Added DJ audio track player

trackdeck.cpp

@@ -0,0 +1,145 @@
+#include "trackdeck.h"
+#include "ui_trackdeck.h"
+
+#include <QAbstractEventDispatcher>
+#include <QDragEnterEvent>
+#include <QDragLeaveEvent>
+#include <QDropEvent>
+#include <QMimeData>
+#include <QTextStream>
+#include <QUrl>
+#include <QFileInfo>
+#include <QDebug>
+
+#include "audiodecoder.h"
+
+TrackDeck::TrackDeck(QWidget *parent) :
+    QWidget{parent},
+    m_ui{std::make_unique<Ui::TrackDeck>()}
+{
+    m_ui->setupUi(this);
+    m_ui->progressBar->hide();
+
+    connect(m_ui->pushButtonPlay, &QAbstractButton::pressed, &m_player, &AudioPlayer::togglePlaying);
+    connect(m_ui->pushButtonStop, &QAbstractButton::pressed, &m_player, &AudioPlayer::stop);
+
+    connect(m_ui->verticalSliderVolume, &QAbstractSlider::valueChanged, &m_player, [&player=m_player](int value){ player.setVolume(float(value)/100.f); });
+
+    connect(m_ui->horizontalSliderSpeed, &QAbstractSlider::valueChanged, &m_player, [&player=m_player](int value){ player.setSpeed(float(value)/100.f); });
+
+    connect(m_ui->previewWidget, &PreviewWidget::positionSelected, &m_player, &AudioPlayer::setPosition);
+    connect(&m_player, &AudioPlayer::positionChanged, m_ui->previewWidget, &PreviewWidget::setPosition);
+    connect(&m_player, &AudioPlayer::positionChanged, m_ui->scratchWidget, &ScratchWidget::setPosition);
+    connect(&m_player, &AudioPlayer::playingChanged, m_ui->pushButtonPlay, [&button=*m_ui->pushButtonPlay](bool playing){ button.setText(playing ? tr("▮▮") : tr("▶")); });
+}
+
+TrackDeck::~TrackDeck() = default;
+
+void TrackDeck::loadTrack(const QString &filename)
+{
+    m_filename = filename;
+    emit startDecoding(filename);
+    m_ui->progressBar->show();
+    m_ui->progressBar->setValue(0);
+}
+
+void TrackDeck::injectDecodingThread(QThread &thread)
+{
+    QMetaObject::invokeMethod(QAbstractEventDispatcher::instance(&thread), [this](){
+        m_decoder = std::make_unique<AudioDecoder>();
+        connect(this, &TrackDeck::startDecoding, m_decoder.get(), &AudioDecoder::startDecodingFilename);
+        connect(m_decoder.get(), &AudioDecoder::progress, this, &TrackDeck::decodingProgress);
+        connect(m_decoder.get(), &AudioDecoder::decodingFinished, this, &TrackDeck::decodingFinished);
+        if (!m_filename.isEmpty())
+            m_decoder->startDecodingFilename(m_filename);
+    });
+}
+
+void TrackDeck::writeSamples(frame_t *begin, frame_t *end)
+{
+    m_player.writeSamples(begin, end);
+}
+
+void TrackDeck::dragEnterEvent(QDragEnterEvent *event)
+{
+    if (!event->mimeData()->hasFormat("text/uri-list"))
+        return;
+
+    auto data = event->mimeData()->data("text/uri-list");
+
+    QTextStream textStream(data, QIODevice::ReadOnly | QIODevice::Text);
+    if (textStream.atEnd())
+        return;
+
+    const QUrl url(textStream.readLine());
+    if (!url.isLocalFile())
+        return;
+
+    const QFileInfo fileInfo(url.toLocalFile());
+    if (!fileInfo.exists())
+        return;
+
+    if (!fileInfo.isFile())
+        return;
+
+    event->acceptProposedAction();
+}
+
+void TrackDeck::dragLeaveEvent(QDragLeaveEvent *event)
+{
+    Q_UNUSED(event)
+}
+
+void TrackDeck::dropEvent(QDropEvent *event)
+{
+    if (!event->mimeData()->hasFormat("text/uri-list"))
+    {
+        qWarning() << "wrong type";
+        return;
+    }
+
+    auto data = event->mimeData()->data("text/uri-list");
+
+    QTextStream textStream(data, QIODevice::ReadOnly | QIODevice::Text);
+    if (textStream.atEnd())
+    {
+        qWarning() << "no lines";
+        return;
+    }
+
+    const QUrl url(textStream.readLine());
+    if (!url.isLocalFile())
+    {
+        qWarning() << "isnt local file";
+        return;
+    }
+
+    const QFileInfo fileInfo(url.toLocalFile());
+    if (!fileInfo.exists())
+    {
+        qWarning() << "doesnt exist";
+        return;
+    }
+
+    if (!fileInfo.isFile())
+    {
+        qWarning() << "isnt file";
+        return;
+    }
+
+    loadTrack(url.toLocalFile());
+}
+
+void TrackDeck::decodingProgress(int progress, int total)
+{
+    m_ui->progressBar->setMaximum(total);
+    m_ui->progressBar->setValue(progress);
+}
+
+void TrackDeck::decodingFinished(const QAudioBuffer &buffer)
+{
+    m_player.setBuffer(buffer);
+    m_ui->previewWidget->setBuffer(buffer);
+    m_ui->scratchWidget->setBuffer(buffer);
+    m_ui->progressBar->hide();
+}