dpi-dependent methods

libs/widgets/rangeslider.cpp

@@ -31,9 +31,9 @@ RangeSlider::RangeSlider(Qt::Orientation ori, Mode m, QWidget * parent)
 
 void RangeSlider::init() {
 	setMouseTracking(true);
-	scHandleSideLength = 16*lineThickness();
-	scSliderBarHeight = 8*lineThickness();
-	scLeftRightMargin = 2*lineThickness();
+	scHandleSideLength = 16*lineThickness(this);
+	scSliderBarHeight = 8*lineThickness(this);
+	scLeftRightMargin = 2*lineThickness(this);
 }
 
 void RangeSlider::paintEvent(QPaintEvent *) {