Polish the player example.

- Port it to use URLs and mime types.
- Introduce QCommandLineParser.
- Resize according to screen size.
- Add some bells and whistles, set window file paths,
  always display duration and file name, handle drop.

Change-Id: I75aa101d32cfde0c0c75a0686a50c2d7d5dce827
Reviewed-by: Topi Reiniö <topi.reinio@theqtcompany.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

5 files changed, 158 insertions, 73 deletions

diff --git a/examples/winextras/musicplayer/main.cpp b/examples/winextras/musicplayer/main.cpp
index 5cace0d..0502015 100644
--- a/examples/winextras/musicplayer/main.cpp
+++ b/examples/winextras/musicplayer/main.cpp
@@ -41,50 +41,79 @@
 #include "musicplayer.h"
 
 #include <QApplication>
+#include <QCommandLineParser>
+#include <QCommandLineOption>
+#include <QDesktopWidget>
 #include <QFileInfo>
+#include <QMimeDatabase>
 #include <QSettings>
 #include <QIcon>
 #include <QDir>
+#include <QUrl>
 
 //! [0]
-static void associateFileTypes(const QStringList &fileTypes)
+static bool associateFileTypes()
 {
     QString displayName = QGuiApplication::applicationDisplayName();
     QString filePath = QCoreApplication::applicationFilePath();
     QString fileName = QFileInfo(filePath).fileName();
 
-    QSettings settings("HKEY_CURRENT_USER\\Software\\Classes\\Applications\\" + fileName, QSettings::NativeFormat);
-    settings.setValue("FriendlyAppName", displayName);
+    const QString key = QStringLiteral("HKEY_CURRENT_USER\\Software\\Classes\\Applications\\") + fileName;
+    QSettings settings(key, QSettings::NativeFormat);
+    if (settings.status() != QSettings::NoError) {
+        qWarning() << "Cannot access registry key" << key;
+        return false;
+    }
+    settings.setValue(QStringLiteral("FriendlyAppName"), displayName);
 
-    settings.beginGroup("SupportedTypes");
-    foreach (const QString& fileType, fileTypes)
-        settings.setValue(fileType, QString());
+    settings.beginGroup(QStringLiteral("SupportedTypes"));
+    QMimeDatabase mimeDatabase;
+    foreach (const QString &fileType, MusicPlayer::supportedMimeTypes()) {
+        foreach (QString suffix, mimeDatabase.mimeTypeForName(fileType).suffixes()) {
+            suffix.prepend('.');
+            settings.setValue(suffix, QString());
+        }
+    }
     settings.endGroup();
 
-    settings.beginGroup("shell");
-    settings.beginGroup("open");
-    settings.setValue("FriendlyAppName", displayName);
-    settings.beginGroup("Command");
-    settings.setValue(".", QChar('"') + QDir::toNativeSeparators(filePath) + QString("\" \"%1\""));
+    settings.beginGroup(QStringLiteral("shell"));
+    settings.beginGroup(QStringLiteral("open"));
+    settings.setValue(QStringLiteral("FriendlyAppName"), displayName);
+    settings.beginGroup(QStringLiteral("Command"));
+    settings.setValue(QStringLiteral("."),
+                      QLatin1Char('"') + QDir::toNativeSeparators(filePath) + QStringLiteral("\" \"%1\""));
+
+    return true;
 }
 //! [0]
 
 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
-    app.setApplicationName("MusicPlayer");
-    app.setOrganizationName("QtWinExtras");
-    app.setOrganizationDomain("qt-project.org");
-    app.setApplicationDisplayName("QtWinExtras Music Player");
-    app.setWindowIcon(QIcon(":/logo.png"));
+    QCoreApplication::setApplicationName(QStringLiteral("MusicPlayer"));
+    QCoreApplication::setApplicationVersion( QLatin1String(QT_VERSION_STR));
+    QCoreApplication::setOrganizationName(QStringLiteral("QtWinExtras"));
+    QCoreApplication::setOrganizationDomain("qt-project.org");
+    QGuiApplication::setApplicationDisplayName(QStringLiteral("QtWinExtras Music Player"));
+    QApplication::setWindowIcon(QIcon(QStringLiteral(":/logo.png")));
+
+    if (!associateFileTypes())
+        return -1;
 
