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); }