diff --git a/mainwindow.cpp b/mainwindow.cpp
index 9393c0b..c572ac9 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -1,539 +1,540 @@
-#include "mainwindow.h"
-#include "./ui_mainwindow.h"
-
-#include "playlistmodel.h"
-#include "qt/qmediaplaylist.h"
-
-#include "ID3v2Pic.h"
-#include "FlacPic.h"
-
-// taglib
-#ifndef NO_TAGLIB
-#include <fileref.h>
-#endif // NO_TAGLIB
-
-#include <QPainter>
-#include <QMediaPlayer>
-#include <QAudioOutput>
-#include <QPropertyAnimation>
-#include <QFileDialog>
-#include <QTime>
-#include <QStyle>
-#include <QScreen>
-#include <QListView>
-#include <QCollator>
-#include <QMimeData>
-#include <QWindow>
-
-MainWindow::MainWindow(QWidget *parent)
-    : QMainWindow(parent)
-    , ui(new Ui::MainWindow)
-    , m_mediaPlayer(new QMediaPlayer(this))
-    , m_audioOutput(new QAudioOutput(this))
-    , m_playlistModel(new PlaylistModel(this))
-{
-    ui->setupUi(this);
-
-    m_mediaPlayer->setAudioOutput(m_audioOutput);
-
-    this->setWindowFlags(Qt::FramelessWindowHint | Qt::WindowSystemMenuHint | Qt::WindowMinimizeButtonHint);
-    this->setAttribute(Qt::WA_TranslucentBackground, true);
-
-    initConnections();
-    initUiAndAnimation();
-
-    centerWindow();
-}
-
-MainWindow::~MainWindow()
-{
-    delete ui;
-}
-
-void MainWindow::commandlinePlayAudioFiles(QStringList audioFiles)
-{
-    QList<QUrl> audioFileUrls = strlst2urllst(audioFiles);
-
-    if (!audioFileUrls.isEmpty()) {
-        if (audioFileUrls.count() == 1) {
-            loadPlaylistBySingleLocalFile(audioFileUrls.first().toLocalFile());
-        } else {
-            createPlaylist(audioFileUrls);
-        }
-        m_mediaPlayer->play();
-    }
-}
-
-void MainWindow::loadPlaylistBySingleLocalFile(const QString &path)
-{
-    QFileInfo info(path);
-    QDir dir(info.path());
-    QString currentFileName = info.fileName();
-    QStringList entryList = dir.entryList({"*.mp3", "*.wav", "*.aiff", "*.ape", "*.flac", "*.ogg", "*.oga", "*.mpga"},
-                                          QDir::Files | QDir::NoSymLinks, QDir::NoSort);
-
-    QCollator collator;
-    collator.setNumericMode(true);
-
-    std::sort(entryList.begin(), entryList.end(), collator);
-
-    QList<QUrl> urlList;
-    int currentFileIndex = -1;
-    for (int i = 0; i < entryList.count(); i++) {
-        const QString & oneEntry = entryList.at(i);
-        urlList.append(QUrl::fromLocalFile(dir.absoluteFilePath(oneEntry)));
-        if (oneEntry == currentFileName) {
-            currentFileIndex = i;
-        }
-    }
-
-    if (currentFileIndex == -1) {
-        // not in the list probably because of the suffix is not a common one, add it to the first one anyway.
-        urlList.prepend(QUrl::fromLocalFile(path));
-        currentFileIndex = 0;
-    }
-
-    createPlaylist(urlList);
-}
-
-void MainWindow::setAudioPropertyInfoForDisplay(int sampleRate, int bitrate, int channelCount, QString audioExt)
-{
-    QStringList uiStrs;
-    QStringList tooltipStrs;
-
-    auto channelStr = [](int channelCnt) {
-        switch (channelCnt) {
-        case 1:
-            return tr("Mono");
-        case 2:
-            return tr("Stereo");
-        default:
-            return tr("%1 Channels").arg(channelCnt);
-        }
-    };
-
-    if (sampleRate >= 0) {
-        uiStrs << QString("%1 Hz").arg(sampleRate);
-        tooltipStrs << tr("Sample Rate: %1 Hz").arg(sampleRate);
-    }
-
-    if (bitrate >= 0) {
-        uiStrs << QString("%1 Kbps").arg(bitrate);
-        tooltipStrs << tr("Bitrate: %1 Kbps").arg(bitrate);
-    }
-
-    if (channelCount >= 0) {
-        uiStrs << channelStr(channelCount);
-        tooltipStrs << tr("Channel Count: %1").arg(channelCount);
-    }
-
-    uiStrs << audioExt;
-
-    ui->propLabel->setText(uiStrs.join(" | "));
-    ui->propLabel->setToolTip(tooltipStrs.join('\n'));
-}
-
-void MainWindow::setAudioMetadataForDisplay(QString title, QString artist, QString album)
-{
-    Q_UNUSED(album);
-
-    if (!title.isEmpty()) {
-        if (!artist.isEmpty()) {
-            ui->titleLabel->setText(QString("%1 - %2").arg(artist, title));
-        } else if (!album.isEmpty()) {
-            ui->titleLabel->setText(QString("%1 - %2").arg(album, title));
-        } else {
-            ui->titleLabel->setText(QString("%1").arg(title));
-        }
-    }
-}
-
-void MainWindow::localSocketPlayAudioFiles(QVariant audioFilesVariant)
-{
-    QStringList urlStrList = audioFilesVariant.toStringList();
-    qDebug() << urlStrList << "MainWindow::localSocketPlayAudioFiles";
-    commandlinePlayAudioFiles(urlStrList);
-
-    showNormal();
-    activateWindow();
-    raise();
-}
-
-void MainWindow::closeEvent(QCloseEvent *)
-{
-    qApp->exit();
-}
-
-void MainWindow::paintEvent(QPaintEvent * e)
-{
-    QPainter painter(this);
-
-    painter.setPen(Qt::NoPen);
-
-    // Temp bg
-    painter.setBrush(QColor(20, 32, 83));
-    painter.drawRect(0, 0, width(), height());
-
-    painter.setBrush(QBrush(m_bgLinearGradient));
-    painter.drawRect(0, 0, width(), height());
-
-    return QMainWindow::paintEvent(e);
-}
-
-void MainWindow::mousePressEvent(QMouseEvent *event)
-{
-    if (event->buttons() & Qt::LeftButton && !isMaximized()) {
-        m_clickedOnWindow = true;
-        event->accept();
-    }
-
-    return QMainWindow::mousePressEvent(event);
-}
-
-void MainWindow::mouseMoveEvent(QMouseEvent *event)
-{
-    if (event->buttons() & Qt::LeftButton && m_clickedOnWindow) {
-        window()->windowHandle()->startSystemMove();
-        event->accept();
-    }
-
-    return QMainWindow::mouseMoveEvent(event);
-}
-
-void MainWindow::mouseReleaseEvent(QMouseEvent *event)
-{
-    m_clickedOnWindow = false;
-
-    return QMainWindow::mouseReleaseEvent(event);
-}
-
-void MainWindow::dragEnterEvent(QDragEnterEvent *e)
-{
-    // TODO: file/format filter?
