bool
nsColumnSetFrame::ReflowChildren(nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus,
const ReflowConfig& aConfig,
bool aUnboundedLastColumn,
nsCollapsingMargin* aBottomMarginCarriedOut,
ColumnBalanceData& aColData)
{
aColData.Reset();
bool allFit = true;
bool RTL = StyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL;
bool shrinkingHeightOnly = !NS_SUBTREE_DIRTY(this) &&
mLastBalanceHeight > aConfig.mColMaxHeight;
#ifdef DEBUG_roc
printf("*** Doing column reflow pass: mLastBalanceHeight=%d, mColMaxHeight=%d, RTL=%d\n, mBalanceColCount=%d, mColWidth=%d, mColGap=%d\n",
mLastBalanceHeight, aConfig.mColMaxHeight, RTL, aConfig.mBalanceColCount,
aConfig.mColWidth, aConfig.mColGap);
#endif
DrainOverflowColumns();
const bool colHeightChanged = mLastBalanceHeight != aConfig.mColMaxHeight;
if (colHeightChanged) {
mLastBalanceHeight = aConfig.mColMaxHeight;
// XXX Seems like this could fire if incremental reflow pushed the column set
// down so we reflow incrementally with a different available height.
// We need a way to do an incremental reflow and be sure availableHeight
// changes are taken account of! Right now I think block frames with absolute
// children might exit early.
//NS_ASSERTION(aKidReason != eReflowReason_Incremental,
// "incremental reflow should not have changed the balance height");
}
// get our border and padding
nsMargin borderPadding = aReflowState.ComputedPhysicalBorderPadding();
borderPadding.ApplySkipSides(GetSkipSides(&aReflowState));
nsRect contentRect(0, 0, 0, 0);
nsOverflowAreas overflowRects;
nsIFrame* child = mFrames.FirstChild();
nsPoint childOrigin = nsPoint(borderPadding.left, borderPadding.top);
// For RTL, figure out where the last column's left edge should be. Since the
// columns might not fill the frame exactly, we need to account for the
// slop. Otherwise we'll waste time moving the columns by some tiny
// amount unnecessarily.
if (RTL) {
nscoord availWidth = aReflowState.AvailableWidth();
if (aReflowState.ComputedWidth() != NS_INTRINSICSIZE) {
availWidth = aReflowState.ComputedWidth();
}
if (availWidth != NS_INTRINSICSIZE) {
childOrigin.x += availWidth - aConfig.mColWidth;
#ifdef DEBUG_roc
printf("*** childOrigin.x = %d\n", childOrigin.x);
#endif
}
}
int columnCount = 0;
int contentBEnd = 0;
bool reflowNext = false;
while (child) {
// Try to skip reflowing the child. We can't skip if the child is dirty. We also can't
// skip if the next column is dirty, because the next column's first line(s)
// might be pullable back to this column. We can't skip if it's the last child
// because we need to obtain the bottom margin. We can't skip
// if this is the last column and we're supposed to assign unbounded
// height to it, because that could change the available height from
// the last time we reflowed it and we should try to pull all the
// content from its next sibling. (Note that it might be the last
// column, but not be the last child because the desired number of columns
// has changed.)
bool skipIncremental = !aReflowState.ShouldReflowAllKids()
&& !NS_SUBTREE_DIRTY(child)
&& child->GetNextSibling()
&& !(aUnboundedLastColumn && columnCount == aConfig.mBalanceColCount - 1)
&& !NS_SUBTREE_DIRTY(child->GetNextSibling());
// If we need to pull up content from the prev-in-flow then this is not just
// a height shrink. The prev in flow will have set the dirty bit.
// Check the overflow rect YMost instead of just the child's content height. The child
// may have overflowing content that cares about the available height boundary.
// (It may also have overflowing content that doesn't care about the available height
// boundary, but if so, too bad, this optimization is defeated.)
// We want scrollable overflow here since this is a calculation that
// affects layout.
bool skipResizeHeightShrink = shrinkingHeightOnly
&& child->GetScrollableOverflowRect().YMost() <= aConfig.mColMaxHeight;
nscoord childContentBEnd = 0;
WritingMode wm = child->GetWritingMode();
if (!reflowNext && (skipIncremental || skipResizeHeightShrink)) {
// This child does not need to be reflowed, but we may need to move it
MoveChildTo(this, child, childOrigin);
// If this is the last frame then make sure we get the right status
nsIFrame* kidNext = child->GetNextSibling();
if (kidNext) {
aStatus = (kidNext->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER)
? NS_FRAME_OVERFLOW_INCOMPLETE
: NS_FRAME_NOT_COMPLETE;
} else {
aStatus = mLastFrameStatus;
}
childContentBEnd = nsLayoutUtils::CalculateContentBEnd(wm, child);
#ifdef DEBUG_roc
printf("*** Skipping child #%d %p (incremental %d, resize height shrink %d): status = %d\n",
columnCount, (void*)child, skipIncremental, skipResizeHeightShrink, aStatus);
#endif
} else {
nsSize physicalSize(aConfig.mColWidth, aConfig.mColMaxHeight);
if (aUnboundedLastColumn && columnCount == aConfig.mBalanceColCount - 1) {
physicalSize.height = GetAvailableContentHeight(aReflowState);
}
LogicalSize availSize(wm, physicalSize);
LogicalSize computedSize = aReflowState.ComputedSize(wm);
if (reflowNext)
child->AddStateBits(NS_FRAME_IS_DIRTY);
nsHTMLReflowState kidReflowState(PresContext(), aReflowState, child,
availSize, availSize.ISize(wm),
computedSize.BSize(wm));
kidReflowState.mFlags.mIsTopOfPage = true;
kidReflowState.mFlags.mTableIsSplittable = false;
kidReflowState.mFlags.mIsColumnBalancing = aConfig.mBalanceColCount < INT32_MAX;
// We need to reflow any float placeholders, even if our column height
// hasn't changed.
