gecko-dev/layout/generic/nsColumnSetFrame.cpp
Ting-Yu Lin 26a6db6fb1 Bug 1909761 Part 2 - Create a helper struct IntrinsicSizeInput to aggregate needed data when computing intrinsic inline size. r=dholbert
This patch changes the signature to `GetMinISize()`, `GetPrefISize()`,
`IntrinsicISize` by adding a helper struct as a preparation. Then we can just
add more data such as a percentage basis to the struct without altering the
signature in the future.

When passing `IntrinsicSizeInput` struct down to another helper method, we
generally just pass the original one if the method is computing the intrinsic
size of our own or our anonymous children. If the method is computing our
children's intrinsic contribution, we'll need to create a brand new
`IntrinsicSizeInput` for our children.

Differential Revision: https://phabricator.services.mozilla.com/D219521
2024-09-03 04:25:41 +00:00

1356 lines
56 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* rendering object for css3 multi-column layout */
#include "nsColumnSetFrame.h"
#include "mozilla/ColumnUtils.h"
#include "mozilla/Logging.h"
#include "mozilla/PresShell.h"
#include "mozilla/StaticPrefs_layout.h"
#include "mozilla/ToString.h"
#include "nsCSSRendering.h"
#include "nsDisplayList.h"
#include "nsIFrameInlines.h"
#include "nsLayoutUtils.h"
using namespace mozilla;
using namespace mozilla::layout;
// To see this log, use $ MOZ_LOG=ColumnSet:4 ./mach run
static LazyLogModule sColumnSetLog("ColumnSet");
#define COLUMN_SET_LOG(msg, ...) \
MOZ_LOG(sColumnSetLog, LogLevel::Debug, (msg, ##__VA_ARGS__))
class nsDisplayColumnRule : public nsPaintedDisplayItem {
public:
nsDisplayColumnRule(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsPaintedDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayColumnRule);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayColumnRule)
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override {
*aSnap = false;
// We just return the frame's ink-overflow rect, which is guaranteed to
// contain all the column-rule areas. It's not worth calculating the exact
// union of those areas since it would only lead to performance improvements
// during painting in rare edge cases.
return mFrame->InkOverflowRect() + ToReferenceFrame();
}
bool CreateWebRenderCommands(
mozilla::wr::DisplayListBuilder& aBuilder,
mozilla::wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
mozilla::layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
NS_DISPLAY_DECL_NAME("ColumnRule", TYPE_COLUMN_RULE);
private:
nsTArray<nsCSSBorderRenderer> mBorderRenderers;
};
void nsDisplayColumnRule::Paint(nsDisplayListBuilder* aBuilder,
gfxContext* aCtx) {
static_cast<nsColumnSetFrame*>(mFrame)->CreateBorderRenderers(
mBorderRenderers, aCtx, GetPaintRect(aBuilder, aCtx), ToReferenceFrame());
for (auto iter = mBorderRenderers.begin(); iter != mBorderRenderers.end();
iter++) {
iter->DrawBorders();
}
}
bool nsDisplayColumnRule::CreateWebRenderCommands(
mozilla::wr::DisplayListBuilder& aBuilder,
mozilla::wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
mozilla::layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) {
RefPtr dt = gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
if (!dt || !dt->IsValid()) {
return false;
}
gfxContext screenRefCtx(dt);
bool dummy;
static_cast<nsColumnSetFrame*>(mFrame)->CreateBorderRenderers(
mBorderRenderers, &screenRefCtx, GetBounds(aDisplayListBuilder, &dummy),
ToReferenceFrame());
if (mBorderRenderers.IsEmpty()) {
return true;
}
for (auto& renderer : mBorderRenderers) {
renderer.CreateWebRenderCommands(this, aBuilder, aResources, aSc);
}
return true;
}
// The maximum number of columns we support.
static constexpr int32_t kMaxColumnCount = 1000;
/**
* Tracking issues:
*
* XXX cursor movement around the top and bottom of colums seems to make the
* editor lose the caret.
*
* XXX should we support CSS columns applied to table elements?
*/
nsContainerFrame* NS_NewColumnSetFrame(PresShell* aPresShell,
ComputedStyle* aStyle,
nsFrameState aStateFlags) {
nsColumnSetFrame* it =
new (aPresShell) nsColumnSetFrame(aStyle, aPresShell->GetPresContext());
it->AddStateBits(aStateFlags);
return it;
}
NS_IMPL_FRAMEARENA_HELPERS(nsColumnSetFrame)
nsColumnSetFrame::nsColumnSetFrame(ComputedStyle* aStyle,
nsPresContext* aPresContext)
: nsContainerFrame(aStyle, aPresContext, kClassID),
mLastBalanceBSize(NS_UNCONSTRAINEDSIZE) {}
void nsColumnSetFrame::ForEachColumnRule(
const std::function<void(const nsRect& lineRect)>& aSetLineRect,
const nsPoint& aPt) const {
nsIFrame* child = mFrames.FirstChild();
if (!child) return; // no columns
nsIFrame* nextSibling = child->GetNextSibling();
if (!nextSibling) return; // 1 column only - this means no gap to draw on
const nsStyleColumn* colStyle = StyleColumn();
nscoord ruleWidth = colStyle->GetColumnRuleWidth();
if (!ruleWidth) return;
WritingMode wm = GetWritingMode();
bool isVertical = wm.IsVertical();
bool isRTL = wm.IsBidiRTL();
nsRect contentRect = GetContentRectRelativeToSelf() + aPt;
nsSize ruleSize = isVertical ? nsSize(contentRect.width, ruleWidth)
: nsSize(ruleWidth, contentRect.height);
while (nextSibling) {
// The frame tree goes RTL in RTL.
// The |prevFrame| and |nextFrame| frames here are the visually preceding
// (left/above) and following (right/below) frames, not in logical writing-
// mode direction.
nsIFrame* prevFrame = isRTL ? nextSibling : child;
nsIFrame* nextFrame = isRTL ? child : nextSibling;
// Each child frame's position coordinates is actually relative to this
// nsColumnSetFrame.
