[CSS Regions] position: fixed is computed relative to the first region, not the viewport
https://bugs.webkit.org/show_bug.cgi?id=111176
Reviewed by David Hyatt.
Source/WebCore:
Fixed positioned elements inside a named flow should be positioned and sized relative to the viewport,
not on the first region, as described in the spec: http://dev.w3.org/csswg/css-regions/#the-flow-into-property.
While the flow thread will still act as containing block for the fixed positioned elements, the painting and hit
testing for the fixed positioned elements is done by RenderView. The layers for the fixed positioned elements
are collected by the flow thread.
Tests: fast/regions/element-in-named-flow-absolute-from-fixed.html
fast/regions/element-in-named-flow-fixed-from-absolute.html
fast/regions/element-inflow-fixed-from-outflow-static.html
fast/regions/element-outflow-static-from-inflow-fixed.html
fast/regions/fixed-element-transformed-parent.html
fast/regions/fixed-in-named-flow-scroll.html
fast/regions/fixed-inside-fixed-in-named-flow.html
fast/regions/fixed-inside-named-flow-zIndex.html
fast/regions/fixed-pos-elem-in-namedflow-noregions.html
fast/regions/fixed-pos-region-in-nested-flow.html
- rendering/FlowThreadController.cpp:
(WebCore::FlowThreadController::collectFixedPositionedLayers):
Return the list of layers for the fixed positioned elements with named flows as containing blocks.
Used in RenderLayer:: paintFixedLayersInNamedFlows and RenderLayer:: hitTestFixedLayersInNamedFlows.
- rendering/FlowThreadController.h:
- rendering/RenderBox.cpp:
(WebCore::RenderBox::mapLocalToContainer):
(WebCore::RenderBox::containingBlockLogicalWidthForPositioned):
(WebCore::RenderBox::containingBlockLogicalHeightForPositioned):
For fixed positioned elements, width and height are given by the view instead of the first region.
- rendering/RenderLayer.cpp:
(WebCore::accumulateOffsetTowardsAncestor):
Modified for the fixed positioned elements inside named flows with the named flows as containing block
to take into account the view scroll.
(WebCore::compareZIndex):
Moved upwards because it is used in RenderLayer::paintFixedLayersInNamedFlows.
(WebCore::RenderLayer::paintFixedLayersInNamedFlows):
Paint the list of fixed layers directly from the RenderView instead of painting them through regions -> named flows.
(WebCore::RenderLayer::paintLayerContents):
(WebCore::RenderLayer::paintList):
(WebCore::RenderLayer::hitTestFixedLayersInNamedFlows):
Hit test the layers for the fix positioned elements inside named flows from the RenderView layer
instead of the region -> named flow layer.
(WebCore::RenderLayer::hitTestLayer):
(WebCore::RenderLayer::calculateRects):
- rendering/RenderLayer.h:
- rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::updateLayerTreeGeometry):
We do not support yet the accelerated compositing for elements in named flows,
so bail out early here. We need to revisit fixed elements once we finish accelerated compositing for elements in named flows.
- rendering/RenderObject.cpp:
(WebCore::RenderObject::fixedPositionedWithNamedFlowContainingBlock):
(WebCore::hasFixedPosInNamedFlowContainingBlock):
(WebCore::RenderObject::containerForRepaint):
Changed to take into account that RenderView should be the repaintContainer for the
fixed positioned elements with named flow as the containing block.
- rendering/RenderObject.h:
LayoutTests:
Added new tests and changed the existing ones that were relying on incorrect positioning
for fixed elements.
- fast/regions/element-in-named-flow-absolute-from-fixed-expected.txt: Added.
- fast/regions/element-in-named-flow-absolute-from-fixed.html: Added.
- fast/regions/element-in-named-flow-fixed-from-absolute-expected.txt: Added.
- fast/regions/element-in-named-flow-fixed-from-absolute.html: Added.
- fast/regions/element-inflow-fixed-from-outflow-static-expected.txt: Added.
- fast/regions/element-inflow-fixed-from-outflow-static.html: Added.
- fast/regions/element-outflow-static-from-inflow-fixed-expected.txt: Added.
- fast/regions/element-outflow-static-from-inflow-fixed.html: Added.
- fast/regions/fixed-element-transformed-parent-expected.txt: Added.
- fast/regions/fixed-element-transformed-parent.html: Added.
- fast/regions/fixed-in-named-flow-scroll-expected.txt: Added.
- fast/regions/fixed-in-named-flow-scroll.html: Added.
- fast/regions/fixed-inside-fixed-in-named-flow-expected.html: Added.
- fast/regions/fixed-inside-fixed-in-named-flow.html: Added.
- fast/regions/fixed-inside-named-flow-zIndex-expected.html: Added.
- fast/regions/fixed-inside-named-flow-zIndex.html: Added.
- fast/regions/fixed-pos-elem-in-namedflow-noregions-expected.html: Added.
- fast/regions/fixed-pos-elem-in-namedflow-noregions.html: Added.
- fast/regions/fixed-pos-elem-in-region-expected.html:
- fast/regions/fixed-pos-elem-in-region.html:
- fast/regions/fixed-pos-region-in-nested-flow-expected.html: Added.
- fast/regions/fixed-pos-region-in-nested-flow.html: Added.
