[CSS Grid Layout] Fix positioned grid children position and size

Source/core/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.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 2651 matching lines @@
 
     // Use viewport as container for top-level fixed-position elements.
     if (style()->position() == FixedPosition && containingBlock->isRenderView()) {
         const RenderView* view = toRenderView(containingBlock);
         if (FrameView* frameView = view->frameView()) {
             LayoutRect viewportRect = frameView->viewportConstrainedVisibleContentRect();
             return containingBlock->isHorizontalWritingMode() ? viewportRect.width() : viewportRect.height();
         }
     }
 
+    if (hasOverrideContainingBlockLogicalWidth())
+        return overrideContainingBlockContentLogicalWidth();
+
     if (containingBlock->isBox())
         return toRenderBox(containingBlock)->clientLogicalWidth();
 
     ASSERT(containingBlock->isRenderInline() && containingBlock->isRelPositioned());
 
     const RenderInline* flow = toRenderInline(containingBlock);
     InlineFlowBox* first = flow->firstLineBox();
     InlineFlowBox* last = flow->lastLineBox();
 
     // If the containing block is empty, return a width of 0.
@@ skipping 20 matching lines @@
 
     // Use viewport as container for top-level fixed-position elements.
     if (style()->position() == FixedPosition && containingBlock->isRenderView()) {
         const RenderView* view = toRenderView(containingBlock);
         if (FrameView* frameView = view->frameView()) {
             LayoutRect viewportRect = frameView->viewportConstrainedVisibleContentRect();
             return containingBlock->isHorizontalWritingMode() ? viewportRect.height() : viewportRect.width();
         }
     }
 
+    if (hasOverrideContainingBlockLogicalHeight())
+        return overrideContainingBlockContentLogicalHeight();
+
     if (containingBlock->isBox()) {
         const RenderBlock* cb = containingBlock->isRenderBlock() ?
             toRenderBlock(containingBlock) : containingBlock->containingBlock();
         return cb->clientLogicalHeight();
     }
 
     ASSERT(containingBlock->isRenderInline() && containingBlock->isRelPositioned());
 
     const RenderInline* flow = toRenderInline(containingBlock);
     InlineFlowBox* first = flow->firstLineBox();
     InlineFlowBox* last = flow->lastLineBox();
 
     // If the containing block is empty, return a height of 0.
     if (!first || !last)
         return 0;
 
     LayoutUnit heightResult;
     LayoutRect boundingBox = flow->linesBoundingBox();
     if (containingBlock->isHorizontalWritingMode())
         heightResult = boundingBox.height();
     else
         heightResult = boundingBox.width();
     heightResult -= (containingBlock->borderBefore() + containingBlock->borderAfter());
     return heightResult;
 }
 
+static LayoutUnit computeInlineStaticPositionForGridItem(Length& logicalLeft, Length& logicalRight, const RenderBox* child, LayoutUnit containerLogicalWidth)
+{
+    ASSERT(child->parent()->isRenderGrid());

[Julien - ping for review, 2014/11/11 17:27:35]

I think this should be child->containingBlock()->isRenderGrid() (even better,
just passing |containerBlock| below).

This can be easily tested by wrapping one of your absolutely positioned element
below into a statically positioned element.

+
+    LayoutUnit staticPosition = 0;
+    if (child->parent()->style()->direction() == LTR) {

[Julien - ping for review, 2014/11/11 17:27:35]

Same comment.

+        if (!logicalLeft.isAuto())
+            staticPosition += valueForLength(logicalLeft, containerLogicalWidth);
+        else if (!logicalRight.isAuto())
+            staticPosition -= valueForLength(logicalRight, containerLogicalWidth);
+    } else {
+        if (!logicalRight.isAuto())
+            staticPosition += valueForLength(logicalRight, containerLogicalWidth);
+        else if (!logicalLeft.isAuto())
+            staticPosition -= valueForLength(logicalLeft, containerLogicalWidth);
+    }
+    return staticPosition;
+}
+
 static void computeInlineStaticDistance(Length& logicalLeft, Length& logicalRight, const RenderBox* child, const RenderBoxModelObject* containerBlock, LayoutUnit containerLogicalWidth)
 {
-    if (!logicalLeft.isAuto() || !logicalRight.isAuto())
+    if ((!logicalLeft.isAuto() || !logicalRight.isAuto()) && !child->parent()->isRenderGrid())
         return;
 