-    associateFileTypes(QStringList(".mp3"));
+    QCommandLineParser parser;
+    parser.setApplicationDescription(QGuiApplication::applicationDisplayName());
+    parser.addHelpOption();
+    parser.addVersionOption();
+    parser.addPositionalArgument(QStringLiteral("url"), MusicPlayer::tr("The URL to open."));
+    parser.process(app);
 
     MusicPlayer player;
-    const QStringList arguments = QCoreApplication::arguments();
-    if (arguments.size() > 1)
-        player.playFile(arguments.at(1));
-    player.resize(300, 60);
+
+    if (!parser.positionalArguments().isEmpty())
+        player.playUrl(QUrl::fromUserInput(parser.positionalArguments().constFirst(), QDir::currentPath(), QUrl::AssumeLocalFile));
+
+    const QRect availableGeometry = QApplication::desktop()->availableGeometry(&player);
+    player.resize(availableGeometry.width() / 6, availableGeometry.height() / 17);
     player.show();
 
     return app.exec();
diff --git a/examples/winextras/musicplayer/musicplayer.cpp b/examples/winextras/musicplayer/musicplayer.cpp
index 26b6fa8..6093976 100644
--- a/examples/winextras/musicplayer/musicplayer.cpp
+++ b/examples/winextras/musicplayer/musicplayer.cpp
@@ -44,11 +44,7 @@
 #include <QtWidgets>
 #include <QtWinExtras>
 
-MusicPlayer::MusicPlayer(QWidget *parent) : QWidget(parent),
-    taskbarButton(0), taskbarProgress(0), thumbnailToolBar(0),
-    playToolButton(0), forwardToolButton(0), backwardToolButton(0),
-    mediaPlayer(0), playButton(0), volumeButton(0),
-    positionSlider(0), positionLabel(0), infoLabel(0)
+MusicPlayer::MusicPlayer(QWidget *parent) : QWidget(parent)
 {
     createWidgets();
     createShortcuts();
@@ -67,25 +63,42 @@ MusicPlayer::MusicPlayer(QWidget *parent) : QWidget(parent),
             this, &MusicPlayer::updateState);
 
     stylize();
+    setAcceptDrops(true);
+}
+
+QStringList MusicPlayer::supportedMimeTypes()
+{
+    QStringList result = QMediaPlayer::supportedMimeTypes();
+    if (result.isEmpty())
+        result.append(QStringLiteral("audio/mpeg"));
+    return result;
 }
 
 void MusicPlayer::openFile()
 {
-    const QStringList musicPaths = QStandardPaths::standardLocations(QStandardPaths::MusicLocation);
-    const QString filePath =
-        QFileDialog::getOpenFileName(this, tr("Open File"),
-                                     musicPaths.isEmpty() ? QDir::homePath() : musicPaths.first(),
-                                     tr("MP3 files (*.mp3);;All files (*.*)"));
-    if (!filePath.isEmpty())
-        playFile(filePath);
+    QFileDialog fileDialog(this);
+    fileDialog.setAcceptMode(QFileDialog::AcceptOpen);
+    fileDialog.setWindowTitle(tr("Open File"));
+    fileDialog.setMimeTypeFilters(MusicPlayer::supportedMimeTypes());
+    fileDialog.setDirectory(QStandardPaths::standardLocations(QStandardPaths::MusicLocation).value(0, QDir::homePath()));
+    if (fileDialog.exec() == QDialog::Accepted)
+        playUrl(fileDialog.selectedUrls().constFirst());
 }
 
-void MusicPlayer::playFile(const QString &filePath)
+void MusicPlayer::playUrl(const QUrl &url)
 {
     playButton->setEnabled(true);
-    infoLabel->setText(QFileInfo(filePath).fileName());
-
-    mediaPlayer.setMedia(QUrl::fromLocalFile(filePath));
+    if (url.isLocalFile()) {
+        const QString filePath = url.toLocalFile();
+        setWindowFilePath(filePath);
+        infoLabel->setText(QDir::toNativeSeparators(filePath));
+        fileName = QFileInfo(filePath).fileName();
+    } else {
+        setWindowFilePath(QString());
+        infoLabel->setText(url.toString());
+        fileName.clear();
+    }
+    mediaPlayer.setMedia(url);
     mediaPlayer.play();
 }
 
@@ -118,6 +131,27 @@ bool MusicPlayer::event(QEvent *event)
 }
 //! [0]
 