-
-    e->acceptProposedAction();
-}
-
-void MainWindow::dropEvent(QDropEvent *e)
-{
-    QList<QUrl> urls = e->mimeData()->urls();
-    if (urls.isEmpty()) {
-        return;
-    }
-
-    QString fileName = urls.first().toLocalFile();
-    if (fileName.isEmpty()) {
-        return;
-    }
-
-    // TODO: file/format filter?
-
-    createPlaylist(urls);
-    m_mediaPlayer->play();
-}
-
-void MainWindow::loadFile()
-{
-    QStringList files = QFileDialog::getOpenFileNames(this,
-                                                      tr("Select songs to play"),
-                                                      QDir::homePath(),
-                                                      tr("Audio Files") + " (*.mp3 *.wav *.aiff *.ape *.flac *.ogg *.oga)");
-    QList<QUrl> urlList;
-    for (const QString & fileName : files) {
-        urlList.append(QUrl::fromLocalFile(fileName));
-    }
-
-    createPlaylist(urlList);
-}
-
-/*
- * The returned QMediaPlaylist* ownership belongs to the internal QMediaPlayer instance.
- */
-void MainWindow::createPlaylist(QList<QUrl> urlList)
-{
-    QMediaPlaylist* playlist = m_playlistModel->playlist();
-    playlist->clear();
-    playlist->addMedia(urlList);
-
-    connect(playlist, &QMediaPlaylist::playbackModeChanged, this, [=](QMediaPlaylist::PlaybackMode mode) {
-        switch (mode) {
-        case QMediaPlaylist::CurrentItemInLoop:
-            ui->playbackModeBtn->setIcon(QIcon(":/icons/icons/media-playlist-repeat-song.png"));
-            break;
-        case QMediaPlaylist::Loop:
-            ui->playbackModeBtn->setIcon(QIcon(":/icons/icons/media-playlist-repeat.png"));
-            break;
-        case QMediaPlaylist::Sequential:
-            ui->playbackModeBtn->setIcon(QIcon(":/icons/icons/media-playlist-normal.png"));
-            break;
-//        case QMediaPlaylist::Random:
-//            ui->playbackModeBtn->setIcon(QIcon(":/icons/icons/media-playlist-shuffle.png"));
-//            break;
-        default:
-            break;
-        }
-    });
-
-    playlist->setPlaybackMode(QMediaPlaylist::CurrentItemInLoop);
-    playlist->setCurrentIndex(0);
-}
-
-void MainWindow::centerWindow()
-{
-    this->setGeometry(
-        QStyle::alignedRect(
-            Qt::LeftToRight,
-            Qt::AlignCenter,
-            this->size(),
-            qApp->screenAt(QCursor::pos())->geometry()
-        )
-    );
-}
-
-void MainWindow::on_closeWindowBtn_clicked()
-{
-    m_fadeOutAnimation->start();
-}
-
-void MainWindow::on_playBtn_clicked()
-{
-    if (m_mediaPlayer->mediaStatus() == QMediaPlayer::NoMedia) {
-        loadFile();
-        m_mediaPlayer->play();
-    } else if (m_mediaPlayer->mediaStatus() == QMediaPlayer::InvalidMedia) {
-        ui->propLabel->setText("Error: InvalidMedia" + m_mediaPlayer->errorString());
-    } else {
-        if (QList<QMediaPlayer::PlaybackState> {QMediaPlayer::PausedState, QMediaPlayer::StoppedState}
-                .contains(m_mediaPlayer->playbackState())) {
-            m_mediaPlayer->play();
-        } else {
-            m_mediaPlayer->pause();
-        }
-    }
-}
-
-QString MainWindow::ms2str(qint64 ms)
-{
-    QTime duaTime(QTime::fromMSecsSinceStartOfDay(ms));
-    if (duaTime.hour() > 0) {
-        return duaTime.toString("h:mm:ss");
-    } else {
-        return duaTime.toString("m:ss");
-    }
-}
-
-QList<QUrl> MainWindow::strlst2urllst(QStringList strlst)
-{
-    QList<QUrl> urlList;
-    for (const QString & str : strlst) {
-        QUrl url = QUrl::fromLocalFile(str);
-        if (url.isValid()) {
-            urlList.append(url);
-        }
-    }
-
-    return urlList;
-}
-
-void MainWindow::on_volumeSlider_valueChanged(int value)
-{
-    if (m_audioOutput->isMuted()) {
-        m_audioOutput->setMuted(false);
-    }
-    m_audioOutput->setVolume(value / 100.0);
-}
-
-void MainWindow::on_stopBtn_clicked()
-{
-    m_mediaPlayer->stop();
-}
-
-void MainWindow::on_playbackSlider_valueChanged(int value)
-{
-    qint64 currPos = m_mediaPlayer->duration() == 0 ? value : m_mediaPlayer->position() * ui->playbackSlider->maximum() / m_mediaPlayer->duration();
-    if (qAbs(currPos - value) > 2) {
-        m_mediaPlayer->setPosition(ui->playbackSlider->value() * 1.0 / ui->playbackSlider->maximum() * m_mediaPlayer->duration());
-    }
-}
-
-void MainWindow::on_prevBtn_clicked()
-{
-    // QMediaPlaylist::previous() won't work when in CurrentItemInLoop playmode,
-    // and also works not as intended when in other playmode, so do it manually...
