Support intrinsic values for height, min-height and max-height

Source/WebCore/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 489 matching lines @@
 }
 
 LayoutUnit RenderBox::constrainLogicalWidthInRegionByMinMax(LayoutUnit logicalWidth, LayoutUnit availableWidth, RenderBlock* cb, RenderRegion* region, LayoutUnit offsetFromLogicalTopOfFirstPage) const
 {
     RenderStyle* styleToUse = style();
     if (!styleToUse->logicalMaxWidth().isUndefined())
         logicalWidth = min(logicalWidth, computeLogicalWidthInRegionUsing(MaxSize, styleToUse->logicalMaxWidth(), availableWidth, cb, region, offsetFromLogicalTopOfFirstPage));
     return max(logicalWidth, computeLogicalWidthInRegionUsing(MinSize, styleToUse->logicalMinWidth(), availableWidth, cb, region, offsetFromLogicalTopOfFirstPage));
 }
 
-LayoutUnit RenderBox::constrainLogicalHeightByMinMax(LayoutUnit logicalHeight) const
+LayoutUnit RenderBox::constrainLogicalHeightByMinMax(LayoutUnit logicalHeight, LayoutUnit contentHeight) const
 {
     RenderStyle* styleToUse = style();
     if (!styleToUse->logicalMaxHeight().isUndefined()) {
-        LayoutUnit maxH = computeLogicalHeightUsing(styleToUse->logicalMaxHeight());
+        LayoutUnit maxH = computeLogicalHeightUsing(styleToUse->logicalMaxHeight(), contentHeight);
         if (maxH != -1)
             logicalHeight = min(logicalHeight, maxH);
     }
-    return max(logicalHeight, computeLogicalHeightUsing(styleToUse->logicalMinHeight()));
+    return max(logicalHeight, computeLogicalHeightUsing(styleToUse->logicalMinHeight(), contentHeight));
 }
 
-LayoutUnit RenderBox::constrainContentBoxLogicalHeightByMinMax(LayoutUnit logicalHeight) const
+LayoutUnit RenderBox::constrainContentBoxLogicalHeightByMinMax(LayoutUnit logicalHeight, LayoutUnit contentHeight) const
 {
     RenderStyle* styleToUse = style();
     if (!styleToUse->logicalMaxHeight().isUndefined()) {
-        LayoutUnit maxH = computeContentLogicalHeight(styleToUse->logicalMaxHeight());
+        LayoutUnit maxH = computeContentLogicalHeight(styleToUse->logicalMaxHeight(), contentHeight);
         if (maxH != -1)
             logicalHeight = min(logicalHeight, maxH);
     }
-    return max(logicalHeight, computeContentLogicalHeight(styleToUse->logicalMinHeight()));
+    return max(logicalHeight, computeContentLogicalHeight(styleToUse->logicalMinHeight(), contentHeight));
 }
 
 IntRect RenderBox::absoluteContentBox() const
 {
     // This is wrong with transforms and flipped writing modes.
     IntRect rect = pixelSnappedIntRect(contentBoxRect());
     FloatPoint absPos = localToAbsolute();
     rect.move(absPos.x(), absPos.y());
     return rect;
 }
@@ skipping 1963 matching lines @@
         // FIXME: Account for block-flow in flexible boxes.
         // https://bugs.webkit.org/show_bug.cgi?id=46418
         if (h.isAuto() && parent()->isDeprecatedFlexibleBox() && parent()->style()->boxOrient() == HORIZONTAL
                 && parent()->isStretchingChildren()) {
             h = Length(parentBox()->contentLogicalHeight() - marginBefore() - marginAfter() - borderAndPaddingLogicalHeight(), Fixed);
             checkMinMaxHeight = false;
         }
 
