, arcLength);
break;
case Pie:
painter.drawPie(rect, startAngle, arcLength);
break;
case Path:
painter.drawPath(path);
break;
case Text:
painter.drawText(rect, Qt::AlignCenter, tr("Qt by\nNokia"));
break;
case Pixmap:
painter.drawPixmap(10, 10, pixmap);
}
painter.restore();
}
}
painter.setRenderHint(QPainter::Antialiasing, false);
painter.setPen(palette().dark().color());
painter.setBrush(Qt::NoBrush);
painter.drawRect(QRect(0, 0, width() - 1, height() - 1));
}