Port away from deprecated QStyle::SH_Widget_Animate

Summary:
Use the new QStyle::SH_Widget_Animation_Duration instead,
which allows us to not manually hardcode the duration.
We still use 1 if animations are disabled,
otherwise the scroll would not work at all.

See also D5883 for some background.

Test Plan: Played with different values in the Animation tab of the Breeze config dialog.

Reviewers: #dolphin, broulik

Reviewed By: broulik

Subscribers: broulik

Differential Revision: https://phabricator.kde.org/D10005

1 files changed, 8 insertions, 2 deletions

diff --git a/src/kitemviews/private/kitemlistsmoothscroller.cpp b/src/kitemviews/private/kitemlistsmoothscroller.cpp
index 17eac3b39..77a842838 100644
--- a/src/kitemviews/private/kitemlistsmoothscroller.cpp
+++ b/src/kitemviews/private/kitemlistsmoothscroller.cpp
@@ -35,8 +35,14 @@ KItemListSmoothScroller::KItemListSmoothScroller(QScrollBar* scrollBar,
     m_animation(nullptr)
 {
     m_animation = new QPropertyAnimation(this);
-    const int duration = m_scrollBar->style()->styleHint(QStyle::SH_Widget_Animate, nullptr, m_scrollBar) ? 100 : 1;
-    m_animation->setDuration(duration);
+#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
+    const int animationDuration = m_scrollBar->style()->styleHint(QStyle::SH_Widget_Animation_Duration, nullptr, m_scrollBar);
+    const bool animationEnabled = (animationDuration > 0);
+ #else
+    const int animationDuration = 100;
+    const bool animationEnabled = m_scrollBar->style()->styleHint(QStyle::SH_Widget_Animate, nullptr, m_scrollBar);
+#endif
+    m_animation->setDuration(animationEnabled ? animationDuration : 1);
     connect(m_animation, &QPropertyAnimation::stateChanged,
             this, &KItemListSmoothScroller::slotAnimationStateChanged);