Add artist biography

data/data.qrc

@@ -12,6 +12,7 @@
         <file>schema/schema-18.sql</file>
         <file>schema/device-schema.sql</file>
         <file>style/strawberry.css</file>
+        <file>style/artistbio.css</file>
         <file>style/smartplaylistsearchterm.css</file>
         <file>html/oauthsuccess.html</file>
         <file>pictures/strawberry.png</file>

data/icons.qrc

@@ -97,6 +97,7 @@
         <file>icons/128x128/somafm.png</file>
         <file>icons/128x128/radioparadise.png</file>
         <file>icons/128x128/musicbrainz.png</file>
+        <file>icons/128x128/guitar.png</file>
         <file>icons/64x64/albums.png</file>
         <file>icons/64x64/alsa.png</file>
         <file>icons/64x64/application-exit.png</file>
@@ -195,6 +196,7 @@
         <file>icons/64x64/somafm.png</file>
         <file>icons/64x64/radioparadise.png</file>
         <file>icons/64x64/musicbrainz.png</file>
+        <file>icons/64x64/guitar.png</file>
         <file>icons/48x48/albums.png</file>
         <file>icons/48x48/alsa.png</file>
         <file>icons/48x48/application-exit.png</file>
@@ -297,6 +299,7 @@
         <file>icons/48x48/somafm.png</file>
         <file>icons/48x48/radioparadise.png</file>
         <file>icons/48x48/musicbrainz.png</file>
+        <file>icons/48x48/guitar.png</file>
         <file>icons/32x32/albums.png</file>
         <file>icons/32x32/alsa.png</file>
         <file>icons/32x32/application-exit.png</file>
@@ -399,6 +402,7 @@
         <file>icons/32x32/somafm.png</file>
         <file>icons/32x32/radioparadise.png</file>
         <file>icons/32x32/musicbrainz.png</file>
+        <file>icons/32x32/guitar.png</file>
         <file>icons/22x22/albums.png</file>
         <file>icons/22x22/alsa.png</file>
         <file>icons/22x22/application-exit.png</file>
@@ -501,5 +505,6 @@
         <file>icons/22x22/somafm.png</file>
         <file>icons/22x22/radioparadise.png</file>
         <file>icons/22x22/musicbrainz.png</file>
+        <file>icons/22x22/guitar.png</file>
     </qresource>
 </RCC>

data/style/artistbio.css

@@ -0,0 +1,7 @@
+QScrollArea {
+  background: qpalette(base);
+}
+
+QTextEdit {
+  border: 0px;
+}

src/CMakeLists.txt

@@ -39,6 +39,7 @@ set(SOURCES
   core/scopedtransaction.cpp
   core/translations.cpp
   core/systemtrayicon.cpp
+  core/latch.cpp
 
   utilities/strutils.cpp
   utilities/envutils.cpp
@@ -245,6 +246,12 @@ set(SOURCES
   widgets/loginstatewidget.cpp
   widgets/ratingwidget.cpp
   widgets/resizabletextedit.cpp
+  widgets/widgetfadehelper.cpp
+  widgets/prettyimageview.cpp
+  widgets/prettyimage.cpp
+  widgets/collapsibleinfoheader.cpp
+  widgets/collapsibleinfopane.cpp
+  widgets/infotextview.cpp
 
   osd/osdbase.cpp
   osd/osdpretty.cpp
@@ -291,6 +298,12 @@ set(SOURCES
   organize/organizedialog.cpp
   organize/organizeerrordialog.cpp
 
+  artistbio/artistbioview.cpp
+  artistbio/artistbiofetcher.cpp
+  artistbio/artistbioprovider.cpp
+  artistbio/lastfmartistbio.cpp
+  artistbio/wikipediaartistbio.cpp
+
 )
 
 set(HEADERS
@@ -316,6 +329,7 @@ set(HEADERS
   core/potranslator.h
   core/mimedata.h
   core/stylesheetloader.h
+  core/latch.h
 
   engine/enginebase.h
   engine/devicefinders.h
@@ -486,6 +500,13 @@ set(HEADERS
   widgets/qsearchfield.h
   widgets/ratingwidget.h
   widgets/forcescrollperpixel.h
+  widgets/resizabletextedit.h
+  widgets/widgetfadehelper.h
+  widgets/prettyimage.h
+  widgets/prettyimageview.h
+  widgets/collapsibleinfoheader.h
+  widgets/collapsibleinfopane.h
+  widgets/infotextview.h
 
   osd/osdbase.h
   osd/osdpretty.h
@@ -527,6 +548,12 @@ set(HEADERS
   organize/organizedialog.h
   organize/organizeerrordialog.h
 
+  artistbio/artistbiofetcher.h
+  artistbio/artistbioprovider.h
+  artistbio/artistbioview.h
+  artistbio/lastfmartistbio.h
+  artistbio/wikipediaartistbio.h
+
 )
 
 set(UI

src/artistbio/artistbiofetcher.cpp

@@ -0,0 +1,126 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QObject>
+#include <QTimer>
+#include <QUrl>
+
+#include "artistbiofetcher.h"
+#include "artistbioprovider.h"
+#include "core/logging.h"
+
+ArtistBioFetcher::ArtistBioFetcher(QObject *parent)
+    : QObject(parent),
+      timeout_duration_(kDefaultTimeoutDuration),
+      next_id_(1) {}
+
+void ArtistBioFetcher::AddProvider(ArtistBioProvider *provider) {
+
+  providers_ << provider;
+  connect(provider, SIGNAL(ImageReady(int, QUrl)), SLOT(ImageReady(int, QUrl)), Qt::QueuedConnection);
+  connect(provider, SIGNAL(InfoReady(int, CollapsibleInfoPane::Data)), SLOT(InfoReady(int, CollapsibleInfoPane::Data)), Qt::QueuedConnection);
+  connect(provider, SIGNAL(Finished(int)), SLOT(ProviderFinished(int)), Qt::QueuedConnection);
+
+}
+
+ArtistBioFetcher::~ArtistBioFetcher() {
+
+  while (!providers_.isEmpty()) {
+    ArtistBioProvider *provider = providers_.takeFirst();
+    provider->deleteLater();
+  }
+
+}
+
+int ArtistBioFetcher::FetchInfo(const Song &metadata) {
+
+  const int id = next_id_++;
+  results_[id] = Result();
+  timeout_timers_[id] = new QTimer(this);
+  timeout_timers_[id]->setSingleShot(true);
+  timeout_timers_[id]->setInterval(timeout_duration_);
+  timeout_timers_[id]->start();
+
+  connect(timeout_timers_[id], &QTimer::timeout, [this, id]() { Timeout(id); });
+
+  for (ArtistBioProvider *provider : providers_) {
+    if (provider->is_enabled()) {
+      waiting_for_[id].append(provider);
+      provider->Start(id, metadata);
+    }
+  }
+  return id;
+
+}
+
+void ArtistBioFetcher::ImageReady(const int id, const QUrl &url) {
+
+  if (!results_.contains(id)) return;
+  results_[id].images_ << url;
+
+}
+
+void ArtistBioFetcher::InfoReady(const int id, const CollapsibleInfoPane::Data &data) {
+
+  if (!results_.contains(id)) return;
+  results_[id].info_ << data;
+
+  if (!waiting_for_.contains(id)) return;
+  emit InfoResultReady(id, data);
+
+}
+
+void ArtistBioFetcher::ProviderFinished(const int id) {
+
+  if (!results_.contains(id)) return;
+  if (!waiting_for_.contains(id)) return;
+
+  ArtistBioProvider *provider = qobject_cast<ArtistBioProvider*>(sender());
+  if (!waiting_for_[id].contains(provider)) return;
+
+  waiting_for_[id].removeAll(provider);
+  if (waiting_for_[id].isEmpty()) {
+    Result result = results_.take(id);
+    emit ResultReady(id, result);
+    waiting_for_.remove(id);
+    delete timeout_timers_.take(id);
+  }
+
+}
+
+void ArtistBioFetcher::Timeout(const int id) {
+
+  if (!results_.contains(id)) return;
+  if (!waiting_for_.contains(id)) return;
+
+  // Emit the results that we have already
+  emit ResultReady(id, results_.take(id));
+
+  // Cancel any providers that we're still waiting for
+  for (ArtistBioProvider *provider : waiting_for_[id]) {
+    qLog(Info) << "Request timed out from info provider" << provider->name();
+    provider->Cancel(id);
+  }
+  waiting_for_.remove(id);
+
+  // Remove the timer
+  delete timeout_timers_.take(id);
+
+}

src/artistbio/artistbiofetcher.h

@@ -0,0 +1,75 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef ARTISTBIOFETCHER_H
+#define ARTISTBIOFETCHER_H
+
+#include <QObject>
+#include <QList>
+#include <QMap>
+#include <QUrl>
+
+#include "widgets/collapsibleinfopane.h"
+#include "core/song.h"
+
+class QTimer;
+class ArtistBioProvider;
+
+class ArtistBioFetcher : public QObject {
+  Q_OBJECT
+
+ public:
+  explicit ArtistBioFetcher(QObject *parent = nullptr);
+  ~ArtistBioFetcher() override;
+
+  struct Result {
+    QList<QUrl> images_;
+    QList<CollapsibleInfoPane::Data> info_;
+  };
+
+  static const int kDefaultTimeoutDuration = 25000;
+
+  void AddProvider(ArtistBioProvider *provider);
+  int FetchInfo(const Song &metadata);
+
+  QList<ArtistBioProvider*> providers() const { return providers_; }
+
+ signals:
+  void InfoResultReady(int, CollapsibleInfoPane::Data);
+  void ResultReady(int, ArtistBioFetcher::Result);
+
+ private slots:
+  void ImageReady(const int id, const QUrl &url);
+  void InfoReady(const int id, const CollapsibleInfoPane::Data &data);
+  void ProviderFinished(const int id);
+  void Timeout(const int id);
+
+ private:
+  QList<ArtistBioProvider*> providers_;
+
+  QMap<int, Result> results_;
+  QMap<int, QList<ArtistBioProvider*>> waiting_for_;
+  QMap<int, QTimer*> timeout_timers_;
+
+  int timeout_duration_;
+  int next_id_;
+};
+
+#endif  // ARTISTBIOFETCHER_H

src/artistbio/artistbioprovider.cpp

@@ -0,0 +1,25 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "artistbioprovider.h"
+
+ArtistBioProvider::ArtistBioProvider() : enabled_(true) {}
+
+QString ArtistBioProvider::name() const { return metaObject()->className(); }

src/artistbio/artistbioprovider.h

@@ -0,0 +1,53 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef ARTISTBIOPROVIDER_H
+#define ARTISTBIOPROVIDER_H
+
+#include <QObject>
+#include <QUrl>
+
+#include "widgets/collapsibleinfopane.h"
+#include "core/song.h"
+
+class ArtistBioProvider : public QObject {
+  Q_OBJECT
+
+ public:
+  explicit ArtistBioProvider();
+
+  virtual void Start(const int id, const Song &song) = 0;
+  virtual void Cancel(const int) {}
+
+  virtual QString name() const;
+
+  bool is_enabled() const { return enabled_; }
+  void set_enabled(bool enabled) { enabled_ = enabled; }
+
+ signals:
+  void ImageReady(int, QUrl);
+  void InfoReady(int, CollapsibleInfoPane::Data);
+  void Finished(int);
+
+ private:
+  bool enabled_;
+};
+
+#endif  // ARTISTBIOPROVIDER_H

