static void updateLineConstrains(const RenderBlockFlow& flow, LineState& line, bool isFirstLine)
{
bool shouldApplyTextIndent = !flow.isAnonymous() || flow.parent()->firstChild() == &flow;
LayoutUnit height = flow.logicalHeight();
LayoutUnit logicalHeight = flow.minLineHeightForReplacedRenderer(false, 0);
float logicalRightOffset = flow.logicalRightOffsetForLine(height, false, logicalHeight);
line.setLogicalLeftOffset(flow.logicalLeftOffsetForLine(height, false, logicalHeight) + (shouldApplyTextIndent && isFirstLine ? flow.textIndentOffset() : LayoutUnit(0)));
line.setAvailableWidth(std::max<float>(0, logicalRightOffset - line.logicalLeftOffset()));
}
static AvoidanceReasonFlags canUseForWithReason(const RenderBlockFlow& flow, FallThrough fallthrough)
{
#ifndef NDEBUG
static std::once_flag onceFlag;
std::call_once(onceFlag, [] {
registerNotifyCallback("com.apple.WebKit.showSimpleLineLayoutCoverage", printSimpleLineLayoutCoverage);
registerNotifyCallback("com.apple.WebKit.showSimpleLineLayoutReasons", printSimpleLineLayoutBlockList);
});
#endif
AvoidanceReasonFlags reasons = NoReason;
if (!flow.frame().settings().simpleLineLayoutEnabled())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FeatureIsDisabled, fallthrough);
if (!flow.parent())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasNoParent, fallthrough);
if (!flow.firstChild())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasNoChild, fallthrough);
if (flow.flowThreadState() != RenderObject::NotInsideFlowThread)
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowIsInsideRegion, fallthrough);
if (!flow.isHorizontalWritingMode())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasHorizonalWritingMode, fallthrough);
if (flow.hasOutline())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasOutline, fallthrough);
if (flow.isRubyText() || flow.isRubyBase())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowIsRuby, fallthrough);
// Printing does pagination without a flow thread.
if (flow.document().paginated())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowIsPaginated, fallthrough);
if (flow.isAnonymous() && flow.firstLineBlock())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasPseudoFirstLine, fallthrough);
if (flow.isAnonymousBlock() && flow.parent()->style().textOverflow())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasTextOverflow, fallthrough);
if (flow.parent()->isDeprecatedFlexibleBox())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowIsDepricatedFlexBox, fallthrough);
// FIXME: Placeholders do something strange.
if (is<RenderTextControl>(*flow.parent()) && downcast<RenderTextControl>(*flow.parent()).textFormControlElement().placeholderElement())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowParentIsPlaceholderElement, fallthrough);
// FIXME: Implementation of wrap=hard looks into lineboxes.
if (flow.parent()->isTextArea() && flow.parent()->element()->fastHasAttribute(HTMLNames::wrapAttr))
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowParentIsTextAreaWithWrapping, fallthrough);
// This currently covers <blockflow>#text</blockflow>, <blockflow>#text<br></blockflow> and mutiple (sibling) RenderText cases.
// The <blockflow><inline>#text</inline></blockflow> case is also popular and should be relatively easy to cover.
for (const auto* child = flow.firstChild(); child;) {
if (is<RenderText>(*child)) {
child = child->nextSibling();
continue;
}
if (is<RenderLineBreak>(child) && !downcast<RenderLineBreak>(*child).isWBR() && child->style().clear() == CNONE) {
child = child->nextSibling();
continue;
}
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasNonSupportedChild, fallthrough);
break;
}
auto styleReasons = canUseForStyle(flow.style(), fallthrough);
if (styleReasons != NoReason)
SET_REASON_AND_RETURN_IF_NEEDED(reasons, styleReasons, fallthrough);
// We can't use the code path if any lines would need to be shifted below floats. This is because we don't keep per-line y coordinates.
if (flow.containsFloats()) {
float minimumWidthNeeded = std::numeric_limits<float>::max();
for (const auto& textRenderer : childrenOfType<RenderText>(flow)) {
minimumWidthNeeded = std::min(minimumWidthNeeded, textRenderer.minLogicalWidth());
for (auto& floatingObject : *flow.floatingObjectSet()) {
ASSERT(floatingObject);
#if ENABLE(CSS_SHAPES)
// if a float has a shape, we cannot tell if content will need to be shifted until after we lay it out,
// since the amount of space is not uniform for the height of the float.
if (floatingObject->renderer().shapeOutsideInfo())
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasUnsupportedFloat, fallthrough);
#endif
float availableWidth = flow.availableLogicalWidthForLine(floatingObject->y(), false);
if (availableWidth < minimumWidthNeeded)
SET_REASON_AND_RETURN_IF_NEEDED(reasons, FlowHasUnsupportedFloat, fallthrough);
}
}
}
auto fontAndTextReasons = canUseForFontAndText(flow, fallthrough);
if (fontAndTextReasons != NoReason)
SET_REASON_AND_RETURN_IF_NEEDED(reasons, fontAndTextReasons, fallthrough);
return reasons;
}