-    QMediaPlaylist * playlist = m_playlistModel->playlist();
-    if (playlist) {
-        int index = playlist->currentIndex();
-        int count = playlist->mediaCount();
-
-        playlist->setCurrentIndex(index == 0 ? count - 1 : index - 1);
-    }
-}
-
-void MainWindow::on_nextBtn_clicked()
-{
-    // see also: MainWindow::on_prevBtn_clicked()
-    QMediaPlaylist * playlist = m_playlistModel->playlist();
-    if (playlist) {
-        int index = playlist->currentIndex();
-        int count = playlist->mediaCount();
-
-        playlist->setCurrentIndex(index == (count - 1) ? 0 : index + 1);
-    }
-}
-
-void MainWindow::on_volumeBtn_clicked()
-{
-    m_audioOutput->setMuted(!m_audioOutput->isMuted());
-}
-
-void MainWindow::on_minimumWindowBtn_clicked()
-{
-    this->showMinimized();
-}
-
-void MainWindow::initUiAndAnimation()
-{
-    m_bgLinearGradient.setColorAt(0, QColor(255, 255, 255, 25)); // a:0
-    m_bgLinearGradient.setColorAt(1, QColor(255, 255, 255, 75)); // a:200
-    m_bgLinearGradient.setStart(0, 0);
-    m_bgLinearGradient.setFinalStop(0, height());
-
-    m_fadeOutAnimation = new QPropertyAnimation(this, "windowOpacity", this);
-    m_fadeOutAnimation->setDuration(400);
-    m_fadeOutAnimation->setStartValue(1);
-    m_fadeOutAnimation->setEndValue(0);
-    connect(m_fadeOutAnimation, &QPropertyAnimation::finished, this, &QMainWindow::close);
-
-    // temp: a playlist for debug...
-    QListView * tmp_listview = new QListView(ui->pluginWidget);
-    tmp_listview->setModel(m_playlistModel);
-    tmp_listview->setGeometry({0,0,490,250});
-    this->setGeometry({0,0,490,160}); // temp size, hide the playlist thing.
-}
-
-void MainWindow::initConnections()
-{
-    connect(m_playlistModel->playlist(), &QMediaPlaylist::currentIndexChanged, this, [=](int currentItem) {
-        bool isPlaying = m_mediaPlayer->playbackState() == QMediaPlayer::PlayingState;
-        m_mediaPlayer->setSource(m_playlistModel->playlist()->currentMedia());
-        if (isPlaying) m_mediaPlayer->play();
-    });
-    connect(m_playlistModel->playlist(), &QMediaPlaylist::currentMediaChanged, this, [=](const QUrl &fileUrl) {
-        ui->titleLabel->setText(fileUrl.fileName());
-        ui->titleLabel->setToolTip(fileUrl.fileName());
-
-        if (fileUrl.isLocalFile()) {
-            QString filePath(fileUrl.toLocalFile());
-            QString suffix(filePath.mid(filePath.lastIndexOf('.') + 1));
-            suffix = suffix.toUpper();
-
-#ifndef NO_TAGLIB
-            TagLib::FileRef fileRef(filePath.toLocal8Bit().data());
-
-            if (!fileRef.isNull() && fileRef.audioProperties()) {
-                TagLib::AudioProperties *prop = fileRef.audioProperties();
-                setAudioPropertyInfoForDisplay(prop->sampleRate(), prop->bitrate(), prop->channels(), suffix);
-            }
-
-            if (!fileRef.isNull() && fileRef.tag()) {
-                TagLib::Tag * tag = fileRef.tag();
-                setAudioMetadataForDisplay(QString::fromStdString(tag->title().to8Bit(true)),
-                                           QString::fromStdString(tag->artist().to8Bit(true)),
-                                           QString::fromStdString(tag->album().to8Bit(true)));
-            }
-#endif // NO_TAGLIB
-
-            using namespace spID3;
-            using namespace spFLAC;
-
-            bool coverLoaded = false;
-
-            if (suffix == "MP3") {
-                if (spID3::loadPictureData(filePath.toLocal8Bit().data())) {
-                    coverLoaded = true;
-                    QByteArray picData((const char*)spID3::getPictureDataPtr(), spID3::getPictureLength());
-                    ui->coverLabel->setPixmap(QPixmap::fromImage(QImage::fromData(picData)));
-                    spID3::freePictureData();
-                }
-            } else if (suffix == "FLAC") {
-                if (spFLAC::loadPictureData(filePath.toLocal8Bit().data())) {
-                    coverLoaded = true;
-                    QByteArray picData((const char*)spFLAC::getPictureDataPtr(), spFLAC::getPictureLength());
-                    ui->coverLabel->setPixmap(QPixmap::fromImage(QImage::fromData(picData)));
-                    spFLAC::freePictureData();
-                }
-            }
-
-            if (!coverLoaded) {
-                ui->coverLabel->setPixmap(QPixmap(":/icons/icons/media-album-cover.svg"));
-            }
-        }
-    });
-
-    connect(m_mediaPlayer, &QMediaPlayer::positionChanged, this, [=](qint64 pos) {
-        ui->nowTimeLabel->setText(ms2str(pos));
-        if (m_mediaPlayer->duration() != 0) {
-            ui->playbackSlider->setSliderPosition(ui->playbackSlider->maximum() * pos / m_mediaPlayer->duration());