         LayoutUnit heightResult;
         if (checkMinMaxHeight) {
-            heightResult = computeLogicalHeightUsing(style()->logicalHeight());
+            heightResult = computeLogicalHeightUsing(style()->logicalHeight(), computedValues.m_extent - borderAndPaddingLogicalHeight());
             if (heightResult == -1)
                 heightResult = computedValues.m_extent;
-            heightResult = constrainLogicalHeightByMinMax(heightResult);
+            heightResult = constrainLogicalHeightByMinMax(heightResult, computedValues.m_extent - borderAndPaddingLogicalHeight());
         } else {
             // The only times we don't check min/max height are when a fixed length has
             // been given as an override.  Just use that.  The value has already been adjusted
             // for box-sizing.
+            ASSERT(h.isFixed());
             heightResult = h.value() + borderAndPaddingLogicalHeight();
         }
 
         computedValues.m_extent = heightResult;
         
         if (hasPerpendicularContainingBlock) {
             bool shouldFlipBeforeAfter = shouldFlipBeforeAfterMargins(cb->style(), style());
             computeInlineDirectionMargins(cb, containingBlockLogicalWidthForContent(), heightResult,
                     shouldFlipBeforeAfter ? computedValues.m_margins.m_after : computedValues.m_margins.m_before,
                     shouldFlipBeforeAfter ? computedValues.m_margins.m_before : computedValues.m_margins.m_after);
@@ skipping 19 matching lines @@
     }
 }
 
 LayoutUnit RenderBox::viewLogicalHeightForPercentages() const
 {
     if (document()->printing())
         return static_cast<LayoutUnit>(view()->pageLogicalHeight());
     return view()->viewLogicalHeight();
 }
 
-LayoutUnit RenderBox::computeLogicalHeightUsing(const Length& height) const
+LayoutUnit RenderBox::computeLogicalHeightUsing(const Length& height, LayoutUnit contentHeight) const
 {
-    LayoutUnit logicalHeight = computeContentAndScrollbarLogicalHeightUsing(height);
+    LayoutUnit logicalHeight = computeContentAndScrollbarLogicalHeightUsing(height, contentHeight);
     if (logicalHeight != -1)
         logicalHeight = adjustBorderBoxLogicalHeightForBoxSizing(logicalHeight);
     return logicalHeight;
 }
 
-LayoutUnit RenderBox::computeContentLogicalHeight(const Length& height) const
+LayoutUnit RenderBox::computeContentLogicalHeight(const Length& height, LayoutUnit contentHeight) const
 {
-    LayoutUnit heightIncludingScrollbar = computeContentAndScrollbarLogicalHeightUsing(height);
+    LayoutUnit heightIncludingScrollbar = computeContentAndScrollbarLogicalHeightUsing(height, contentHeight);
     if (heightIncludingScrollbar == -1)
         return -1;
     return std::max<LayoutUnit>(0, adjustContentBoxLogicalHeightForBoxSizing(heightIncludingScrollbar) - scrollbarLogicalHeight());
 }
 
-LayoutUnit RenderBox::computeContentAndScrollbarLogicalHeightUsing(const Length& height) const
+LayoutUnit RenderBox::computeContentAndScrollbarLogicalHeightUsing(const Length& height, LayoutUnit contentHeight) const
 {
+    if (height.isMinContent() || height.isMaxContent() || height.isFitContent())

[ojan, 2013/04/11 03:21:46]

Maybe include a FIXME that the spec is considering having mincontent/maxcontent
resolve to different values? I'm skeptical we'll actually want that in the end,
but worth documenting since the spec isn't resolve yet.

[cbiesinger, 2013/04/12 01:17:52]

Done.

+        return contentHeight;
+    if (height.isFillAvailable())
+        return containingBlock()->availableLogicalHeight(ExcludeMarginBorderPadding) - borderAndPaddingLogicalHeight();
     if (height.isFixed())
         return height.value();
     if (height.isPercent())
         return computePercentageLogicalHeight(height);
     if (height.isViewportPercentage())
         return valueForLength(height, 0, view());
     return -1;
 }
 
