void GraphicsLayer::didScroll()
{
if (m_scrollableArea) {
DoublePoint newPosition = m_scrollableArea->minimumScrollPosition() + toDoubleSize(m_layer->layer()->scrollPositionDouble());
// FIXME: Remove the toFloatPoint(). crbug.com/414283.
m_scrollableArea->scrollToOffsetWithoutAnimation(toFloatPoint(newPosition));
}
}
LayoutRect RootFrameViewport::scrollIntoView(const LayoutRect& rectInContent, const ScrollAlignment& alignX, const ScrollAlignment& alignY)
{
// We want to move the rect into the viewport that excludes the scrollbars so we intersect
// the visual viewport with the scrollbar-excluded frameView content rect. However, we don't
// use visibleContentRect directly since it floors the scroll position. Instead, we use
// FrameView::scrollPositionDouble and construct a LayoutRect from that (the FrameView size
// is always integer sized.
LayoutRect frameRectInContent = LayoutRect(
layoutViewport().scrollPositionDouble(),
layoutViewport().visibleContentRect().size());
LayoutRect visualRectInContent = LayoutRect(
layoutViewport().scrollPositionDouble() + toDoubleSize(visualViewport().scrollPositionDouble()),
visualViewport().visibleContentRect().size());
LayoutRect viewRectInContent = intersection(visualRectInContent, frameRectInContent);
LayoutRect targetViewport =
ScrollAlignment::getRectToExpose(viewRectInContent, rectInContent, alignX, alignY);
// visualViewport.scrollIntoView will attempt to center the given rect within the viewport
// so to prevent it from adjusting r's coordinates the rect must match the viewport's size
// i.e. add the subtracted scrollbars from above back in.
// FIXME: This is hacky and required because getRectToExpose doesn't naturally account
// for the two viewports. crbug.com/449340.
targetViewport.setSize(LayoutSize(visualViewport().visibleContentRect().size()));
// Snap the visible rect to layout units to match the calculated target viewport rect.
FloatRect visible =
LayoutRect(visualViewport().scrollPositionDouble(), visualViewport().visibleContentRect().size());
float centeringOffsetX = (visible.width() - targetViewport.width()) / 2;
float centeringOffsetY = (visible.height() - targetViewport.height()) / 2;
DoublePoint targetOffset(
targetViewport.x() - centeringOffsetX,
targetViewport.y() - centeringOffsetY);
setScrollPosition(targetOffset, ProgrammaticScroll);
// RootFrameViewport only changes the viewport relative to the document so we can't change the input
// rect's location relative to the document origin.
return rectInContent;
}
ScrollResult RootFrameViewport::handleWheel(const PlatformWheelEvent& event)
{
updateScrollAnimator();
ScrollableArea& primary = !m_invertScrollOrder ? layoutViewport() : visualViewport();
ScrollableArea& secondary = !m_invertScrollOrder ? visualViewport() : layoutViewport();
ScrollResult viewScrollResult = primary.handleWheel(event);
// The visual viewport will only accept pixel scrolls.
if (!event.canScroll() || event.granularity() == ScrollByPageWheelEvent)
return viewScrollResult;
// TODO(sataya.m) : The delta in PlatformWheelEvent is negative when scrolling the
// wheel towards the user, so negate it to get the scroll delta that should be applied
// to the page. unusedScrollDelta computed in the ScrollResult is also negative. Say
// there is WheelEvent({0, -10} and page scroll by 2px and unusedScrollDelta computed
// is {0, -8}. Due to which we have to negate the unusedScrollDelta to obtain the expected
// animation.Please address http://crbug.com/504389.
DoublePoint oldOffset = secondary.scrollPositionDouble();
DoublePoint locationDelta;
if (viewScrollResult.didScroll()) {
locationDelta = -DoublePoint(viewScrollResult.unusedScrollDeltaX, viewScrollResult.unusedScrollDeltaY);
} else {
if (event.railsMode() != PlatformEvent::RailsModeVertical)
locationDelta.setX(-event.deltaX());
if (event.railsMode() != PlatformEvent::RailsModeHorizontal)
locationDelta.setY(-event.deltaY());
}
DoublePoint targetPosition = secondary.clampScrollPosition(
secondary.scrollPositionDouble() + toDoubleSize(locationDelta));
secondary.setScrollPosition(targetPosition, UserScroll);
DoublePoint usedLocationDelta(secondary.scrollPositionDouble() - oldOffset);
bool didScrollX = viewScrollResult.didScrollX || usedLocationDelta.x();
bool didScrollY = viewScrollResult.didScrollY || usedLocationDelta.y();
return ScrollResult(didScrollX, didScrollY, -viewScrollResult.unusedScrollDeltaX - usedLocationDelta.x(), -viewScrollResult.unusedScrollDeltaY - usedLocationDelta.y());
}
DoublePoint RootFrameViewport::maximumScrollPositionDouble() const
{
return layoutViewport().maximumScrollPositionDouble() + toDoubleSize(visualViewport().maximumScrollPositionDouble());
}