// linePt will be at the top-left edge to paint the line.
nsPoint linePt;
if (isVertical) {
nscoord edgeOfPrev = prevFrame->GetRect().YMost() + aPt.y;
nscoord edgeOfNext = nextFrame->GetRect().Y() + aPt.y;
linePt = nsPoint(contentRect.x,
(edgeOfPrev + edgeOfNext - ruleSize.height) / 2);
} else {
nscoord edgeOfPrev = prevFrame->GetRect().XMost() + aPt.x;
nscoord edgeOfNext = nextFrame->GetRect().X() + aPt.x;
linePt = nsPoint((edgeOfPrev + edgeOfNext - ruleSize.width) / 2,
contentRect.y);
}
aSetLineRect(nsRect(linePt, ruleSize));
child = nextSibling;
nextSibling = nextSibling->GetNextSibling();
}
}
void nsColumnSetFrame::CreateBorderRenderers(
nsTArray<nsCSSBorderRenderer>& aBorderRenderers, gfxContext* aCtx,
const nsRect& aDirtyRect, const nsPoint& aPt) {
WritingMode wm = GetWritingMode();
bool isVertical = wm.IsVertical();
const nsStyleColumn* colStyle = StyleColumn();
StyleBorderStyle ruleStyle;
// Per spec, inset => ridge and outset => groove
if (colStyle->mColumnRuleStyle == StyleBorderStyle::Inset) {
ruleStyle = StyleBorderStyle::Ridge;
} else if (colStyle->mColumnRuleStyle == StyleBorderStyle::Outset) {
ruleStyle = StyleBorderStyle::Groove;
} else {
ruleStyle = colStyle->mColumnRuleStyle;
}
nscoord ruleWidth = colStyle->GetColumnRuleWidth();
if (!ruleWidth) {
return;
}
aBorderRenderers.Clear();
nscolor ruleColor =
GetVisitedDependentColor(&nsStyleColumn::mColumnRuleColor);
nsPresContext* pc = PresContext();
// In order to re-use a large amount of code, we treat the column rule as a
// border. We create a new border style object and fill in all the details of
// the column rule as the left border. PaintBorder() does all the rendering
// for us, so we not only save an enormous amount of code but we'll support
// all the line styles that we support on borders!
nsStyleBorder border;
Sides skipSides;
if (isVertical) {
border.SetBorderWidth(eSideTop, ruleWidth, pc->AppUnitsPerDevPixel());
border.SetBorderStyle(eSideTop, ruleStyle);
border.mBorderTopColor = StyleColor::FromColor(ruleColor);
skipSides |= mozilla::SideBits::eLeftRight;
skipSides |= mozilla::SideBits::eBottom;
} else {
border.SetBorderWidth(eSideLeft, ruleWidth, pc->AppUnitsPerDevPixel());
border.SetBorderStyle(eSideLeft, ruleStyle);
border.mBorderLeftColor = StyleColor::FromColor(ruleColor);
skipSides |= mozilla::SideBits::eTopBottom;
skipSides |= mozilla::SideBits::eRight;
}
// If we use box-decoration-break: slice (the default), the border
// renderers will require clipping if we have continuations (see the
// aNeedsClip parameter to ConstructBorderRenderer in nsCSSRendering).
//
// Since it doesn't matter which box-decoration-break we use since
// we're only drawing borders (and not border-images), use 'clone'.
border.mBoxDecorationBreak = StyleBoxDecorationBreak::Clone;
ForEachColumnRule(
[&](const nsRect& aLineRect) {
// Assert that we're not drawing a border-image here; if we were, we
// couldn't ignore the ImgDrawResult that PaintBorderWithStyleBorder
// returns.
MOZ_ASSERT(border.mBorderImageSource.IsNone());
gfx::DrawTarget* dt = aCtx ? aCtx->GetDrawTarget() : nullptr;
bool borderIsEmpty = false;
Maybe<nsCSSBorderRenderer> br =
nsCSSRendering::CreateBorderRendererWithStyleBorder(
pc, dt, this, aDirtyRect, aLineRect, border, Style(),
&borderIsEmpty, skipSides);
if (br.isSome()) {
MOZ_ASSERT(!borderIsEmpty);
aBorderRenderers.AppendElement(br.value());
}
},
aPt);
}
static uint32_t ColumnBalancingDepth(const ReflowInput& aReflowInput,
uint32_t aMaxDepth) {
uint32_t depth = 0;
for (const ReflowInput* ri = aReflowInput.mParentReflowInput;
ri && depth < aMaxDepth; ri = ri->mParentReflowInput) {
if (ri->mFlags.mIsColumnBalancing) {
++depth;
}
}
return depth;
}
nsColumnSetFrame::ReflowConfig nsColumnSetFrame::ChooseColumnStrategy(
const ReflowInput& aReflowInput, bool aForceAuto = false) const {
const nsStyleColumn* colStyle = StyleColumn();
nscoord availContentISize = aReflowInput.AvailableISize();
if (aReflowInput.ComputedISize() != NS_UNCONSTRAINEDSIZE) {
availContentISize = aReflowInput.ComputedISize();
}
nscoord colBSize = aReflowInput.AvailableBSize();
nscoord colGap =
ColumnUtils::GetColumnGap(this, aReflowInput.ComputedISize());
int32_t numColumns =
colStyle->mColumnCount.IsAuto()
? 0
: std::min(colStyle->mColumnCount.AsInteger(), kMaxColumnCount);
// If column-fill is set to 'balance' or we have a column-span sibling, then
// we want to balance the columns.
bool isBalancing = (colStyle->mColumnFill == StyleColumnFill::Balance ||
HasColumnSpanSiblings()) &&
!aForceAuto;
if (isBalancing) {
const uint32_t kMaxNestedColumnBalancingDepth = 2;
const uint32_t balancingDepth =
ColumnBalancingDepth(aReflowInput, kMaxNestedColumnBalancingDepth);
if (balancingDepth == kMaxNestedColumnBalancingDepth) {
isBalancing = false;
numColumns = 1;
}
}
nscoord colISize;
// In vertical writing-mode, "column-width" (inline size) will actually be
// physical height, but its CSS name is still column-width.
if (colStyle->mColumnWidth.IsLength()) {
colISize =
ColumnUtils::ClampUsedColumnWidth(colStyle->mColumnWidth.AsLength());
NS_ASSERTION(colISize >= 0, "negative column width");
// Reduce column count if necessary to make columns fit in the
// available width. Compute max number of columns that fit in
// availContentISize, satisfying colGap*(maxColumns - 1) +
// colISize*maxColumns <= availContentISize
if (availContentISize != NS_UNCONSTRAINEDSIZE && colGap + colISize > 0 &&
numColumns > 0) {
// This expression uses truncated rounding, which is what we
// want
int32_t maxColumns =
std::min(nscoord(kMaxColumnCount),
(availContentISize + colGap) / (colGap + colISize));
numColumns = std::max(1, std::min(numColumns, maxColumns));
}
} else if (numColumns > 0 && availContentISize != NS_UNCONSTRAINEDSIZE) {
nscoord iSizeMinusGaps = availContentISize - colGap * (numColumns - 1);
colISize = iSizeMinusGaps / numColumns;
} else {
colISize = NS_UNCONSTRAINEDSIZE;
}
// Take care of the situation where there's only one column but it's
// still too wide
colISize = std::max(1, std::min(colISize, availContentISize));
nscoord expectedISizeLeftOver = 0;
if (colISize != NS_UNCONSTRAINEDSIZE &&
availContentISize != NS_UNCONSTRAINEDSIZE) {
// distribute leftover space
// First, determine how many columns will be showing if the column
// count is auto
if (numColumns <= 0) {
// choose so that colGap*(nominalColumnCount - 1) +
// colISize*nominalColumnCount is nearly availContentISize
// make sure to round down
if (colGap + colISize > 0) {
numColumns = (availContentISize + colGap) / (colGap + colISize);
// The number of columns should never exceed kMaxColumnCount.