 bool RenderBox::skipContainingBlockForPercentHeightCalculation(const RenderBox* containingBlock) const
@@ skipping 50 matching lines @@
                 RenderTableCell* cell = toRenderTableCell(cb);
                 if (scrollsOverflowY() && (!cell->style()->logicalHeight().isAuto() || !cell->table()->style()->logicalHeight().isAuto()))
                     return 0;
                 return -1;
             }
             availableHeight = cb->overrideLogicalContentHeight();
             includeBorderPadding = true;
         }
     } else if (cbstyle->logicalHeight().isFixed()) {
         LayoutUnit contentBoxHeight = cb->adjustContentBoxLogicalHeightForBoxSizing(cbstyle->logicalHeight().value());
-        availableHeight = max<LayoutUnit>(0, cb->constrainContentBoxLogicalHeightByMinMax(contentBoxHeight - cb->scrollbarLogicalHeight()));
+        availableHeight = max<LayoutUnit>(0, cb->constrainContentBoxLogicalHeightByMinMax(contentBoxHeight - cb->scrollbarLogicalHeight(), -1));
     } else if (cbstyle->logicalHeight().isPercent() && !isOutOfFlowPositionedWithSpecifiedHeight) {
         // We need to recur and compute the percentage height for our containing block.
         LayoutUnit heightWithScrollbar = cb->computePercentageLogicalHeight(cbstyle->logicalHeight());
         if (heightWithScrollbar != -1) {
             LayoutUnit contentBoxHeightWithScrollbar = cb->adjustContentBoxLogicalHeightForBoxSizing(heightWithScrollbar);
             // We need to adjust for min/max height because this method does not
             // handle the min/max of the current block, its caller does. So the
             // return value from the recursive call will not have been adjusted
             // yet.
-            LayoutUnit contentBoxHeight = cb->constrainContentBoxLogicalHeightByMinMax(contentBoxHeightWithScrollbar - cb->scrollbarLogicalHeight());
+            LayoutUnit contentBoxHeight = cb->constrainContentBoxLogicalHeightByMinMax(contentBoxHeightWithScrollbar - cb->scrollbarLogicalHeight(), -1);
             availableHeight = max<LayoutUnit>(0, contentBoxHeight);
         }
     } else if (isOutOfFlowPositionedWithSpecifiedHeight) {
         // Don't allow this to affect the block' height() member variable, since this
         // can get called while the block is still laying out its kids.
         LogicalExtentComputedValues computedValues;
         cb->computeLogicalHeight(cb->logicalHeight(), 0, computedValues);
         availableHeight = computedValues.m_extent - cb->borderAndPaddingLogicalHeight() - cb->scrollbarLogicalHeight();
     } else if (cb->isRenderView())
         availableHeight = viewLogicalHeightForPercentages();
@@ skipping 141 matching lines @@
         case ViewportPercentageMin:
         case ViewportPercentageMax:
             return adjustContentBoxLogicalHeightForBoxSizing(valueForLength(logicalHeight, 0, view()));
         default:
             return intrinsicLogicalHeight();
     }
 }
 
 LayoutUnit RenderBox::availableLogicalHeight(AvailableLogicalHeightType heightType) const
 {
-    return constrainLogicalHeightByMinMax(availableLogicalHeightUsing(style()->logicalHeight(), heightType));
+    return constrainLogicalHeightByMinMax(availableLogicalHeightUsing(style()->logicalHeight(), heightType), -1);
 }
 
 LayoutUnit RenderBox::availableLogicalHeightUsing(const Length& h, AvailableLogicalHeightType heightType) const
 {
     if (isRenderView())
         return isHorizontalWritingMode() ? toRenderView(this)->frameView()->visibleHeight() : toRenderView(this)->frameView()->visibleWidth();
 
     // We need to stop here, since we don't want to increase the height of the table
     // artificially.  We're going to rely on this cell getting expanded to some new
     // height, and then when we lay out again we'll use the calculation below.
     if (isTableCell() && (h.isAuto() || h.isPercent())) {
         if (hasOverrideHeight())
             return overrideLogicalContentHeight();
         return logicalHeight() - borderAndPaddingLogicalHeight();
     }
 
     if (h.isPercent() && isOutOfFlowPositioned()) {
         // FIXME: This is wrong if the containingBlock has a perpendicular writing mode.
         LayoutUnit availableHeight = containingBlockLogicalHeightForPositioned(containingBlock());
         return adjustContentBoxLogicalHeightForBoxSizing(valueForLength(h, availableHeight));
     }
 
-    LayoutUnit heightIncludingScrollbar = computeContentAndScrollbarLogicalHeightUsing(h);
+    LayoutUnit heightIncludingScrollbar = computeContentAndScrollbarLogicalHeightUsing(h, -1);
     if (heightIncludingScrollbar != -1)
         return std::max<LayoutUnit>(0, adjustContentBoxLogicalHeightForBoxSizing(heightIncludingScrollbar) - scrollbarLogicalHeight());
 