+static bool canHandleDrop(const QDropEvent *event)
+{
+    const QList<QUrl> urls = event->mimeData()->urls();
+    if (urls.size() != 1)
+        return false;
+    QMimeDatabase mimeDatabase;
+    return MusicPlayer::supportedMimeTypes().
+        contains(mimeDatabase.mimeTypeForUrl(urls.constFirst()).name());
+}
+
+void MusicPlayer::dragEnterEvent(QDragEnterEvent *event)
+{
+    event->setAccepted(canHandleDrop(event));
+}
+
+void MusicPlayer::dropEvent(QDropEvent *event)
+{
+    event->accept();
+    playUrl(event->mimeData()->urls().constFirst());
+}
+
 void MusicPlayer::mousePressEvent(QMouseEvent *event)
 {
     offset = event->globalPos() - pos();
@@ -143,11 +177,11 @@ void MusicPlayer::stylize()
         QtWin::extendFrameIntoClientArea(this, -1, -1, -1, -1);
         setAttribute(Qt::WA_TranslucentBackground, true);
         setAttribute(Qt::WA_NoSystemBackground, false);
-        setStyleSheet("MusicPlayer { background: transparent; }");
+        setStyleSheet(QStringLiteral("MusicPlayer { background: transparent; }"));
     } else {
         QtWin::resetExtendedFrame(this);
         setAttribute(Qt::WA_TranslucentBackground, false);
-        setStyleSheet(QString("MusicPlayer { background: %1; }").arg(QtWin::realColorizationColor().name()));
+        setStyleSheet(QStringLiteral("MusicPlayer { background: %1; }").arg(QtWin::realColorizationColor().name()));
     }
     volumeButton->stylize();
 }
@@ -164,12 +198,20 @@ void MusicPlayer::updateState(QMediaPlayer::State state)
     }
 }
 
+static QString formatTime(qint64 timeMilliSeconds)
+{
+    qint64 seconds = timeMilliSeconds / 1000;
+    const qint64 minutes = seconds / 60;
+    seconds -= minutes * 60;
+    return QStringLiteral("%1:%2")
+        .arg(minutes, 2, 10, QLatin1Char('0'))
+        .arg(seconds, 2, 10, QLatin1Char('0'));
+}
+
 void MusicPlayer::updatePosition(qint64 position)
 {
     positionSlider->setValue(position);
-
-    QTime duration(0, position / 60000, qRound((position % 60000) / 1000.0));
-    positionLabel->setText(duration.toString(tr("mm:ss")));
+    positionLabel->setText(formatTime(position));
 }
 
 void MusicPlayer::updateDuration(qint64 duration)
@@ -177,6 +219,7 @@ void MusicPlayer::updateDuration(qint64 duration)
     positionSlider->setRange(0, duration);
     positionSlider->setEnabled(duration > 0);
     positionSlider->setPageStep(duration / 10);
+    updateInfo();
 }
 
 void MusicPlayer::setPosition(int position)
@@ -189,20 +232,27 @@ void MusicPlayer::setPosition(int position)
 void MusicPlayer::updateInfo()
 {
     QStringList info;
-    QString author = mediaPlayer.metaData("Author").toString();
-    if (!author.isEmpty())
-        info += author;
-    QString title = mediaPlayer.metaData("Title").toString();
-    if (!title.isEmpty())
-        info += title;
-    if (!info.isEmpty())
-        infoLabel->setText(info.join(tr(" - ")));
+    if (!fileName.isEmpty())
+        info.append(fileName);
+    if (mediaPlayer.isMetaDataAvailable()) {
+        QString author = mediaPlayer.metaData(QStringLiteral("Author")).toString();
+        if (!author.isEmpty())
+            info.append(author);
+        QString title = mediaPlayer.metaData(QStringLiteral("Title")).toString();
+        if (!title.isEmpty())
+            info.append(title);
+    }
+    info.append(formatTime(mediaPlayer.duration()));
+    infoLabel->setText(info.join(tr(" - ")));
 }
 
 void MusicPlayer::handleError()
 {
     playButton->setEnabled(false);
-    infoLabel->setText(tr("Error: %1").arg(mediaPlayer.errorString()));
+    const QString errorString = mediaPlayer.errorString();
+    infoLabel->setText(errorString.isEmpty()
+                       ? tr("Unknown error #%1").arg(int(mediaPlayer.error()))
+                       : tr("Error: %1").arg(errorString));
 }
 