src/artistbio/artistbioview.cpp

@@ -0,0 +1,287 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QWidget>
+#include <QFile>
+#include <QScrollArea>
+#include <QSettings>
+#include <QSpacerItem>
+#include <QTimer>
+#include <QVBoxLayout>
+#include <QShowEvent>
+
+#include "core/song.h"
+#include "core/networkaccessmanager.h"
+#include "widgets/prettyimageview.h"
+#include "widgets/widgetfadehelper.h"
+#include "artistbiofetcher.h"
+#include "lastfmartistbio.h"
+#include "wikipediaartistbio.h"
+
+#include "artistbioview.h"
+
+const char *ArtistBioView::kSettingsGroup = "ArtistBio";
+
+ArtistBioView::ArtistBioView(QWidget *parent)
+    : QWidget(parent),
+      network_(new NetworkAccessManager(this)),
+      fetcher_(new ArtistBioFetcher(this)),
+      current_request_id_(-1),
+      container_(new QVBoxLayout),
+      section_container_(nullptr),
+      fader_(new WidgetFadeHelper(this, 1000)),
+      dirty_(false) {
+
+  // Add the top-level scroll area
+  QScrollArea *scrollarea = new QScrollArea(this);
+  setLayout(new QVBoxLayout);
+  layout()->setContentsMargins(0, 0, 0, 0);
+  layout()->addWidget(scrollarea);
+
+  // Add a container widget to the scroll area
+  QWidget *container_widget = new QWidget;
+  container_widget->setLayout(container_);
+  container_widget->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Minimum);
+  container_widget->setBackgroundRole(QPalette::Base);
+  container_->setSizeConstraint(QLayout::SetMinAndMaxSize);
+  container_->setContentsMargins(0, 0, 0, 0);
+  container_->setSpacing(6);
+  scrollarea->setWidget(container_widget);
+  scrollarea->setWidgetResizable(true);
+
+  // Add a spacer to the bottom of the container
+  container_->addStretch();
+
+  // Set stylesheet
+  QFile stylesheet(":/style/artistbio.css");
+  if (stylesheet.open(QIODevice::ReadOnly)) {
+    setStyleSheet(QString::fromLatin1(stylesheet.readAll()));
+    stylesheet.close();
+  }
+
+  fetcher_->AddProvider(new LastFMArtistBio);
+  fetcher_->AddProvider(new WikipediaArtistBio);
+
+  connect(fetcher_, SIGNAL(ResultReady(int, ArtistBioFetcher::Result)), SLOT(ResultReady(int, ArtistBioFetcher::Result)));
+  connect(fetcher_, SIGNAL(InfoResultReady(int, CollapsibleInfoPane::Data)), SLOT(InfoResultReady(int, CollapsibleInfoPane::Data)));
+
+}
+
+ArtistBioView::~ArtistBioView() {}
+
+void ArtistBioView::showEvent(QShowEvent *e) {
+
+  if (dirty_) {
+    MaybeUpdate(queued_metadata_);
+    dirty_ = false;
+  }
+
+  QWidget::showEvent(e);
+
+}
+
+void ArtistBioView::ReloadSettings() {
+
+  for (CollapsibleInfoPane *pane : sections_) {
+    QWidget *contents = pane->data().contents_;
+    if (!contents) continue;
+
+    QMetaObject::invokeMethod(contents, "ReloadSettings");
+  }
+
+}
+
+bool ArtistBioView::NeedsUpdate(const Song &old_metadata, const Song &new_metadata) const {
+
+  if (new_metadata.artist().isEmpty()) return false;
+
+  return old_metadata.artist() != new_metadata.artist();
+
+}
+
+void ArtistBioView::InfoResultReady(const int id, const CollapsibleInfoPane::Data &_data) {
+
+  if (id != current_request_id_) return;
+
+  AddSection(new CollapsibleInfoPane(_data, this));
+  CollapseSections();
+
+}
+
+void ArtistBioView::ResultReady(const int id, const ArtistBioFetcher::Result &result) {
+
+  if (id != current_request_id_) return;
+
+  if (!result.images_.isEmpty()) {
+    // Image view goes at the top
+    PrettyImageView *image_view = new PrettyImageView(network_, this);
+    AddWidget(image_view);
+
+    for (const QUrl& url : result.images_) {
+      image_view->AddImage(url);
+    }
+  }
+
+  CollapseSections();
+
+}
+
+void ArtistBioView::Clear() {
+
+  fader_->StartFade();
+
+  qDeleteAll(widgets_);
+  widgets_.clear();
+  if (section_container_) {
+    container_->removeWidget(section_container_);
+    delete section_container_;
+  }
+  sections_.clear();
+
+  // Container for collapsible sections goes below
+  section_container_ = new QWidget;
+  section_container_->setLayout(new QVBoxLayout);
+  section_container_->layout()->setContentsMargins(0, 0, 0, 0);
+  section_container_->layout()->setSpacing(1);
+  section_container_->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Minimum);
+  container_->insertWidget(0, section_container_);
+
+}
+
+void ArtistBioView::AddSection(CollapsibleInfoPane *section) {
+
+  int i = 0;
+  for (; i < sections_.count(); ++i) {
+    if (section->data() < sections_[i]->data()) break;
+  }
+
+  ConnectWidget(section->data().contents_);
+
+  sections_.insert(i, section);
+  qobject_cast<QVBoxLayout*>(section_container_->layout())->insertWidget(i, section);
+  section->show();
+
+}
+
+void ArtistBioView::AddWidget(QWidget *widget) {
+
+  ConnectWidget(widget);
+
+  container_->insertWidget(container_->count() - 2, widget);
+  widgets_ << widget;
+
+}
+
+void ArtistBioView::SongChanged(const Song &metadata) {
+
+  if (isVisible()) {
+    MaybeUpdate(metadata);
+    dirty_ = false;
+  }
+  else {
+    queued_metadata_ = metadata;
+    dirty_ = true;
+  }
+
+}
+
+void ArtistBioView::SongFinished() { dirty_ = false; }
+
+void ArtistBioView::MaybeUpdate(const Song &metadata) {
+
+  if (old_metadata_.is_valid()) {
+    if (!NeedsUpdate(old_metadata_, metadata)) {
+      return;
+    }
+  }
+
+  Update(metadata);
+  old_metadata_ = metadata;
+
+}
+
+void ArtistBioView::Update(const Song &metadata) {
+
+  current_request_id_ = fetcher_->FetchInfo(metadata);
+
+  // Do this after the new pane has been shown otherwise it'll just grab a black rectangle.
+  Clear();
+  QTimer::singleShot(0, fader_, SLOT(StartBlur()));
+
+}
+
+void ArtistBioView::CollapseSections() {
+
+  QSettings s;
+  s.beginGroup(kSettingsGroup);
+
+  // Sections are already sorted by type and relevance, so the algorithm we use to determine which ones to show by default is:
+  //   * In the absence of any user preference, show the first (highest relevance section of each type and hide the rest)
+  //   * If one or more sections in a type have been explicitly hidden/shown by the user before then hide all sections in that type and show only the ones that are explicitly shown.
+
+  QMultiMap<CollapsibleInfoPane::Data::Type, CollapsibleInfoPane*> types_;
+  QSet<CollapsibleInfoPane::Data::Type> has_user_preference_;
+  for (CollapsibleInfoPane *pane : sections_) {
+    const CollapsibleInfoPane::Data::Type type = pane->data().type_;
+    types_.insert(type, pane);
+
+    QVariant preference = s.value(pane->data().id_);
+    if (preference.isValid()) {
+      has_user_preference_.insert(type);
+      if (preference.toBool()) {
+        pane->Expand();
+      }
+    }
+  }
+
+  for (CollapsibleInfoPane::Data::Type type : types_.keys()) {
+    if (!has_user_preference_.contains(type)) {
+      // Expand the first one
+      types_.values(type).last()->Expand();
+    }
+  }
+
+  for (CollapsibleInfoPane *pane : sections_) {
+    connect(pane, SIGNAL(Toggled(bool)), SLOT(SectionToggled(bool)));
+  }
+
+}
+
+void ArtistBioView::SectionToggled(const bool value) {
+
+  CollapsibleInfoPane *pane = qobject_cast<CollapsibleInfoPane*>(sender());
+  if (!pane || !sections_.contains(pane)) return;
+
+  QSettings s;
+  s.beginGroup(kSettingsGroup);
+  s.setValue(pane->data().id_, value);
+  s.endGroup();
+
+}
+
+void ArtistBioView::ConnectWidget(QWidget *widget) {
+
+  const QMetaObject *m = widget->metaObject();
+
+  if (m->indexOfSignal("ShowSettingsDialog()") != -1) {
+    connect(widget, SIGNAL(ShowSettingsDialog()), SIGNAL(ShowSettingsDialog()));
+  }
+
+}

src/artistbio/artistbioview.h

@@ -0,0 +1,104 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef ARTISTBIOVIEW_H
+#define ARTISTBIOVIEW_H
+
+#include <QObject>
+#include <QWidget>
+#include <QList>
+
+#include "core/song.h"
+#include "widgets/collapsibleinfopane.h"
+#include "widgets/widgetfadehelper.h"
+#include "widgets/collapsibleinfopane.h"
+#include "playlist/playlistitem.h"
+#include "smartplaylists/playlistgenerator_fwd.h"
+#include "artistbiofetcher.h"
+
+class QNetworkAccessManager;
+class QTimeLine;
+class QVBoxLayout;
+class QScrollArea;
+class QShowEvent;
+
+class PrettyImageView;
+class CollapsibleInfoPane;
+class WidgetFadeHelper;
+
+class ArtistBioView : public QWidget {
+  Q_OBJECT
+
+ public:
+  explicit ArtistBioView(QWidget *parent = nullptr);
+  ~ArtistBioView() override;
+
+  static const char *kSettingsGroup;
+
+ public slots:
+  void SongChanged(const Song& metadata);
+  void SongFinished();
+  virtual void ReloadSettings();
+
+ signals:
+  void ShowSettingsDialog();
+
+ protected:
+  void showEvent(QShowEvent *e) override;
+
+  void Update(const Song &metadata);
+  void AddWidget(QWidget *widget);
+  void AddSection(CollapsibleInfoPane *section);
+  void Clear();
+  void CollapseSections();
+
+  bool NeedsUpdate(const Song& old_metadata, const Song &new_metadata) const;
+
+ protected slots:
+  void ResultReady(const int id, const ArtistBioFetcher::Result &result);
+  void InfoResultReady(const int id, const CollapsibleInfoPane::Data &data);
+
+ protected:
+  QNetworkAccessManager *network_;
+  ArtistBioFetcher *fetcher_;
+  int current_request_id_;
+
+ private:
+  void MaybeUpdate(const Song &metadata);
+  void ConnectWidget(QWidget *widget);
+
+ private slots:
+  void SectionToggled(const bool value);
+
+ private:
+  QVBoxLayout *container_;
+  QList<QWidget*> widgets_;
+
+  QWidget *section_container_;
+  QList<CollapsibleInfoPane*> sections_;
+
+  WidgetFadeHelper *fader_;
+
+  Song queued_metadata_;
+  Song old_metadata_;
+  bool dirty_;
+};
+
+#endif  // ARTISTBIOVIEW_H