     // FIXME: Check logicalTop/logicalBottom here to correctly handle vertical writing-mode.
     // https://bugs.webkit.org/show_bug.cgi?id=46500
     if (isRenderBlock() && isOutOfFlowPositioned() && style()->height().isAuto() && !(style()->top().isAuto() || style()->bottom().isAuto())) {
         RenderBlock* block = const_cast<RenderBlock*>(toRenderBlock(this));
         LogicalExtentComputedValues computedValues;
         block->computeLogicalHeight(block->logicalHeight(), 0, computedValues);
         LayoutUnit newContentHeight = computedValues.m_extent - block->borderAndPaddingLogicalHeight() - block->scrollbarLogicalHeight();
@@ skipping 593 matching lines @@
 
         if (computedValues.m_extent > maxValues.m_extent) {
             computedValues.m_extent = maxValues.m_extent;
             computedValues.m_position = maxValues.m_position;
             computedValues.m_margins.m_before = maxValues.m_margins.m_before;
             computedValues.m_margins.m_after = maxValues.m_margins.m_after;
         }
     }
 
     // Calculate constraint equation values for 'min-height' case.
-    if (!styleToUse->logicalMinHeight().isZero()) {
+    if (!styleToUse->logicalMinHeight().isZero() || styleToUse->logicalMinHeight().isIntrinsic()) {
         LogicalExtentComputedValues minValues;
 
         computePositionedLogicalHeightUsing(styleToUse->logicalMinHeight(), containerBlock, containerLogicalHeight, bordersPlusPadding, logicalHeight,
                                             logicalTopLength, logicalBottomLength, marginBefore, marginAfter,
                                             minValues);
 
         if (computedValues.m_extent < minValues.m_extent) {
             computedValues.m_extent = minValues.m_extent;
             computedValues.m_position = minValues.m_position;
             computedValues.m_margins.m_before = minValues.m_margins.m_before;
@@ skipping 66 matching lines @@
     bool logicalTopIsAuto = logicalTop.isAuto();
     bool logicalBottomIsAuto = logicalBottom.isAuto();
     RenderView* renderView = view();
 
     // Height is never unsolved for tables.
     if (isTable()) {
         logicalHeightLength.setValue(Fixed, contentLogicalHeight);
         logicalHeightIsAuto = false;
     }
 
+    LayoutUnit resolvedLogicalHeight;
+    if (logicalHeightLength.isMinContent() || logicalHeightLength.isMaxContent() || logicalHeightLength.isFitContent())

[ojan, 2013/04/11 03:21:46]

Can you make a computeIntrinsicLogicalHeightUsing (analgous to
RenderBox::computeIntrinsicLogicalWidthUsing) method and use it here and in
computeContentAndScrollbarLogicalHeightUsing to avoid a bit of code duplication?

[cbiesinger, 2013/04/12 01:17:52]

Done (named it computeIntrinsicLogicalContentHeightUsing, because it doesn't
include border and padding)

I'm a little unhappy about the fact that the function signature now uses
"content height" with two meanings - the height of the RenderObject excluding
border/padding, and the intrinsic height of the content. Should I rename the
argument to intrinsicContentHeight?

[ojan, 2013/04/12 04:03:11]

SGTM

+        resolvedLogicalHeight = contentLogicalHeight;
+    else if (logicalHeightLength.isFillAvailable())
+        resolvedLogicalHeight = containingBlock()->availableLogicalHeight(ExcludeMarginBorderPadding) - bordersPlusPadding;
+    else
+        resolvedLogicalHeight = adjustContentBoxLogicalHeightForBoxSizing(valueForLength(logicalHeightLength, containerLogicalHeight, renderView));
+
     if (!logicalTopIsAuto && !logicalHeightIsAuto && !logicalBottomIsAuto) {
         /*-----------------------------------------------------------------------*\
          * If none of the three are 'auto': If both 'margin-top' and 'margin-
          * bottom' are 'auto', solve the equation under the extra constraint that
          * the two margins get equal values. If one of 'margin-top' or 'margin-
          * bottom' is 'auto', solve the equation for that value. If the values
          * are over-constrained, ignore the value for 'bottom' and solve for that
          * value.
         \*-----------------------------------------------------------------------*/
         // NOTE:  It is not necessary to solve for 'bottom' in the over constrained
         // case because the value is not used for any further calculations.
 