 //! [2]
diff --git a/examples/winextras/musicplayer/musicplayer.h b/examples/winextras/musicplayer/musicplayer.h
index b848840..567aeb7 100644
--- a/examples/winextras/musicplayer/musicplayer.h
+++ b/examples/winextras/musicplayer/musicplayer.h
@@ -58,20 +58,25 @@ class MusicPlayer : public QWidget
 {
     Q_OBJECT
 public:
-    MusicPlayer(QWidget *parent = 0);
+    explicit MusicPlayer(QWidget *parent = nullptr);
+
+    static QStringList supportedMimeTypes();
+    static QStringList supportedSuffixes();
 
 public slots:
     void openFile();
-    void playFile(const QString& filePath);
+    void playUrl(const QUrl& url);
     void togglePlayback();
     void seekForward();
     void seekBackward();
 
 protected:
-    bool event(QEvent *event);
-    void mousePressEvent(QMouseEvent *event);
-    void mouseMoveEvent(QMouseEvent *event);
-    void mouseReleaseEvent(QMouseEvent *event);
+    bool event(QEvent *event) override;
+    void dragEnterEvent(QDragEnterEvent *event) override;
+    void dropEvent(QDropEvent *event) override;
+    void mousePressEvent(QMouseEvent *event) override;
+    void mouseMoveEvent(QMouseEvent *event) override;
+    void mouseReleaseEvent(QMouseEvent *event) override;
 
 private slots:
     void stylize();
@@ -92,20 +97,21 @@ private:
     void createTaskbar();
     void createThumbnailToolBar();
 
-    QWinTaskbarButton* taskbarButton;
-    QWinTaskbarProgress* taskbarProgress;
-    QWinThumbnailToolBar* thumbnailToolBar;
-    QWinThumbnailToolButton *playToolButton;
-    QWinThumbnailToolButton *forwardToolButton;
-    QWinThumbnailToolButton *backwardToolButton;
+    QWinTaskbarButton *taskbarButton = nullptr;
+    QWinTaskbarProgress *taskbarProgress = nullptr;
+    QWinThumbnailToolBar *thumbnailToolBar = nullptr;
+    QWinThumbnailToolButton *playToolButton = nullptr;
+    QWinThumbnailToolButton *forwardToolButton = nullptr;
+    QWinThumbnailToolButton *backwardToolButton = nullptr;
 
     QMediaPlayer mediaPlayer;
-    QAbstractButton *playButton;
-    VolumeButton *volumeButton;
-    QSlider *positionSlider;
-    QLabel *positionLabel;
-    QLabel *infoLabel;
+    QAbstractButton *playButton = nullptr;
+    VolumeButton *volumeButton = nullptr;
+    QSlider *positionSlider = nullptr;
+    QLabel *positionLabel = nullptr;
+    QLabel *infoLabel = nullptr;
     QPoint offset;
+    QString fileName;
 };
 
 #endif // MUSICPLAYER_H
diff --git a/examples/winextras/musicplayer/volumebutton.cpp b/examples/winextras/musicplayer/volumebutton.cpp
index 37eb0c1..44be5cf 100644
--- a/examples/winextras/musicplayer/volumebutton.cpp
+++ b/examples/winextras/musicplayer/volumebutton.cpp
@@ -44,7 +44,7 @@
 #include <QtWinExtras>
 
 VolumeButton::VolumeButton(QWidget *parent) :
-    QToolButton(parent), menu(0), label(0), slider(0)
+    QToolButton(parent)
 {
     setIcon(style()->standardIcon(QStyle::SP_MediaVolume));
     setPopupMode(QToolButton::InstantPopup);
diff --git a/examples/winextras/musicplayer/volumebutton.h b/examples/winextras/musicplayer/volumebutton.h
index 99d6da9..3fc3c87 100644
--- a/examples/winextras/musicplayer/volumebutton.h
+++ b/examples/winextras/musicplayer/volumebutton.h
@@ -53,7 +53,7 @@ class VolumeButton : public QToolButton
     Q_PROPERTY(int volume READ volume WRITE setVolume NOTIFY volumeChanged)
 
 public:
-    VolumeButton(QWidget *parent = 0);
+    explicit VolumeButton(QWidget *parent = nullptr);
 
     int volume() const;
 
@@ -67,9 +67,9 @@ signals:
     void volumeChanged(int volume);
 
 private:
-    QMenu *menu;
-    QLabel *label;
-    QSlider *slider;
+    QMenu *menu = nullptr;
+    QLabel *label = nullptr;
+    QSlider *slider = nullptr;
 };
 
 #endif // VOLUMEBUTTON_H