numColumns = std::min(kMaxColumnCount, numColumns);
}
if (numColumns <= 0) {
numColumns = 1;
}
}
// Compute extra space and divide it among the columns
nscoord extraSpace =
std::max(0, availContentISize -
(colISize * numColumns + colGap * (numColumns - 1)));
nscoord extraToColumns = extraSpace / numColumns;
colISize += extraToColumns;
expectedISizeLeftOver = extraSpace - (extraToColumns * numColumns);
}
if (isBalancing) {
if (numColumns <= 0) {
// Hmm, auto column count, column width or available width is unknown,
// and balancing is required. Let's just use one column then.
numColumns = 1;
}
colBSize = std::min(mLastBalanceBSize, colBSize);
} else {
// CSS Fragmentation spec says, "To guarantee progress, fragmentainers are
// assumed to have a minimum block size of 1px regardless of their used
// size." https://drafts.csswg.org/css-break/#breaking-rules
//
// Note: we don't enforce the minimum block-size during balancing because
// this affects the result. If a balancing column container or its
// next-in-flows has zero block-size, it eventually gives up balancing, and
// ends up here.
colBSize = std::max(colBSize, nsPresContext::CSSPixelsToAppUnits(1));
}
ReflowConfig config;
config.mUsedColCount = numColumns;
config.mColISize = colISize;
config.mExpectedISizeLeftOver = expectedISizeLeftOver;
config.mColGap = colGap;
config.mColBSize = colBSize;
config.mIsBalancing = isBalancing;
config.mForceAuto = aForceAuto;
config.mKnownFeasibleBSize = NS_UNCONSTRAINEDSIZE;
config.mKnownInfeasibleBSize = 0;
COLUMN_SET_LOG(
"%s: this=%p, mUsedColCount=%d, mColISize=%d, "
"mExpectedISizeLeftOver=%d, mColGap=%d, mColBSize=%d, mIsBalancing=%d",
__func__, this, config.mUsedColCount, config.mColISize,
config.mExpectedISizeLeftOver, config.mColGap, config.mColBSize,
config.mIsBalancing);
return config;
}
static void MarkPrincipalChildrenDirty(nsIFrame* aFrame) {
for (nsIFrame* childFrame : aFrame->PrincipalChildList()) {
childFrame->MarkSubtreeDirty();
}
}
static void MoveChildTo(nsIFrame* aChild, LogicalPoint aOrigin, WritingMode aWM,
const nsSize& aContainerSize) {
if (aChild->GetLogicalPosition(aWM, aContainerSize) == aOrigin) {
return;
}
aChild->SetPosition(aWM, aOrigin, aContainerSize);
nsContainerFrame::PlaceFrameView(aChild);
}
nscoord nsColumnSetFrame::IntrinsicISize(const IntrinsicSizeInput& input,
IntrinsicISizeType aType) {
return aType == IntrinsicISizeType::MinISize ? MinISize(input)
: PrefISize(input);
}
nscoord nsColumnSetFrame::MinISize(const IntrinsicSizeInput& aInput) {
nscoord iSize = 0;
if (mFrames.FirstChild()) {
iSize = mFrames.FirstChild()->GetMinISize(aInput);
}
const nsStyleColumn* colStyle = StyleColumn();
if (colStyle->mColumnWidth.IsLength()) {
nscoord colISize =
ColumnUtils::ClampUsedColumnWidth(colStyle->mColumnWidth.AsLength());
// As available width reduces to zero, we reduce our number of columns
// to one, and don't enforce the column width, so just return the min
// of the child's min-width with any specified column width.
iSize = std::min(iSize, colISize);
} else {
NS_ASSERTION(!colStyle->mColumnCount.IsAuto(),
"column-count and column-width can't both be auto");
// As available width reduces to zero, we still have mColumnCount columns,
// so compute our minimum size based on the number of columns and their gaps
// and minimum per-column size.
nscoord colGap = ColumnUtils::GetColumnGap(this, NS_UNCONSTRAINEDSIZE);
iSize = ColumnUtils::IntrinsicISize(colStyle->mColumnCount.AsInteger(),
colGap, iSize);
}
// XXX count forced column breaks here? Maybe we should return the child's
// min-width times the minimum number of columns.
return iSize;
}
nscoord nsColumnSetFrame::PrefISize(const IntrinsicSizeInput& aInput) {
// Our preferred width is our desired column width, if specified, otherwise
// the child's preferred width, times the number of columns, plus the width
// of any required column gaps
// XXX what about forced column breaks here?
const nsStyleColumn* colStyle = StyleColumn();
nscoord colISize;
if (colStyle->mColumnWidth.IsLength()) {
colISize =
ColumnUtils::ClampUsedColumnWidth(colStyle->mColumnWidth.AsLength());
} else if (mFrames.FirstChild()) {
colISize = mFrames.FirstChild()->GetPrefISize(aInput);
} else {
colISize = 0;
}
// If column-count is auto, assume one column.
uint32_t numColumns =
colStyle->mColumnCount.IsAuto() ? 1 : colStyle->mColumnCount.AsInteger();
nscoord colGap = ColumnUtils::GetColumnGap(this, NS_UNCONSTRAINEDSIZE);
return ColumnUtils::IntrinsicISize(numColumns, colGap, colISize);
}
nsColumnSetFrame::ColumnBalanceData nsColumnSetFrame::ReflowColumns(
ReflowOutput& aDesiredSize, const ReflowInput& aReflowInput,
nsReflowStatus& aStatus, const ReflowConfig& aConfig,
bool aUnboundedLastColumn) {
ColumnBalanceData colData;
bool allFit = true;
WritingMode wm = GetWritingMode();
const bool isRTL = wm.IsBidiRTL();
const bool shrinkingBSize = mLastBalanceBSize > aConfig.mColBSize;
const bool changingBSize = mLastBalanceBSize != aConfig.mColBSize;
COLUMN_SET_LOG(
"%s: Doing column reflow pass: mLastBalanceBSize=%d,"
" mColBSize=%d, RTL=%d, mUsedColCount=%d,"
" mColISize=%d, mColGap=%d",
__func__, mLastBalanceBSize, aConfig.mColBSize, isRTL,
aConfig.mUsedColCount, aConfig.mColISize, aConfig.mColGap);
DrainOverflowColumns();
if (changingBSize) {
mLastBalanceBSize = aConfig.mColBSize;
// 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");
*/
}
nsRect contentRect(0, 0, 0, 0);
OverflowAreas overflowRects;
nsIFrame* child = mFrames.FirstChild();
LogicalPoint childOrigin(wm, 0, 0);
// In vertical-rl mode, columns will not be correctly placed if the
// reflowInput's ComputedWidth() is UNCONSTRAINED (in which case we'll get
// a containerSize.width of zero here). In that case, the column positions
// will be adjusted later, after our correct contentSize is known.
