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    41 

    42 #include "spectrograph.h"

    43 #include <QPainter>

    44 #include <QMouseEvent>

    45 #include <QDebug>

    46 #include <QTimerEvent>

    47 

    48 const int NullTimerId = -1;

    49 const int NullIndex = -1;

    50 const int BarSelectionInterval = 2000;

    51 

    52 Spectrograph::Spectrograph(QWidget *parent)

    53     :   QWidget(parent)

    54     ,   m_barSelected(NullIndex)

    55     ,   m_timerId(NullTimerId)

    56     ,   m_lowFreq(0.0)

    57     ,   m_highFreq(0.0)

    58 {

    59     setMinimumHeight(100);

    60 }

    61 

    62 Spectrograph::~Spectrograph()

    63 {

    64 

    65 }

    66 

    67 void Spectrograph::setParams(int numBars, qreal lowFreq, qreal highFreq)

    68 {

    69     Q_ASSERT(numBars > 0);

    70     Q_ASSERT(highFreq > lowFreq);

    71     m_bars.resize(numBars);

    72     m_lowFreq = lowFreq;

    73     m_highFreq = highFreq;

    74     updateBars();

    75 }

    76 

    77 void Spectrograph::timerEvent(QTimerEvent *event)

    78 {

    79     Q_ASSERT(event->timerId() == m_timerId);

    80     Q_UNUSED(event) // suppress warnings in release builds

    81     killTimer(m_timerId);

    82     m_timerId = NullTimerId;

    83     m_barSelected = NullIndex;

    84     update();

    85 }

    86 

    87 void Spectrograph::paintEvent(QPaintEvent *event)

    88 {

    89     Q_UNUSED(event)

    90 

    91     QPainter painter(this);

    92     painter.fillRect(rect(), Qt::black);

    93 

    94     const int numBars = m_bars.count();

    95 

    96     // Highlight region of selected bar

    97     if (m_barSelected != NullIndex && numBars) {

    98         QRect regionRect = rect();

    99         regionRect.setLeft(m_barSelected * rect().width() / numBars);

   100         regionRect.setWidth(rect().width() / numBars);

   101         QColor regionColor(202, 202, 64);

   102         painter.setBrush(Qt::DiagCrossPattern);

   103         painter.fillRect(regionRect, regionColor);

   104         painter.setBrush(Qt::NoBrush);

   105     }

   106 

   107     QColor barColor(51, 204, 102);

   108     QColor clipColor(255, 255, 0);

   109 

   110     // Draw the outline

   111     const QColor gridColor = barColor.darker();

   112     QPen gridPen(gridColor);

   113     painter.setPen(gridPen);

   114     painter.drawLine(rect().topLeft(), rect().topRight());

   115     painter.drawLine(rect().topRight(), rect().bottomRight());

   116     painter.drawLine(rect().bottomRight(), rect().bottomLeft());

   117     painter.drawLine(rect().bottomLeft(), rect().topLeft());

   118 

   119     QVector<qreal> dashes;

   120     dashes << 2 << 2;

   121     gridPen.setDashPattern(dashes);

   122     painter.setPen(gridPen);

   123 

   124     // Draw vertical lines between bars

   125     if (numBars) {

   126         const int numHorizontalSections = numBars;

   127         QLine line(rect().topLeft(), rect().bottomLeft());

   128         for (int i=1; i<numHorizontalSections; ++i) {

   129             line.translate(rect().width()/numHorizontalSections, 0);

   130             painter.drawLine(line);

   131         }

   132     }

   133 

   134     // Draw horizontal lines

   135     const int numVerticalSections = 10;

   136     QLine line(rect().topLeft(), rect().topRight());

   137     for (int i=1; i<numVerticalSections; ++i) {

   138         line.translate(0, rect().height()/numVerticalSections);

   139         painter.drawLine(line);

   140     }

   141 

   142     barColor = barColor.lighter();

   143     barColor.setAlphaF(0.75);

   144     clipColor.setAlphaF(0.75);

