LayoutUnit RenderReplaced::computeReplacedLogicalWidth(ShouldComputePreferred shouldComputePreferred) const
{
if (style()->logicalWidth().isSpecified() || style()->logicalWidth().isIntrinsic())
return computeReplacedLogicalWidthRespectingMinMaxWidth(computeReplacedLogicalWidthUsing(style()->logicalWidth()), shouldComputePreferred);
// 10.3.2 Inline, replaced elements: http://www.w3.org/TR/CSS21/visudet.html#inline-replaced-width
double intrinsicRatio = 0;
FloatSize constrainedSize;
computeAspectRatioInformationForRenderBox(constrainedSize, intrinsicRatio);
if (style()->logicalWidth().isAuto()) {
bool computedHeightIsAuto = hasAutoHeightOrContainingBlockWithAutoHeight();
bool hasIntrinsicWidth = constrainedSize.width() > 0;
// If 'height' and 'width' both have computed values of 'auto' and the element also has an intrinsic width, then that intrinsic width is the used value of 'width'.
if (computedHeightIsAuto && hasIntrinsicWidth)
return computeReplacedLogicalWidthRespectingMinMaxWidth(constrainedSize.width(), shouldComputePreferred);
bool hasIntrinsicHeight = constrainedSize.height() > 0;
if (intrinsicRatio) {
// If 'height' and 'width' both have computed values of 'auto' and the element has no intrinsic width, but does have an intrinsic height and intrinsic ratio;
// or if 'width' has a computed value of 'auto', 'height' has some other computed value, and the element does have an intrinsic ratio; then the used value
// of 'width' is: (used height) * (intrinsic ratio)
if (intrinsicRatio && ((computedHeightIsAuto && !hasIntrinsicWidth && hasIntrinsicHeight) || !computedHeightIsAuto)) {
LayoutUnit logicalHeight = computeReplacedLogicalHeight();
return computeReplacedLogicalWidthRespectingMinMaxWidth(roundToInt(round(logicalHeight * intrinsicRatio)), shouldComputePreferred);
}
// If 'height' and 'width' both have computed values of 'auto' and the element has an intrinsic ratio but no intrinsic height or width, then the used value of
// 'width' is undefined in CSS 2.1. However, it is suggested that, if the containing block's width does not itself depend on the replaced element's width, then
// the used value of 'width' is calculated from the constraint equation used for block-level, non-replaced elements in normal flow.
if (computedHeightIsAuto && !hasIntrinsicWidth && !hasIntrinsicHeight) {
if (shouldComputePreferred == ComputePreferred)
return 0;
// The aforementioned 'constraint equation' used for block-level, non-replaced elements in normal flow:
// 'margin-left' + 'border-left-width' + 'padding-left' + 'width' + 'padding-right' + 'border-right-width' + 'margin-right' = width of containing block
LayoutUnit logicalWidth = containingBlock()->availableLogicalWidth();
// This solves above equation for 'width' (== logicalWidth).
LayoutUnit marginStart = minimumValueForLength(style()->marginStart(), logicalWidth);
LayoutUnit marginEnd = minimumValueForLength(style()->marginEnd(), logicalWidth);
logicalWidth = std::max<LayoutUnit>(0, logicalWidth - (marginStart + marginEnd + (width() - clientWidth())));
return computeReplacedLogicalWidthRespectingMinMaxWidth(logicalWidth, shouldComputePreferred);
}
}
// Otherwise, if 'width' has a computed value of 'auto', and the element has an intrinsic width, then that intrinsic width is the used value of 'width'.
if (hasIntrinsicWidth)
return computeReplacedLogicalWidthRespectingMinMaxWidth(constrainedSize.width(), shouldComputePreferred);
// Otherwise, if 'width' has a computed value of 'auto', but none of the conditions above are met, then the used value of 'width' becomes 300px. If 300px is too
// wide to fit the device, UAs should use the width of the largest rectangle that has a 2:1 ratio and fits the device instead.
// Note: We fall through and instead return intrinsicLogicalWidth() here - to preserve existing WebKit behavior, which might or might not be correct, or desired.
// Changing this to return cDefaultWidth, will affect lots of test results. Eg. some tests assume that a blank <img> tag (which implies width/height=auto)
// has no intrinsic size, which is wrong per CSS 2.1, but matches our behavior since a long time.
