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50
51#include "mouse.h"
52
53#include <QGraphicsScene>
54#include <QPainter>
55#include <QRandomGenerator>
56#include <QStyleOption>
57#include <qmath.h>
58
59constexpr qreal Pi = M_PI;
60constexpr qreal TwoPi = 2 * M_PI;
61
62static qreal normalizeAngle(qreal angle)
63{
64 while (angle < 0)
65 angle += TwoPi;
66 while (angle > TwoPi)
67 angle -= TwoPi;
68 return angle;
69}
70
71//! [0]
72Mouse::Mouse() : color(QRandomGenerator::global()->bounded(highest: 256),
73 QRandomGenerator::global()->bounded(highest: 256),
74 QRandomGenerator::global()->bounded(highest: 256))
75{
76 setTransform(matrix: QTransform().rotate(a: QRandomGenerator::global()->bounded(highest: 360 * 16)), combine: true);
77 startTimer(interval: 1000 / 33);
78}
79//! [0]
80
81//! [1]
82QRectF Mouse::boundingRect() const
83{
84 qreal adjust = 0.5;
85 return QRectF(-18 - adjust, -22 - adjust,
86 36 + adjust, 60 + adjust);
87}
88//! [1]
89
90//! [2]
91QPainterPath Mouse::shape() const
92{
93 QPainterPath path;
94 path.addRect(x: -10, y: -20, w: 20, h: 40);
95 return path;
96}
97//! [2]
98
99//! [3]
100void Mouse::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
101{
102 // Body
103 painter->setBrush(color);
104 painter->drawEllipse(x: -10, y: -20, w: 20, h: 40);
105
106 // Eyes
107 painter->setBrush(Qt::white);
108 painter->drawEllipse(x: -10, y: -17, w: 8, h: 8);
109 painter->drawEllipse(x: 2, y: -17, w: 8, h: 8);
110
111 // Nose
112 painter->setBrush(Qt::black);
113 painter->drawEllipse(r: QRectF(-2, -22, 4, 4));
114
115 // Pupils
116 painter->drawEllipse(r: QRectF(-8.0 + mouseEyeDirection, -17, 4, 4));
117 painter->drawEllipse(r: QRectF(4.0 + mouseEyeDirection, -17, 4, 4));
118
119 // Ears
120 painter->setBrush(scene()->collidingItems(item: this).isEmpty() ? Qt::darkYellow : Qt::red);
121 painter->drawEllipse(x: -17, y: -12, w: 16, h: 16);
122 painter->drawEllipse(x: 1, y: -12, w: 16, h: 16);
123
124 // Tail
125 QPainterPath path(QPointF(0, 20));
126 path.cubicTo(ctrlPt1x: -5, ctrlPt1y: 22, ctrlPt2x: -5, ctrlPt2y: 22, endPtx: 0, endPty: 25);
127 path.cubicTo(ctrlPt1x: 5, ctrlPt1y: 27, ctrlPt2x: 5, ctrlPt2y: 32, endPtx: 0, endPty: 30);
128 path.cubicTo(ctrlPt1x: -5, ctrlPt1y: 32, ctrlPt2x: -5, ctrlPt2y: 42, endPtx: 0, endPty: 35);
129 painter->setBrush(Qt::NoBrush);
130 painter->drawPath(path);
131}
132//! [3]
133
134//! [4]
135void Mouse::timerEvent(QTimerEvent *)
136{
137//! [4]
138 // Don't move too far away
139//! [5]
140 QLineF lineToCenter(QPointF(0, 0), mapFromScene(ax: 0, ay: 0));
141 if (lineToCenter.length() > 150) {
142 qreal angleToCenter = std::atan2(y: lineToCenter.dy(), x: lineToCenter.dx());
143 angleToCenter = normalizeAngle(angle: (Pi - angleToCenter) + Pi / 2);
144
145 if (angleToCenter < Pi && angleToCenter > Pi / 4) {
146 // Rotate left
147 angle += (angle < -Pi / 2) ? 0.25 : -0.25;
148 } else if (angleToCenter >= Pi && angleToCenter < (Pi + Pi / 2 + Pi / 4)) {
149 // Rotate right
150 angle += (angle < Pi / 2) ? 0.25 : -0.25;
151 }
152 } else if (::sin(x: angle) < 0) {
153 angle += 0.25;
154 } else if (::sin(x: angle) > 0) {
155 angle -= 0.25;
156//! [5] //! [6]
157 }
158//! [6]
159
160 // Try not to crash with any other mice
161//! [7]
162 QList<QGraphicsItem *> dangerMice = scene()->items(polygon: QPolygonF()
163 << mapToScene(ax: 0, ay: 0)
164 << mapToScene(ax: -30, ay: -50)
165 << mapToScene(ax: 30, ay: -50));
166 for (QGraphicsItem *item : dangerMice) {
167 if (item == this)
168 continue;
169
170 QLineF lineToMouse(QPointF(0, 0), mapFromItem(item, ax: 0, ay: 0));
171 qreal angleToMouse = std::atan2(y: lineToMouse.dy(), x: lineToMouse.dx());
172 angleToMouse = normalizeAngle(angle: (Pi - angleToMouse) + Pi / 2);
173
174 if (angleToMouse >= 0 && angleToMouse < Pi / 2) {
175 // Rotate right
176 angle += 0.5;
177 } else if (angleToMouse <= TwoPi && angleToMouse > (TwoPi - Pi / 2)) {
178 // Rotate left
179 angle -= 0.5;
180//! [7] //! [8]
181 }
182//! [8] //! [9]
183 }
184//! [9]
185
186 // Add some random movement
187//! [10]
188 if (dangerMice.size() > 1 && QRandomGenerator::global()->bounded(highest: 10) == 0) {
189 if (QRandomGenerator::global()->bounded(highest: 1))
190 angle += QRandomGenerator::global()->bounded(highest: 1 / 500.0);
191 else
192 angle -= QRandomGenerator::global()->bounded(highest: 1 / 500.0);
193 }
194//! [10]
195
196//! [11]
197 speed += (-50 + QRandomGenerator::global()->bounded(highest: 100)) / 100.0;
198
199 qreal dx = ::sin(x: angle) * 10;
200 mouseEyeDirection = (qAbs(t: dx / 5) < 1) ? 0 : dx / 5;
201
202 setTransform(matrix: QTransform().rotate(a: dx), combine: true);
203 setPos(mapToParent(ax: 0, ay: -(3 + sin(x: speed) * 3)));
204}
205//! [11]
206

source code of qtbase/examples/widgets/touch/pinchzoom/mouse.cpp