Move specialized computePositionedLogicalWidth to LayoutReplaced.

third_party/WebKit/Source/core/layout/LayoutReplaced.cpp

Index: third_party/WebKit/Source/core/layout/LayoutReplaced.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutReplaced.cpp b/third_party/WebKit/Source/core/layout/LayoutReplaced.cpp
index 7621248b5e277c8cbf02522cb478a92fcb16eab5..6bb54e15e914b155eab4f15610e83bcf929e3a09 100644
--- a/third_party/WebKit/Source/core/layout/LayoutReplaced.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutReplaced.cpp
@@ -27,6 +27,7 @@
 #include "core/layout/LayoutAnalyzer.h"
 #include "core/layout/LayoutBlock.h"
 #include "core/layout/LayoutImage.h"
+#include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutView.h"
 #include "core/paint/PaintInfo.h"
 #include "core/paint/PaintLayer.h"
@@ -210,6 +211,304 @@ void LayoutReplaced::computeAspectRatioInformationForLayoutBox(LayoutBox* conten
     }
 }
 
+void LayoutReplaced::computePositionedLogicalWidth(LogicalExtentComputedValues& computedValues) const
+{
+    // The following is based off of the W3C Working Draft from April 11, 2006 of
+    // CSS 2.1: Section 10.3.8 "Absolutely positioned, replaced elements"
+    // <http://www.w3.org/TR/2005/WD-CSS21-20050613/visudet.html#abs-replaced-width>
+    // (block-style-comments in this function correspond to text from the spec and
+    // the numbers correspond to numbers in spec)
+
+    // We don't use containingBlock(), since we may be positioned by an enclosing
+    // relative positioned inline.
+    const LayoutBoxModelObject* containerBlock = toLayoutBoxModelObject(container());
+
+    const LayoutUnit containerLogicalWidth = containingBlockLogicalWidthForPositioned(containerBlock);
+    const LayoutUnit containerRelativeLogicalWidth = containingBlockLogicalWidthForPositioned(containerBlock, false);
+
+    // To match WinIE, in quirks mode use the parent's 'direction' property
+    // instead of the the container block's.
+    TextDirection containerDirection = containerBlock->style()->direction();
+
+    // Variables to solve.
+    bool isHorizontal = isHorizontalWritingMode();
+    Length logicalLeft = style()->logicalLeft();
+    Length logicalRight = style()->logicalRight();
+    Length marginLogicalLeft = isHorizontal ? style()->marginLeft() : style()->marginTop();
+    Length marginLogicalRight = isHorizontal ? style()->marginRight() : style()->marginBottom();
+    LayoutUnit& marginLogicalLeftAlias = style()->isLeftToRightDirection() ? computedValues.m_margins.m_start : computedValues.m_margins.m_end;
+    LayoutUnit& marginLogicalRightAlias = style()->isLeftToRightDirection() ? computedValues.m_margins.m_end : computedValues.m_margins.m_start;
+
+    /*-----------------------------------------------------------------------*\
+     * 1. The used value of 'width' is determined as for inline replaced
+     *    elements.
+    \*-----------------------------------------------------------------------*/
+    // NOTE: This value of width is final in that the min/max width calculations
+    // are dealt with in computeReplacedWidth().  This means that the steps to produce
+    // correct max/min in the non-replaced version, are not necessary.
+    computedValues.m_extent = computeReplacedLogicalWidth() + borderAndPaddingLogicalWidth();
+
+    const LayoutUnit availableSpace = containerLogicalWidth - computedValues.m_extent;
+
+    /*-----------------------------------------------------------------------*\
+     * 2. If both 'left' and 'right' have the value 'auto', then if 'direction'
+     *    of the containing block is 'ltr', set 'left' to the static position;
+     *    else if 'direction' is 'rtl', set 'right' to the static position.
+    \*-----------------------------------------------------------------------*/
+    // see FIXME 1
+    computeInlineStaticDistance(logicalLeft, logicalRight, this, containerBlock, containerLogicalWidth);
+
+    /*-----------------------------------------------------------------------*\
+     * 3. If 'left' or 'right' are 'auto', replace any 'auto' on 'margin-left'
+     *    or 'margin-right' with '0'.