//
// When column-span is enabled, containerSize.width is always constrained.
// However, for RTL, we need to adjust the column positions as well after our
// correct containerSize is known.
nsSize containerSize = aReflowInput.ComputedSizeAsContainerIfConstrained();
const nscoord computedBSize =
aReflowInput.mParentReflowInput->ComputedBSize();
nscoord contentBEnd = 0;
bool reflowNext = false;
while (child) {
const bool reflowLastColumnWithUnconstrainedAvailBSize =
aUnboundedLastColumn && colData.mColCount == aConfig.mUsedColCount &&
aConfig.mIsBalancing;
// We need to reflow the child (column) ...
bool reflowChild =
// if we are told to do so;
aReflowInput.ShouldReflowAllKids() ||
// if the child is dirty;
child->IsSubtreeDirty() ||
// if it's the last child because we need to obtain the block-end
// margin;
!child->GetNextSibling() ||
// if the next column is dirty, because the next column's first line(s)
// might be pullable back to this column;
child->GetNextSibling()->IsSubtreeDirty() ||
// if this is the last column and we are supposed to assign unbounded
// block-size to it, because that could change the available block-size
// 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.)
reflowLastColumnWithUnconstrainedAvailBSize;
// If column-fill is auto (not the default), then we might need to
// move content between columns for any change in column block-size.
//
// The same is true if we have a non-'auto' computed block-size.
//
// FIXME: It's not clear to me why it's *ever* valid to have
// reflowChild be false when changingBSize is true, since it
// seems like a child broken over multiple columns might need to
// change the size of the fragment in each column.
if (!reflowChild && changingBSize &&
(StyleColumn()->mColumnFill == StyleColumnFill::Auto ||
computedBSize != NS_UNCONSTRAINEDSIZE)) {
reflowChild = true;
}
// If we need to pull up content from the prev-in-flow then this is not just
// a block-size shrink. The prev in flow will have set the dirty bit.
// Check the overflow rect YMost instead of just the child's content
// block-size. The child may have overflowing content that cares about the
// available block-size boundary. (It may also have overflowing content that
// doesn't care about the available block-size boundary, but if so, too bad,
// this optimization is defeated.) We want scrollable overflow here since
// this is a calculation that affects layout.
if (!reflowChild && shrinkingBSize) {
switch (wm.GetBlockDir()) {
case WritingMode::BlockDir::TB:
if (child->ScrollableOverflowRect().YMost() > aConfig.mColBSize) {
reflowChild = true;
}
break;
case WritingMode::BlockDir::LR:
if (child->ScrollableOverflowRect().XMost() > aConfig.mColBSize) {
reflowChild = true;
}
break;
case WritingMode::BlockDir::RL:
// XXX not sure how to handle this, so for now just don't attempt
// the optimization
reflowChild = true;
break;
default:
MOZ_ASSERT_UNREACHABLE("unknown block direction");
break;
}
}
nscoord childContentBEnd = 0;
if (!reflowNext && !reflowChild) {
// This child does not need to be reflowed, but we may need to move it
MoveChildTo(child, childOrigin, wm, containerSize);
// If this is the last frame then make sure we get the right status
nsIFrame* kidNext = child->GetNextSibling();
if (kidNext) {
aStatus.Reset();
if (kidNext->HasAnyStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER)) {
aStatus.SetOverflowIncomplete();
} else {
aStatus.SetIncomplete();
}
} else {
aStatus = mLastFrameStatus;
}
childContentBEnd = nsLayoutUtils::CalculateContentBEnd(wm, child);
COLUMN_SET_LOG("%s: Skipping child #%d %p: status=%s", __func__,
colData.mColCount, child, ToString(aStatus).c_str());
} else {
LogicalSize availSize(wm, aConfig.mColISize, aConfig.mColBSize);
if (reflowLastColumnWithUnconstrainedAvailBSize) {
availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
COLUMN_SET_LOG(
"%s: Reflowing last column with unconstrained block-size. Change "
"available block-size from %d to %d",
__func__, aConfig.mColBSize, availSize.BSize(wm));
}
if (reflowNext) {
child->MarkSubtreeDirty();
}
LogicalSize kidCBSize(wm, availSize.ISize(wm), computedBSize);
ReflowInput kidReflowInput(PresContext(), aReflowInput, child, availSize,
Some(kidCBSize));
kidReflowInput.mFlags.mIsTopOfPage = [&]() {
const bool isNestedMulticolOrInRootPaginatedDoc =
aReflowInput.mParentReflowInput->mFrame->HasAnyStateBits(
NS_FRAME_HAS_MULTI_COLUMN_ANCESTOR) ||
PresContext()->IsRootPaginatedDocument();
if (isNestedMulticolOrInRootPaginatedDoc) {
if (aConfig.mForceAuto) {
// If we are forced to fill columns sequentially, force fit the
// content whether we are at top of page or not.
return true;
}
if (aReflowInput.mFlags.mIsTopOfPage) {
// If this is the last balancing reflow, we want to force fit
// content to avoid infinite loops.
return !aConfig.mIsBalancing || aConfig.mIsLastBalancingReflow;
}
// If we are a not at the top of page, we shouldn't force fit content.
// This is because our ColumnSetWrapperFrame can be pushed to the next
// column or page and reflowed again with a potentially larger
// available block-size.
return false;
}
// We are a top-level multicol in a non-paginated root document or in a
// subdocument (regardless of whether the root document is paginated).