-        }
-    });
-
-    connect(m_audioOutput, &QAudioOutput::mutedChanged, this, [=](bool muted) {
-        if (muted) {
-            ui->volumeBtn->setIcon(QIcon(":/icons/icons/audio-volume-muted.png"));
-        } else {
-            ui->volumeBtn->setIcon(QIcon(":/icons/icons/audio-volume-high.png"));
-        }
-    });
-
-    connect(m_mediaPlayer, &QMediaPlayer::durationChanged, this, [=](qint64 dua) {
-        ui->totalTimeLabel->setText(ms2str(dua));
-    });
-
-    connect(m_mediaPlayer, &QMediaPlayer::playbackStateChanged, this, [=](QMediaPlayer::PlaybackState newState) {
-        switch (newState) {
-        case QMediaPlayer::PlayingState:
-            ui->playBtn->setIcon(QIcon(":/icons/icons/media-playback-pause.png"));
-            break;
-        case QMediaPlayer::StoppedState:
-        case QMediaPlayer::PausedState:
-            ui->playBtn->setIcon(QIcon(":/icons/icons/media-playback-start.png"));
-            break;
-        }
-    });
-
-    connect(m_audioOutput, &QAudioOutput::volumeChanged, this, [=](float vol) {
-        ui->volumeSlider->setValue(vol * 100);
-    });
-
-//    connect(m_mediaPlayer, static_cast<void(QMediaPlayer::*)(QMediaPlayer::Error)>(&QMediaPlayer::error),
-//            this, [=](QMediaPlayer::Error error) {
-//        switch (error) {
-//        default:
-//            break;
-//        }
-//        qDebug("%s aaaaaaaaaaaaa", m_mediaPlayer->errorString().toUtf8().data());
-//    });
-}
-
-void MainWindow::on_playbackModeBtn_clicked()
-{
-    QMediaPlaylist * playlist = m_playlistModel->playlist();
-    if (!playlist) return;
-
-    switch (playlist->playbackMode()) {
-    case QMediaPlaylist::CurrentItemInLoop:
-        playlist->setPlaybackMode(QMediaPlaylist::Loop);
-        break;
-    case QMediaPlaylist::Loop:
-        playlist->setPlaybackMode(QMediaPlaylist::Sequential);
-        break;
-    case QMediaPlaylist::Sequential:
-        playlist->setPlaybackMode(QMediaPlaylist::CurrentItemInLoop);
-        break;
-//    case QMediaPlaylist::Random:
-//        playlist->setPlaybackMode(QMediaPlaylist::CurrentItemInLoop);
-//        break;
-    default:
-        break;
-    }
-}
+#include "mainwindow.h"
+#include "./ui_mainwindow.h"
+
+#include "playlistmodel.h"
+#include "qt/qmediaplaylist.h"
+
+#include "ID3v2Pic.h"
+#include "FlacPic.h"
+
+// taglib
+#ifndef NO_TAGLIB
+#include <fileref.h>
+#endif // NO_TAGLIB
+
+#include <QPainter>
+#include <QMediaPlayer>
+#include <QAudioOutput>
+#include <QPropertyAnimation>
+#include <QFileDialog>
+#include <QTime>
+#include <QStyle>
+#include <QScreen>
+#include <QListView>
+#include <QCollator>
+#include <QMimeData>
+#include <QWindow>
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent)
+    , ui(new Ui::MainWindow)
+    , m_mediaPlayer(new QMediaPlayer(this))
+    , m_audioOutput(new QAudioOutput(this))
+    , m_playlistModel(new PlaylistModel(this))
+{
+    ui->setupUi(this);
+
+    m_mediaPlayer->setAudioOutput(m_audioOutput);
+
+    this->setWindowFlags(Qt::FramelessWindowHint | Qt::WindowSystemMenuHint | Qt::WindowMinimizeButtonHint);
+    this->setAttribute(Qt::WA_TranslucentBackground, true);
+
+    initConnections();
+    initUiAndAnimation();
+
+    centerWindow();
+}
+
+MainWindow::~MainWindow()
+{
+    delete ui;
+}
+
+void MainWindow::commandlinePlayAudioFiles(QStringList audioFiles)
+{
+    QList<QUrl> audioFileUrls = strlst2urllst(audioFiles);
+
+    if (!audioFileUrls.isEmpty()) {
+        if (audioFileUrls.count() == 1) {
+            loadPlaylistBySingleLocalFile(audioFileUrls.first().toLocalFile());
+        } else {
+            createPlaylist(audioFileUrls);
+        }
+        m_mediaPlayer->play();
+    }
+}
+
+void MainWindow::loadPlaylistBySingleLocalFile(const QString &path)
+{
+    QFileInfo info(path);
+    QDir dir(info.path());
+    QString currentFileName = info.fileName();
+    QStringList entryList = dir.entryList({"*.mp3", "*.wav", "*.aiff", "*.ape", "*.flac", "*.ogg", "*.oga", "*.mpga"},
+                                          QDir::Files | QDir::NoSymLinks, QDir::NoSort);
+
+    QCollator collator;
+    collator.setNumericMode(true);
+
+    std::sort(entryList.begin(), entryList.end(), collator);
+
+    QList<QUrl> urlList;
+    int currentFileIndex = -1;
+    for (int i = 0; i < entryList.count(); i++) {
+        const QString & oneEntry = entryList.at(i);
+        urlList.append(QUrl::fromLocalFile(dir.absoluteFilePath(oneEntry)));
+        if (oneEntry == currentFileName) {
+            currentFileIndex = i;
+        }
+    }
+
+    if (currentFileIndex == -1) {
+        // not in the list probably because of the suffix is not a common one, add it to the first one anyway.