+    LayoutUnit staticPosition = 0;
+    if (child->parent()->isRenderGrid())
+        staticPosition = computeInlineStaticPositionForGridItem(logicalLeft, logicalRight, child, containerLogicalWidth);
+
     // FIXME: The static distance computation has not been patched for mixed writing modes yet.
     if (child->parent()->style()->direction() == LTR) {
-        LayoutUnit staticPosition = child->layer()->staticInlinePosition() - containerBlock->borderLogicalLeft();
+        staticPosition += child->layer()->staticInlinePosition() - containerBlock->borderLogicalLeft();
         for (RenderObject* curr = child->parent(); curr && curr != containerBlock; curr = curr->container()) {
             if (curr->isBox()) {
                 staticPosition += toRenderBox(curr)->logicalLeft();
                 if (toRenderBox(curr)->isRelPositioned())
                     staticPosition += toRenderBox(curr)->relativePositionOffset().width();
             } else if (curr->isInline()) {
                 if (curr->isRelPositioned()) {
                     if (!curr->style()->logicalLeft().isAuto())
                         staticPosition += curr->style()->logicalLeft().value();
                     else
                         staticPosition -= curr->style()->logicalRight().value();
                 }
             }
         }
         logicalLeft.setValue(Fixed, staticPosition);
     } else {
         RenderBox* enclosingBox = child->parent()->enclosingBox();
-        LayoutUnit staticPosition = child->layer()->staticInlinePosition() + containerLogicalWidth + containerBlock->borderLogicalLeft();
+        staticPosition += child->layer()->staticInlinePosition() + containerLogicalWidth + containerBlock->borderLogicalLeft();
         for (RenderObject* curr = child->parent(); curr; curr = curr->container()) {
             if (curr->isBox()) {
                 if (curr != containerBlock) {
                     staticPosition -= toRenderBox(curr)->logicalLeft();
                     if (toRenderBox(curr)->isRelPositioned())
                         staticPosition -= toRenderBox(curr)->relativePositionOffset().width();
                 }
                 if (curr == enclosingBox)
                     staticPosition -= enclosingBox->logicalWidth();
             } else if (curr->isInline()) {
@@ skipping 322 matching lines @@
     }
 
     if (containerBlock->isBox() && toRenderBox(containerBlock)->scrollsOverflowY() && containerBlock->style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft()) {
         logicalLeftValue = logicalLeftValue + toRenderBox(containerBlock)->verticalScrollbarWidth();
     }
 
     computedValues.m_position = logicalLeftValue + marginLogicalLeftValue;
     computeLogicalLeftPositionedOffset(computedValues.m_position, this, computedValues.m_extent, containerBlock, containerLogicalWidth);
 }
 
-static void computeBlockStaticDistance(Length& logicalTop, Length& logicalBottom, const RenderBox* child, const RenderBoxModelObject* containerBlock)
+static LayoutUnit computeBlockStaticPositionForGridItem(Length& logicalTop, Length& logicalBottom, const RenderBox* child, LayoutUnit containerLogicalHeight)
 {
-    if (!logicalTop.isAuto() || !logicalBottom.isAuto())
+    ASSERT(child->parent()->isRenderGrid());
+
+    LayoutUnit staticPosition = 0;
+    if (!logicalTop.isAuto())
+        staticPosition += valueForLength(logicalTop, containerLogicalHeight);
+    else if (!logicalBottom.isAuto())
+        staticPosition -= valueForLength(logicalBottom, containerLogicalHeight);
+    return staticPosition;
+}
+
+static void computeBlockStaticDistance(Length& logicalTop, Length& logicalBottom, const RenderBox* child, const RenderBoxModelObject* containerBlock, LayoutUnit containerLogicalHeight)
+{
+    if ((!logicalTop.isAuto() || !logicalBottom.isAuto()) && !child->parent()->isRenderGrid())
         return;
 