// Force fit the content only if we are not balancing columns.
return !aConfig.mIsBalancing;
}();
kidReflowInput.mFlags.mTableIsSplittable = false;
kidReflowInput.mFlags.mIsColumnBalancing = aConfig.mIsBalancing;
kidReflowInput.mFlags.mIsInLastColumnBalancingReflow =
aConfig.mIsLastBalancingReflow;
kidReflowInput.mBreakType = ReflowInput::BreakType::Column;
// We need to reflow any float placeholders, even if our column block-size
// hasn't changed.
kidReflowInput.mFlags.mMustReflowPlaceholders = !changingBSize;
COLUMN_SET_LOG(
"%s: Reflowing child #%d %p: availSize=(%d,%d), kidCBSize=(%d,%d), "
"child's mIsTopOfPage=%d",
__func__, colData.mColCount, child, availSize.ISize(wm),
availSize.BSize(wm), kidCBSize.ISize(wm), kidCBSize.BSize(wm),
kidReflowInput.mFlags.mIsTopOfPage);
// 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() && !HasAnyStateBits(NS_FRAME_IS_DIRTY) &&
!child->GetNextSibling()->HasAnyStateBits(NS_FRAME_IS_DIRTY)) {
kidReflowInput.mFlags.mNextInFlowUntouched = true;
}
ReflowOutput kidDesiredSize(wm);
// 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.
MOZ_ASSERT(kidReflowInput.ComputedLogicalMargin(wm).IsAllZero(),
"-moz-column-content has no margin!");
aStatus.Reset();
ReflowChild(child, PresContext(), kidDesiredSize, kidReflowInput, wm,
childOrigin, containerSize, ReflowChildFlags::Default,
aStatus);
if (colData.mColCount == 1 && aStatus.IsInlineBreakBefore()) {
COLUMN_SET_LOG("%s: Content in the first column reports break-before!",
__func__);
allFit = false;
break;
}
reflowNext = aStatus.NextInFlowNeedsReflow();
// The carried-out block-end margin of column content might be non-zero
// when we try to find the best column balancing block size, but it should
// never affect the size column set nor be further carried out. Set it to
// zero.
//
// FIXME: For some types of fragmentation, we should carry the margin into
// the next column. Also see
// https://drafts.csswg.org/css-break-4/#break-margins
//
// FIXME: This should never happen for the last column, since it should be
// a margin root; see nsBlockFrame::IsMarginRoot(). However, sometimes the
// last column has an empty continuation while searching for the best
// column balancing bsize, which prevents the last column from being a
// margin root.
kidDesiredSize.mCarriedOutBEndMargin.Zero();
NS_FRAME_TRACE_REFLOW_OUT("Column::Reflow", aStatus);
FinishReflowChild(child, PresContext(), kidDesiredSize, &kidReflowInput,
wm, childOrigin, containerSize,
ReflowChildFlags::Default);
childContentBEnd = nsLayoutUtils::CalculateContentBEnd(wm, child);
if (childContentBEnd > aConfig.mColBSize) {
allFit = false;
}
if (childContentBEnd > availSize.BSize(wm)) {
colData.mMaxOverflowingBSize =
std::max(childContentBEnd, colData.mMaxOverflowingBSize);
}
COLUMN_SET_LOG(
"%s: Reflowed child #%d %p: status=%s, desiredSize=(%d,%d), "
"childContentBEnd=%d, CarriedOutBEndMargin=%d (ignored)",
__func__, colData.mColCount, child, ToString(aStatus).c_str(),
kidDesiredSize.ISize(wm), kidDesiredSize.BSize(wm), childContentBEnd,
kidDesiredSize.mCarriedOutBEndMargin.Get());
}
contentRect.UnionRect(contentRect, child->GetRect());
ConsiderChildOverflow(overflowRects, child);
contentBEnd = std::max(contentBEnd, childContentBEnd);
colData.mLastBSize = childContentBEnd;
colData.mSumBSize += childContentBEnd;
// Build a continuation column if necessary
nsIFrame* kidNextInFlow = child->GetNextInFlow();
if (aStatus.IsFullyComplete()) {
NS_ASSERTION(!kidNextInFlow, "next in flow should have been deleted");
child = nullptr;
break;
}
// 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.NextInFlowNeedsReflow(),
"We have to create a continuation, but the block doesn't "
"want us to reflow it?");
// We need to create a continuing column
kidNextInFlow = CreateNextInFlow(child);
}
// Make sure we reflow a next-in-flow when it switches between being
// normal or overflow container
if (aStatus.IsOverflowIncomplete()) {
if (!kidNextInFlow->HasAnyStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER)) {
aStatus.SetNextInFlowNeedsReflow();
reflowNext = true;
kidNextInFlow->AddStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
}
} else if (kidNextInFlow->HasAnyStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER)) {
aStatus.SetNextInFlowNeedsReflow();
reflowNext = true;
kidNextInFlow->RemoveStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
}
// We have reached the maximum number of columns. If we are balancing, stop
// this reflow and continue finding the optimal balancing block-size.
//
// Otherwise, i.e. we are not balancing, stop this reflow and let the parent
// of our multicol container create a next-in-flow if all of the following
// conditions are met.
//
// 1) We fill columns sequentially by the request of the style, not by our
// internal needs, i.e. aConfig.mForceAuto is false.
//
// We don't want to stop this reflow when we force fill the columns
// sequentially. We usually go into this mode when giving up balancing, and
// this is the last resort to fit all our children by creating overflow
// columns.
//
// 2) In a fragmented context, our multicol container still has block-size
// left for its next-in-flow, i.e.
// aReflowInput.mFlags.mColumnSetWrapperHasNoBSizeLeft is false.
//
// Note that in a continuous context, i.e. our multicol container's
// available block-size is unconstrained, if it has a fixed block-size
// mColumnSetWrapperHasNoBSizeLeft is always true because nothing stops it
// from applying all its block-size in the first-in-flow. Otherwise, i.e.
// our multicol container has an unconstrained block-size, we shouldn't be
// here because all our children should fit in the very first column even if
// mColumnSetWrapperHasNoBSizeLeft is false.
//
// According to the definition of mColumnSetWrapperHasNoBSizeLeft, if the
// bit is *not* set, either our multicol container has unconstrained
// block-size, or it has a constrained block-size and has block-size left
// for its next-in-flow. In either cases, the parent of our multicol
// container can create a next-in-flow for the container that guaranteed to
// have non-zero block-size for the container's children.