+        urlList.prepend(QUrl::fromLocalFile(path));
+        currentFileIndex = 0;
+    }
+
+    createPlaylist(urlList, currentFileIndex);
+}
+
+void MainWindow::setAudioPropertyInfoForDisplay(int sampleRate, int bitrate, int channelCount, QString audioExt)
+{
+    QStringList uiStrs;
+    QStringList tooltipStrs;
+
+    auto channelStr = [](int channelCnt) {
+        switch (channelCnt) {
+        case 1:
+            return tr("Mono");
+        case 2:
+            return tr("Stereo");
+        default:
+            return tr("%1 Channels").arg(channelCnt);
+        }
+    };
+
+    if (sampleRate >= 0) {
+        uiStrs << QString("%1 Hz").arg(sampleRate);
+        tooltipStrs << tr("Sample Rate: %1 Hz").arg(sampleRate);
+    }
+
+    if (bitrate >= 0) {
+        uiStrs << QString("%1 Kbps").arg(bitrate);
+        tooltipStrs << tr("Bitrate: %1 Kbps").arg(bitrate);
+    }
+
+    if (channelCount >= 0) {
+        uiStrs << channelStr(channelCount);
+        tooltipStrs << tr("Channel Count: %1").arg(channelCount);
+    }
+
+    uiStrs << audioExt;
+
+    ui->propLabel->setText(uiStrs.join(" | "));
+    ui->propLabel->setToolTip(tooltipStrs.join('\n'));
+}
+
+void MainWindow::setAudioMetadataForDisplay(QString title, QString artist, QString album)
+{
+    Q_UNUSED(album);
+
+    if (!title.isEmpty()) {
+        if (!artist.isEmpty()) {
+            ui->titleLabel->setText(QString("%1 - %2").arg(artist, title));
+        } else if (!album.isEmpty()) {
+            ui->titleLabel->setText(QString("%1 - %2").arg(album, title));
+        } else {
+            ui->titleLabel->setText(QString("%1").arg(title));
+        }
+    }
+}
+
+void MainWindow::localSocketPlayAudioFiles(QVariant audioFilesVariant)
+{
+    QStringList urlStrList = audioFilesVariant.toStringList();
+    qDebug() << urlStrList << "MainWindow::localSocketPlayAudioFiles";
+    commandlinePlayAudioFiles(urlStrList);
+
+    showNormal();
+    activateWindow();
+    raise();
+}
+
+void MainWindow::closeEvent(QCloseEvent *)
+{
+    qApp->exit();
+}
+
+void MainWindow::paintEvent(QPaintEvent * e)
+{
+    QPainter painter(this);
+
+    painter.setPen(Qt::NoPen);
+
+    // Temp bg
+    painter.setBrush(QColor(20, 32, 83));
+    painter.drawRect(0, 0, width(), height());
+
+    painter.setBrush(QBrush(m_bgLinearGradient));
+    painter.drawRect(0, 0, width(), height());
+
+    return QMainWindow::paintEvent(e);
+}
+
+void MainWindow::mousePressEvent(QMouseEvent *event)
+{
+    if (event->buttons() & Qt::LeftButton && !isMaximized()) {
+        m_clickedOnWindow = true;
+        event->accept();
+    }
+
+    return QMainWindow::mousePressEvent(event);
+}
+
+void MainWindow::mouseMoveEvent(QMouseEvent *event)
+{
+    if (event->buttons() & Qt::LeftButton && m_clickedOnWindow) {
+        qDebug() << "??" << event << event->flags() << event->isBeginEvent() << event->isEndEvent();
+        window()->windowHandle()->startSystemMove();
+        event->accept();
+    }
+
+    return QMainWindow::mouseMoveEvent(event);
+}
+
+void MainWindow::mouseReleaseEvent(QMouseEvent *event)
+{
+    m_clickedOnWindow = false;
+    qDebug() << "?";
+    return QMainWindow::mouseReleaseEvent(event);
+}
+
+void MainWindow::dragEnterEvent(QDragEnterEvent *e)
+{
+    // TODO: file/format filter?
+
+    e->acceptProposedAction();
+}
+
+void MainWindow::dropEvent(QDropEvent *e)
+{
+    QList<QUrl> urls = e->mimeData()->urls();
+    if (urls.isEmpty()) {
+        return;
+    }
+
+    QString fileName = urls.first().toLocalFile();
+    if (fileName.isEmpty()) {
+        return;
+    }
+
+    // TODO: file/format filter?
+
+    createPlaylist(urls);
+    m_mediaPlayer->play();
+}
+
+void MainWindow::loadFile()
+{
+    QStringList files = QFileDialog::getOpenFileNames(this,
+                                                      tr("Select songs to play"),
+                                                      QDir::homePath(),
+                                                      tr("Audio Files") + " (*.mp3 *.wav *.aiff *.ape *.flac *.ogg *.oga)");
+    QList<QUrl> urlList;
+    for (const QString & fileName : files) {
+        urlList.append(QUrl::fromLocalFile(fileName));
+    }
+
+    createPlaylist(urlList);
+}
+
+/*
+ * The returned QMediaPlaylist* ownership belongs to the internal QMediaPlayer instance.
