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Diffstat (limited to 'examples/multimedia/spectrum/app/spectrograph.cpp')
| -rw-r--r-- | examples/multimedia/spectrum/app/spectrograph.cpp | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/examples/multimedia/spectrum/app/spectrograph.cpp b/examples/multimedia/spectrum/app/spectrograph.cpp new file mode 100644 index 000000000..b1785e728 --- /dev/null +++ b/examples/multimedia/spectrum/app/spectrograph.cpp @@ -0,0 +1,241 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/legal +** +** This file is part of the examples of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:BSD$ +** You may use this file under the terms of the BSD license as follows: +** +** "Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions are +** met: +** * Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** * Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names +** of its contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#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() +{ + +} + +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()); + + QVector<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(); +} + + |