Qt: Extend seekslider to use the old native look

(cherry picked from commit 910b0583beb2523e5e092317c35e26d0856441f5)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt4/util/input_slider.cpp

@@ -55,8 +55,8 @@
 #define FADEDURATION 300
 #define FADEOUTDELAY 2000
 
-SeekSlider::SeekSlider( Qt::Orientation q, QWidget *_parent )
-          : QSlider( q, _parent )
+SeekSlider::SeekSlider( Qt::Orientation q, QWidget *_parent, bool _static )
+          : QSlider( q, _parent ), b_classic( _static )
 {
     isSliding = false;
     f_buffering = 1.0;
@@ -349,7 +349,8 @@ QSize SeekSlider::handleSize() const
 
 void SeekSlider::paintEvent( QPaintEvent *event )
 {
-    Q_UNUSED( event );
+    if( b_classic )
+        return QSlider::paintEvent( event );
 
     QStyleOptionSlider option;
     initStyleOption( &option );

modules/gui/qt4/util/input_slider.hpp

@@ -46,7 +46,7 @@ class SeekSlider : public QSlider
     Q_OBJECT
     Q_PROPERTY(qreal handleOpacity READ handleOpacity WRITE setHandleOpacity)
 public:
-    SeekSlider( Qt::Orientation q, QWidget *_parent = 0 );
+    SeekSlider( Qt::Orientation q, QWidget *_parent = 0, bool _classic = false );
     ~SeekSlider();
     void setChapters( SeekPoints * );
 
@@ -78,6 +78,7 @@ private:
     TimeTooltip *mTimeTooltip;
     float f_buffering;
     SeekPoints* chapters;
+    bool b_classic;
 
     /* Handle's animation */
     qreal mHandleOpacity;