Modified: trunk/Source/WebCore/layout/blockformatting/BlockMarginCollapse.cpp (240435 => 240436)
--- trunk/Source/WebCore/layout/blockformatting/BlockMarginCollapse.cpp 2019-01-24 16:10:43 UTC (rev 240435)
+++ trunk/Source/WebCore/layout/blockformatting/BlockMarginCollapse.cpp 2019-01-24 17:15:46 UTC (rev 240436)
@@ -156,6 +156,9 @@
auto& previousInFlowSibling = *layoutBox.previousInFlowSibling();
+ if (Quirks::shouldIgnoreMarginAfter(layoutState, previousInFlowSibling))
+ return false;
+
// Margins between a floated box and any other box do not collapse.
if (layoutBox.isFloatingPositioned() || previousInFlowSibling.isFloatingPositioned())
return false;
@@ -200,6 +203,9 @@
return false;
auto& firstInFlowChild = *downcast<Container>(layoutBox).firstInFlowChild();
+ if (Quirks::shouldIgnoreMarginBefore(layoutState, firstInFlowChild))
+ return false;
+
if (!firstInFlowChild.isBlockLevelBox())
return false;
@@ -320,6 +326,9 @@
return false;
auto& lastInFlowChild = *downcast<Container>(layoutBox).lastInFlowChild();
+ if (Quirks::shouldIgnoreMarginAfter(layoutState, lastInFlowChild))
+ return false;
+
if (!lastInFlowChild.isBlockLevelBox())
return false;
@@ -535,27 +544,15 @@
PositiveAndNegativeVerticalMargin::Values BlockFormattingContext::MarginCollapse::positiveNegativeMarginBefore(const LayoutState& layoutState, const Box& layoutBox, const UsedVerticalMargin::NonCollapsedValues& nonCollapsedValues)
{
auto firstChildCollapsedMarginBefore = [&]() -> PositiveAndNegativeVerticalMargin::Values {
- if (!is<Container>(layoutBox))
- return { };
- auto* firstInFlowChild = downcast<Container>(layoutBox).firstInFlowChild();
- if (!firstInFlowChild)
- return { };
if (!marginBeforeCollapsesWithFirstInFlowChildMarginBefore(layoutState, layoutBox))
return { };
- if (Quirks::shouldIgnoreMarginBefore(layoutState, *firstInFlowChild))
- return { };
- return positiveNegativeValues(layoutState, *firstInFlowChild, MarginType::Before);
+ return positiveNegativeValues(layoutState, *downcast<Container>(layoutBox).firstInFlowChild(), MarginType::Before);
};
auto previouSiblingCollapsedMarginAfter = [&]() -> PositiveAndNegativeVerticalMargin::Values {
- auto* previousInFlowSibling = layoutBox.previousInFlowSibling();
- if (!previousInFlowSibling)
- return { };
if (!marginBeforeCollapsesWithPreviousSiblingMarginAfter(layoutState, layoutBox))
return { };
- if (Quirks::shouldIgnoreMarginAfter(layoutState, *previousInFlowSibling))
- return { };
- return positiveNegativeValues(layoutState, *previousInFlowSibling, MarginType::After);
+ return positiveNegativeValues(layoutState, *downcast<Container>(layoutBox).previousInFlowSibling(), MarginType::After);
};
// 1. Gather positive and negative margin values from first child if margins are adjoining.
@@ -568,16 +565,9 @@
PositiveAndNegativeVerticalMargin::Values BlockFormattingContext::MarginCollapse::positiveNegativeMarginAfter(const LayoutState& layoutState, const Box& layoutBox, const UsedVerticalMargin::NonCollapsedValues& nonCollapsedValues)
{
auto lastChildCollapsedMarginAfter = [&]() -> PositiveAndNegativeVerticalMargin::Values {
- if (!is<Container>(layoutBox))
- return { };
- auto* lastInFlowChild = downcast<Container>(layoutBox).lastInFlowChild();
- if (!lastInFlowChild)
- return { };
if (!marginAfterCollapsesWithLastInFlowChildMarginAfter(layoutState, layoutBox))
return { };
- if (Quirks::shouldIgnoreMarginAfter(layoutState, *lastInFlowChild))
- return { };
- return positiveNegativeValues(layoutState, *lastInFlowChild, MarginType::After);
+ return positiveNegativeValues(layoutState, *downcast<Container>(layoutBox).lastInFlowChild(), MarginType::After);
};
// We don't know yet the margin before value of the next sibling. Let's just pretend it does not have one and
@@ -624,20 +614,28 @@
// 1. Get min/max margin top values from the first in-flow child if we are collapsing margin top with it.
// 2. Get min/max margin top values from the previous in-flow sibling, if we are collapsing margin top with it.
// 3. Get this layout box's computed margin top value.
- // 4. Update the min/max value and compute the final margin.
+ // 4. Update the min/max value and compute the final margin.
auto positiveNegativeMarginBefore = MarginCollapse::positiveNegativeMarginBefore(layoutState, layoutBox, nonCollapsedValues);
auto positiveNegativeMarginAfter = MarginCollapse::positiveNegativeMarginAfter(layoutState, layoutBox, nonCollapsedValues);
- auto marginsCollapseThrough = MarginCollapse::marginsCollapseThrough(layoutState, layoutBox);
+ auto marginsCollapseThrough = MarginCollapse::marginsCollapseThrough(layoutState, layoutBox);
if (marginsCollapseThrough) {
positiveNegativeMarginBefore = computedPositiveAndNegativeMargin(positiveNegativeMarginBefore, positiveNegativeMarginAfter);
- positiveNegativeMarginAfter = positiveNegativeMarginBefore;
+ positiveNegativeMarginAfter = positiveNegativeMarginBefore;
}
+ // FIXME: Move state saving out of this function.
auto& blockFormattingState = downcast<BlockFormattingState>(layoutState.formattingStateForBox(layoutBox));
blockFormattingState.setPositiveAndNegativeVerticalMargin(layoutBox, { positiveNegativeMarginBefore, positiveNegativeMarginAfter });
- return { marginValue(positiveNegativeMarginBefore), marginValue(positiveNegativeMarginAfter), marginsCollapseThrough };
+ auto beforeMarginIsCollapsedValue = marginBeforeCollapsesWithFirstInFlowChildMarginBefore(layoutState, layoutBox) || marginBeforeCollapsesWithPreviousSiblingMarginAfter(layoutState, layoutBox);
+ auto afterMarginIsCollapsedValue = marginAfterCollapsesWithLastInFlowChildMarginAfter(layoutState, layoutBox);
+
+ if ((beforeMarginIsCollapsedValue && afterMarginIsCollapsedValue) || marginsCollapseThrough)
+ return { marginValue(positiveNegativeMarginBefore), marginValue(positiveNegativeMarginAfter), marginsCollapseThrough };
+ if (beforeMarginIsCollapsedValue)
+ return { marginValue(positiveNegativeMarginBefore), { }, false };
+ return { { }, marginValue(positiveNegativeMarginAfter), false };
}
}
