QScrollBar: fix horizontal scrollbars in RTL mode

When a QScrollBar had a stylesheet the subControlRect() was not properly
mirrored which lead to a wrong scrolling behavior.
Fix it by adjusting the resulting rect with visualRect().
This reverts 00c9ec63a552d040e851b561c11428fabf1a2b08 since it did not
completely fixed the issue for all use cases.

Fixes: QTBUG-27279
Fixes: QTBUG-38748
Fixes: QTBUG-40443
Change-Id: I19718287be7b4cfc9dbe6951fff99ae48264a855
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

1 files changed, 6 insertions, 10 deletions

diff --git a/src/widgets/styles/qstylesheetstyle.cpp b/src/widgets/styles/qstylesheetstyle.cpp
index fe6a4d0e40..96c6fdf2e2 100644
--- a/src/widgets/styles/qstylesheetstyle.cpp
+++ b/src/widgets/styles/qstylesheetstyle.cpp
@@ -5632,22 +5632,18 @@ QRect QStyleSheetStyle::subControlRect(ComplexControl cc, const QStyleOptionComp
                     } else {
                         sliderlen = maxlen;
                     }
-                    const int sliderPosition = sb->orientation == Qt::Horizontal && sb->direction == Qt::RightToLeft ? sb->maximum - sb->sliderPosition + sb->minimum : sb->sliderPosition;
                     int sliderstart = (styleOptionSlider.orientation == Qt::Horizontal ? contentRect.left() : contentRect.top())
-                        + sliderPositionFromValue(sb->minimum, sb->maximum, sliderPosition,
+                        + sliderPositionFromValue(sb->minimum, sb->maximum, sb->sliderPosition,
                                                   maxlen - sliderlen, sb->upsideDown);
 
                     QRect sr = (sb->orientation == Qt::Horizontal)
                                ? QRect(sliderstart, contentRect.top(), sliderlen, contentRect.height())
                                : QRect(contentRect.left(), sliderstart, contentRect.width(), sliderlen);
-                    if (sc == SC_ScrollBarSlider) {
-                        return sr;
-                    } else if (sc == SC_ScrollBarSubPage) {
-                        return QRect(contentRect.topLeft(), sb->orientation == Qt::Horizontal ? sr.bottomLeft() : sr.topRight());
-                    } else { // SC_ScrollBarAddPage
-                        return QRect(sb->orientation == Qt::Horizontal ? sr.topRight() : sr.bottomLeft(), contentRect.bottomRight());
-                    }
-                    break;
+                    if (sc == SC_ScrollBarSubPage)
+                        sr = QRect(contentRect.topLeft(), sb->orientation == Qt::Horizontal ? sr.bottomLeft() : sr.topRight());
+                    else if (sc == SC_ScrollBarAddPage)
+                        sr = QRect(sb->orientation == Qt::Horizontal ? sr.topRight() : sr.bottomLeft(), contentRect.bottomRight());
+                    return visualRect(styleOptionSlider.direction, grooveRect, sr);
                 }
                 case SC_ScrollBarAddLine: pe = PseudoElement_ScrollBarAddLine; break;
                 case SC_ScrollBarSubLine: pe = PseudoElement_ScrollBarSubLine; break;