+ */
+void MainWindow::createPlaylist(QList<QUrl> urlList, int index)
+{
+    QMediaPlaylist* playlist = m_playlistModel->playlist();
+    playlist->clear();
+    playlist->addMedia(urlList);
+
+    connect(playlist, &QMediaPlaylist::playbackModeChanged, this, [=](QMediaPlaylist::PlaybackMode mode) {
+        switch (mode) {
+        case QMediaPlaylist::CurrentItemInLoop:
+            ui->playbackModeBtn->setIcon(QIcon(":/icons/icons/media-playlist-repeat-song.png"));
+            break;
+        case QMediaPlaylist::Loop:
+            ui->playbackModeBtn->setIcon(QIcon(":/icons/icons/media-playlist-repeat.png"));
+            break;
+        case QMediaPlaylist::Sequential:
+            ui->playbackModeBtn->setIcon(QIcon(":/icons/icons/media-playlist-normal.png"));
+            break;
+//        case QMediaPlaylist::Random:
+//            ui->playbackModeBtn->setIcon(QIcon(":/icons/icons/media-playlist-shuffle.png"));
+//            break;
+        default:
+            break;
+        }
+    });
+
+    playlist->setPlaybackMode(QMediaPlaylist::CurrentItemInLoop);
+    playlist->setCurrentIndex(index < 0 ? 0 : index);
+}
+
+void MainWindow::centerWindow()
+{
+    this->setGeometry(
+        QStyle::alignedRect(
+            Qt::LeftToRight,
+            Qt::AlignCenter,
+            this->size(),
+            qApp->screenAt(QCursor::pos())->geometry()
+        )
+    );
+}
+
+void MainWindow::on_closeWindowBtn_clicked()
+{
+    m_fadeOutAnimation->start();
+}
+
+void MainWindow::on_playBtn_clicked()
+{
+    if (m_mediaPlayer->mediaStatus() == QMediaPlayer::NoMedia) {
+        loadFile();
+        m_mediaPlayer->play();
+    } else if (m_mediaPlayer->mediaStatus() == QMediaPlayer::InvalidMedia) {
+        ui->propLabel->setText("Error: InvalidMedia" + m_mediaPlayer->errorString());
+    } else {
+        if (QList<QMediaPlayer::PlaybackState> {QMediaPlayer::PausedState, QMediaPlayer::StoppedState}
+                .contains(m_mediaPlayer->playbackState())) {
+            m_mediaPlayer->play();
+        } else {
+            m_mediaPlayer->pause();
+        }
+    }
+}
+
+QString MainWindow::ms2str(qint64 ms)
+{
+    QTime duaTime(QTime::fromMSecsSinceStartOfDay(ms));
+    if (duaTime.hour() > 0) {
+        return duaTime.toString("h:mm:ss");
+    } else {
+        return duaTime.toString("m:ss");
+    }
+}
+
+QList<QUrl> MainWindow::strlst2urllst(QStringList strlst)
+{
+    QList<QUrl> urlList;
+    for (const QString & str : strlst) {
+        QUrl url = QUrl::fromLocalFile(str);
+        if (url.isValid()) {
+            urlList.append(url);
+        }
+    }
+
+    return urlList;
+}
+
+void MainWindow::on_volumeSlider_valueChanged(int value)
+{
+    if (m_audioOutput->isMuted()) {
+        m_audioOutput->setMuted(false);
+    }
+    m_audioOutput->setVolume(value / 100.0);
+}
+
+void MainWindow::on_stopBtn_clicked()
+{
+    m_mediaPlayer->stop();
+}
+
+void MainWindow::on_playbackSlider_valueChanged(int value)
+{
+    qint64 currPos = m_mediaPlayer->duration() == 0 ? value : m_mediaPlayer->position() * ui->playbackSlider->maximum() / m_mediaPlayer->duration();
+    if (qAbs(currPos - value) > 2) {
+        m_mediaPlayer->setPosition(ui->playbackSlider->value() * 1.0 / ui->playbackSlider->maximum() * m_mediaPlayer->duration());
+    }
+}
+
+void MainWindow::on_prevBtn_clicked()
+{
+    // QMediaPlaylist::previous() won't work when in CurrentItemInLoop playmode,
+    // and also works not as intended when in other playmode, so do it manually...
+    QMediaPlaylist * playlist = m_playlistModel->playlist();
+    if (playlist) {
+        int index = playlist->currentIndex();
+        int count = playlist->mediaCount();
+
+        playlist->setCurrentIndex(index == 0 ? count - 1 : index - 1);
+    }
+}
+
+void MainWindow::on_nextBtn_clicked()
+{
+    // see also: MainWindow::on_prevBtn_clicked()
+    QMediaPlaylist * playlist = m_playlistModel->playlist();
+    if (playlist) {
+        int index = playlist->currentIndex();
+        int count = playlist->mediaCount();
+
+        playlist->setCurrentIndex(index == (count - 1) ? 0 : index + 1);
+    }
+}
+
+void MainWindow::on_volumeBtn_clicked()
+{
+    m_audioOutput->setMuted(!m_audioOutput->isMuted());
+}
+
+void MainWindow::on_minimumWindowBtn_clicked()
+{
+    this->showMinimized();
+}
+
+void MainWindow::initUiAndAnimation()
+{
+    m_bgLinearGradient.setColorAt(0, QColor(255, 255, 255, 25)); // a:0
+    m_bgLinearGradient.setColorAt(1, QColor(255, 255, 255, 75)); // a:200
+    m_bgLinearGradient.setStart(0, 0);
+    m_bgLinearGradient.setFinalStop(0, height());
+
+    m_fadeOutAnimation = new QPropertyAnimation(this, "windowOpacity", this);
+    m_fadeOutAnimation->setDuration(400);
+    m_fadeOutAnimation->setStartValue(1);
+    m_fadeOutAnimation->setEndValue(0);
+    connect(m_fadeOutAnimation, &QPropertyAnimation::finished, this, &QMainWindow::close);
+
+    // temp: a playlist for debug...