src/artistbio/lastfmartistbio.cpp

@@ -0,0 +1,209 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2020, Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "config.h"
+
+#include <algorithm>
+
+#include <QtGlobal>
+#include <QLocale>
+#include <QVariant>
+#include <QByteArray>
+#include <QString>
+#include <QUrl>
+#include <QUrlQuery>
+#include <QDateTime>
+#include <QNetworkRequest>
+#include <QNetworkReply>
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QJsonValue>
+
+#include "core/networkaccessmanager.h"
+#include "core/song.h"
+#include "core/logging.h"
+#include "core/iconloader.h"
+
+#include "lastfmartistbio.h"
+#include "widgets/infotextview.h"
+#include "scrobbler/scrobblingapi20.h"
+#include "scrobbler/lastfmscrobbler.h"
+
+LastFMArtistBio::LastFMArtistBio() : ArtistBioProvider(), network_(new NetworkAccessManager(this)) {}
+
+LastFMArtistBio::~LastFMArtistBio() {
+
+  while (!replies_.isEmpty()) {
+    QNetworkReply *reply = replies_.takeFirst();
+    disconnect(reply, nullptr, this, nullptr);
+    reply->abort();
+    reply->deleteLater();
+  }
+
+}
+
+void LastFMArtistBio::Start(const int id, const Song &song) {
+
+  ParamList params = ParamList()
+    << Param("api_key", ScrobblingAPI20::kApiKey)
+    << Param("lang", QLocale().name().left(2).toLower())
+    << Param("format", "json")
+    << Param("method", "artist.getinfo")
+    << Param("artist", song.artist());
+
+  std::sort(params.begin(), params.end());
+
+  QUrlQuery url_query;
+  for (const Param &param : params) {
+    url_query.addQueryItem(QUrl::toPercentEncoding(param.first), QUrl::toPercentEncoding(param.second));
+  }
+
+  QUrl url(LastFMScrobbler::kApiUrl);
+  url.setQuery(url_query);
+  QNetworkRequest req(url);
+#if QT_VERSION >= QT_VERSION_CHECK(5, 9, 0)
+  req.setAttribute(QNetworkRequest::RedirectPolicyAttribute, QNetworkRequest::NoLessSafeRedirectPolicy);
+#else
+  req.setAttribute(QNetworkRequest::FollowRedirectsAttribute, true);
+#endif
+  req.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");
+
+  QNetworkReply *reply = network_->get(req);
+  replies_ << reply;
+  connect(reply, &QNetworkReply::finished, [=] { RequestFinished(reply, id); });
+
+  qLog(Debug) << "Sending request" << url_query.toString(QUrl::FullyDecoded);
+
+}
+
+QByteArray LastFMArtistBio::GetReplyData(QNetworkReply *reply) {
+
+  QByteArray data;
+
+  if (reply->error() == QNetworkReply::NoError && reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt() == 200) {
+    data = reply->readAll();
+  }
+  else {
+    if (reply->error() != QNetworkReply::NoError && reply->error() < 200) {
+      // This is a network error, there is nothing more to do.
+      Error(QString("%1 (%2)").arg(reply->errorString()).arg(reply->error()));
+    }
+    else {
+      QString error;
+      // See if there is Json data containing "error" and "message" - then use that instead.
+      data = reply->readAll();
+      QJsonParseError json_error;
+      QJsonDocument json_doc = QJsonDocument::fromJson(data, &json_error);
+      int error_code = -1;
+      if (json_error.error == QJsonParseError::NoError && !json_doc.isEmpty() && json_doc.isObject()) {
+        QJsonObject json_obj = json_doc.object();
+        if (json_obj.contains("error") && json_obj.contains("message")) {
+          error_code = json_obj["error"].toInt();
+          QString error_message = json_obj["message"].toString();
+          error = QString("%1 (%2)").arg(error_message).arg(error_code);
+        }
+      }
+      if (error.isEmpty()) {
+        if (reply->error() != QNetworkReply::NoError) {
+          error = QString("%1 (%2)").arg(reply->errorString()).arg(reply->error());
+        }
+        else {
+          error = QString("Received HTTP code %1").arg(reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt());
+        }
+      }
+      Error(error);
+    }
+    return QByteArray();
+  }
+
+  return data;
+
+}
+
+QJsonObject LastFMArtistBio::ExtractJsonObj(const QByteArray &data) {
+
+  if (data.isEmpty()) return QJsonObject();
+
+  QJsonParseError error;
+  QJsonDocument json_doc = QJsonDocument::fromJson(data, &error);
+
+  if (error.error != QJsonParseError::NoError) {
+    Error("Reply from server missing Json data.", data);
+    return QJsonObject();
+  }
+  if (json_doc.isEmpty()) {
+    Error("Received empty Json document.", json_doc);
+    return QJsonObject();
+  }
+  if (!json_doc.isObject()) {
+    Error("Json document is not an object.", json_doc);
+    return QJsonObject();
+  }
+  QJsonObject json_obj = json_doc.object();
+  if (json_obj.isEmpty()) {
+    Error("Received empty Json object.", json_doc);
+    return QJsonObject();
+  }
+
+  return json_obj;
+
+}
+
+void LastFMArtistBio::RequestFinished(QNetworkReply *reply, const int id) {
+
+  if (!replies_.contains(reply)) return;
+  replies_.removeAll(reply);
+  disconnect(reply, nullptr, this, nullptr);
+  reply->deleteLater();
+
+  QJsonObject json_obj = ExtractJsonObj(GetReplyData(reply));
+
+  QString title;
+  QString text;
+  if (!json_obj.isEmpty() && json_obj.contains("artist") && json_obj["artist"].isObject()) {
+    json_obj = json_obj["artist"].toObject();
+    if (json_obj.contains("bio") && json_obj["bio"].isObject()) {
+      title = json_obj["name"].toString();
+      QJsonObject obj_bio = json_obj["bio"].toObject();
+      if (obj_bio.contains("content")) {
+        text = obj_bio["content"].toString();
+      }
+    }
+  }
+
+  CollapsibleInfoPane::Data info_data;
+  info_data.id_ = title;
+  info_data.title_ = tr("Biography");
+  info_data.type_ = CollapsibleInfoPane::Data::Type_Biography;
+  info_data.icon_ = IconLoader::Load("scrobble");
+  InfoTextView *editor = new InfoTextView;
+  editor->SetHtml(text);
+  info_data.contents_ = editor;
+  emit InfoReady(id, info_data);
+  emit Finished(id);
+
+}
+
+void LastFMArtistBio::Error(const QString &error, const QVariant &debug) {
+
+  qLog(Error) << error;
+  if (debug.isValid()) qLog(Debug) << debug;
+
+}

src/artistbio/lastfmartistbio.h

@@ -0,0 +1,66 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2020, Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef LASTFMARTISTBIO_H
+#define LASTFMARTISTBIO_H
+
+#include "config.h"
+
+#include <QtGlobal>
+#include <QObject>
+#include <QList>
+#include <QVariant>
+#include <QByteArray>
+#include <QString>
+
+#include "core/song.h"
+
+#include "artistbioprovider.h"
+
+class NetworkAccessManager;
+class QNetworkReply;
+
+class LastFMArtistBio : public ArtistBioProvider {
+  Q_OBJECT
+
+ public:
+  explicit LastFMArtistBio();
+  ~LastFMArtistBio();
+
+  void Start(const int id, const Song &song) override;
+
+ private:
+  typedef QPair<QString, QString> Param;
+  typedef QList<Param> ParamList;
+
+  QNetworkReply *CreateRequest(const ParamList &request_params);
+  QByteArray GetReplyData(QNetworkReply *reply);
+  QJsonObject ExtractJsonObj(const QByteArray &data);
+  void Error(const QString &error, const QVariant &debug = QVariant());
+
+ private slots:
+  void RequestFinished(QNetworkReply *reply, const int id);
+
+ private:
+  NetworkAccessManager *network_;
+  QList<QNetworkReply*> replies_;
+
+};
+
+#endif  // LASTFMARTISTBIO_H