   145 

   146     // Draw the bars

   147     if (numBars) {

   148         // Calculate width of bars and gaps

   149         const int widgetWidth = rect().width();

   150         const int barPlusGapWidth = widgetWidth / numBars;

   151         const int barWidth = 0.8 * barPlusGapWidth;

   152         const int gapWidth = barPlusGapWidth - barWidth;

   153         const int paddingWidth = widgetWidth - numBars * (barWidth + gapWidth);

   154         const int leftPaddingWidth = (paddingWidth + gapWidth) / 2;

   155         const int barHeight = rect().height() - 2 * gapWidth;

   156 

   157         for (int i=0; i<numBars; ++i) {

   158             const qreal value = m_bars[i].value;

   159             Q_ASSERT(value >= 0.0 && value <= 1.0);

   160             QRect bar = rect();

   161             bar.setLeft(rect().left() + leftPaddingWidth + (i * (gapWidth + barWidth)));

   162             bar.setWidth(barWidth);

   163             bar.setTop(rect().top() + gapWidth + (1.0 - value) * barHeight);

   164             bar.setBottom(rect().bottom() - gapWidth);

   165 

   166             QColor color = barColor;

   167             if (m_bars[i].clipped)

   168                 color = clipColor;

   169 

   170             painter.fillRect(bar, color);

   171         }

   172     }

   173 }

   174 

   175 void Spectrograph::mousePressEvent(QMouseEvent *event)

   176 {

   177     const QPoint pos = event->pos();

   178     const int index = m_bars.count() * (pos.x() - rect().left()) / rect().width();

   179     selectBar(index);

   180 }

   181 

   182 void Spectrograph::reset()

   183 {

   184     m_spectrum.reset();

   185     spectrumChanged(m_spectrum);

   186 }

   187 

   188 void Spectrograph::spectrumChanged(const FrequencySpectrum &spectrum)

   189 {

   190     m_spectrum = spectrum;

   191     updateBars();

   192 }

   193 

   194 int Spectrograph::barIndex(qreal frequency) const

   195 {

   196     Q_ASSERT(frequency >= m_lowFreq && frequency < m_highFreq);

   197     const qreal bandWidth = (m_highFreq - m_lowFreq) / m_bars.count();

   198     const int index = (frequency - m_lowFreq) / bandWidth;

   199     if(index <0 || index >= m_bars.count())

   200         Q_ASSERT(false);

   201     return index;

   202 }

   203 

   204 QPair<qreal, qreal> Spectrograph::barRange(int index) const

   205 {

   206     Q_ASSERT(index >= 0 && index < m_bars.count());

   207     const qreal bandWidth = (m_highFreq - m_lowFreq) / m_bars.count();

   208     return QPair<qreal, qreal>(index * bandWidth, (index+1) * bandWidth);

   209 }

   210 

   211 void Spectrograph::updateBars()

   212 {

   213     m_bars.fill(Bar());

   214     FrequencySpectrum::const_iterator i = m_spectrum.begin();

   215     const FrequencySpectrum::const_iterator end = m_spectrum.end();

   216     for ( ; i != end; ++i) {

   217         const FrequencySpectrum::Element e = *i;

   218         if (e.frequency >= m_lowFreq && e.frequency < m_highFreq) {

   219             Bar &bar = m_bars[barIndex(e.frequency)];

   220             bar.value = qMax(bar.value, e.amplitude);

   221             bar.clipped |= e.clipped;

   222         }

   223     }

   224     update();

   225 }

   226 

   227 void Spectrograph::selectBar(int index) {

   228     const QPair<qreal, qreal> frequencyRange = barRange(index);

   229     const QString message = QString("%1 - %2 Hz")

   230                                 .arg(frequencyRange.first)

   231                                 .arg(frequencyRange.second);

   232     emit infoMessage(message, BarSelectionInterval);

   233 

   234     if (NullTimerId != m_timerId)

   235         killTimer(m_timerId);

   236     m_timerId = startTimer(BarSelectionInterval);

   237 

   238     m_barSelected = index;

   239     update();

   240 }

   241 

   242