+    QListView * tmp_listview = new QListView(ui->pluginWidget);
+    tmp_listview->setModel(m_playlistModel);
+    tmp_listview->setGeometry({0,0,490,250});
+    this->setGeometry({0,0,490,160}); // temp size, hide the playlist thing.
+}
+
+void MainWindow::initConnections()
+{
+    connect(m_playlistModel->playlist(), &QMediaPlaylist::currentIndexChanged, this, [=](int currentItem) {
+        bool isPlaying = m_mediaPlayer->playbackState() == QMediaPlayer::PlayingState;
+        m_mediaPlayer->setSource(m_playlistModel->playlist()->currentMedia());
+        if (isPlaying) m_mediaPlayer->play();
+    });
+    connect(m_playlistModel->playlist(), &QMediaPlaylist::currentMediaChanged, this, [=](const QUrl &fileUrl) {
+        ui->titleLabel->setText(fileUrl.fileName());
+        ui->titleLabel->setToolTip(fileUrl.fileName());
+
+        if (fileUrl.isLocalFile()) {
+            QString filePath(fileUrl.toLocalFile());
+            QString suffix(filePath.mid(filePath.lastIndexOf('.') + 1));
+            suffix = suffix.toUpper();
+
+#ifndef NO_TAGLIB
+            TagLib::FileRef fileRef(filePath.toLocal8Bit().data());
+
+            if (!fileRef.isNull() && fileRef.audioProperties()) {
+                TagLib::AudioProperties *prop = fileRef.audioProperties();
+                setAudioPropertyInfoForDisplay(prop->sampleRate(), prop->bitrate(), prop->channels(), suffix);
+            }
+
+            if (!fileRef.isNull() && fileRef.tag()) {
+                TagLib::Tag * tag = fileRef.tag();
+                setAudioMetadataForDisplay(QString::fromStdString(tag->title().to8Bit(true)),
+                                           QString::fromStdString(tag->artist().to8Bit(true)),
+                                           QString::fromStdString(tag->album().to8Bit(true)));
+            }
+#endif // NO_TAGLIB
+
+            using namespace spID3;
+            using namespace spFLAC;
+
+            bool coverLoaded = false;
+
+            if (suffix == "MP3") {
+                if (spID3::loadPictureData(filePath.toLocal8Bit().data())) {
+                    coverLoaded = true;
+                    QByteArray picData((const char*)spID3::getPictureDataPtr(), spID3::getPictureLength());
+                    ui->coverLabel->setPixmap(QPixmap::fromImage(QImage::fromData(picData)));
+                    spID3::freePictureData();
+                }
+            } else if (suffix == "FLAC") {
+                if (spFLAC::loadPictureData(filePath.toLocal8Bit().data())) {
+                    coverLoaded = true;
+                    QByteArray picData((const char*)spFLAC::getPictureDataPtr(), spFLAC::getPictureLength());
+                    ui->coverLabel->setPixmap(QPixmap::fromImage(QImage::fromData(picData)));
+                    spFLAC::freePictureData();
+                }
+            }
+
+            if (!coverLoaded) {
+                ui->coverLabel->setPixmap(QPixmap(":/icons/icons/media-album-cover.svg"));
+            }
+        }
+    });
+
+    connect(m_mediaPlayer, &QMediaPlayer::positionChanged, this, [=](qint64 pos) {
+        ui->nowTimeLabel->setText(ms2str(pos));
+        if (m_mediaPlayer->duration() != 0) {
+            ui->playbackSlider->setSliderPosition(ui->playbackSlider->maximum() * pos / m_mediaPlayer->duration());
+        }
+    });
+
+    connect(m_audioOutput, &QAudioOutput::mutedChanged, this, [=](bool muted) {
+        if (muted) {
+            ui->volumeBtn->setIcon(QIcon(":/icons/icons/audio-volume-muted.png"));
+        } else {
+            ui->volumeBtn->setIcon(QIcon(":/icons/icons/audio-volume-high.png"));
+        }
+    });
+
+    connect(m_mediaPlayer, &QMediaPlayer::durationChanged, this, [=](qint64 dua) {
+        ui->totalTimeLabel->setText(ms2str(dua));
+    });
+
+    connect(m_mediaPlayer, &QMediaPlayer::playbackStateChanged, this, [=](QMediaPlayer::PlaybackState newState) {
+        switch (newState) {
+        case QMediaPlayer::PlayingState:
+            ui->playBtn->setIcon(QIcon(":/icons/icons/media-playback-pause.png"));
+            break;
+        case QMediaPlayer::StoppedState:
+        case QMediaPlayer::PausedState:
+            ui->playBtn->setIcon(QIcon(":/icons/icons/media-playback-start.png"));
+            break;
+        }
+    });
+
+    connect(m_audioOutput, &QAudioOutput::volumeChanged, this, [=](float vol) {
+        ui->volumeSlider->setValue(vol * 100);
+    });
+
+//    connect(m_mediaPlayer, static_cast<void(QMediaPlayer::*)(QMediaPlayer::Error)>(&QMediaPlayer::error),
+//            this, [=](QMediaPlayer::Error error) {
+//        switch (error) {
+//        default:
+//            break;
+//        }
+//        qDebug("%s aaaaaaaaaaaaa", m_mediaPlayer->errorString().toUtf8().data());
+//    });
+}
+
+void MainWindow::on_playbackModeBtn_clicked()
+{
+    QMediaPlaylist * playlist = m_playlistModel->playlist();
+    if (!playlist) return;
+
+    switch (playlist->playbackMode()) {
+    case QMediaPlaylist::CurrentItemInLoop:
+        playlist->setPlaybackMode(QMediaPlaylist::Loop);
