tree 70d3f323d5e225e02c005f36d84bebea348f136e
parent 5bd663b95d2fa0048c9b51d7e90d3c09992ceb28
author simon.fraser@apple.com <simon.fraser@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1571684349 +0000
committer simon.fraser@apple.com <simon.fraser@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1571684349 +0000

[iOS WK2] Support hiding iframe scrollbars via ::-webkit-scrollbar style
https://bugs.webkit.org/show_bug.cgi?id=203178

Reviewed by Dean Jackson.
Source/WebCore:

::-webkit-scrollbar {
    display: none;
}
is supported for overflow:scroll, but not for iframes. To make the latter work,
two fixes were necessary.

First, FrameView had to implement horizontalScrollbarHiddenByStyle()/verticalScrollbarHiddenByStyle().
This is a little tricky on iOS because we never create RenderScrollbars, so we have to consult
pseudo-styles directly; a bit of refactoring makes that cleaner.

Second, ScrollableAreaParameters was failing to check horizontalScrollbarHiddenByStyle/verticalScrollbarHiddenByStyle
in operator==, meaning that these data often didn't make it to the UI process.

Test: fast/scrolling/ios/scrollbar-hiding-iframes.html

* page/FrameView.cpp:
(WebCore::FrameView::rootElementForCustomScrollbarPartStyle const):
(WebCore::FrameView::createScrollbar):
(WebCore::FrameView::styleHidesScrollbarWithOrientation const):
(WebCore::FrameView::horizontalScrollbarHiddenByStyle const):
(WebCore::FrameView::verticalScrollbarHiddenByStyle const):
(WebCore::FrameView::updateScrollCorner):
* page/FrameView.h:
* page/scrolling/ScrollingCoordinatorTypes.h:
(WebCore::ScrollableAreaParameters::operator== const):
* platform/Scrollbar.h:
(WebCore::Scrollbar::isHiddenByStyle const):
* rendering/RenderLayer.cpp:
(WebCore::scrollbarHiddenByStyle):
* rendering/RenderScrollbar.cpp:
(WebCore::RenderScrollbar::getScrollbarPseudoStyle const):
(WebCore::RenderScrollbar::isHiddenByStyle const):
(WebCore::RenderScrollbar::getScrollbarPseudoStyle): Deleted.
* rendering/RenderScrollbar.h:

LayoutTests:

Tests that dumps the scrolling tree.

* fast/scrolling/ios/scrollbar-hiding-iframes-expected.txt: Added.
* fast/scrolling/ios/scrollbar-hiding-iframes.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@251369 268f45cc-cd09-0410-ab3c-d52691b4dbfc