/**
* Attempt to place the block frame within the available space. If
* it fits, apply horizontal positioning (CSS 10.3.3), collapse
* margins (CSS2 8.3.1). Also apply relative positioning.
*/
bool
nsBlockReflowContext::PlaceBlock(const nsHTMLReflowState& aReflowState,
bool aForceFit,
nsLineBox* aLine,
nsCollapsingMargin& aBottomMarginResult,
nsRect& aInFlowBounds,
nsOverflowAreas& aOverflowAreas,
nsReflowStatus aReflowStatus)
{
// Compute collapsed bottom margin value.
if (NS_FRAME_IS_COMPLETE(aReflowStatus)) {
aBottomMarginResult = mMetrics.mCarriedOutBottomMargin;
aBottomMarginResult.Include(aReflowState.ComputedPhysicalMargin().bottom);
} else {
// The used bottom-margin is set to zero above a break.
aBottomMarginResult.Zero();
}
nsPoint position(mX, mY);
nscoord backupContainingBlockAdvance = 0;
// Check whether the block's bottom margin collapses with its top
// margin. See CSS 2.1 section 8.3.1; those rules seem to match
// nsBlockFrame::IsEmpty(). Any such block must have zero height so
// check that first. Note that a block can have clearance and still
// have adjoining top/bottom margins, because the clearance goes
// above the top margin.
// Mark the frame as non-dirty; it has been reflowed (or we wouldn't
// be here), and we don't want to assert in CachedIsEmpty()
mFrame->RemoveStateBits(NS_FRAME_IS_DIRTY);
bool empty = 0 == mMetrics.Height() && aLine->CachedIsEmpty();
if (empty) {
// Collapse the bottom margin with the top margin that was already
// applied.
aBottomMarginResult.Include(mTopMargin);
#ifdef NOISY_VERTICAL_MARGINS
printf(" ");
nsFrame::ListTag(stdout, mOuterReflowState.frame);
printf(": ");
nsFrame::ListTag(stdout, mFrame);
printf(" -- collapsing top & bottom margin together; y=%d spaceY=%d\n",
position.y, mSpace.y);
#endif
// Section 8.3.1 of CSS 2.1 says that blocks with adjoining
// top/bottom margins whose top margin collapses with their
// parent's top margin should have their top border-edge at the
// top border-edge of their parent. We actually don't have to do
// anything special to make this happen. In that situation,
// nsBlockFrame::ShouldApplyTopMargin will have returned false,
// and mTopMargin and aClearance will have been zero in
// ReflowBlock.
// If we did apply our top margin, but now we're collapsing it
// into the bottom margin, we need to back up the containing
// block's y-advance by our top margin so that it doesn't get
// counted twice. Note that here we're allowing the line's bounds
// to become different from the block's position; we do this
// because the containing block will place the next line at the
// line's YMost, and it must place the next line at a different
// point from where this empty block will be.
backupContainingBlockAdvance = mTopMargin.get();
}
// See if the frame fit. If it's the first frame or empty then it
// always fits. If the height is unconstrained then it always fits,
// even if there's some sort of integer overflow that makes y +
// mMetrics.Height() appear to go beyond the available height.
if (!empty && !aForceFit && mSpace.height != NS_UNCONSTRAINEDSIZE) {
nscoord yMost = position.y - backupContainingBlockAdvance + mMetrics.Height();
if (yMost > mSpace.YMost()) {
// didn't fit, we must acquit.
mFrame->DidReflow(mPresContext, &aReflowState, nsDidReflowStatus::FINISHED);
return false;
}
}
aInFlowBounds = nsRect(position.x, position.y - backupContainingBlockAdvance,
mMetrics.Width(), mMetrics.Height());
aReflowState.ApplyRelativePositioning(&position);
// Now place the frame and complete the reflow process
nsContainerFrame::FinishReflowChild(mFrame, mPresContext, mMetrics,
&aReflowState, position.x, position.y, 0);
aOverflowAreas = mMetrics.mOverflowAreas + position;
return true;
}
/**
* Attempt to place the block frame within the available space. If
* it fits, apply inline-dir ("horizontal") positioning (CSS 10.3.3),
* collapse margins (CSS2 8.3.1). Also apply relative positioning.
*/
bool
nsBlockReflowContext::PlaceBlock(const nsHTMLReflowState& aReflowState,
bool aForceFit,
nsLineBox* aLine,
nsCollapsingMargin& aBEndMarginResult,
nsOverflowAreas& aOverflowAreas,
nsReflowStatus aReflowStatus)
{
// Compute collapsed block-end margin value.
