Add an extra line to the track slider popup to show the difference between the current time and the destination time.

src/core/utilities.cpp

@@ -45,6 +45,10 @@ static QString tr(const char* str) {
   return QCoreApplication::translate("", str);
 }
 
+QString PrettyTimeDelta(int seconds) {
+  return (seconds >= 0 ? "+" : "-") + PrettyTime(seconds);
+}
+
 QString PrettyTime(int seconds) {
   // last.fm sometimes gets the track length wrong, so you end up with
   // negative times.

src/core/utilities.h

@@ -28,6 +28,7 @@ class QIODevice;
 
 namespace Utilities {
   QString PrettyTime(int seconds);
+  QString PrettyTimeDelta(int seconds);
   QString PrettyTimeNanosec(qint64 nanoseconds);
   QString PrettySize(quint64 bytes);
   QString WordyTime(quint64 seconds);

src/widgets/tracksliderpopup.cpp

@@ -18,14 +18,17 @@ void qt_blurImage(QPainter *p, QImage &blurImage, qreal radius, bool quality, bo
 
 TrackSliderPopup::TrackSliderPopup(QWidget* parent)
   : QWidget(parent),
-    font_metrics_(fontMetrics())
+    font_metrics_(fontMetrics()),
+    small_font_metrics_(fontMetrics())
 {
   setAttribute(Qt::WA_TransparentForMouseEvents);
   setMouseTracking(true);
 
   font_.setPointSizeF(7.5);
   font_.setBold(true);
+  small_font_.setPointSizeF(6.5);
   font_metrics_ = QFontMetrics(font_);
+  small_font_metrics_ = QFontMetrics(small_font_);
 }
 
 void TrackSliderPopup::SetText(const QString& text) {
@@ -33,6 +36,11 @@ void TrackSliderPopup::SetText(const QString& text) {
   UpdatePixmap();
 }
 
+void TrackSliderPopup::SetSmallText(const QString& text) {
+  small_text_ = text;
+  UpdatePixmap();
+}
+
 void TrackSliderPopup::SetPopupPosition(const QPoint& pos) {
   pos_ = pos;
   UpdatePosition();
@@ -44,10 +52,15 @@ void TrackSliderPopup::paintEvent(QPaintEvent*) {
 }
 
 void TrackSliderPopup::UpdatePixmap() {
-  const QRect text_rect(kBlurRadius + kTextMargin, kBlurRadius + kTextMargin,
-                        font_metrics_.width(text_) + 2, font_metrics_.height());
-  const int bubble_bottom = text_rect.bottom() + kTextMargin;
-  const QRect total_rect(0, 0, text_rect.right() + kBlurRadius + kTextMargin,
+  const int text_width = qMax(font_metrics_.width(text_),
+                              small_font_metrics_.width(small_text_));
+  const QRect text_rect1(kBlurRadius + kTextMargin, kBlurRadius + kTextMargin,
+                         text_width + 2, font_metrics_.height());
+  const QRect text_rect2(kBlurRadius + kTextMargin, text_rect1.bottom(),
+                         text_width, small_font_metrics_.height());
+
+  const int bubble_bottom = text_rect2.bottom() + kTextMargin;
+  const QRect total_rect(0, 0, text_rect1.right() + kBlurRadius + kTextMargin,
                          kBlurRadius + bubble_bottom + kPointLength);
   const QRect bubble_rect(kBlurRadius, kBlurRadius,
                           total_rect.width() - kBlurRadius * 2,
@@ -127,7 +140,12 @@ void TrackSliderPopup::UpdatePixmap() {
   // Text
   p.setPen(palette().color(QPalette::Text));
   p.setFont(font_);
-  p.drawText(text_rect, Qt::AlignHCenter, text_);
+  p.drawText(text_rect1, Qt::AlignHCenter, text_);
+
+  p.setFont(small_font_);
+  p.setOpacity(0.65);
+  p.drawText(text_rect2, Qt::AlignHCenter, small_text_);
+
   p.end();
 
   resize(pixmap_.size());

src/widgets/tracksliderpopup.h

@@ -11,6 +11,7 @@ public:
 
 public slots:
   void SetText(const QString& text);
+  void SetSmallText(const QString& small_text);
   void SetPopupPosition(const QPoint& pos);
 
 protected:
@@ -29,10 +30,13 @@ private:
 
 private:
   QString text_;
+  QString small_text_;
   QPoint pos_;
 
   QFont font_;
+  QFont small_font_;
   QFontMetrics font_metrics_;
+  QFontMetrics small_font_metrics_;
   QPixmap pixmap_;
   QPixmap background_cache_;
 };

src/widgets/tracksliderslider.cpp

@@ -74,8 +74,10 @@ void TrackSliderSlider::mouseMoveEvent(QMouseEvent* e) {
   int seconds = QStyle::sliderValueFromPosition(
       minimum(), maximum(), e->x() - slider_length/2 - slider_min + 1,
       slider_max - slider_min);
+  int delta_seconds = seconds - value();
 
   popup_->SetText(Utilities::PrettyTime(seconds));
+  popup_->SetSmallText(Utilities::PrettyTimeDelta(delta_seconds));
   popup_->SetPopupPosition(mapTo(window(), QPoint(
       e->x(), rect().center().y())));
 }