src/artistbio/wikipediaartistbio.cpp

@@ -0,0 +1,316 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2020, Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QObject>
+#include <QList>
+#include <QString>
+#include <QStringList>
+#include <QUrl>
+#include <QUrlQuery>
+#include <QJsonDocument>
+#include <QJsonArray>
+#include <QJsonObject>
+#include <QJsonValue>
+#include <QNetworkReply>
+
+#include "core/logging.h"
+#include "core/networkaccessmanager.h"
+#include "core/iconloader.h"
+#include "core/latch.h"
+
+#include "widgets/infotextview.h"
+#include "wikipediaartistbio.h"
+
+const char *WikipediaArtistBio::kApiUrl = "https://en.wikipedia.org/w/api.php";
+const int WikipediaArtistBio::kMinimumImageSize = 400;
+
+WikipediaArtistBio::WikipediaArtistBio() : ArtistBioProvider(), network_(new NetworkAccessManager(this)) {}
+
+WikipediaArtistBio::~WikipediaArtistBio() {
+
+  while (!replies_.isEmpty()) {
+    QNetworkReply *reply = replies_.takeFirst();
+    disconnect(reply, nullptr, this, nullptr);
+    if (reply->isRunning()) reply->abort();
+    reply->deleteLater();
+  }
+
+}
+
+QNetworkReply *WikipediaArtistBio::CreateRequest(QList<Param> &params) {
+
+  params << Param("format", "json");
+  params << Param("action", "query");
+
+  QUrlQuery url_query;
+  for (const Param &param : params) {
+    url_query.addQueryItem(QUrl::toPercentEncoding(param.first), QUrl::toPercentEncoding(param.second));
+  }
+
+  QUrl url(kApiUrl);
+  url.setQuery(url_query);
+  QNetworkRequest req(url);
+#if QT_VERSION >= QT_VERSION_CHECK(5, 9, 0)
+  req.setAttribute(QNetworkRequest::RedirectPolicyAttribute, QNetworkRequest::NoLessSafeRedirectPolicy);
+#else
+  req.setAttribute(QNetworkRequest::FollowRedirectsAttribute, true);
+#endif
+  req.setHeader(QNetworkRequest::ContentTypeHeader, "application/x-www-form-urlencoded");
+
+  QNetworkReply *reply = network_->get(req);
+  connect(reply, SIGNAL(sslErrors(QList<QSslError>)), this, SLOT(HandleSSLErrors(QList<QSslError>)));
+  replies_ << reply;
+
+  return reply;
+
+}
+
+QByteArray WikipediaArtistBio::GetReplyData(QNetworkReply *reply) {
+
+  QByteArray data;
+
+  if (reply->error() == QNetworkReply::NoError && reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt() == 200) {
+    data = reply->readAll();
+  }
+  else {
+    if (reply->error() == QNetworkReply::NoError) {
+      qLog(Error) << "Wikipedia artist biography error: Received HTTP code" << reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
+    }
+    else {
+      qLog(Error) << "Wikipedia artist biography error:" << reply->error() << reply->errorString();
+    }
+  }
+
+  return data;
+
+}
+
+QJsonObject WikipediaArtistBio::ExtractJsonObj(const QByteArray &data) {
+
+  if (data.isEmpty()) return QJsonObject();
+
+  QJsonParseError json_error;
+  QJsonDocument json_doc = QJsonDocument::fromJson(data, &json_error);
+
+  if (json_error.error != QJsonParseError::NoError) {
+    qLog(Error) << "Wikipedia artist biography error: Failed to parse json data:" << json_error.errorString();
+    return QJsonObject();
+  }
+
+  if (json_doc.isEmpty()) {
+    qLog(Error) << "Wikipedia artist biography error: Received empty Json document.";
+    return QJsonObject();
+  }
+
+  if (!json_doc.isObject()) {
+    qLog(Error) << "Wikipedia artist biography error: Json document is not an object.";
+    return QJsonObject();
+  }
+
+  QJsonObject json_obj = json_doc.object();
+  if (json_obj.isEmpty()) {
+    qLog(Error) << "Wikipedia artist biography error: Received empty Json object.";
+    return QJsonObject();
+  }
+
+  return json_obj;
+
+}
+
+void WikipediaArtistBio::HandleSSLErrors(QList<QSslError>) {}
+
+void WikipediaArtistBio::Start(const int id, const Song &metadata) {
+
+  if (metadata.artist().isEmpty()) {
+    emit Finished(id);
+    return;
+  }
+
+  CountdownLatch *latch = new CountdownLatch;
+  connect(latch, &CountdownLatch::Done, [this, id, latch](){
+    latch->deleteLater();
+    emit Finished(id);
+  });
+
+  GetImageTitles(id, metadata.artist(), latch);
+  //GetArticle(id, metadata.artist(), latch);
+
+}
+
+void WikipediaArtistBio::GetArticle(const int id, const QString &artist, CountdownLatch *latch) {
+
+  latch->Wait();
+
+  ParamList params = ParamList() << Param("titles", artist)
+                                 << Param("prop", "extracts");
+
+  QNetworkReply *reply = CreateRequest(params);
+  connect(reply, &QNetworkReply::finished, [this, reply, id, latch]() { GetArticleReply(reply, id, latch); });
+
+}
+
+void WikipediaArtistBio::GetArticleReply(QNetworkReply *reply, const int id, CountdownLatch *latch) {
+
+  reply->deleteLater();
+  replies_.removeAll(reply);
+
+  QJsonObject json_obj = ExtractJsonObj(GetReplyData(reply));
+
+  QString title;
+  QString text;
+  if (!json_obj.isEmpty() && json_obj.contains("query") && json_obj["query"].isObject()) {
+    json_obj = json_obj["query"].toObject();
+    if (json_obj.contains("pages") && json_obj["pages"].isObject()) {
+      QJsonObject value_pages = json_obj["pages"].toObject();
+      for (const QJsonValue value_page : value_pages) {
+        if (!value_page.isObject()) continue;
+        QJsonObject obj_page = value_page.toObject();
+        if (!obj_page.contains("title") || !obj_page.contains("extract")) continue;
+        title = obj_page["title"].toString();
+        text = obj_page["extract"].toString();
+      }
+    }
+  }
+
+  CollapsibleInfoPane::Data info_data;
+  info_data.id_ = title;
+  info_data.title_ = tr("Biography");
+  info_data.type_ = CollapsibleInfoPane::Data::Type_Biography;
+  info_data.icon_ = IconLoader::Load("wikipedia");
+  InfoTextView *editor = new InfoTextView;
+  editor->SetHtml(text);
+  info_data.contents_ = editor;
+  emit InfoReady(id, info_data);
+
+  latch->CountDown();
+
+}
+
+void WikipediaArtistBio::GetImageTitles(const int id, const QString &artist, CountdownLatch *latch) {
+
+  latch->Wait();
+
+  ParamList params = ParamList() << Param("titles", artist)
+                                 << Param("prop", "images")
+                                 << Param("imlimit", "25");
+
+  QNetworkReply *reply = CreateRequest(params);
+  connect(reply, &QNetworkReply::finished, [this, reply, id, latch]() { GetImageTitlesFinished(reply, id, latch); });
+
+}
+
+void WikipediaArtistBio::GetImageTitlesFinished(QNetworkReply *reply, const int id, CountdownLatch *latch) {
+
+  reply->deleteLater();
+  replies_.removeAll(reply);
+
+  QJsonObject json_obj = ExtractJsonObj(GetReplyData(reply));
+
+  QString title;
+  QStringList titles;
+  if (!json_obj.isEmpty() && json_obj.contains("query") && json_obj["query"].isObject()) {
+    json_obj = json_obj["query"].toObject();
+    if (json_obj.contains("pages") && json_obj["pages"].isObject()) {
+      QJsonObject value_pages = json_obj["pages"].toObject();
+      for (const QJsonValue value_page : value_pages) {
+        if (!value_page.isObject()) continue;
+        QJsonObject obj_page = value_page.toObject();
+        if (!obj_page.contains("title") || !obj_page.contains("images") || !obj_page["images"].isArray()) continue;
+        title = obj_page["title"].toString();
+        QJsonArray array_images = obj_page["images"].toArray();
+        for (const QJsonValue value_image : array_images) {
+          if (!value_image.isObject()) continue;
+          QJsonObject obj_image = value_image.toObject();
+          if (!obj_image.contains("title")) continue;
+          QString filename = obj_image["title"].toString();
+          if (filename.endsWith(".jpg", Qt::CaseInsensitive) || filename.endsWith(".png", Qt::CaseInsensitive)) {
+            titles << filename;
+          }
+        }
+      }
+    }
+  }
+
+  for (const QString &image_title : titles) {
+    GetImage(id, image_title, latch);
+  }
+
+  latch->CountDown();
+
+}
+
+void WikipediaArtistBio::GetImage(const int id, const QString &title, CountdownLatch *latch) {
+
+  latch->Wait();
+
+  ParamList params2 = ParamList() << Param("titles", title)
+                                  << Param("prop", "imageinfo")
+                                  << Param("iiprop", "url|size");
+
+  QNetworkReply *reply = CreateRequest(params2);
+  connect(reply, &QNetworkReply::finished, [this, reply, id, latch]() { GetImageFinished(reply, id, latch); });
+
+}
+
+void WikipediaArtistBio::GetImageFinished(QNetworkReply *reply, const int id, CountdownLatch *latch) {
+
+  reply->deleteLater();
+  replies_.removeAll(reply);
+
+  QJsonObject json_obj = ExtractJsonObj(GetReplyData(reply));
+
+  if (!json_obj.isEmpty()) {
+    QList<QUrl> urls = ExtractImageUrls(json_obj);
+    for (const QUrl &url : urls) {
+      emit ImageReady(id, url);
+    }
+  }
+
+  latch->CountDown();
+
+}
+
+QList<QUrl> WikipediaArtistBio::ExtractImageUrls(QJsonObject json_obj) {
+
+  QList<QUrl> urls;
+  if (json_obj.contains("query") && json_obj["query"].isObject()) {
+    json_obj = json_obj["query"].toObject();
+    if (json_obj.contains("pages") && json_obj["pages"].isObject()) {
+      QJsonObject value_pages = json_obj["pages"].toObject();
+      for (const QJsonValue value_page : value_pages) {
+        if (!value_page.isObject()) continue;
+        QJsonObject obj_page = value_page.toObject();
+        if (!obj_page.contains("title") || !obj_page.contains("imageinfo") || !obj_page["imageinfo"].isArray()) continue;
+        QJsonArray array_images = obj_page["imageinfo"].toArray();
+        for (const QJsonValue value_image : array_images) {
+          if (!value_image.isObject()) continue;
+          QJsonObject obj_image = value_image.toObject();
+          if (!obj_image.contains("url") || !obj_image.contains("width") || !obj_image.contains("height")) continue;
+          QUrl url(obj_image["url"].toString());
+          const int width = obj_image["width"].toInt();
+          const int height = obj_image["height"].toInt();
+          if (!url.isValid() || width < kMinimumImageSize || height < kMinimumImageSize) continue;
+          urls << url;
+        }
+      }
+    }
+  }
+  return urls;
+
+}

src/artistbio/wikipediaartistbio.h

@@ -0,0 +1,72 @@
+/*
+ * Strawberry Music Player
+ * Copyright 2020, Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef WIKIPEDIAARTISTBIO_H
+#define WIKIPEDIAARTISTBIO_H
+
+#include <QList>
+#include <QString>
+#include <QStringList>
+#include <QUrl>
+#include <QSslError>
+#include <QJsonObject>
+
+#include "artistbioprovider.h"
+
+class QNetworkReply;
+class CountdownLatch;
+class NetworkAccessManager;
+
+class WikipediaArtistBio : public ArtistBioProvider {
+  Q_OBJECT
+
+ public:
+  explicit WikipediaArtistBio();
+  ~WikipediaArtistBio();
+
+  void Start(const int id, const Song &song) override;
+
+ private:
+  typedef QPair<QString, QString> Param;
+  typedef QList<Param> ParamList;
+
+  QNetworkReply *CreateRequest(QList<Param> &params);
+  QByteArray GetReplyData(QNetworkReply *reply);
+  QJsonObject ExtractJsonObj(const QByteArray &data);
+  void GetArticle(const int id, const QString &artist, CountdownLatch* latch);
+  void GetImageTitles(const int id, const QString &artist, CountdownLatch* latch);
+  void GetImage(const int id, const QString &title, CountdownLatch *latch);
+  QList<QUrl> ExtractImageUrls(QJsonObject json_obj);
+
+ private slots:
+  void HandleSSLErrors(QList<QSslError> ssl_errors);
+  void GetArticleReply(QNetworkReply *reply, const int id, CountdownLatch *latch);
+  void GetImageTitlesFinished(QNetworkReply *reply, const int id, CountdownLatch *latch);
+  void GetImageFinished(QNetworkReply *reply, const int id, CountdownLatch *latch);
+
+ private:
+  static const char *kApiUrl;
+  static const int kMinimumImageSize;
+
+  NetworkAccessManager *network_;
+  QList<QNetworkReply*> replies_;
+
+};
+
+#endif  // WIKIPEDIAARTISTBIO_H

src/core/latch.cpp

@@ -0,0 +1,39 @@
+/* This file is part of Clementine.
+   Copyright 2016, John Maguire <john.maguire@gmail.com>
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+#include <QMutexLocker>
+
+#include "latch.h"
+
+CountdownLatch::CountdownLatch() : count_(0) {}
+
+void CountdownLatch::Wait() {
+
+  QMutexLocker l(&mutex_);
+  ++count_;
+
+}
+
+void CountdownLatch::CountDown() {
+
+  QMutexLocker l(&mutex_);
+  Q_ASSERT(count_ > 0);
+  --count_;
+  if (count_ == 0) {
+    emit Done();
+  }
+
+}

src/core/latch.h

@@ -0,0 +1,39 @@
+/* This file is part of Clementine.
+   Copyright 2016, John Maguire <john.maguire@gmail.com>
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+#ifndef LATCH_H
+#define LATCH_H
+
+#include <QObject>
+#include <QMutex>
+
+class CountdownLatch : public QObject {
+  Q_OBJECT
+
+ public:
+  explicit CountdownLatch();
+  void Wait();
+  void CountDown();
+
+ signals:
+  void Done();
+
+ private:
+  QMutex mutex_;
+  int count_;
+};
+
+#endif  // LATCH_H

src/core/mainwindow.cpp

@@ -204,6 +204,8 @@
 
 #include "smartplaylists/smartplaylistsviewcontainer.h"
 