+        break;
+    case QMediaPlaylist::Loop:
+        playlist->setPlaybackMode(QMediaPlaylist::Sequential);
+        break;
+    case QMediaPlaylist::Sequential:
+        playlist->setPlaybackMode(QMediaPlaylist::CurrentItemInLoop);
+        break;
+//    case QMediaPlaylist::Random:
+//        playlist->setPlaybackMode(QMediaPlaylist::CurrentItemInLoop);
+//        break;
+    default:
+        break;
+    }
+}
diff --git a/mainwindow.h b/mainwindow.h
index 04e9d97..ce83ad6 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -1,75 +1,75 @@
-#ifndef MAINWINDOW_H
-#define MAINWINDOW_H
-
-#include <QMainWindow>
-#include <QVariant>
-
-QT_BEGIN_NAMESPACE
-namespace Ui { class MainWindow; }
-
-class QMediaPlayer;
-class QAudioOutput;
-class QPropertyAnimation;
-QT_END_NAMESPACE
-
-class PlaylistModel;
-class MainWindow : public QMainWindow
-{
-    Q_OBJECT
-
-public:
-    MainWindow(QWidget *parent = nullptr);
-    ~MainWindow() override;
-
-    void commandlinePlayAudioFiles(QStringList audioFiles);
-    void loadPlaylistBySingleLocalFile(const QString &path);
-    void setAudioPropertyInfoForDisplay(int sampleRate, int bitrate, int channelCount, QString audioExt);
-    void setAudioMetadataForDisplay(QString title, QString artist, QString album);
-
-public slots:
-    void localSocketPlayAudioFiles(QVariant audioFilesVariant);
-
-protected:
-    void closeEvent(QCloseEvent *) override;
-    void paintEvent(QPaintEvent *e) override;
-    void mousePressEvent(QMouseEvent *event) override;
-    void mouseMoveEvent(QMouseEvent *event) override;
-    void mouseReleaseEvent(QMouseEvent *event) override;
-    void dragEnterEvent(QDragEnterEvent *e) override;
-    void dropEvent(QDropEvent *e) override;
-
-    void loadFile();
-    void centerWindow();
-    void createPlaylist(QList<QUrl> urlList);
-
-private slots:
-    void on_playbackModeBtn_clicked();
-    void on_closeWindowBtn_clicked();
-    void on_playBtn_clicked();
-    void on_volumeSlider_valueChanged(int value);
-    void on_stopBtn_clicked();
-    void on_playbackSlider_valueChanged(int value);
-    void on_prevBtn_clicked();
-    void on_nextBtn_clicked();
-    void on_volumeBtn_clicked();
-    void on_minimumWindowBtn_clicked();
-
-private:
-    bool m_clickedOnWindow = false;
-    bool m_playbackSliderPressed = false;
-    QLinearGradient m_bgLinearGradient;
-
-    Ui::MainWindow *ui;
-
-    QMediaPlayer *m_mediaPlayer;
-    QAudioOutput *m_audioOutput;
-    QPropertyAnimation *m_fadeOutAnimation;
-    PlaylistModel *m_playlistModel = nullptr; // TODO: move playback logic to player.cpp
-
-    void initUiAndAnimation();
-    void initConnections();
-
-    static QString ms2str(qint64 ms);
-    static QList<QUrl> strlst2urllst(QStringList strlst);
-};
-#endif // MAINWINDOW_H
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+#include <QVariant>
+
+QT_BEGIN_NAMESPACE
+namespace Ui { class MainWindow; }
+
+class QMediaPlayer;
+class QAudioOutput;
+class QPropertyAnimation;
+QT_END_NAMESPACE
+
+class PlaylistModel;
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow(QWidget *parent = nullptr);
+    ~MainWindow() override;
+
+    void commandlinePlayAudioFiles(QStringList audioFiles);
+    void loadPlaylistBySingleLocalFile(const QString &path);
+    void setAudioPropertyInfoForDisplay(int sampleRate, int bitrate, int channelCount, QString audioExt);
+    void setAudioMetadataForDisplay(QString title, QString artist, QString album);
+
+public slots:
+    void localSocketPlayAudioFiles(QVariant audioFilesVariant);
+
+protected:
+    void closeEvent(QCloseEvent *) override;
+    void paintEvent(QPaintEvent *e) override;
+    void mousePressEvent(QMouseEvent *event) override;
+    void mouseMoveEvent(QMouseEvent *event) override;
+    void mouseReleaseEvent(QMouseEvent *event) override;
+    void dragEnterEvent(QDragEnterEvent *e) override;
+    void dropEvent(QDropEvent *e) override;
+
+    void loadFile();
+    void centerWindow();
+    void createPlaylist(QList<QUrl> urlList, int index = -1);
+
+private slots:
+    void on_playbackModeBtn_clicked();
+    void on_closeWindowBtn_clicked();
+    void on_playBtn_clicked();
+    void on_volumeSlider_valueChanged(int value);
+    void on_stopBtn_clicked();
+    void on_playbackSlider_valueChanged(int value);
+    void on_prevBtn_clicked();
+    void on_nextBtn_clicked();
+    void on_volumeBtn_clicked();
+    void on_minimumWindowBtn_clicked();
+
+private:
+    bool m_clickedOnWindow = false;
+    bool m_playbackSliderPressed = false;
+    QLinearGradient m_bgLinearGradient;
+
+    Ui::MainWindow *ui;
+
+    QMediaPlayer *m_mediaPlayer;
+    QAudioOutput *m_audioOutput;
+    QPropertyAnimation *m_fadeOutAnimation;
+    PlaylistModel *m_playlistModel = nullptr; // TODO: move playback logic to player.cpp
+
+    void initUiAndAnimation();
+    void initConnections();
+
+    static QString ms2str(qint64 ms);
+    static QList<QUrl> strlst2urllst(QStringList strlst);
+};
+#endif // MAINWINDOW_H