1  #include "renderarea.h"
2  #include <QPainter>


3  RenderArea::RenderArea(QWidget *parent)
    : QWidget(parent)
4  {
5    shape = Polygon;
6    antialiased = false;
7    transformed = false;
8    pixmap.load("d:\\Qt-Examples\\images\\qtlogo.jpg");
9
10   setBackgroundRole(QPalette::Base);
11   setAutoFillBackground(true);
12 }

13 QSize RenderArea::minimumSizeHint() const {
14    return QSize(100, 100);
15 }

16 QSize RenderArea::sizeHint() const {
17    return QSize(400, 200);
18 }

19 void RenderArea::setShape(Shape shape) {
20    this->shape = shape;
21    update();
22 }

23 void RenderArea::setPen(const QPen &pen) {
24    this->pen = pen;
25    update();
26 }

27 void RenderArea::setBrush(const QBrush &brush) {
28    this->brush = brush;
29    update();
30 }

31 void RenderArea::setAntialiased(bool antialiased) {
32    this->antialiased = antialiased;
33    update();
34 }

35 void RenderArea::setTransformed(bool transformed) {
36    this->transformed = transformed;
37    update();
38 }

39 void RenderArea::paintEvent(QPaintEvent * /* event */) {
40    static const QPoint points[4] = {
41        QPoint(10, 80),
42        QPoint(20, 10),
43        QPoint(80, 30),
44        QPoint(90, 70)
45    };

46    QRect rect(10, 20, 80, 60);

47    QPainterPath path;
48    path.moveTo(20, 80);
49    path.lineTo(20, 30);
50    path.cubicTo(80, 0, 50, 50, 80, 80);

51    int startAngle = 20 * 16;
52    int arcLength = 120 * 16;

53    QPainter painter(this);
54    painter.setPen(pen);
55    painter.setBrush(brush);
56    if (antialiased)
57        painter.setRenderHint(QPainter::Antialiasing, true);

58    for (int x = 0; x < width(); x += 100) {
59        for (int y = 0; y < height(); y += 100) {
60            painter.save();
61            painter.translate(x, y);

62            if (transformed) {
63                painter.translate(50, 50);
64                painter.rotate(60.0);
65                painter.scale(0.6, 0.9);
66                painter.translate(-50, -50);
67            }

68         switch (shape) {
69            case Line:
70                painter.drawLine(rect.bottomLeft(), rect.topRight());
71                break;
72            case Points:
73                painter.drawPoints(points, 4);
74                break;
75            case Polyline:
76                painter.drawPolyline(points, 4);
77                break;
78            case Polygon:
79                painter.drawPolygon(points, 4);
80                break;
81            case Rect:
82                painter.drawRect(rect);
83                break;
84            case RoundedRect:
85                painter.drawRoundedRect(rect, 25, 25, Qt::RelativeSize);
86                break;
87            case Ellipse:
88                painter.drawEllipse(rect);
89                break;
90            case Arc:
91                painter.drawArc(rect, startAngle, arcLength);
92                break;
93            case Chord:
94                painter.drawChord(rect, startAngle, arcLength);
95                break;
96            case Pie:
97                painter.drawPie(rect, startAngle, arcLength);
98                break;
99            case Path:
100               painter.drawPath(path);
101               break;
102          case Text:
103               painter.drawText(rect,
104                                Qt::AlignCenter,
105                                tr("Qt by\n The Qt Company"));
106               break;
107           case Pixmap:
108               painter.drawPixmap(10, 10, pixmap);
109         } // end of switch
110         painter.restore();
111       }//end of for y
112    } // end for x
113
114    painter.setRenderHint(QPainter::Antialiasing, false);
115    painter.setPen(palette().dark().color());
116    painter.setBrush(Qt::NoBrush);
117    painter.drawRect(QRect(0, 0, width() - 1, height() - 1));
117 }