kidReflowState.mFlags.mMustReflowPlaceholders = !colHeightChanged;
#ifdef DEBUG_roc
printf("*** Reflowing child #%d %p: availHeight=%d\n",
columnCount, (void*)child,availSize.BSize(wm));
#endif
// Note if the column's next in flow is not being changed by this incremental reflow.
// This may allow the current column to avoid trying to pull lines from the next column.
if (child->GetNextSibling() &&
!(GetStateBits() & NS_FRAME_IS_DIRTY) &&
!(child->GetNextSibling()->GetStateBits() & NS_FRAME_IS_DIRTY)) {
kidReflowState.mFlags.mNextInFlowUntouched = true;
}
nsHTMLReflowMetrics kidDesiredSize(wm, aDesiredSize.mFlags);
// XXX it would be cool to consult the float manager for the
// previous block to figure out the region of floats from the
// previous column that extend into this column, and subtract
// that region from the new float manager. So you could stick a
// really big float in the first column and text in following
// columns would flow around it.
// Reflow the frame
ReflowChild(child, PresContext(), kidDesiredSize, kidReflowState,
childOrigin.x + kidReflowState.ComputedPhysicalMargin().left,
childOrigin.y + kidReflowState.ComputedPhysicalMargin().top,
0, aStatus);
reflowNext = (aStatus & NS_FRAME_REFLOW_NEXTINFLOW) != 0;
#ifdef DEBUG_roc
printf("*** Reflowed child #%d %p: status = %d, desiredSize=%d,%d CarriedOutBottomMargin=%d\n",
columnCount, (void*)child, aStatus, kidDesiredSize.Width(), kidDesiredSize.Height(),
kidDesiredSize.mCarriedOutBEndMargin.get());
#endif
NS_FRAME_TRACE_REFLOW_OUT("Column::Reflow", aStatus);
*aBottomMarginCarriedOut = kidDesiredSize.mCarriedOutBEndMargin;
FinishReflowChild(child, PresContext(), kidDesiredSize,
&kidReflowState, childOrigin.x, childOrigin.y, 0);
childContentBEnd = nsLayoutUtils::CalculateContentBEnd(wm, child);
if (childContentBEnd > aConfig.mColMaxHeight) {
allFit = false;
}
if (childContentBEnd > availSize.BSize(wm)) {
aColData.mMaxOverflowingHeight = std::max(childContentBEnd,
aColData.mMaxOverflowingHeight);
}
}
contentRect.UnionRect(contentRect, child->GetRect());
ConsiderChildOverflow(overflowRects, child);
contentBEnd = std::max(contentBEnd, childContentBEnd);
aColData.mLastHeight = childContentBEnd;
aColData.mSumHeight += childContentBEnd;
// Build a continuation column if necessary
nsIFrame* kidNextInFlow = child->GetNextInFlow();
if (NS_FRAME_IS_FULLY_COMPLETE(aStatus) && !NS_FRAME_IS_TRUNCATED(aStatus)) {
NS_ASSERTION(!kidNextInFlow, "next in flow should have been deleted");
child = nullptr;
break;
} else {
++columnCount;
// Make sure that the column has a next-in-flow. If not, we must
// create one to hold the overflowing stuff, even if we're just
// going to put it on our overflow list and let *our*
// next in flow handle it.
if (!kidNextInFlow) {
NS_ASSERTION(aStatus & NS_FRAME_REFLOW_NEXTINFLOW,
"We have to create a continuation, but the block doesn't want us to reflow it?");
// We need to create a continuing column
nsresult rv = CreateNextInFlow(child, kidNextInFlow);
if (NS_FAILED(rv)) {
NS_NOTREACHED("Couldn't create continuation");
child = nullptr;
break;
}
}
// Make sure we reflow a next-in-flow when it switches between being
// normal or overflow container
if (NS_FRAME_OVERFLOW_IS_INCOMPLETE(aStatus)) {
if (!(kidNextInFlow->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER)) {
aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
reflowNext = true;
kidNextInFlow->AddStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
}
}
else if (kidNextInFlow->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER) {
aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
reflowNext = true;
kidNextInFlow->RemoveStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
}
if ((contentBEnd > aReflowState.ComputedMaxBSize() ||
contentBEnd > aReflowState.ComputedBSize()) &&
aConfig.mBalanceColCount < INT32_MAX) {
// We overflowed vertically, but have not exceeded the number of
// columns. We're going to go into overflow columns now, so balancing
// no longer applies.