+    \*-----------------------------------------------------------------------*/
+    if (logicalLeft.isAuto() || logicalRight.isAuto()) {
+        if (marginLogicalLeft.isAuto())
+            marginLogicalLeft.setValue(Fixed, 0);
+        if (marginLogicalRight.isAuto())
+            marginLogicalRight.setValue(Fixed, 0);
+    }
+
+    /*-----------------------------------------------------------------------*\
+     * 4. If at this point both 'margin-left' and 'margin-right' are still
+     *    'auto', solve the equation under the extra constraint that the two
+     *    margins must get equal values, unless this would make them negative,
+     *    in which case when the direction of the containing block is 'ltr'
+     *    ('rtl'), set 'margin-left' ('margin-right') to zero and solve for
+     *    'margin-right' ('margin-left').
+    \*-----------------------------------------------------------------------*/
+    LayoutUnit logicalLeftValue = 0;
+    LayoutUnit logicalRightValue = 0;
+
+    if (marginLogicalLeft.isAuto() && marginLogicalRight.isAuto()) {
+        // 'left' and 'right' cannot be 'auto' due to step 3
+        ASSERT(!(logicalLeft.isAuto() && logicalRight.isAuto()));
+
+        logicalLeftValue = valueForLength(logicalLeft, containerLogicalWidth);
+        logicalRightValue = valueForLength(logicalRight, containerLogicalWidth);
+
+        LayoutUnit difference = availableSpace - (logicalLeftValue + logicalRightValue);
+        if (difference > 0) {
+            marginLogicalLeftAlias = difference / 2; // split the difference
+            marginLogicalRightAlias = difference - marginLogicalLeftAlias; // account for odd valued differences
+        } else {
+            // Use the containing block's direction rather than the parent block's
+            // per CSS 2.1 reference test abspos-replaced-width-margin-000.
+            if (containerDirection == LTR) {
+                marginLogicalLeftAlias = 0;
+                marginLogicalRightAlias = difference; // will be negative
+            } else {
+                marginLogicalLeftAlias = difference; // will be negative
+                marginLogicalRightAlias = 0;
+            }
+        }
+
+    /*-----------------------------------------------------------------------*\
+     * 5. If at this point there is an 'auto' left, solve the equation for
+     *    that value.
+    \*-----------------------------------------------------------------------*/
+    } else if (logicalLeft.isAuto()) {
+        marginLogicalLeftAlias = valueForLength(marginLogicalLeft, containerRelativeLogicalWidth);
+        marginLogicalRightAlias = valueForLength(marginLogicalRight, containerRelativeLogicalWidth);
+        logicalRightValue = valueForLength(logicalRight, containerLogicalWidth);
+
+        // Solve for 'left'
+        logicalLeftValue = availableSpace - (logicalRightValue + marginLogicalLeftAlias + marginLogicalRightAlias);
+    } else if (logicalRight.isAuto()) {
+        marginLogicalLeftAlias = valueForLength(marginLogicalLeft, containerRelativeLogicalWidth);
+        marginLogicalRightAlias = valueForLength(marginLogicalRight, containerRelativeLogicalWidth);
+        logicalLeftValue = valueForLength(logicalLeft, containerLogicalWidth);
+
+        // Solve for 'right'
+        logicalRightValue = availableSpace - (logicalLeftValue + marginLogicalLeftAlias + marginLogicalRightAlias);
+    } else if (marginLogicalLeft.isAuto()) {
+        marginLogicalRightAlias = valueForLength(marginLogicalRight, containerRelativeLogicalWidth);
+        logicalLeftValue = valueForLength(logicalLeft, containerLogicalWidth);
+        logicalRightValue = valueForLength(logicalRight, containerLogicalWidth);
+
+        // Solve for 'margin-left'
+        marginLogicalLeftAlias = availableSpace - (logicalLeftValue + logicalRightValue + marginLogicalRightAlias);
+    } else if (marginLogicalRight.isAuto()) {
+        marginLogicalLeftAlias = valueForLength(marginLogicalLeft, containerRelativeLogicalWidth);
+        logicalLeftValue = valueForLength(logicalLeft, containerLogicalWidth);
+        logicalRightValue = valueForLength(logicalRight, containerLogicalWidth);
+
+        // Solve for 'margin-right'
+        marginLogicalRightAlias = availableSpace - (logicalLeftValue + logicalRightValue + marginLogicalLeftAlias);
+    } else {
+        // Nothing is 'auto', just calculate the values.
