diff options
Diffstat (limited to 'content_scripts')
| -rw-r--r-- | content_scripts/scroller.coffee | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/content_scripts/scroller.coffee b/content_scripts/scroller.coffee index 03be9694..8d6ca128 100644 --- a/content_scripts/scroller.coffee +++ b/content_scripts/scroller.coffee @@ -30,16 +30,19 @@ getDimension = (el, direction, amount) -> amount # Test whether element should be scrolled. -isScrollAllowed = (element, direction) -> +shouldScroll = (element, direction) -> computedStyle = window.getComputedStyle(element) # Elements with `overflow: hidden` should not be scrolled. - return computedStyle.getPropertyValue("overflow-#{direction}") != "hidden" and - ["hidden", "collapse"].indexOf(computedStyle.getPropertyValue("visibility")) == -1 and - computedStyle.getPropertyValue("display") != "none" - -# Test whether element actually scrolls in the direction required when asked to do so. -# Due to chrome bug 110149, scrollHeight and clientHeight cannot be used to reliably determine whether an -# element will scroll. Instead, we scroll the element by 1 or -1 and see if it moved. + return false if computedStyle.getPropertyValue("overflow-#{direction}") == "hidden" + # Non-visible elements should not be scrolled. + return false if ["hidden", "collapse"].indexOf(computedStyle.getPropertyValue("visibility")) != -1 + return false if computedStyle.getPropertyValue("display") == "none" + true + +# Test whether element actually scrolls in the direction required when asked to do so. Due to chrome bug +# 110149, scrollHeight and clientHeight cannot be used to reliably determine whether an element will scroll. +# Instead, we scroll the element by 1 or -1 and see if it moved (then put it back). +# Bug verified in Chrome 38.0.2125.104. isScrollPossible = (element, direction, amount, factor) -> axisName = scrollProperties[direction].axisName # delta, here, is treated as a relative amount, which is correct for relative scrolls. For absolute scrolls @@ -55,10 +58,10 @@ isScrollPossible = (element, direction, amount, factor) -> before != after # Find the element we should and can scroll. -findScrollableElement = (element = document.body, direction, amount, factor = 1) -> +findScrollableElement = (element, direction, amount, factor = 1) -> axisName = scrollProperties[direction].axisName while element != document.body and - not (isScrollPossible(element, direction, amount, factor) and isScrollAllowed(element, direction)) + not (isScrollPossible(element, direction, amount, factor) and shouldScroll(element, direction)) element = element.parentElement || document.body element @@ -87,7 +90,7 @@ performScroll = (element, axisName, amount, checkVisibility = true) -> # Scroll by a relative amount (a number) in some direction, possibly smoothly. doScrollBy = do -> - time = 0 + time = 0 # Logical time. mostRecentActivationId = -1 lastEvent = null keyHandler = null |