aColData.mHasExcessHeight = true;
}
if (columnCount >= aConfig.mBalanceColCount) {
// No more columns allowed here. Stop.
aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
kidNextInFlow->AddStateBits(NS_FRAME_IS_DIRTY);
// Move any of our leftover columns to our overflow list. Our
// next-in-flow will eventually pick them up.
const nsFrameList& continuationColumns = mFrames.RemoveFramesAfter(child);
if (continuationColumns.NotEmpty()) {
SetOverflowFrames(continuationColumns);
}
child = nullptr;
break;
}
}
if (PresContext()->HasPendingInterrupt()) {
// Stop the loop now while |child| still points to the frame that bailed
// out. We could keep going here and condition a bunch of the code in
// this loop on whether there's an interrupt, or even just keep going and
// trying to reflow the blocks (even though we know they'll interrupt
// right after their first line), but stopping now is conceptually the
// simplest (and probably fastest) thing.
break;
}
// Advance to the next column
child = child->GetNextSibling();
if (child) {
if (!RTL) {
childOrigin.x += aConfig.mColWidth + aConfig.mColGap;
} else {
childOrigin.x -= aConfig.mColWidth + aConfig.mColGap;
}
#ifdef DEBUG_roc
printf("*** NEXT CHILD ORIGIN.x = %d\n", childOrigin.x);
#endif
}
}
if (PresContext()->CheckForInterrupt(this) &&
(GetStateBits() & NS_FRAME_IS_DIRTY)) {
// Mark all our kids starting with |child| dirty
// Note that this is a CheckForInterrupt call, not a HasPendingInterrupt,
// because we might have interrupted while reflowing |child|, and since
// we're about to add a dirty bit to |child| we need to make sure that
// |this| is scheduled to have dirty bits marked on it and its ancestors.
// Otherwise, when we go to mark dirty bits on |child|'s ancestors we'll
// bail out immediately, since it'll already have a dirty bit.
for (; child; child = child->GetNextSibling()) {
child->AddStateBits(NS_FRAME_IS_DIRTY);
}
}
aColData.mMaxHeight = contentBEnd;
contentRect.height = std::max(contentRect.height, contentBEnd);
mLastFrameStatus = aStatus;
// contentRect included the borderPadding.left,borderPadding.top of the child rects
contentRect -= nsPoint(borderPadding.left, borderPadding.top);
WritingMode wm = aReflowState.GetWritingMode();
LogicalSize contentSize(wm, nsSize(contentRect.XMost(), contentRect.YMost()));
// Apply computed and min/max values
// (aConfig members need to be converted from Width/Height to ISize/BSize)
if (aConfig.mComputedHeight != NS_INTRINSICSIZE) {
if (aReflowState.AvailableHeight() != NS_INTRINSICSIZE) {
contentSize.BSize(wm) = std::min(contentSize.BSize(wm),
aConfig.mComputedHeight);
} else {
contentSize.BSize(wm) = aConfig.mComputedHeight;
}
} else {
// We add the "consumed" height back in so that we're applying
// constraints to the correct height value, then subtract it again
// after we've finished with the min/max calculation. This prevents us from
// having a last continuation that is smaller than the min height. but which
// has prev-in-flows, trigger a larger height than actually required.
contentSize.BSize(wm) =
aReflowState.ApplyMinMaxHeight(contentSize.BSize(wm),
aConfig.mConsumedHeight);
}
if (aReflowState.ComputedISize() != NS_INTRINSICSIZE) {
contentSize.ISize(wm) = aReflowState.ComputedISize();
} else {
contentSize.ISize(wm) =
aReflowState.ApplyMinMaxWidth(contentSize.ISize(wm));
}
LogicalMargin bp(wm, borderPadding);
contentSize.ISize(wm) += bp.IStartEnd(wm);
contentSize.BSize(wm) += bp.BStartEnd(wm);
aDesiredSize.SetSize(wm, contentSize);
aDesiredSize.mOverflowAreas = overflowRects;
aDesiredSize.UnionOverflowAreasWithDesiredBounds();
#ifdef DEBUG_roc
printf("*** DONE PASS feasible=%d\n", allFit && NS_FRAME_IS_FULLY_COMPLETE(aStatus)
&& !NS_FRAME_IS_TRUNCATED(aStatus));
#endif
return allFit && NS_FRAME_IS_FULLY_COMPLETE(aStatus)
&& !NS_FRAME_IS_TRUNCATED(aStatus);
}