+        marginLogicalLeftAlias = valueForLength(marginLogicalLeft, containerRelativeLogicalWidth);
+        marginLogicalRightAlias = valueForLength(marginLogicalRight, containerRelativeLogicalWidth);
+        logicalRightValue = valueForLength(logicalRight, containerLogicalWidth);
+        logicalLeftValue = valueForLength(logicalLeft, containerLogicalWidth);
+        // If the containing block is right-to-left, then push the left position as far to the right as possible
+        if (containerDirection == RTL) {
+            int totalLogicalWidth = computedValues.m_extent + logicalLeftValue + logicalRightValue +  marginLogicalLeftAlias + marginLogicalRightAlias;
+            logicalLeftValue = containerLogicalWidth - (totalLogicalWidth - logicalLeftValue);
+        }
+    }
+
+    /*-----------------------------------------------------------------------*\
+     * 6. If at this point the values are over-constrained, ignore the value
+     *    for either 'left' (in case the 'direction' property of the
+     *    containing block is 'rtl') or 'right' (in case 'direction' is
+     *    'ltr') and solve for that value.
+    \*-----------------------------------------------------------------------*/
+    // NOTE: Constraints imposed by the width of the containing block and its content have already been accounted for above.
+
+    // FIXME: Deal with differing writing modes here.  Our offset needs to be in the containing block's coordinate space, so that
+    // can make the result here rather complicated to compute.
+
+    // Use computed values to calculate the horizontal position.
+
+    // FIXME: This hack is needed to calculate the logical left position for a 'rtl' relatively
+    // positioned, inline containing block because right now, it is using the logical left position
+    // of the first line box when really it should use the last line box.  When
+    // this is fixed elsewhere, this block should be removed.
+    if (containerBlock->isLayoutInline() && !containerBlock->style()->isLeftToRightDirection()) {
+        const LayoutInline* flow = toLayoutInline(containerBlock);
+        InlineFlowBox* firstLine = flow->firstLineBox();
+        InlineFlowBox* lastLine = flow->lastLineBox();
+        if (firstLine && lastLine && firstLine != lastLine) {
+            computedValues.m_position = logicalLeftValue + marginLogicalLeftAlias + lastLine->borderLogicalLeft() + (lastLine->logicalLeft() - firstLine->logicalLeft());
+            return;
+        }
+    }
+
+    LayoutUnit logicalLeftPos = logicalLeftValue + marginLogicalLeftAlias;
+    computeLogicalLeftPositionedOffset(logicalLeftPos, this, computedValues.m_extent, containerBlock, containerLogicalWidth);
+    computedValues.m_position = logicalLeftPos;
+}
+
+void LayoutReplaced::computePositionedLogicalHeight(LogicalExtentComputedValues& computedValues) const
+{
+    // The following is based off of the W3C Working Draft from April 11, 2006 of
+    // CSS 2.1: Section 10.6.5 "Absolutely positioned, replaced elements"
+    // <http://www.w3.org/TR/2005/WD-CSS21-20050613/visudet.html#abs-replaced-height>
+    // (block-style-comments in this function correspond to text from the spec and
+    // the numbers correspond to numbers in spec)
+
+    // We don't use containingBlock(), since we may be positioned by an enclosing relpositioned inline.
+    const LayoutBoxModelObject* containerBlock = toLayoutBoxModelObject(container());
+
+    const LayoutUnit containerLogicalHeight = containingBlockLogicalHeightForPositioned(containerBlock);
+    const LayoutUnit containerRelativeLogicalWidth = containingBlockLogicalWidthForPositioned(containerBlock, false);
+
+    // Variables to solve.
+    Length marginBefore = style()->marginBefore();
+    Length marginAfter = style()->marginAfter();
+    LayoutUnit& marginBeforeAlias = computedValues.m_margins.m_before;
+    LayoutUnit& marginAfterAlias = computedValues.m_margins.m_after;
+
+    Length logicalTop = style()->logicalTop();
+    Length logicalBottom = style()->logicalBottom();
+
+    /*-----------------------------------------------------------------------*\
+     * 1. The used value of 'height' is determined as for inline replaced
+     *    elements.
+    \*-----------------------------------------------------------------------*/
+    // NOTE: This value of height is final in that the min/max height calculations
+    // 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);
+
+    /*-----------------------------------------------------------------------*\
+     * 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);
+        if (marginAfter.isAuto())
+            marginAfter.setValue(Fixed, 0);
+    }
+
+    /*-----------------------------------------------------------------------*\
+     * 4. If at this point both 'margin-top' and 'margin-bottom' are still
+     *    'auto', solve the equation under the extra constraint that the two
+     *    margins must get equal values.