-        logicalHeightValue = adjustContentBoxLogicalHeightForBoxSizing(valueForLength(logicalHeightLength, containerLogicalHeight, renderView));
+        logicalHeightValue = resolvedLogicalHeight;
         logicalTopValue = valueForLength(logicalTop, containerLogicalHeight, renderView);
 
         const LayoutUnit availableSpace = containerLogicalHeight - (logicalTopValue + logicalHeightValue + valueForLength(logicalBottom, containerLogicalHeight, renderView) + bordersPlusPadding);
 
         // Margins are now the only unknown
         if (marginBefore.isAuto() && marginAfter.isAuto()) {
             // Both margins auto, solve for equality
             // NOTE: This may result in negative values.
             computedValues.m_margins.m_before = availableSpace / 2; // split the difference
             computedValues.m_margins.m_after = availableSpace - computedValues.m_margins.m_before; // account for odd valued differences
@@ skipping 46 matching lines @@
         if (logicalTopIsAuto && logicalHeightIsAuto && !logicalBottomIsAuto) {
             // RULE 1: (height is content based, solve of top)
             logicalHeightValue = contentLogicalHeight;
             logicalTopValue = availableSpace - (logicalHeightValue + valueForLength(logicalBottom, containerLogicalHeight, renderView));
         } else if (!logicalTopIsAuto && logicalHeightIsAuto && logicalBottomIsAuto) {
             // RULE 3: (height is content based, no need solve of bottom)
             logicalTopValue = valueForLength(logicalTop, containerLogicalHeight, renderView);
             logicalHeightValue = contentLogicalHeight;
         } else if (logicalTopIsAuto && !logicalHeightIsAuto && !logicalBottomIsAuto) {
             // RULE 4: (solve of top)
-            logicalHeightValue = adjustContentBoxLogicalHeightForBoxSizing(valueForLength(logicalHeightLength, containerLogicalHeight, renderView));
+            logicalHeightValue = resolvedLogicalHeight;
             logicalTopValue = availableSpace - (logicalHeightValue + valueForLength(logicalBottom, containerLogicalHeight, renderView));
         } else if (!logicalTopIsAuto && logicalHeightIsAuto && !logicalBottomIsAuto) {
             // RULE 5: (solve of height)
             logicalTopValue = valueForLength(logicalTop, containerLogicalHeight, renderView);
             logicalHeightValue = max<LayoutUnit>(0, availableSpace - (logicalTopValue + valueForLength(logicalBottom, containerLogicalHeight, renderView)));
         } else if (!logicalTopIsAuto && !logicalHeightIsAuto && logicalBottomIsAuto) {
             // RULE 6: (no need solve of bottom)
-            logicalHeightValue = adjustContentBoxLogicalHeightForBoxSizing(valueForLength(logicalHeightLength, containerLogicalHeight, renderView));
+            logicalHeightValue = resolvedLogicalHeight;
             logicalTopValue = valueForLength(logicalTop, containerLogicalHeight, renderView);
         }
     }
     computedValues.m_extent = logicalHeightValue;
 
     // Use computed values to calculate the vertical position.
     computedValues.m_position = logicalTopValue + computedValues.m_margins.m_before;
     computeLogicalTopPositionedOffset(computedValues.m_position, this, logicalHeightValue, containerBlock, containerLogicalHeight);
 }
 
@@ skipping 956 matching lines @@
 
 void RenderBox::reportStaticMembersMemoryUsage(MemoryInstrumentation* memoryInstrumentation)
 {
     memoryInstrumentation->addRootObject(gOverrideHeightMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gOverrideWidthMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gOverrideContainingBlockLogicalHeightMap, WebCoreMemoryTypes::RenderingStructures);
     memoryInstrumentation->addRootObject(gOverrideContainingBlockLogicalWidthMap, WebCoreMemoryTypes::RenderingStructures);
 }
 
 } // namespace WebCore