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50
51#include "gruesensorimpl.h"
52#include <QDebug>
53#include <QTimer>
54
55char const * const gruesensorimpl::id("grue.gruesensor");
56
57gruesensorimpl::gruesensorimpl(QSensor *sensor)
58 : QSensorBackend(sensor)
59 , lightLevel(QAmbientLightReading::Undefined)
60{
61 // We need a light sensor
62 lightSensor = new QAmbientLightSensor(this);
63 connect(sender: lightSensor, SIGNAL(readingChanged()), receiver: this, SLOT(lightChanged()));
64 lightSensor->connectToBackend();
65
66 // We need a timer
67 darkTimer = new QTimer(this);
68 darkTimer->setInterval(1000);
69 connect(sender: darkTimer, SIGNAL(timeout()), receiver: this, SLOT(increaseChance()));
70
71 // We use this as our timestamp source
72 timer.start();
73
74//! [setReading]
75 // Register our reading instance
76 setReading<GrueSensorReading>(&m_reading);
77//! [setReading]
78
79//! [metadata]
80 // Supply metadata
81 // We can run as fast as the light sensor does
82 setDataRates(lightSensor);
83 // Only one output range, 0 to 1 in .1 increments
84 addOutputRange(min: 0, max: 1, accuracy: 0.1);
85 setDescription(QLatin1String("Grue Sensor"));
86//! [metadata]
87}
88
89void gruesensorimpl::start()
90{
91//! [start]
92 lightSensor->setDataRate(sensor()->dataRate());
93 lightSensor->start();
94 // If the light sensor doesn't work we don't work either
95 if (!lightSensor->isActive())
96 sensorStopped();
97 if (lightSensor->isBusy())
98 sensorBusy();
99//! [start]
100}
101
102void gruesensorimpl::stop()
103{
104 lightSensor->stop();
105}
106
107void gruesensorimpl::lightChanged()
108{
109 if (lightLevel == lightSensor->reading()->lightLevel())
110 return;
111
112 lightLevel = lightSensor->reading()->lightLevel();
113
114 int chance = 0;
115 darkTimer->stop();
116
117 switch (lightSensor->reading()->lightLevel()) {
118 case QAmbientLightReading::Dark:
119 // It is dark. You are likely to be eaten by a grue.
120 chance = 10;
121 darkTimer->start();
122 break;
123 default:
124 break;
125 }
126
127 // Only send an update if the value has changed.
128 if (chance != m_reading.chanceOfBeingEaten() || m_reading.timestamp() == 0) {
129 m_reading.setTimestamp(timer.elapsed());
130 m_reading.setChanceOfBeingEaten(chance);
131 newReadingAvailable();
132 }
133}
134
135void gruesensorimpl::increaseChance()
136{
137 // The longer you stay in the dark, the higher your chance of being eaten
138 int chance = m_reading.chanceOfBeingEaten() + 10;
139
140 m_reading.setTimestamp(timer.elapsed());
141 m_reading.setChanceOfBeingEaten(chance);
142
143 newReadingAvailable();
144
145 // No point in using the timer anymore if we've hit 100... you can't get more
146 // likely to be eaten than 100%
147 if (chance >= 100)
148 darkTimer->stop();
149}
150
151

source code of qtsensors/examples/sensors/grue/plugin/gruesensorimpl.cpp