+#include "artistbio/artistbioview.h"
+
 #ifdef Q_OS_WIN
 #  include "windows7thumbbar.h"
 #endif
@@ -218,6 +220,7 @@
 
 using std::make_unique;
 using std::make_shared;
+
 using namespace std::chrono_literals;
 
 const char *MainWindow::kSettingsGroup = "MainWindow";
@@ -308,6 +311,7 @@ MainWindow::MainWindow(Application *app, SharedPtr<SystemTrayIcon> tray_icon, OS
       qobuz_view_(new InternetTabsView(app_, app->internet_services()->ServiceBySource(Song::Source::Qobuz), QobuzSettingsPage::kSettingsGroup, SettingsDialog::Page::Qobuz, this)),
 #endif
       radio_view_(new RadioViewContainer(this)),
+      artistbio_view_(new ArtistBioView(this)),
       lastfm_import_dialog_(new LastFMImportDialog(app_->lastfm_import(), this)),
       collection_show_all_(nullptr),
       collection_show_duplicates_(nullptr),
@@ -389,6 +393,7 @@ MainWindow::MainWindow(Application *app, SharedPtr<SystemTrayIcon> tray_icon, OS
 #ifdef HAVE_QOBUZ
   ui_->tabs->AddTab(qobuz_view_, "qobuz", IconLoader::Load("qobuz", true, 0, 32), tr("Qobuz"));
 #endif
+  ui_->tabs->AddTab(artistbio_view_, "artistbio", IconLoader::Load("guitar"), tr("Artist biography"));
 
   // Add the playing widget to the fancy tab widget
   ui_->tabs->addBottomWidget(ui_->widget_playing);
@@ -907,6 +912,10 @@ MainWindow::MainWindow(Application *app, SharedPtr<SystemTrayIcon> tray_icon, OS
   QObject::connect(&*app_->lastfm_import(), &LastFMImport::UpdateTotal, lastfm_import_dialog_, &LastFMImportDialog::UpdateTotal);
   QObject::connect(&*app_->lastfm_import(), &LastFMImport::UpdateProgress, lastfm_import_dialog_, &LastFMImportDialog::UpdateProgress);
 
+  connect(app_->playlist_manager(), SIGNAL(CurrentSongChanged(Song)), artistbio_view_, SLOT(SongChanged(Song)));
+  connect(app_->player(), SIGNAL(PlaylistFinished()), artistbio_view_, SLOT(SongFinished()));
+  connect(app_->player(), SIGNAL(Stopped()), artistbio_view_, SLOT(SongFinished()));
+
   // Load settings
   qLog(Debug) << "Loading settings";
   settings_.beginGroup(kSettingsGroup);
@@ -1148,6 +1157,16 @@ void MainWindow::ReloadSettings() {
 
   album_cover_choice_controller_->search_cover_auto_action()->setChecked(settings_.value("search_for_cover_auto", true).toBool());
 
+  s.beginGroup(BehaviourSettingsPage::kSettingsGroup);
+  bool artistbio = s.value("artistbio", false).toBool();
+  s.endGroup();
+  if (artistbio) {
+    ui_->tabs->EnableTab(artistbio_view_);
+  }
+  else {
+    ui_->tabs->DisableTab(artistbio_view_);
+  }
+
 #ifdef HAVE_SUBSONIC
   s.beginGroup(SubsonicSettingsPage::kSettingsGroup);
   bool enable_subsonic = s.value("enabled", false).toBool();

src/core/mainwindow.h

@@ -99,6 +99,7 @@ class Windows7ThumbBar;
 class AddStreamDialog;
 class LastFMImportDialog;
 class RadioViewContainer;
+class ArtistBioView;
 
 class MainWindow : public QMainWindow, public PlatformInterface {
   Q_OBJECT
@@ -343,6 +344,8 @@ class MainWindow : public QMainWindow, public PlatformInterface {
 
   RadioViewContainer *radio_view_;
 
+  ArtistBioView* artistbio_view_;
+
   LastFMImportDialog *lastfm_import_dialog_;
 
   QAction *collection_show_all_;

src/core/metatypes.cpp

@@ -71,6 +71,7 @@
 #include "smartplaylists/playlistgenerator_fwd.h"
 
 #include "radios/radiochannel.h"
+#include "widgets/collapsibleinfopane.h"
 
 #ifdef HAVE_LIBMTP
 #  include "device/mtpconnection.h"
@@ -153,6 +154,8 @@ void RegisterMetaTypes() {
   qRegisterMetaType<RadioChannel>("RadioChannel");
   qRegisterMetaType<RadioChannelList>("RadioChannelList");
 
+  qRegisterMetaType<CollapsibleInfoPane::Data>("CollapsibleInfoPane::Data");
+
 #ifdef HAVE_LIBMTP
   qRegisterMetaType<MtpConnection*>("MtpConnection*");
 #endif

src/settings/behavioursettingspage.cpp

@@ -160,6 +160,7 @@ void BehaviourSettingsPage::Load() {
 
   ui_->checkbox_resumeplayback->setChecked(s.value("resumeplayback", false).toBool());
   ui_->checkbox_playingwidget->setChecked(s.value("playing_widget", true).toBool());
+  ui_->checkbox_artistbio->setChecked(s.value("artistbio", false).toBool());
 
 #ifndef Q_OS_MACOS
   const StartupBehaviour startup_behaviour = static_cast<StartupBehaviour>(s.value("startupbehaviour", static_cast<int>(StartupBehaviour::Remember)).toInt());
@@ -224,6 +225,7 @@ void BehaviourSettingsPage::Save() {
   s.setValue("trayicon_progress", ui_->checkbox_trayicon_progress->isChecked());
   s.setValue("resumeplayback", ui_->checkbox_resumeplayback->isChecked());
   s.setValue("playing_widget", ui_->checkbox_playingwidget->isChecked());
+  s.setValue("artistbio", ui_->checkbox_artistbio->isChecked());
 
   StartupBehaviour startup_behaviour = StartupBehaviour::Remember;
   if (ui_->radiobutton_remember->isChecked()) startup_behaviour = StartupBehaviour::Remember;

src/settings/behavioursettingspage.ui

@@ -58,6 +58,13 @@
      </property>
     </widget>
    </item>
+   <item>
+    <widget class="QCheckBox" name="checkbox_artistbio">
+     <property name="text">
+      <string>Artist biography</string>
+     </property>
+    </widget>
+   </item>
    <item>
     <widget class="QGroupBox" name="groupbox_startup">
      <property name="title">

src/widgets/collapsibleinfoheader.cpp

@@ -0,0 +1,174 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QWidget>
+#include <QApplication>
+#include <QString>
+#include <QIcon>
+#include <QPainter>
+#include <QPalette>
+#include <QColor>
+#include <QStyle>
+#include <QFont>
+#include <QPropertyAnimation>
+#include <QStyleOption>
+#include <QEnterEvent>
+#include <QPaintEvent>
+#include <QMouseEvent>
+#include <QEvent>
+
+#include "collapsibleinfoheader.h"
+
+const int CollapsibleInfoHeader::kHeight = 20;
+const int CollapsibleInfoHeader::kIconSize = 16;
+
+CollapsibleInfoHeader::CollapsibleInfoHeader(QWidget* parent)
+    : QWidget(parent),
+      expanded_(false),
+      hovering_(false),
+      animation_(new QPropertyAnimation(this, "opacity", this)),
+      opacity_(0.0) {
+
+  setMinimumHeight(kHeight);
+  setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+  setCursor(QCursor(Qt::PointingHandCursor));
+
+}
+
+void CollapsibleInfoHeader::SetTitle(const QString &title) {
+  title_ = title;
+  update();
+}
+
+void CollapsibleInfoHeader::SetIcon(const QIcon &icon) {
+  icon_ = icon;
+  update();
+}
+
+void CollapsibleInfoHeader::SetExpanded(const bool expanded) {
+
+  expanded_ = expanded;
+
+  emit ExpandedToggled(expanded);
+  if (expanded)
+    emit Expanded();
+  else
+    emit Collapsed();
+}
+
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+void CollapsibleInfoHeader::enterEvent(QEnterEvent*) {
+#else
+void CollapsibleInfoHeader::enterEvent(QEvent*) {
+#endif
+
+  hovering_ = true;
+  if (!expanded_) {
+    animation_->stop();
+    animation_->setEndValue(1.0);
+    animation_->setDuration(80);
+    animation_->start();
+  }
+
+}
+
+void CollapsibleInfoHeader::leaveEvent(QEvent*) {
+
+  hovering_ = false;
+  if (!expanded_) {
+    animation_->stop();
+    animation_->setEndValue(0.0);
+    animation_->setDuration(160);
+    animation_->start();
+  }
+
+}
+
+void CollapsibleInfoHeader::set_opacity(const float opacity) {
+  opacity_ = opacity;
+  update();
+}
+
+void CollapsibleInfoHeader::paintEvent(QPaintEvent*) {
+
+  QPainter p(this);
+
+  QColor active_text_color(palette().color(QPalette::Active, QPalette::HighlightedText));
+  QColor inactive_text_color(palette().color(QPalette::Active, QPalette::Text));
+  QColor text_color;
+  if (expanded_) {
+    text_color = active_text_color;
+  }
+  else {
+    p.setOpacity(0.4 + opacity_ * 0.6);
+    text_color = QColor(active_text_color.red() * opacity_ + inactive_text_color.red() * (1.0 - opacity_), active_text_color.green() * opacity_ + inactive_text_color.green() * (1.0 - opacity_), active_text_color.blue() * opacity_ + inactive_text_color.blue() * (1.0 - opacity_));
+  }
+
+  QRect indicator_rect(0, 0, height(), height());
+  QRect icon_rect(height() + 2, (kHeight - kIconSize) / 2, kIconSize, kIconSize);
+  QRect text_rect(rect());
+  text_rect.setLeft(icon_rect.right() + 4);
+
+  // Draw the background
+  QColor highlight(palette().color(QPalette::Active, QPalette::Highlight));
+  const QColor bg_color_1(highlight.lighter(120));
+  const QColor bg_color_2(highlight.darker(120));
+  const QColor bg_border(palette().color(QPalette::Dark));
+  QLinearGradient bg_brush(rect().topLeft(), rect().bottomLeft());
+  bg_brush.setColorAt(0.0, bg_color_1);
+  bg_brush.setColorAt(0.5, bg_color_1);
+  bg_brush.setColorAt(0.5, bg_color_2);
+  bg_brush.setColorAt(1.0, bg_color_2);
+
+  p.setPen(Qt::NoPen);
+  p.fillRect(rect(), bg_brush);
+
+  p.setPen(bg_border);
+  p.drawLine(rect().topLeft(), rect().topRight());
+  p.drawLine(rect().bottomLeft(), rect().bottomRight());
+
+  // Draw the expand/collapse indicator
+  QStyleOption opt;
+  opt.initFrom(this);
+  opt.rect = indicator_rect;
+  opt.state |= QStyle::State_Children;
+  if (expanded_) opt.state |= QStyle::State_Open;
+  if (hovering_) opt.state |= QStyle::State_Active;
+
+  // Have to use the application's style here because using the widget's style
+  // will trigger QStyleSheetStyle's recursion guard (I don't know why).
+  QApplication::style()->drawPrimitive(QStyle::PE_IndicatorBranch, &opt, &p, this);
+
+  // Draw the icon
+  p.drawPixmap(icon_rect, icon_.pixmap(kIconSize));
+
+  // Draw the title text
+  QFont bold_font(font());
+  bold_font.setBold(true);
+  p.setFont(bold_font);
+
+  p.setPen(text_color);
+  p.drawText(text_rect, Qt::AlignLeft | Qt::AlignVCenter, title_);
+
+}
+
+void CollapsibleInfoHeader::mouseReleaseEvent(QMouseEvent*) {
+  SetExpanded(!expanded_);
+}

