X-Git-Url: https://cloud.milkyroute.net/gitweb/dolphin.git/blobdiff_plain/32b51b7b92e16cfaf1121cbe80ca267fc8bb0718..b7ad5fb99d32d43fe4e083a8ffc2ebfbd046d2db:/src/kitemviews/private/kitemlistsmoothscroller.cpp

diff --git a/src/kitemviews/private/kitemlistsmoothscroller.cpp b/src/kitemviews/private/kitemlistsmoothscroller.cpp
index 24eea0cef..c89d3cf8f 100644
--- a/src/kitemviews/private/kitemlistsmoothscroller.cpp
+++ b/src/kitemviews/private/kitemlistsmoothscroller.cpp
@@ -19,13 +19,12 @@
 
 #include "kitemlistsmoothscroller.h"
 
-#include <KGlobalSettings>
+#include <QApplication>
 #include <QEvent>
 #include <QPropertyAnimation>
 #include <QScrollBar>
 #include <QWheelEvent>
-
-#include <KDebug>
+#include <QStyle>
 
 KItemListSmoothScroller::KItemListSmoothScroller(QScrollBar* scrollBar,
                                                  QObject* parent) :
@@ -36,7 +35,7 @@ KItemListSmoothScroller::KItemListSmoothScroller(QScrollBar* scrollBar,
     m_animation(0)
 {
     m_animation = new QPropertyAnimation(this);
-    const int duration = (KGlobalSettings::graphicEffectsLevel() == KGlobalSettings::NoEffects) ? 1 : 100;
+    const int duration = m_scrollBar->style()->styleHint(QStyle::SH_Widget_Animate, nullptr, m_scrollBar) ? 100 : 1;
     m_animation->setDuration(duration);
     connect(m_animation, &QPropertyAnimation::stateChanged,
             this, &KItemListSmoothScroller::slotAnimationStateChanged);
@@ -174,7 +173,7 @@ bool KItemListSmoothScroller::eventFilter(QObject* obj, QEvent* event)
 
     case QEvent::Wheel:
         handleWheelEvent(static_cast<QWheelEvent*>(event));
-        break;
+        return true; // eat event so that QScrollBar does not scroll one step more by itself
 
     default:
         break;
@@ -194,15 +193,25 @@ void KItemListSmoothScroller::slotAnimationStateChanged(QAbstractAnimation::Stat
 
 void KItemListSmoothScroller::handleWheelEvent(QWheelEvent* event)
 {
-    const int numDegrees = event->delta() / 8;
-    const int numSteps = numDegrees / 15;
-
     const bool previous = m_smoothScrolling;
 
     m_smoothScrolling = true;
-    const int value = m_scrollBar->value();
-    const int pageStep = m_scrollBar->pageStep();
-    m_scrollBar->setValue(value - numSteps * pageStep);
+    int numPixels;
+    if (!event->pixelDelta().isNull()) {
+        numPixels = event->pixelDelta().y();
+    } else {
+        const int numDegrees = event->angleDelta().y() / 8;
+        const int numSteps = qApp->wheelScrollLines() * numDegrees / 15;
+        numPixels = numSteps * m_scrollBar->pageStep() / 12;
+    }
+    int value = m_scrollBar->value();
+    if (event->modifiers().testFlag(Qt::ShiftModifier)) {
+        const int scrollingDirection = numPixels > 0 ? 1 : -1;
+        value -= m_scrollBar->pageStep() * scrollingDirection;
+    } else {
+        value -= numPixels;
+    }
+    m_scrollBar->setValue(value);
 
     m_smoothScrolling = previous;