[Backend] Reimplement createTimestamp in C++.

src/MpvPlayerBackend.cpp

@@ -8,7 +8,7 @@
 #include <QOpenGLContext>
 #include <QOpenGLFramebufferObject>
 #include <QQuickWindow>
-
+#include <math.h>
 namespace {
 
 void
@@ -282,6 +282,22 @@ MpvPlayerBackend::getTracks() const
   return mpv::qt::get_property_variant(mpv, "track-list");
 }
 
+QVariant
+MpvPlayerBackend::createTimestamp(const QVariant& seconds) const
+{
+  int d = seconds.toInt();
+  double h = floor(d / 3600);
+  double m = floor(d % 3600 / 60);
+  double s = floor(d % 3600 % 60);
+
+  QString hour = h > 0 ? QString::number(h) + ":" : "";
+  QString minute = h < 1 ? QString::number(m) + ":"
+                         : (m < 10 ? "0" + QString::number(m) + ":"
+                                   : QString::number(m) + ":");
+  QString second = s < 10 ? "0" + QString::number(s) : QString::number(s);
+  return hour + minute + second;
+}
+
 void
 MpvPlayerBackend::on_mpv_events()
 {

src/MpvPlayerBackend.h

@@ -45,6 +45,7 @@ public slots:
   void setProperty(const QString& name, const QVariant& value);
   void setOption(const QString& name, const QVariant& value);
   QVariant getProperty(const QString& name) const;
+  QVariant createTimestamp(const QVariant& seconds) const;
 
 signals:
   void onUpdate();

src/qml/main.qml

@@ -145,24 +145,12 @@ ApplicationWindow {
             }
         }
 
-        function createTimestamp(d) {
-            d = Number(d)
-            var h = Math.floor(d / 3600)
-            var m = Math.floor(d % 3600 / 60)
-            var s = Math.floor(d % 3600 % 60)
-
-            var hour = h > 0 ? h + ":" : ""
-            var minute = h < 1 ? m + ":" : (m < 10 ? "0" + m + ":" : m + ":")
-            var second = s < 10 ? "0" + s : s
-            return hour + minute + second
-        }
-
         function setProgressBarEnd(val) {
             progressBar.to = val
         }
 
         function setProgressBarValue(val) {
-            timeLabel.text = createTimestamp(val) + " / " + createTimestamp(
+            timeLabel.text = player.createTimestamp(val) + " / " + player.createTimestamp(
                         progressBar.to) + " (" + parseFloat(
                         player.getProperty("speed").toFixed(2)) + "x)"
             progressBar.value = val