//
// Put simply, if either one of the above conditions is not met, we are
// going to create more overflow columns until all our children are fit.
if (colData.mColCount >= aConfig.mUsedColCount &&
(aConfig.mIsBalancing ||
(!aConfig.mForceAuto &&
!aReflowInput.mFlags.mColumnSetWrapperHasNoBSizeLeft))) {
NS_ASSERTION(aConfig.mIsBalancing ||
aReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE,
"Why are we here if we have unlimited block-size to fill "
"columns sequentially.");
// No more columns allowed here. Stop.
aStatus.SetNextInFlowNeedsReflow();
kidNextInFlow->MarkSubtreeDirty();
// Move any of our leftover columns to our overflow list. Our
// next-in-flow will eventually pick them up.
nsFrameList continuationColumns = mFrames.TakeFramesAfter(child);
if (continuationColumns.NotEmpty()) {
SetOverflowFrames(std::move(continuationColumns));
}
child = nullptr;
COLUMN_SET_LOG("%s: We are not going to create overflow columns.",
__func__);
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();
++colData.mColCount;
if (child) {
childOrigin.I(wm) += aConfig.mColISize + aConfig.mColGap;
COLUMN_SET_LOG("%s: Next childOrigin.iCoord=%d", __func__,
childOrigin.I(wm));
}
}
if (PresContext()->CheckForInterrupt(this) &&
HasAnyStateBits(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->MarkSubtreeDirty();
}
}
colData.mMaxBSize = contentBEnd;
LogicalSize contentSize = LogicalSize(wm, contentRect.Size());
contentSize.BSize(wm) = std::max(contentSize.BSize(wm), contentBEnd);
mLastFrameStatus = aStatus;
if (computedBSize != NS_UNCONSTRAINEDSIZE && !HasColumnSpanSiblings()) {
NS_ASSERTION(aReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE,
"Available block-size should be constrained because it's "
"restricted by the computed block-size when our reflow "
"input is created in nsBlockFrame::ReflowBlockFrame()!");
// If a) our parent ColumnSetWrapper has constrained block-size
// (nsBlockFrame::ReflowBlockFrame() applies the block-size constraint
// when creating a ReflowInput for ColumnSetFrame child); and b) we are the
// sole ColumnSet or the last ColumnSet continuation split by column-spans
// in a ColumnSetWrapper, extend our block-size to consume the available
// block-size so that the column-rules are drawn to the content block-end
// edge of the multicol container.
contentSize.BSize(wm) =
std::max(contentSize.BSize(wm), aReflowInput.AvailableBSize());
}
aDesiredSize.SetSize(wm, contentSize);
aDesiredSize.mOverflowAreas = overflowRects;
aDesiredSize.UnionOverflowAreasWithDesiredBounds();
// In vertical-rl mode, make a second pass if necessary to reposition the
// columns with the correct container width. (In other writing modes,
// correct containerSize was not required for column positioning so we don't
// need this fixup.)
//
// RTL column positions also depend on ColumnSet's actual contentSize. We need
// this fixup, too.
if ((wm.IsVerticalRL() || isRTL) &&
containerSize.width != contentSize.Width(wm)) {
const nsSize finalContainerSize = aDesiredSize.PhysicalSize();
OverflowAreas overflowRects;
for (nsIFrame* child : mFrames) {
// Get the logical position as set previously using a provisional or
// dummy containerSize, and reset with the correct container size.
child->SetPosition(wm, child->GetLogicalPosition(wm, containerSize),
finalContainerSize);
ConsiderChildOverflow(overflowRects, child);
}
aDesiredSize.mOverflowAreas = overflowRects;
aDesiredSize.UnionOverflowAreasWithDesiredBounds();
}
colData.mFeasible = allFit && aStatus.IsFullyComplete();
COLUMN_SET_LOG(
"%s: Done column reflow pass: %s, mMaxBSize=%d, mSumBSize=%d, "
"mLastBSize=%d, mMaxOverflowingBSize=%d",
__func__, colData.mFeasible ? "Feasible :)" : "Infeasible :(",
colData.mMaxBSize, colData.mSumBSize, colData.mLastBSize,
colData.mMaxOverflowingBSize);
return colData;
}
void nsColumnSetFrame::DrainOverflowColumns() {
// First grab the prev-in-flows overflows and reparent them to this
// frame.
nsPresContext* presContext = PresContext();
nsColumnSetFrame* prev = static_cast<nsColumnSetFrame*>(GetPrevInFlow());
if (prev) {
AutoFrameListPtr overflows(presContext, prev->StealOverflowFrames());
if (overflows) {
nsContainerFrame::ReparentFrameViewList(*overflows, prev, this);
mFrames.InsertFrames(this, nullptr, std::move(*overflows));
}
}
// Now pull back our own overflows and append them to our children.
// We don't need to reparent them since we're already their parent.
AutoFrameListPtr overflows(presContext, StealOverflowFrames());
if (overflows) {
// We're already the parent for these frames, so no need to set
// their parent again.
mFrames.AppendFrames(nullptr, std::move(*overflows));
}
}
void nsColumnSetFrame::FindBestBalanceBSize(const ReflowInput& aReflowInput,
nsPresContext* aPresContext,
ReflowConfig& aConfig,
ColumnBalanceData aColData,
ReflowOutput& aDesiredSize,
bool aUnboundedLastColumn,
nsReflowStatus& aStatus) {
MOZ_ASSERT(aConfig.mIsBalancing,
"Why are we here if we are not balancing columns?");
const nscoord availableContentBSize = aReflowInput.AvailableBSize();
// Termination of the algorithm below is guaranteed because
// aConfig.knownFeasibleBSize - aConfig.knownInfeasibleBSize decreases in
// every iteration.
int32_t iterationCount = 1;
// We set this flag when we detect that we may contain a frame
// that can break anywhere (thus foiling the linear decrease-by-one
// search)
bool maybeContinuousBreakingDetected = false;
bool possibleOptimalBSizeDetected = false;
// This is the extra block-size added to the optimal column block-size
// estimation which is calculated in the while-loop by dividing
// aColData.mSumBSize into N columns.
//
// The constant is arbitrary. We use a half of line-height first. In case a
// column container uses *zero* (or a very small) line-height, use a half of
// default line-height 1140/2 = 570 app units as the minimum value. Otherwise
// we might take more than necessary iterations before finding a feasible
// block-size.
nscoord extraBlockSize = std::max(570, aReflowInput.GetLineHeight() / 2);
// We use divide-by-N to estimate the optimal column block-size only if the
// last column's available block-size is unbounded.
bool foundFeasibleBSizeCloserToBest = !aUnboundedLastColumn;
// Stop the binary search when the difference of the feasible and infeasible
// block-size is within this gap. Here we use one device pixel.
const int32_t gapToStop = aPresContext->DevPixelsToAppUnits(1);
while (!aPresContext->HasPendingInterrupt()) {
nscoord lastKnownFeasibleBSize = aConfig.mKnownFeasibleBSize;
// Record what we learned from the last reflow
if (aColData.mFeasible) {
// mMaxBSize is feasible. Also, mLastBalanceBSize is feasible.