}
return computeReplacedLogicalWidthRespectingMinMaxWidth(intrinsicLogicalWidth(), shouldComputePreferred);
}
LayoutUnit LayoutReplaced::computeReplacedLogicalWidth(
ShouldComputePreferred shouldComputePreferred) const {
if (style()->logicalWidth().isSpecified() ||
style()->logicalWidth().isIntrinsic())
return computeReplacedLogicalWidthRespectingMinMaxWidth(
computeReplacedLogicalWidthUsing(MainOrPreferredSize,
style()->logicalWidth()),
shouldComputePreferred);
LayoutReplaced* contentLayoutObject = embeddedReplacedContent();
// 10.3.2 Inline, replaced elements:
// http://www.w3.org/TR/CSS21/visudet.html#inline-replaced-width
IntrinsicSizingInfo intrinsicSizingInfo;
computeIntrinsicSizingInfoForReplacedContent(contentLayoutObject,
intrinsicSizingInfo);
FloatSize constrainedSize =
constrainIntrinsicSizeToMinMax(intrinsicSizingInfo);
if (style()->logicalWidth().isAuto()) {
bool computedHeightIsAuto = style()->logicalHeight().isAuto();
// If 'height' and 'width' both have computed values of 'auto' and the
// element also has an intrinsic width, then that intrinsic width is the
// used value of 'width'.
if (computedHeightIsAuto && intrinsicSizingInfo.hasWidth)
return computeReplacedLogicalWidthRespectingMinMaxWidth(
LayoutUnit(constrainedSize.width()), shouldComputePreferred);
if (!intrinsicSizingInfo.aspectRatio.isEmpty()) {
// If 'height' and 'width' both have computed values of 'auto' and the
// element has no intrinsic width, but does have an intrinsic height and
// intrinsic ratio; or if 'width' has a computed value of 'auto', 'height'
// has some other computed value, and the element does have an intrinsic
// ratio; then the used value of 'width' is: (used height) * (intrinsic
// ratio).
if ((computedHeightIsAuto && !intrinsicSizingInfo.hasWidth &&
intrinsicSizingInfo.hasHeight) ||
!computedHeightIsAuto) {
LayoutUnit estimatedUsedWidth =
intrinsicSizingInfo.hasWidth
? LayoutUnit(constrainedSize.width())
: computeConstrainedLogicalWidth(shouldComputePreferred);
LayoutUnit logicalHeight =
computeReplacedLogicalHeight(estimatedUsedWidth);
return computeReplacedLogicalWidthRespectingMinMaxWidth(
resolveWidthForRatio(logicalHeight,
intrinsicSizingInfo.aspectRatio),
shouldComputePreferred);
}
// If 'height' and 'width' both have computed values of 'auto' and the
// element has an intrinsic ratio but no intrinsic height or width, then
// the used value of 'width' is undefined in CSS 2.1. However, it is
// suggested that, if the containing block's width does not itself depend
// on the replaced element's width, then the used value of 'width' is
// calculated from the constraint equation used for block-level,
// non-replaced elements in normal flow.
if (computedHeightIsAuto && !intrinsicSizingInfo.hasWidth &&
!intrinsicSizingInfo.hasHeight)
return computeConstrainedLogicalWidth(shouldComputePreferred);
}
// Otherwise, if 'width' has a computed value of 'auto', and the element has
// an intrinsic width, then that intrinsic width is the used value of
// 'width'.
if (intrinsicSizingInfo.hasWidth)
return computeReplacedLogicalWidthRespectingMinMaxWidth(
LayoutUnit(constrainedSize.width()), shouldComputePreferred);
// Otherwise, if 'width' has a computed value of 'auto', but none of the
// conditions above are met, then the used value of 'width' becomes 300px.
// If 300px is too wide to fit the device, UAs should use the width of the
// largest rectangle that has a 2:1 ratio and fits the device instead.
// Note: We fall through and instead return intrinsicLogicalWidth() here -
// to preserve existing WebKit behavior, which might or might not be
// correct, or desired.
// Changing this to return cDefaultWidth, will affect lots of test results.
// Eg. some tests assume that a blank <img> tag (which implies
// width/height=auto) has no intrinsic size, which is wrong per CSS 2.1, but
// matches our behavior since a long time.
}
return computeReplacedLogicalWidthRespectingMinMaxWidth(
intrinsicLogicalWidth(), shouldComputePreferred);
}
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;
LayoutUnit logicalBottomValue;
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;
}