src/widgets/collapsibleinfoheader.h

@@ -0,0 +1,82 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef COLLAPSIBLEINFOHEADER_H
+#define COLLAPSIBLEINFOHEADER_H
+
+#include <QWidget>
+#include <QString>
+#include <QIcon>
+
+class QPropertyAnimation;
+class QEnterEvent;
+class QEvent;
+class QPaintEvent;
+class QMouseEvent;
+
+class CollapsibleInfoHeader : public QWidget {
+  Q_OBJECT
+  Q_PROPERTY(float opacity READ opacity WRITE set_opacity)
+
+ public:
+  CollapsibleInfoHeader(QWidget *parent = nullptr);
+
+  static const int kHeight;
+  static const int kIconSize;
+
+  bool expanded() const { return expanded_; }
+  bool hovering() const { return hovering_; }
+  const QString &title() const { return title_; }
+  const QIcon &icon() const { return icon_; }
+
+  float opacity() const { return opacity_; }
+  void set_opacity(const float opacity);
+
+ public slots:
+  void SetExpanded(const bool expanded);
+  void SetTitle(const QString &title);
+  void SetIcon(const QIcon &icon);
+
+ signals:
+  void Expanded();
+  void Collapsed();
+  void ExpandedToggled(const bool expanded);
+
+ protected:
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+  void enterEvent(QEnterEvent*) override;
+#else
+  void enterEvent(QEvent*) override;
+#endif
+  void leaveEvent(QEvent*) override;
+  void paintEvent(QPaintEvent*) override;
+  void mouseReleaseEvent(QMouseEvent*) override;
+
+ private:
+  bool expanded_;
+  bool hovering_;
+  QString title_;
+  QIcon icon_;
+
+  QPropertyAnimation *animation_;
+  float opacity_;
+};
+
+#endif  // COLLAPSIBLEINFOHEADER_H

src/widgets/collapsibleinfopane.cpp

@@ -0,0 +1,64 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "collapsibleinfoheader.h"
+#include "collapsibleinfopane.h"
+
+#include <QVBoxLayout>
+
+CollapsibleInfoPane::CollapsibleInfoPane(const Data &data, QWidget *parent)
+    : QWidget(parent), data_(data), header_(new CollapsibleInfoHeader(this)) {
+
+  QVBoxLayout* layout = new QVBoxLayout(this);
+  layout->setContentsMargins(0, 0, 0, 0);
+  layout->setSpacing(3);
+  layout->setSizeConstraint(QLayout::SetMinAndMaxSize);
+  setLayout(layout);
+
+  layout->addWidget(header_);
+  layout->addWidget(data.contents_);
+  data.contents_->hide();
+
+  header_->SetTitle(data.title_);
+  header_->SetIcon(data.icon_);
+
+  setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Maximum);
+
+  connect(header_, SIGNAL(ExpandedToggled(bool)), SLOT(ExpandedToggled(bool)));
+  connect(header_, SIGNAL(ExpandedToggled(bool)), SIGNAL(Toggled(bool)));
+
+}
+
+void CollapsibleInfoPane::Collapse() { header_->SetExpanded(false); }
+
+void CollapsibleInfoPane::Expand() { header_->SetExpanded(true); }
+
+void CollapsibleInfoPane::ExpandedToggled(bool expanded) {
+  data_.contents_->setVisible(expanded);
+}
+
+bool CollapsibleInfoPane::Data::operator<(const CollapsibleInfoPane::Data &other) const {
+
+  const int my_score = (TypeCount - type_) * 1000 + relevance_;
+  const int other_score = (TypeCount - other.type_) * 1000 + other.relevance_;
+
+  return my_score > other_score;
+
+}

src/widgets/collapsibleinfopane.h

@@ -0,0 +1,72 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef COLLAPSIBLEINFOPANE_H
+#define COLLAPSIBLEINFOPANE_H
+
+#include <QIcon>
+#include <QWidget>
+
+class CollapsibleInfoHeader;
+
+class CollapsibleInfoPane : public QWidget {
+  Q_OBJECT
+
+ public:
+  struct Data {
+    explicit Data() : type_(Type_Biography), relevance_(0) {}
+
+    bool operator<(const Data& other) const;
+
+    enum Type {
+      Type_Biography,
+      TypeCount
+    };
+
+    QString id_;
+    QString title_;
+    QIcon icon_;
+    Type type_;
+    int relevance_;
+
+    QWidget *contents_;
+    QObject *content_object_;
+  };
+
+  CollapsibleInfoPane(const Data &data, QWidget* parent = nullptr);
+
+  const Data &data() const { return data_; }
+
+ public slots:
+  void Expand();
+  void Collapse();
+
+ signals:
+  void Toggled(const bool expanded);
+
+ private slots:
+  void ExpandedToggled(const bool expanded);
+
+ private:
+  Data data_;
+  CollapsibleInfoHeader *header_;
+};
+
+#endif  // COLLAPSIBLEINFOPANE_H

src/widgets/infotextview.cpp

@@ -0,0 +1,89 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QWidget>
+#include <QApplication>
+#include <QMenu>
+#include <QWheelEvent>
+#include <QRegularExpression>
+#include <QtDebug>
+
+#include "core/logging.h"
+#include "infotextview.h"
+
+InfoTextView::InfoTextView(QWidget *parent) : QTextBrowser(parent), last_width_(-1), recursion_filter_(false) {
+    
+  setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+  setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+  setOpenExternalLinks(true);
+
+}
+
+void InfoTextView::resizeEvent(QResizeEvent *e) {
+
+  const int w = qMax(100, width());
+  if (w == last_width_) return;
+  last_width_ = w;
+
+  document()->setTextWidth(w);
+  setMinimumHeight(document()->size().height());
+
+  QTextBrowser::resizeEvent(e);
+
+}
+
+QSize InfoTextView::sizeHint() const { return minimumSize(); }
+
+void InfoTextView::wheelEvent(QWheelEvent *e) { e->ignore(); }
+
+void InfoTextView::SetHtml(const QString &html) {
+
+  QString copy(html.trimmed());
+
+  // Simplify newlines
+  copy.replace(QRegularExpression("\\r\\n?"), "\n");
+
+  // Convert two or more newlines to <p>, convert single newlines to <br>
+  copy.replace(QRegularExpression("([^>])([\\t ]*\\n){2,}"), "\\1<p>");
+  copy.replace(QRegularExpression("([^>])[\\t ]*\\n"), "\\1<br>");
+
+  // Strip any newlines from the end
+  copy.replace(QRegularExpression("((<\\s*br\\s*/?\\s*>)|(<\\s*/?\\s*p\\s*/?\\s*>))+$"), "");
+
+  setHtml(copy);
+
+}
+
+// Prevents QTextDocument from trying to load remote images before they are ready.
+QVariant InfoTextView::loadResource(int type, const QUrl &name) {
+
+  if (recursion_filter_) {
+    recursion_filter_ = false;
+    return QVariant();
+  }
+  recursion_filter_ = true;
+  if (type == QTextDocument::ImageResource && name.scheme() == "http") {
+    if (document()->resource(type, name).isNull()) {
+      return QVariant();
+    }
+  }
+  return QTextBrowser::loadResource(type, name);
+
+}

src/widgets/infotextview.h

@@ -0,0 +1,52 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef INFOTEXTVIEW_H
+#define INFOTEXTVIEW_H
+
+#include <QTextBrowser>
+#include <QString>
+#include <QUrl>
+
+class QResizeEvent;
+class QWheelEvent;
+
+class InfoTextView : public QTextBrowser {
+  Q_OBJECT
+
+ public:
+  explicit InfoTextView(QWidget *parent = nullptr);
+
+  QSize sizeHint() const override;
+
+ public slots:
+  void SetHtml(const QString &html);
+
+ protected:
+  void resizeEvent(QResizeEvent *e) override;
+  void wheelEvent(QWheelEvent *e) override;
+  QVariant loadResource(int type, const QUrl &name) override;
+
+ private:
+  int last_width_;
+  bool recursion_filter_;
+};
+
+#endif  // INFOTEXTVIEW_H