+    LayoutUnit staticLogicalTop = 0;
+    if (child->parent()->isRenderGrid())
+        staticLogicalTop = computeBlockStaticPositionForGridItem(logicalTop, logicalBottom, child, containerLogicalHeight);
+
     // FIXME: The static distance computation has not been patched for mixed writing modes.
-    LayoutUnit staticLogicalTop = child->layer()->staticBlockPosition() - containerBlock->borderBefore();
+    staticLogicalTop += child->layer()->staticBlockPosition() - containerBlock->borderBefore();
     for (RenderObject* curr = child->parent(); curr && curr != containerBlock; curr = curr->container()) {
         if (curr->isBox() && !curr->isTableRow())
             staticLogicalTop += toRenderBox(curr)->logicalTop();
     }
     logicalTop.setValue(Fixed, staticLogicalTop);
 }
 
 void RenderBox::computePositionedLogicalHeight(LogicalExtentComputedValues& computedValues) const
 {
     if (isReplaced()) {
@@ skipping 32 matching lines @@
      * But rather than actually calculating the dimensions of that hypothetical
      * box, user agents are free to make a guess at its probable position.
      *
      * For the purposes of calculating the static position, the containing block
      * of fixed positioned elements is the initial containing block instead of
      * the viewport.
     \*---------------------------------------------------------------------------*/
 
     // see FIXME 1
     // Calculate the static distance if needed.
-    computeBlockStaticDistance(logicalTopLength, logicalBottomLength, this, containerBlock);
+    computeBlockStaticDistance(logicalTopLength, logicalBottomLength, this, containerBlock, containerLogicalHeight);
 
     // Calculate constraint equation values for 'height' case.
     LayoutUnit logicalHeight = computedValues.m_extent;
     computePositionedLogicalHeightUsing(styleToUse->logicalHeight(), containerBlock, containerLogicalHeight, bordersPlusPadding, logicalHeight,
                                         logicalTopLength, logicalBottomLength, marginBefore, marginAfter,
                                         computedValues);
 
     // Avoid doing any work in the common case (where the values of min-height and max-height are their defaults).
     // see FIXME 2
 
@@ skipping 385 matching lines @@
     // are dealt with in computeReplacedHeight().  This means that the steps to produce
     // correct max/min in the non-replaced version, are not necessary.
     computedValues.m_extent = computeReplacedLogicalHeight() + borderAndPaddingLogicalHeight();
     const LayoutUnit availableSpace = containerLogicalHeight - computedValues.m_extent;
 
     /*-----------------------------------------------------------------------*\
      * 2. If both 'top' and 'bottom' have the value 'auto', replace 'top'
      *    with the element's static position.
     \*-----------------------------------------------------------------------*/
     // see FIXME 1
-    computeBlockStaticDistance(logicalTop, logicalBottom, this, containerBlock);
+    computeBlockStaticDistance(logicalTop, logicalBottom, this, containerBlock, containerLogicalHeight);
 
     /*-----------------------------------------------------------------------*\
      * 3. If 'bottom' is 'auto', replace any 'auto' on 'margin-top' or
      *    'margin-bottom' with '0'.
     \*-----------------------------------------------------------------------*/
     // FIXME: The spec. says that this step should only be taken when bottom is
     // auto, but if only top is auto, this makes step 4 impossible.
     if (logicalTop.isAuto() || logicalBottom.isAuto()) {
         if (marginBefore.isAuto())
             marginBefore.setValue(Fixed, 0);
@@ skipping 927 matching lines @@
     ASSERT(style()->hasBackground() || style()->hasBoxDecorations());
 
     if (m_rareData && m_rareData->m_previousBorderBoxSize.width() != -1)
         return m_rareData->m_previousBorderBoxSize;
 
     // We didn't save the old border box size because it was the same as the size of oldBounds.
     return previousBoundsSize;
 }
 
 } // namespace blink