+// https://www.w3.org/TR/CSS22/visudet.html#min-max-heights
+// Specifies a percentage for determining the used value. The percentage is calculated with respect to the height of the generated box's containing block.
+// If the height of the containing block is not specified explicitly (i.e., it depends on content height), and this element is not absolutely positioned,
+// the percentage value is treated as '0' (for 'min-height') or 'none' (for 'max-height').
+std::optional<LayoutUnit> FormattingContext::Geometry::computedMaxHeight(const LayoutContext& layoutContext, const Box& layoutBox)
+{
+ auto maxHeight = layoutBox.style().logicalMaxHeight();
+ if (maxHeight.isUndefined() || maxHeight.isAuto())
+ return { };
+
+ if (maxHeight.isFixed())
+ return { maxHeight.value() };
+
+ std::optional<LayoutUnit> containingBlockHeightValue;
+ auto height = layoutBox.containingBlock()->style().logicalHeight();
+ if (height.isFixed())
+ containingBlockHeightValue = { height.value() };
+ else if (layoutBox.isOutOfFlowPositioned()) {
+ // Containing block's height is already computed.
+ containingBlockHeightValue = layoutContext.displayBoxForLayoutBox(*layoutBox.containingBlock()).height();
+ }
+
+ if (containingBlockHeightValue)
+ return valueForLength(maxHeight, *containingBlockHeightValue);
+
+ return { };
+}
+
+std::optional<LayoutUnit> FormattingContext::Geometry::computedMinHeight(const LayoutContext& layoutContext, const Box& layoutBox)
+{
+ auto minHeight = layoutBox.style().logicalMinHeight();
+ if (minHeight.isUndefined() || minHeight.isAuto())
+ return { };
+
+ if (minHeight.isFixed())
+ return { minHeight.value() };
+
+ std::optional<LayoutUnit> containingBlockHeightValue;
+ auto height = layoutBox.containingBlock()->style().logicalHeight();
+ if (height.isFixed())
+ containingBlockHeightValue = { height.value() };
+ else if (layoutBox.isOutOfFlowPositioned()) {
+ // Containing block's height is already computed.
+ containingBlockHeightValue = layoutContext.displayBoxForLayoutBox(*layoutBox.containingBlock()).height();
+ }
+
+ if (containingBlockHeightValue)
+ return valueForLength(minHeight, *containingBlockHeightValue);
+
+ return { 0 };
+}
+
git://git.webkit.org / WebKit-https.git / commitdiff