Consolidate logic for calculating scrollbar page step size
https://bugs.webkit.org/show_bug.cgi?id=135670
Reviewed by Simon Fraser.
Consolidate the calculation of the scroll step size into a single place.
Improve the handling of sub-pixel layout behavior by performing proper
rounding on the fractional scroll ranges.
* editing/EditorCommand.cpp:
(WebCore::verticalScrollDistance): Switch to Scrollbar::pageStep method.
* platform/ScrollAnimator.cpp:
(WebCore::ScrollAnimator::handleWheelEvent): Ditto.
* platform/ScrollView.cpp:
(WebCore::ScrollView::updateScrollbars): Ditto.
* platform/Scrollbar.h:
(WebCore::Scrollbar::pageStep): Added.
(WebCore::Scrollbar::pageStepDelta): Added.
* rendering/RenderLayer.cpp:
(WebCore::RenderLayer::updateScrollbarsAfterLayout): Switch to Scrollbar method.
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@172182 268f45cc-cd09-0410-ab3c-d52691b4dbfc
6 files changed