+    \*-----------------------------------------------------------------------*/
+    LayoutUnit logicalTopValue = 0;
+    LayoutUnit logicalBottomValue = 0;
+
+    if (marginBefore.isAuto() && marginAfter.isAuto()) {
+        // 'top' and 'bottom' cannot be 'auto' due to step 2 and 3 combined.
+        ASSERT(!(logicalTop.isAuto() || logicalBottom.isAuto()));
+
+        logicalTopValue = valueForLength(logicalTop, containerLogicalHeight);
+        logicalBottomValue = valueForLength(logicalBottom, containerLogicalHeight);
+
+        LayoutUnit difference = availableSpace - (logicalTopValue + logicalBottomValue);
+        // NOTE: This may result in negative values.
+        marginBeforeAlias =  difference / 2; // split the difference
+        marginAfterAlias = difference - marginBeforeAlias; // account for odd valued differences
+
+    /*-----------------------------------------------------------------------*\
+     * 5. If at this point there is only one 'auto' left, solve the equation
+     *    for that value.
+    \*-----------------------------------------------------------------------*/
+    } else if (logicalTop.isAuto()) {
+        marginBeforeAlias = valueForLength(marginBefore, containerRelativeLogicalWidth);
+        marginAfterAlias = valueForLength(marginAfter, containerRelativeLogicalWidth);
+        logicalBottomValue = valueForLength(logicalBottom, containerLogicalHeight);
+
+        // Solve for 'top'
+        logicalTopValue = availableSpace - (logicalBottomValue + marginBeforeAlias + marginAfterAlias);
+    } else if (logicalBottom.isAuto()) {
+        marginBeforeAlias = valueForLength(marginBefore, containerRelativeLogicalWidth);
+        marginAfterAlias = valueForLength(marginAfter, containerRelativeLogicalWidth);
+        logicalTopValue = valueForLength(logicalTop, containerLogicalHeight);
+
+        // Solve for 'bottom'
+        // NOTE: It is not necessary to solve for 'bottom' because we don't ever
+        // use the value.
+    } else if (marginBefore.isAuto()) {
+        marginAfterAlias = valueForLength(marginAfter, containerRelativeLogicalWidth);
+        logicalTopValue = valueForLength(logicalTop, containerLogicalHeight);
+        logicalBottomValue = valueForLength(logicalBottom, containerLogicalHeight);
+
+        // Solve for 'margin-top'
+        marginBeforeAlias = availableSpace - (logicalTopValue + logicalBottomValue + marginAfterAlias);
+    } else if (marginAfter.isAuto()) {
+        marginBeforeAlias = valueForLength(marginBefore, containerRelativeLogicalWidth);
+        logicalTopValue = valueForLength(logicalTop, containerLogicalHeight);
+        logicalBottomValue = valueForLength(logicalBottom, containerLogicalHeight);
+
+        // Solve for 'margin-bottom'
+        marginAfterAlias = availableSpace - (logicalTopValue + logicalBottomValue + marginBeforeAlias);
+    } else {
+        // Nothing is 'auto', just calculate the values.
+        marginBeforeAlias = valueForLength(marginBefore, containerRelativeLogicalWidth);
+        marginAfterAlias = valueForLength(marginAfter, containerRelativeLogicalWidth);
+        logicalTopValue = valueForLength(logicalTop, containerLogicalHeight);
+        // NOTE: It is not necessary to solve for 'bottom' because we don't ever
+        // use the value.
+    }
+
+    /*-----------------------------------------------------------------------*\
+     * 6. If at this point the values are over-constrained, ignore the value
+     *    for 'bottom' and solve for that value.
+    \*-----------------------------------------------------------------------*/
+    // NOTE: It is not necessary to do this step because we don't end up using
+    // the value of 'bottom' regardless of whether the values are over-constrained
+    // or not.
+
+    // Use computed values to calculate the vertical position.
+    LayoutUnit logicalTopPos = logicalTopValue + marginBeforeAlias;
+    computeLogicalTopPositionedOffset(logicalTopPos, this, computedValues.m_extent, containerBlock, containerLogicalHeight);
+    computedValues.m_position = logicalTopPos;
+}
+
 LayoutRect LayoutReplaced::replacedContentRect(const LayoutSize* overriddenIntrinsicSize) const
 {
     LayoutRect contentRect = contentBoxRect();