src/widgets/prettyimage.cpp

@@ -0,0 +1,257 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QApplication>
+#include <QWindow>
+#include <QScreen>
+#include <QtConcurrentRun>
+#include <QFuture>
+#include <QString>
+#include <QImage>
+#include <QPixmap>
+#include <QPainter>
+#include <QFileInfo>
+#include <QDir>
+#include <QFileDialog>
+#include <QNetworkAccessManager>
+#include <QNetworkReply>
+#include <QSettings>
+#include <QLabel>
+#include <QMenu>
+#include <QScrollArea>
+#include <QContextMenuEvent>
+
+#include "core/logging.h"
+#include "core/networkaccessmanager.h"
+#include "core/iconloader.h"
+
+#include "prettyimage.h"
+
+const int PrettyImage::kTotalHeight = 200;
+const int PrettyImage::kReflectionHeight = 40;
+const int PrettyImage::kImageHeight = PrettyImage::kTotalHeight - PrettyImage::kReflectionHeight;
+
+const int PrettyImage::kMaxImageWidth = 300;
+
+const char *PrettyImage::kSettingsGroup = "PrettyImageView";
+
+PrettyImage::PrettyImage(const QUrl &url, QNetworkAccessManager *network, QWidget *parent)
+    : QWidget(parent),
+      network_(network),
+      state_(State_WaitingForLazyLoad),
+      url_(url),
+      menu_(nullptr) {
+
+  setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
+
+  LazyLoad();
+
+}
+
+void PrettyImage::LazyLoad() {
+
+  if (state_ != State_WaitingForLazyLoad) return;
+
+  // Start fetching the image
+  QNetworkReply *reply = network_->get(QNetworkRequest(url_));
+  state_ = State_Fetching;
+  QObject::connect(reply, &QNetworkReply::finished, this, [this, reply]() { ImageFetched(reply); });
+
+}
+
+QSize PrettyImage::image_size() const {
+
+  if (state_ != State_Finished) return QSize(kImageHeight * 1.6, kImageHeight);
+
+  QSize ret = image_.size();
+  ret.scale(kMaxImageWidth, kImageHeight, Qt::KeepAspectRatio);
+  return ret;
+
+}
+
+QSize PrettyImage::sizeHint() const {
+  return QSize(image_size().width(), kTotalHeight);
+}
+
+void PrettyImage::ImageFetched(QNetworkReply *reply) {
+
+  reply->deleteLater();
+
+  QImage image = QImage::fromData(reply->readAll());
+  if (image.isNull()) {
+    qLog(Debug) << "Image failed to load" << reply->request().url() << reply->error();
+    deleteLater();
+  }
+  else {
+    state_ = State_CreatingThumbnail;
+    image_ = image;
+    (void)QtConcurrent::run([=]{ ImageScaled(image_.scaled(image_size(), Qt::KeepAspectRatio, Qt::SmoothTransformation)); });
+  }
+
+}
+
+void PrettyImage::ImageScaled(QImage image) {
+
+  thumbnail_ = QPixmap::fromImage(image);
+  state_ = State_Finished;
+
+  updateGeometry();
+  update();
+  emit Loaded();
+
+}
+
+void PrettyImage::paintEvent(QPaintEvent*) {
+
+  // Draw at the bottom of our area
+  QRect image_rect(QPoint(0, 0), image_size());
+  image_rect.moveBottom(kImageHeight);
+
+  QPainter p(this);
+
+  // Draw the main image
+  DrawThumbnail(&p, image_rect);
+
+  // Draw the reflection
+  // Figure out where to draw it
+  QRect reflection_rect(image_rect);
+  reflection_rect.moveTop(image_rect.bottom());
+
+  // Create the reflected pixmap
+  QImage reflection(reflection_rect.size(), QImage::Format_ARGB32_Premultiplied);
+  reflection.fill(palette().color(QPalette::Base).rgba());
+  QPainter reflection_painter(&reflection);
+
+  // Set up the transformation
+  QTransform transform;
+  transform.scale(1.0, -1.0);
+  transform.translate(0.0, -reflection_rect.height());
+  reflection_painter.setTransform(transform);
+
+  QRect fade_rect(reflection.rect().bottomLeft() - QPoint(0, kReflectionHeight), reflection.rect().bottomRight());
+
+  // Draw the reflection into the buffer
+  DrawThumbnail(&reflection_painter, reflection.rect());
+
+  // Make it fade out towards the bottom
+  QLinearGradient fade_gradient(fade_rect.topLeft(), fade_rect.bottomLeft());
+  fade_gradient.setColorAt(0.0, QColor(0, 0, 0, 0));
+  fade_gradient.setColorAt(1.0, QColor(0, 0, 0, 128));
+
+  reflection_painter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
+  reflection_painter.fillRect(fade_rect, fade_gradient);
+
+  reflection_painter.end();
+
+  // Draw the reflection on the image
+  p.drawImage(reflection_rect, reflection);
+
+}
+
+void PrettyImage::DrawThumbnail(QPainter *p, const QRect &rect) {
+
+  switch (state_) {
+    case State_WaitingForLazyLoad:
+    case State_Fetching:
+    case State_CreatingThumbnail:
+      p->setPen(palette().color(QPalette::Disabled, QPalette::Text));
+      p->drawText(rect, Qt::AlignHCenter | Qt::AlignBottom, tr("Loading..."));
+      break;
+
+    case State_Finished:
+      p->drawPixmap(rect, thumbnail_);
+      break;
+  }
+
+}
+
+void PrettyImage::contextMenuEvent(QContextMenuEvent *e) {
+
+  if (e->pos().y() >= kImageHeight) return;
+
+  if (!menu_) {
+    menu_ = new QMenu(this);
+    menu_->addAction(IconLoader::Load("zoom-in"), tr("Show fullsize..."), this, SLOT(ShowFullsize()));
+    menu_->addAction(IconLoader::Load("document-save"), tr("Save image") + "...", this, SLOT(SaveAs()));
+  }
+
+  menu_->popup(e->globalPos());
+
+}
+
+void PrettyImage::ShowFullsize() {
+
+  // Create the window
+  QScrollArea *pwindow = new QScrollArea;
+  pwindow->setAttribute(Qt::WA_DeleteOnClose, true);
+  pwindow->setWindowTitle(tr("%1 image viewer").arg("Strawberry"));
+
+  // Work out how large to make the window, based on the size of the screen
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 14, 0))
+  QScreen *screen = QWidget::screen();
+#else
+  QScreen *screen = (window() && window()->windowHandle() ? window()->windowHandle()->screen() : QGuiApplication::primaryScreen());
+#endif
+  if (screen) {
+    QRect desktop_rect(screen->availableGeometry());
+    QSize window_size(qMin(desktop_rect.width() - 20, image_.width()), qMin(desktop_rect.height() - 20, image_.height()));
+    pwindow->resize(window_size);
+  }
+
+  // Create the label that displays the image
+  QLabel *label = new QLabel(pwindow);
+  label->setPixmap(QPixmap::fromImage(image_));
+
+  // Show the label in the window
+  pwindow->setWidget(label);
+  pwindow->setFrameShape(QFrame::NoFrame);
+  pwindow->show();
+
+}
+
+void PrettyImage::SaveAs() {
+
+  QString filename = QFileInfo(url_.path()).fileName();
+
+  if (filename.isEmpty()) filename = "artwork.jpg";
+
+  QSettings s;
+  s.beginGroup(kSettingsGroup);
+  QString last_save_dir = s.value("last_save_dir", QDir::homePath()).toString();
+
+  QString path = last_save_dir.isEmpty() ? QDir::homePath() : last_save_dir;
+  QFileInfo path_info(path);
+  if (path_info.isDir()) {
+    path += "/" + filename;
+  }
+  else {
+    path = path_info.path() + "/" + filename;
+  }
+
+  filename = QFileDialog::getSaveFileName(this, tr("Save image"), path);
+  if (filename.isEmpty()) return;
+
+  image_.save(filename);
+
+  s.setValue("last_save_dir", last_save_dir);
+  
+  s.endGroup();
+
+}

src/widgets/prettyimage.h

@@ -0,0 +1,92 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef PRETTYIMAGE_H
+#define PRETTYIMAGE_H
+
+#include <QWidget>
+#include <QString>
+#include <QUrl>
+#include <QImage>
+#include <QPixmap>
+#include <QPainter>
+
+class QMenu;
+class QNetworkAccessManager;
+class QNetworkReply;
+class QContextMenuEvent;
+class QPaintEvent;
+
+class PrettyImage : public QWidget {
+  Q_OBJECT
+
+ public:
+  PrettyImage(const QUrl &url, QNetworkAccessManager *network, QWidget *parent = nullptr);
+
+  static const int kTotalHeight;
+  static const int kReflectionHeight;
+  static const int kImageHeight;
+
+  static const int kMaxImageWidth;
+
+  static const char *kSettingsGroup;
+
+  QSize sizeHint() const override;
+  QSize image_size() const;
+
+signals:
+  void Loaded();
+
+ public slots:
+  void LazyLoad();
+  void SaveAs();
+  void ShowFullsize();
+
+ protected:
+  void contextMenuEvent(QContextMenuEvent*) override;
+  void paintEvent(QPaintEvent*) override;
+
+ private slots:
+  void ImageFetched(QNetworkReply *reply);
+  void ImageScaled(QImage image);
+
+ private:
+  enum State {
+    State_WaitingForLazyLoad,
+    State_Fetching,
+    State_CreatingThumbnail,
+    State_Finished,
+  };
+
+  void DrawThumbnail(QPainter *p, const QRect &rect);
+
+ private:
+  QNetworkAccessManager *network_;
+  State state_;
+  QUrl url_;
+
+  QImage image_;
+  QPixmap thumbnail_;
+
+  QMenu *menu_;
+  QString last_save_dir_;
+};
+
+#endif  // PRETTYIMAGE_H

src/widgets/prettyimageview.cpp

@@ -0,0 +1,189 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QObject>
+#include <QUrl>
+#include <QNetworkAccessManager>
+#include <QPropertyAnimation>
+#include <QAbstractSlider>
+#include <QHBoxLayout>
+#include <QScrollArea>
+#include <QScrollBar>
+#include <QTimer>
+#include <QMouseEvent>
+#include <QResizeEvent>
+#include <QWheelEvent>
+
+#include "core/networkaccessmanager.h"
+
+#include "prettyimage.h"
+#include "prettyimageview.h"
+
+PrettyImageView::PrettyImageView(QNetworkAccessManager *network, QWidget* parent)
+    : QScrollArea(parent),
+      network_(network),
+      container_(new QWidget(this)),
+      layout_(new QHBoxLayout(container_)),
+      current_index_(-1),
+      scroll_animation_(new QPropertyAnimation(horizontalScrollBar(), "value", this)),
+      recursion_filter_(false) {
+
+  setWidget(container_);
+  setWidgetResizable(true);
+  setMinimumHeight(PrettyImage::kTotalHeight + 10);
+  setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+  setFrameShape(QFrame::NoFrame);
+  setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+
+  scroll_animation_->setDuration(250);
+  scroll_animation_->setEasingCurve(QEasingCurve::InOutCubic);
+  connect(horizontalScrollBar(), SIGNAL(sliderReleased()), SLOT(ScrollBarReleased()));
+  connect(horizontalScrollBar(), SIGNAL(actionTriggered(int)), SLOT(ScrollBarAction(int)));
+
+  layout_->setSizeConstraint(QLayout::SetMinAndMaxSize);
+  layout_->setContentsMargins(6, 6, 6, 6);
+  layout_->setSpacing(6);
+  layout_->addSpacing(200);
+  layout_->addSpacing(200);
+
+  container_->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Minimum);
+
+}
+
+bool PrettyImageView::eventFilter(QObject *obj, QEvent *event) {
+
+  // Work around infinite recursion in QScrollArea resizes.
+  if (recursion_filter_) {
+    return false;
+  }
+  recursion_filter_ = true;
+  bool ret = QScrollArea::eventFilter(obj, event);
+  recursion_filter_ = false;
+  return ret;
+
+}
+
+void PrettyImageView::AddImage(const QUrl &url) {
+
+  PrettyImage *image = new PrettyImage(url, network_, container_);
+  connect(image, SIGNAL(destroyed()), SLOT(ScrollToCurrent()));
+  connect(image, SIGNAL(Loaded()), SLOT(ScrollToCurrent()));
+
+  layout_->insertWidget(layout_->count() - 1, image);
+  if (current_index_ == -1) ScrollTo(0);
+
+}
+
+void PrettyImageView::mouseReleaseEvent(QMouseEvent *e) {
+
+  // Find the image that was clicked on
+  QWidget *widget = container_->childAt(container_->mapFrom(this, e->pos()));
+  if (!widget) return;
+
+  // Get the index of that image
+  const int index = layout_->indexOf(widget) - 1;
+  if (index == -1) return;
+
+  if (index == current_index_) {
+    // Show the image fullsize
+    PrettyImage* pretty_image = qobject_cast<PrettyImage*>(widget);
+    if (pretty_image) {
+      pretty_image->ShowFullsize();
+    }
+  }
+  else {
+    // Scroll to the image
+    ScrollTo(index);
+  }
+
+}
+
+void PrettyImageView::ScrollTo(const int index, const bool smooth) {
+
+  current_index_ = qBound(0, index, layout_->count() - 3);
+  const int layout_index = current_index_ + 1;
+
+  const QWidget *target_widget = layout_->itemAt(layout_index)->widget();
+  if (!target_widget) return;
+
+  const int current_x = horizontalScrollBar()->value();
+  const int target_x = target_widget->geometry().center().x() - width() / 2;
+
+  if (current_x == target_x) return;
+
+  if (smooth) {
+    scroll_animation_->setStartValue(current_x);
+    scroll_animation_->setEndValue(target_x);
+    scroll_animation_->start();
+  }
+  else {
+    scroll_animation_->stop();
+    horizontalScrollBar()->setValue(target_x);
+  }
+
+}
+
+void PrettyImageView::ScrollToCurrent() { ScrollTo(current_index_); }
+
+void PrettyImageView::ScrollBarReleased() {
+
+  // Find the nearest widget to where the scroll bar was released
+  const int current_x = horizontalScrollBar()->value() + width() / 2;
+  int layout_index = 1;
+  for (; layout_index < layout_->count() - 1; ++layout_index) {
+    const QWidget *widget = layout_->itemAt(layout_index)->widget();
+    if (widget && widget->geometry().right() > current_x) {
+      break;
+    }
+  }
+
+  ScrollTo(layout_index - 1);
+
+}
+
+void PrettyImageView::ScrollBarAction(const int action) {
+
+  switch (action) {
+    case QAbstractSlider::SliderSingleStepAdd:
+    case QAbstractSlider::SliderPageStepAdd:
+      ScrollTo(current_index_ + 1);
+      break;
+
+    case QAbstractSlider::SliderSingleStepSub:
+    case QAbstractSlider::SliderPageStepSub:
+      ScrollTo(current_index_ - 1);
+      break;
+  }
+
+}
+
+void PrettyImageView::resizeEvent(QResizeEvent *e) {
+
+  QScrollArea::resizeEvent(e);
+  ScrollTo(current_index_, false);
+
+}
+
+void PrettyImageView::wheelEvent(QWheelEvent *e) {
+
+  const int d = e->angleDelta().x() > 0 ? -1 : 1;
+  ScrollTo(current_index_ + d, true);
+
+}

