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// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "spectrograph.h"
#include <QDebug>
#include <QMouseEvent>
#include <QPainter>
#include <QTimerEvent>
const int NullTimerId = -1;
const int NullIndex = -1;
const int BarSelectionInterval = 2000;
Spectrograph::Spectrograph(QWidget *parent)
: QWidget(parent)
, m_barSelected(NullIndex)
, m_timerId(NullTimerId)
, m_lowFreq(0.0)
, m_highFreq(0.0)
{
setMinimumHeight(100);
}
Spectrograph::~Spectrograph()
= default;
void Spectrograph::setParams(int numBars, qreal lowFreq, qreal highFreq)
{
Q_ASSERT(numBars > 0);
Q_ASSERT(highFreq > lowFreq);
m_bars.resize(numBars);
m_lowFreq = lowFreq;
m_highFreq = highFreq;
updateBars();
}
void Spectrograph::timerEvent(QTimerEvent *event)
{
Q_ASSERT(event->timerId() == m_timerId);
Q_UNUSED(event); // suppress warnings in release builds
killTimer(m_timerId);
m_timerId = NullTimerId;
m_barSelected = NullIndex;
update();
}
void Spectrograph::paintEvent(QPaintEvent *event)
{
Q_UNUSED(event);
QPainter painter(this);
painter.fillRect(rect(), Qt::black);
const int numBars = m_bars.count();
// Highlight region of selected bar
if (m_barSelected != NullIndex && numBars) {
QRect regionRect = rect();
regionRect.setLeft(m_barSelected * rect().width() / numBars);
regionRect.setWidth(rect().width() / numBars);
QColor regionColor(202, 202, 64);
painter.setBrush(Qt::DiagCrossPattern);
painter.fillRect(regionRect, regionColor);
painter.setBrush(Qt::NoBrush);
}
QColor barColor(51, 204, 102);
QColor clipColor(255, 255, 0);
// Draw the outline
const QColor gridColor = barColor.darker();
QPen gridPen(gridColor);
painter.setPen(gridPen);
painter.drawLine(rect().topLeft(), rect().topRight());
painter.drawLine(rect().topRight(), rect().bottomRight());
painter.drawLine(rect().bottomRight(), rect().bottomLeft());
painter.drawLine(rect().bottomLeft(), rect().topLeft());
QList<qreal> dashes;
dashes << 2 << 2;
gridPen.setDashPattern(dashes);
painter.setPen(gridPen);
// Draw vertical lines between bars
if (numBars) {
const int numHorizontalSections = numBars;
QLine line(rect().topLeft(), rect().bottomLeft());
for (int i=1; i<numHorizontalSections; ++i) {
line.translate(rect().width()/numHorizontalSections, 0);
painter.drawLine(line);
}
}
// Draw horizontal lines
const int numVerticalSections = 10;
QLine line(rect().topLeft(), rect().topRight());
for (int i=1; i<numVerticalSections; ++i) {
line.translate(0, rect().height()/numVerticalSections);
painter.drawLine(line);
}
barColor = barColor.lighter();
barColor.setAlphaF(0.75);
clipColor.setAlphaF(0.75);
// Draw the bars
if (numBars) {
// Calculate width of bars and gaps
const int widgetWidth = rect().width();
const int barPlusGapWidth = widgetWidth / numBars;
const int barWidth = 0.8 * barPlusGapWidth;
const int gapWidth = barPlusGapWidth - barWidth;
const int paddingWidth = widgetWidth - numBars * (barWidth + gapWidth);
const int leftPaddingWidth = (paddingWidth + gapWidth) / 2;
const int barHeight = rect().height() - 2 * gapWidth;
for (int i=0; i<numBars; ++i) {
const qreal value = m_bars[i].value;
Q_ASSERT(value >= 0.0 && value <= 1.0);
QRect bar = rect();
bar.setLeft(rect().left() + leftPaddingWidth + (i * (gapWidth + barWidth)));
bar.setWidth(barWidth);
bar.setTop(rect().top() + gapWidth + (1.0 - value) * barHeight);
bar.setBottom(rect().bottom() - gapWidth);
QColor color = barColor;
if (m_bars[i].clipped)
color = clipColor;
painter.fillRect(bar, color);
}
}
}
void Spectrograph::mousePressEvent(QMouseEvent *event)
{
const QPoint pos = event->pos();
const int index = m_bars.count() * (pos.x() - rect().left()) / rect().width();
selectBar(index);
}
void Spectrograph::reset()
{
m_spectrum.reset();
spectrumChanged(m_spectrum);
}
void Spectrograph::spectrumChanged(const FrequencySpectrum &spectrum)
{
m_spectrum = spectrum;
updateBars();
}
int Spectrograph::barIndex(qreal frequency) const
{
Q_ASSERT(frequency >= m_lowFreq && frequency < m_highFreq);
const qreal bandWidth = (m_highFreq - m_lowFreq) / m_bars.count();
const int index = (frequency - m_lowFreq) / bandWidth;
if (index <0 || index >= m_bars.count())
Q_ASSERT(false);
return index;
}
QPair<qreal, qreal> Spectrograph::barRange(int index) const
{
Q_ASSERT(index >= 0 && index < m_bars.count());
const qreal bandWidth = (m_highFreq - m_lowFreq) / m_bars.count();
return QPair<qreal, qreal>(index * bandWidth, (index+1) * bandWidth);
}
void Spectrograph::updateBars()
{
m_bars.fill(Bar());
FrequencySpectrum::const_iterator i = m_spectrum.begin();
const FrequencySpectrum::const_iterator end = m_spectrum.end();
for ( ; i != end; ++i) {
const FrequencySpectrum::Element e = *i;
if (e.frequency >= m_lowFreq && e.frequency < m_highFreq) {
Bar &bar = m_bars[barIndex(e.frequency)];
bar.value = qMax(bar.value, e.amplitude);
bar.clipped |= e.clipped;
}
}
update();
}
void Spectrograph::selectBar(int index) {
const QPair<qreal, qreal> frequencyRange = barRange(index);
const QString message = QString("%1 - %2 Hz")
.arg(frequencyRange.first)
.arg(frequencyRange.second);
emit infoMessage(message, BarSelectionInterval);
if (NullTimerId != m_timerId)
killTimer(m_timerId);
m_timerId = startTimer(BarSelectionInterval);
m_barSelected = index;
update();
}
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