WritingMode wm = aReflowState.GetWritingMode();
WritingMode parentWM = mMetrics.GetWritingMode();
if (NS_FRAME_IS_COMPLETE(aReflowStatus)) {
aBEndMarginResult = mMetrics.mCarriedOutBEndMargin;
aBEndMarginResult.Include(aReflowState.ComputedLogicalMargin().
ConvertTo(parentWM, wm).BEnd(parentWM));
} else {
// The used block-end-margin is set to zero before a break.
aBEndMarginResult.Zero();
}
nscoord backupContainingBlockAdvance = 0;
// Check whether the block's block-end margin collapses with its block-start
// margin. See CSS 2.1 section 8.3.1; those rules seem to match
// nsBlockFrame::IsEmpty(). Any such block must have zero block-size so
// check that first. Note that a block can have clearance and still
// have adjoining block-start/end margins, because the clearance goes
// above the block-start margin.
// Mark the frame as non-dirty; it has been reflowed (or we wouldn't
// be here), and we don't want to assert in CachedIsEmpty()
mFrame->RemoveStateBits(NS_FRAME_IS_DIRTY);
bool empty = 0 == mMetrics.BSize(parentWM) && aLine->CachedIsEmpty();
if (empty) {
// Collapse the block-end margin with the block-start margin that was
// already applied.
aBEndMarginResult.Include(mBStartMargin);
#ifdef NOISY_BLOCKDIR_MARGINS
printf(" ");
nsFrame::ListTag(stdout, mOuterReflowState.frame);
printf(": ");
nsFrame::ListTag(stdout, mFrame);
printf(" -- collapsing block start & end margin together; BStart=%d spaceBStart=%d\n",
mBCoord, mSpace.BStart(mWritingMode));
#endif
// Section 8.3.1 of CSS 2.1 says that blocks with adjoining
// "top/bottom" (i.e. block-start/end) margins whose top margin collapses
// with their parent's top margin should have their top border-edge at the
// top border-edge of their parent. We actually don't have to do
// anything special to make this happen. In that situation,
// nsBlockFrame::ShouldApplyBStartMargin will have returned false,
// and mBStartMargin and aClearance will have been zero in
// ReflowBlock.
// If we did apply our block-start margin, but now we're collapsing it
// into the block-end margin, we need to back up the containing
// block's bCoord-advance by our block-start margin so that it doesn't get
// counted twice. Note that here we're allowing the line's bounds
// to become different from the block's position; we do this
// because the containing block will place the next line at the
// line's BEnd, and it must place the next line at a different
// point from where this empty block will be.
backupContainingBlockAdvance = mBStartMargin.get();
}
// See if the frame fit. If it's the first frame or empty then it
// always fits. If the block-size is unconstrained then it always fits,
// even if there's some sort of integer overflow that makes bCoord +
// mMetrics.BSize() appear to go beyond the available block size.
if (!empty && !aForceFit &&
mSpace.BSize(mWritingMode) != NS_UNCONSTRAINEDSIZE) {
nscoord bEnd = mBCoord -
backupContainingBlockAdvance + mMetrics.BSize(mWritingMode);
if (bEnd > mSpace.BEnd(mWritingMode)) {
// didn't fit, we must acquit.
mFrame->DidReflow(mPresContext, &aReflowState,
nsDidReflowStatus::FINISHED);
return false;
}
}
aLine->SetBounds(mWritingMode,
mICoord, mBCoord - backupContainingBlockAdvance,
mMetrics.ISize(mWritingMode), mMetrics.BSize(mWritingMode),
mContainerSize);
WritingMode frameWM = mFrame->GetWritingMode();
LogicalPoint logPos =
LogicalPoint(mWritingMode, mICoord, mBCoord).
ConvertTo(frameWM, mWritingMode,
mContainerSize - mMetrics.PhysicalSize());
// ApplyRelativePositioning in right-to-left writing modes needs to
// know the updated frame width
mFrame->SetSize(mWritingMode, mMetrics.Size(mWritingMode));
aReflowState.ApplyRelativePositioning(&logPos, mContainerSize);
// Now place the frame and complete the reflow process
nsContainerFrame::FinishReflowChild(mFrame, mPresContext, mMetrics,
&aReflowState, frameWM, logPos,
mContainerSize, 0);
aOverflowAreas = mMetrics.mOverflowAreas + mFrame->GetPosition();
return true;
}