src/widgets/prettyimageview.h

@@ -0,0 +1,74 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef PRETTYIMAGEVIEW_H
+#define PRETTYIMAGEVIEW_H
+
+#include <QScrollArea>
+#include <QMap>
+#include <QUrl>
+
+class QNetworkAccessManager;
+class QNetworkReply;
+class QMenu;
+class QHBoxLayout;
+class QPropertyAnimation;
+class QTimeLine;
+class QMouseEvent;
+class QResizeEvent;
+class QWheelEvent;
+
+class PrettyImageView : public QScrollArea {
+  Q_OBJECT
+
+ public:
+  PrettyImageView(QNetworkAccessManager *network, QWidget *parent = nullptr);
+
+  static const char* kSettingsGroup;
+
+ public slots:
+  void AddImage(const QUrl& url);
+
+ protected:
+  void mouseReleaseEvent(QMouseEvent*) override;
+  void resizeEvent(QResizeEvent *e) override;
+  void wheelEvent(QWheelEvent *e) override;
+
+ private slots:
+  void ScrollBarReleased();
+  void ScrollBarAction(const int action);
+  void ScrollTo(const int index, const bool smooth = true);
+  void ScrollToCurrent();
+
+ private:
+  bool eventFilter(QObject*, QEvent*) override;
+
+  QNetworkAccessManager *network_;
+
+  QWidget *container_;
+  QHBoxLayout *layout_;
+
+  int current_index_;
+  QPropertyAnimation *scroll_animation_;
+
+  bool recursion_filter_;
+};
+
+#endif  // PRETTYIMAGEVIEW_H

src/widgets/widgetfadehelper.cpp

@@ -0,0 +1,185 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <QObject>
+#include <QWidget>
+#include <QImage>
+#include <QPixmap>
+#include <QPainter>
+#include <QTimeLine>
+#include <QResizeEvent>
+#include <QEvent>
+
+#include "widgetfadehelper.h"
+#include "core/qt_blurimage.h"
+
+const int WidgetFadeHelper::kLoadingPadding = 9;
+const int WidgetFadeHelper::kLoadingBorderRadius = 10;
+
+WidgetFadeHelper::WidgetFadeHelper(QWidget *parent, const int msec)
+    : QWidget(parent),
+      parent_(parent),
+      blur_timeline_(new QTimeLine(msec, this)),
+      fade_timeline_(new QTimeLine(msec, this)) {
+
+  parent->installEventFilter(this);
+
+  connect(blur_timeline_, SIGNAL(valueChanged(qreal)), SLOT(update()));
+  connect(fade_timeline_, SIGNAL(valueChanged(qreal)), SLOT(update()));
+  connect(fade_timeline_, SIGNAL(finished()), SLOT(FadeFinished()));
+
+  hide();
+
+}
+
+bool WidgetFadeHelper::eventFilter(QObject *obj, QEvent *event) {
+
+  // We're only interested in our parent's resize events
+  if (obj != parent_ || event->type() != QEvent::Resize) return false;
+
+  // Don't care if we're hidden
+  if (!isVisible()) return false;
+
+  QResizeEvent *re = static_cast<QResizeEvent*>(event);
+  if (re->oldSize() == re->size()) {
+    // Ignore phoney resize events
+    return false;
+  }
+
+  // Get a new capture of the parent
+  hide();
+  CaptureParent();
+  show();
+  return false;
+
+}
+
+void WidgetFadeHelper::StartBlur() {
+
+  CaptureParent();
+
+  // Cover the parent
+  raise();
+  show();
+
+  // Start the timeline
+  blur_timeline_->stop();
+  blur_timeline_->start();
+
+  setAttribute(Qt::WA_TransparentForMouseEvents, false);
+
+}
+
+void WidgetFadeHelper::CaptureParent() {
+
+  // Take a "screenshot" of the window
+  original_pixmap_ = parent_->grab();
+  QImage original_image = original_pixmap_.toImage();
+
+  // Blur it
+  QImage blurred(original_image.size(), QImage::Format_ARGB32_Premultiplied);
+  blurred.fill(Qt::transparent);
+
+  QPainter blur_painter(&blurred);
+  blur_painter.save();
+  qt_blurImage(&blur_painter, original_image, 10.0, true, false);
+  blur_painter.restore();
+
+  // Draw some loading text over the top
+  QFont loading_font(font());
+  loading_font.setBold(true);
+  QFontMetrics loading_font_metrics(loading_font);
+
+  const QString loading_text = tr("Loading...");
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 11, 0))
+  const QSize loading_size(kLoadingPadding * 2 + loading_font_metrics.horizontalAdvance(loading_text), kLoadingPadding * 2 + loading_font_metrics.height());
+#else
+  const QSize loading_size(kLoadingPadding * 2 + loading_font_metrics.width(loading_text), kLoadingPadding * 2 + loading_font_metrics.height());
+#endif
+  const QRect loading_rect((blurred.width() - loading_size.width()) / 2, 100, loading_size.width(), loading_size.height());
+
+  blur_painter.setRenderHint(QPainter::Antialiasing);
+
+  blur_painter.translate(0.5, 0.5);
+  blur_painter.setPen(QColor(200, 200, 200, 255));
+  blur_painter.setBrush(QColor(200, 200, 200, 192));
+  blur_painter.drawRoundedRect(loading_rect, kLoadingBorderRadius, kLoadingBorderRadius);
+
+  blur_painter.setPen(palette().brush(QPalette::Text).color());
+  blur_painter.setFont(loading_font);
+  blur_painter.drawText(loading_rect.translated(-1, -1), Qt::AlignCenter, loading_text);
+  blur_painter.translate(-0.5, -0.5);
+
+  blur_painter.end();
+
+  blurred_pixmap_ = QPixmap::fromImage(blurred);
+
+  resize(parent_->size());
+
+}
+
+void WidgetFadeHelper::StartFade() {
+
+  if (blur_timeline_->state() == QTimeLine::Running) {
+    // Blur timeline is still running, so we need render the current state
+    // into a new pixmap.
+    QPixmap pixmap(original_pixmap_);
+    QPainter painter(&pixmap);
+    painter.setOpacity(blur_timeline_->currentValue());
+    painter.drawPixmap(0, 0, blurred_pixmap_);
+    painter.end();
+    blurred_pixmap_ = pixmap;
+  }
+  blur_timeline_->stop();
+  original_pixmap_ = QPixmap();
+
+  // Start the timeline
+  fade_timeline_->stop();
+  fade_timeline_->start();
+
+  setAttribute(Qt::WA_TransparentForMouseEvents, true);
+
+}
+
+void WidgetFadeHelper::paintEvent(QPaintEvent*) {
+
+  QPainter p(this);
+
+  if (fade_timeline_->state() != QTimeLine::Running) {
+    // We're fading in the blur
+    p.drawPixmap(0, 0, original_pixmap_);
+    p.setOpacity(blur_timeline_->currentValue());
+  }
+  else {
+    // Fading out the blur into the new image
+    p.setOpacity(1.0 - fade_timeline_->currentValue());
+  }
+
+  p.drawPixmap(0, 0, blurred_pixmap_);
+
+}
+
+void WidgetFadeHelper::FadeFinished() {
+
+  hide();
+  original_pixmap_ = QPixmap();
+  blurred_pixmap_ = QPixmap();
+
+}

src/widgets/widgetfadehelper.h

@@ -0,0 +1,63 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2010, David Sansome <me@davidsansome.com>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef WIDGETFADEHELPER_H
+#define WIDGETFADEHELPER_H
+
+#include <QWidget>
+#include <QPixmap>
+
+class QTimeLine;
+class QPaintEvent;
+class QEvent;
+
+class WidgetFadeHelper : public QWidget {
+  Q_OBJECT
+
+ public:
+  WidgetFadeHelper(QWidget *parent, const int msec = 500);
+
+ public slots:
+  void StartBlur();
+  void StartFade();
+
+ protected:
+  void paintEvent(QPaintEvent*) override;
+  bool eventFilter(QObject *obj, QEvent *event) override;
+
+ private slots:
+  void FadeFinished();
+
+ private:
+  void CaptureParent();
+
+ private:
+  static const int kLoadingPadding;
+  static const int kLoadingBorderRadius;
+
+  QWidget* parent_;
+  QTimeLine* blur_timeline_;
+  QTimeLine* fade_timeline_;
+
+  QPixmap original_pixmap_;
+  QPixmap blurred_pixmap_;
+};
+
+#endif  // WIDGETFADEHELPER_H