aConfig.mKnownFeasibleBSize =
std::min(aConfig.mKnownFeasibleBSize, aColData.mMaxBSize);
aConfig.mKnownFeasibleBSize =
std::min(aConfig.mKnownFeasibleBSize, mLastBalanceBSize);
// Furthermore, no block-size less than the block-size of the last
// column can ever be feasible. (We might be able to reduce the
// block-size of a non-last column by moving content to a later column,
// but we can't do that with the last column.)
if (aColData.mColCount == aConfig.mUsedColCount) {
aConfig.mKnownInfeasibleBSize =
std::max(aConfig.mKnownInfeasibleBSize, aColData.mLastBSize - 1);
}
} else {
aConfig.mKnownInfeasibleBSize =
std::max(aConfig.mKnownInfeasibleBSize, mLastBalanceBSize);
// If a column didn't fit in its available block-size, then its current
// block-size must be the minimum block-size for unbreakable content in
// the column, and therefore no smaller block-size can be feasible.
aConfig.mKnownInfeasibleBSize = std::max(
aConfig.mKnownInfeasibleBSize, aColData.mMaxOverflowingBSize - 1);
if (aUnboundedLastColumn) {
// The last column is unbounded, so all content got reflowed, so the
// mMaxBSize is feasible.
aConfig.mKnownFeasibleBSize =
std::min(aConfig.mKnownFeasibleBSize, aColData.mMaxBSize);
NS_ASSERTION(mLastFrameStatus.IsComplete(),
"Last column should be complete if the available "
"block-size is unconstrained!");
}
}
COLUMN_SET_LOG(
"%s: this=%p, mKnownInfeasibleBSize=%d, mKnownFeasibleBSize=%d",
__func__, this, aConfig.mKnownInfeasibleBSize,
aConfig.mKnownFeasibleBSize);
if (aConfig.mKnownInfeasibleBSize >= aConfig.mKnownFeasibleBSize - 1) {
// aConfig.mKnownFeasibleBSize is where we want to be. This can happen in
// the very first iteration when a column container solely has a tall
// unbreakable child that overflows the container.
break;
}
if (aConfig.mKnownInfeasibleBSize >= availableContentBSize) {
// There's no feasible block-size to fit our contents. We may need to
// reflow one more time after this loop.
break;
}
const nscoord gap =
aConfig.mKnownFeasibleBSize - aConfig.mKnownInfeasibleBSize;
if (gap <= gapToStop && possibleOptimalBSizeDetected) {
// We detected a possible optimal block-size in the last iteration. If it
// is infeasible, we may need to reflow one more time after this loop.
break;
}
if (lastKnownFeasibleBSize - aConfig.mKnownFeasibleBSize == 1) {
// We decreased the feasible block-size by one twip only. This could
// indicate that there is a continuously breakable child frame
// that we are crawling through.
maybeContinuousBreakingDetected = true;
}
nscoord nextGuess = aConfig.mKnownInfeasibleBSize + gap / 2;
if (aConfig.mKnownFeasibleBSize - nextGuess < extraBlockSize &&
!maybeContinuousBreakingDetected) {
// We're close to our target, so just try shrinking just the
// minimum amount that will cause one of our columns to break
// differently.
nextGuess = aConfig.mKnownFeasibleBSize - 1;
} else if (!foundFeasibleBSizeCloserToBest) {
// Make a guess by dividing mSumBSize into N columns and adding
// extraBlockSize to try to make it on the feasible side.
nextGuess = aColData.mSumBSize / aConfig.mUsedColCount + extraBlockSize;
// Sanitize it
nextGuess = clamped(nextGuess, aConfig.mKnownInfeasibleBSize + 1,
aConfig.mKnownFeasibleBSize - 1);
// We keep doubling extraBlockSize in every iteration until we find a
// feasible guess.
extraBlockSize *= 2;
} else if (aConfig.mKnownFeasibleBSize == NS_UNCONSTRAINEDSIZE) {
// This can happen when we had a next-in-flow so we didn't
// want to do an unbounded block-size measuring step. Let's just increase
// from the infeasible block-size by some reasonable amount.
nextGuess = aConfig.mKnownInfeasibleBSize * 2 + extraBlockSize;
} else if (gap <= gapToStop) {
// Floor nextGuess to the greatest multiple of gapToStop below or equal to
// mKnownFeasibleBSize.
nextGuess = aConfig.mKnownFeasibleBSize / gapToStop * gapToStop;
possibleOptimalBSizeDetected = true;
}
// Don't bother guessing more than our block-size constraint.
nextGuess = std::min(availableContentBSize, nextGuess);
COLUMN_SET_LOG("%s: Choosing next guess=%d, iteration=%d", __func__,
nextGuess, iterationCount);
++iterationCount;
aConfig.mColBSize = nextGuess;
aUnboundedLastColumn = false;
MarkPrincipalChildrenDirty(this);
aColData =
ReflowColumns(aDesiredSize, aReflowInput, aStatus, aConfig, false);
if (!foundFeasibleBSizeCloserToBest && aColData.mFeasible) {
foundFeasibleBSizeCloserToBest = true;
}
}
if (!aColData.mFeasible && !aPresContext->HasPendingInterrupt()) {
// We need to reflow one more time at the feasible block-size to
// get a valid layout.
if (aConfig.mKnownInfeasibleBSize >= availableContentBSize) {
aConfig.mColBSize = availableContentBSize;
if (mLastBalanceBSize == availableContentBSize) {
// If we end up here, we have a constrained available content
// block-size, and our last column's block-size exceeds it. Also, if
// this is the first balancing iteration, the last column is given
// unconstrained available block-size, so it has a fully complete
// reflow status. Therefore, we always want to reflow again at the
// available content block-size to get a valid layout and a correct
// reflow status (likely an *incomplete* status) so that our column
// container can be fragmented if needed.
if (aReflowInput.mFlags.mColumnSetWrapperHasNoBSizeLeft) {
// If our column container has a constrained block-size (either in a
// paginated context or in a nested column container), and is going
// to consume all its computed block-size in this fragment, then our
// column container has no block-size left to contain our
// next-in-flows. We have to give up balancing, and create our
// own overflow columns.
//
// We don't want to create overflow columns immediately when our
// content doesn't fit since this changes our reflow status from
// incomplete to complete. Valid reasons include 1) the outer column
// container might do column balancing, and it can enlarge the
// available content block-size so that the nested one could fit its
// content in next balancing iteration; or 2) the outer column
// container is filling columns sequentially, and may have more
// inline-size to create more column boxes for the nested column
// container's next-in-flows.
aConfig = ChooseColumnStrategy(aReflowInput, true);
}
}
} else {
aConfig.mColBSize = aConfig.mKnownFeasibleBSize;
}
// This is our last attempt to reflow. If our column container's available
// block-size is unconstrained, make sure that the last column is
// allowed to have arbitrary block-size here, even though we were
// balancing. Otherwise we'd have to split, and it's not clear what we'd
// do with that.
