mpvpart: add isSeekable() check

Signed-off-by: Mavridis Philippe <mavridisf@gmail.com>

kaffeine/src/player-parts/libmpv-part/libmpv_part.cpp

@@ -392,12 +392,26 @@ bool MpvPart::isStream() {
     return false;
 }
 
+bool MpvPart::isSeekable() {
+    if (!m_mpv) return false;
+
+    int result;
+    if (mpv_get_property(m_mpv, "seekable", MPV_FORMAT_FLAG, &result) < 0) {
+        return false;
+    }
+    return (bool)result;
+}
+
 void MpvPart::resetTime() {
     m_playtime->setText("0:00:00");
     m_position->setValue(0);
 }
 
 void MpvPart::slotStartSeeking() {
+    if (!isSeekable()) {
+        emit setStatusBarText( i18n("Cannot seek current file!") );
+        return;
+    }
     m_seeking = true;
     slotPause(true);
 }

kaffeine/src/player-parts/libmpv-part/libmpv_part.h

@@ -69,6 +69,7 @@ class MpvPart : public KaffeinePart
         bool isPaused();
         bool isMute();
         bool isStream();
+        bool isSeekable();
 
         bool closeURL();
         static TDEAboutData* createAboutData();