Tray icon gets dimmer when you play more of a track

TODO

@@ -5,6 +5,10 @@
 - Copy to library, move to library
 - Global shortcut keys
 - Clicking play plays selected item
+- Configuration for:
+  - crossfading
+  - osd
+- If there's only one node in a library item then expand it when expanding the parent
 
 - Edit tags in playlist view
 - Disabled fields in tag editor

src/mainwindow.cpp

@@ -281,6 +281,7 @@ void MainWindow::MediaStopped() {
 
   track_position_timer_->stop();
   track_slider_->SetStopped();
+  tray_icon_->SetProgress(0);
 }
 
 void MainWindow::MediaPaused() {
@@ -403,8 +404,11 @@ void MainWindow::FilePathChanged(const QString& path) {
 }
 
 void MainWindow::UpdateTrackPosition() {
-  int position = std::floor(float(player_->GetEngine()->position()) / 1000.0 + 0.5);
+  // Track position in seconds
+  const int position = std::floor(float(player_->GetEngine()->position()) / 1000.0 + 0.5);
+  const int length = playlist_->current_item()->Metadata().length();
 
+  // Time to scrobble?
   LastFMService* lastfm = radio_model_->GetLastFMService();
 
   if (!playlist_->has_scrobbled() &&
@@ -413,7 +417,13 @@ void MainWindow::UpdateTrackPosition() {
     playlist_->set_scrobbled(true);
   }
 
-  track_slider_->SetValue(position, playlist_->current_item()->Metadata().length());
+  // Update the slider
+  track_slider_->SetValue(position, length);
+
+  // Update the tray icon every 10 seconds
+  if (position % 10 == 1) {
+    tray_icon_->SetProgress(double(position) / length * 100);
+  }
 }
 
 void MainWindow::Love() {

src/systemtrayicon.cpp

@@ -2,6 +2,10 @@
 
 #include <QEvent>
 #include <QWheelEvent>
+#include <QPainter>
+#include <QtDebug>
+
+#include <cmath>
 
 SystemTrayIcon::SystemTrayIcon(QObject* parent)
   : QSystemTrayIcon(parent)
@@ -15,3 +19,40 @@ bool SystemTrayIcon::event(QEvent* event) {
   }
   return QSystemTrayIcon::event(event);
 }
+
+void SystemTrayIcon::SetProgress(int percentage) {
+  if (icon_.isNull()) {
+    icon_ = icon().pixmap(geometry().size(), QIcon::Normal);
+    grey_icon_ = icon().pixmap(geometry().size(), QIcon::Disabled);
+
+    if (icon_.isNull())
+      return;
+  }
+
+  QRect rect(icon_.rect());
+
+  // The angle of the line that's used to cover the icon.
+  // Centered on rect.topRight()
+  double angle = double(100 - percentage) / 100.0 * M_PI_2 + M_PI;
+  double length = sqrt(pow(rect.width(), 2.0) + pow(rect.height(), 2.0));
+
+  QPolygon mask;
+  mask << rect.topRight();
+  mask << rect.topRight() + QPoint(
+      length * sin(angle),
+      - length * cos(angle));
+
+  if (percentage > 50)
+    mask << rect.bottomLeft();
+
+  mask << rect.topLeft();
+  mask << rect.topRight();
+
+  QPixmap icon(icon_);
+  QPainter p(&icon);
+  p.setClipRegion(mask);
+  p.drawPixmap(0, 0, grey_icon_);
+  p.end();
+
+  setIcon(icon);
+}

src/systemtrayicon.h

@@ -11,8 +11,15 @@ class SystemTrayIcon : public QSystemTrayIcon {
 
   bool event(QEvent* event);
 
+ public slots:
+  void SetProgress(int percentage);
+
  signals:
   void WheelEvent(int delta);
+
+ private:
+  QPixmap icon_;
+  QPixmap grey_icon_;
 };
 
 #endif // SYSTEMTRAYICON_H