COLUMN_SET_LOG("%s: Last attempt to call ReflowColumns", __func__);
aConfig.mIsLastBalancingReflow = true;
const bool forceUnboundedLastColumn =
aReflowInput.mParentReflowInput->AvailableBSize() ==
NS_UNCONSTRAINEDSIZE;
MarkPrincipalChildrenDirty(this);
ReflowColumns(aDesiredSize, aReflowInput, aStatus, aConfig,
forceUnboundedLastColumn);
}
}
void nsColumnSetFrame::Reflow(nsPresContext* aPresContext,
ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus) {
MarkInReflow();
// Don't support interruption in columns
nsPresContext::InterruptPreventer noInterrupts(aPresContext);
DO_GLOBAL_REFLOW_COUNT("nsColumnSetFrame");
MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
MOZ_ASSERT(aReflowInput.mCBReflowInput->mFrame->StyleColumn()
->IsColumnContainerStyle(),
"The column container should have relevant column styles!");
MOZ_ASSERT(aReflowInput.mParentReflowInput->mFrame->IsColumnSetWrapperFrame(),
"The column container should be ColumnSetWrapperFrame!");
MOZ_ASSERT(
aReflowInput.ComputedLogicalBorderPadding(aReflowInput.GetWritingMode())
.IsAllZero(),
"Only the column container can have border and padding!");
MOZ_ASSERT(
GetChildList(FrameChildListID::OverflowContainers).IsEmpty() &&
GetChildList(FrameChildListID::ExcessOverflowContainers).IsEmpty(),
"ColumnSetFrame should store overflow containers in principal "
"child list!");
//------------ Handle Incremental Reflow -----------------
COLUMN_SET_LOG("%s: Begin Reflow: this=%p, is nested multicol=%d", __func__,
this,
aReflowInput.mParentReflowInput->mFrame->HasAnyStateBits(
NS_FRAME_HAS_MULTI_COLUMN_ANCESTOR));
// If inline size is unconstrained, set aForceAuto to true to allow
// the columns to expand in the inline direction. (This typically
// happens in orthogonal flows where the inline direction is the
// container's block direction).
ReflowConfig config = ChooseColumnStrategy(
aReflowInput, aReflowInput.ComputedISize() == NS_UNCONSTRAINEDSIZE);
// If balancing, then we allow the last column to grow to unbounded
// block-size during the first reflow. This gives us a way to estimate
// what the average column block-size should be, because we can measure
// the block-size of all the columns and sum them up. But don't do this
// if we have a next in flow because we don't want to suck all its
// content back here and then have to push it out again!
nsIFrame* nextInFlow = GetNextInFlow();
bool unboundedLastColumn = config.mIsBalancing && !nextInFlow;
const ColumnBalanceData colData = ReflowColumns(
aDesiredSize, aReflowInput, aStatus, config, unboundedLastColumn);
// If we're not balancing, then we're already done, since we should have
// reflown all of our children, and there is no need for a binary search to
// determine proper column block-size.
if (config.mIsBalancing && !aPresContext->HasPendingInterrupt()) {
FindBestBalanceBSize(aReflowInput, aPresContext, config, colData,
aDesiredSize, unboundedLastColumn, aStatus);
}
if (aPresContext->HasPendingInterrupt() &&
aReflowInput.AvailableBSize() == NS_UNCONSTRAINEDSIZE) {
// In this situation, we might be lying about our reflow status, because
// our last kid (the one that got interrupted) was incomplete. Fix that.
aStatus.Reset();
}
NS_ASSERTION(aStatus.IsFullyComplete() ||
aReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE,
"Column set should be complete if the available block-size is "
"unconstrained");
MOZ_ASSERT(!HasAbsolutelyPositionedChildren(),
"ColumnSetWrapperFrame should be the abs.pos container!");
FinishAndStoreOverflow(&aDesiredSize, aReflowInput.mStyleDisplay);
COLUMN_SET_LOG("%s: End Reflow: this=%p", __func__, this);
}
void nsColumnSetFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsDisplayListSet& aLists) {
DisplayBorderBackgroundOutline(aBuilder, aLists);
if (IsVisibleForPainting()) {
aLists.BorderBackground()->AppendNewToTop<nsDisplayColumnRule>(aBuilder,
this);
}
// Our children won't have backgrounds so it doesn't matter where we put them.
for (nsIFrame* f : mFrames) {
BuildDisplayListForChild(aBuilder, f, aLists);
}
}
void nsColumnSetFrame::AppendDirectlyOwnedAnonBoxes(
nsTArray<OwnedAnonBox>& aResult) {
// Everything in mFrames is continuations of the first thing in mFrames.
nsIFrame* column = mFrames.FirstChild();
// We might not have any columns, apparently?
if (!column) {
return;
}
MOZ_ASSERT(column->Style()->GetPseudoType() == PseudoStyleType::columnContent,
"What sort of child is this?");
aResult.AppendElement(OwnedAnonBox(column));
}
Maybe<nscoord> nsColumnSetFrame::GetNaturalBaselineBOffset(
WritingMode aWM, BaselineSharingGroup aBaselineGroup,
BaselineExportContext aExportContext) const {
Maybe<nscoord> result;
for (const auto* kid : mFrames) {
auto kidBaseline =
kid->GetNaturalBaselineBOffset(aWM, aBaselineGroup, aExportContext);
if (!kidBaseline) {
continue;
}
// The kid frame may not necessarily be aligned with the columnset frame.
LogicalRect kidRect{aWM, kid->GetLogicalNormalPosition(aWM, GetSize()),
kid->GetLogicalSize(aWM)};
if (aBaselineGroup == BaselineSharingGroup::First) {
*kidBaseline += kidRect.BStart(aWM);
} else {
*kidBaseline += (GetLogicalSize().BSize(aWM) - kidRect.BEnd(aWM));
}
// Take the smallest of the baselines (i.e. Closest to border-block-start
// for `BaselineSharingGroup::First`, border-block-end for
// `BaselineSharingGroup::Last`)
if (!result || *kidBaseline < *result) {
result = kidBaseline;
}
}
return result;
}
#ifdef DEBUG
void nsColumnSetFrame::SetInitialChildList(ChildListID aListID,
nsFrameList&& aChildList) {
MOZ_ASSERT(aListID != FrameChildListID::Principal || aChildList.OnlyChild(),
"initial principal child list must have exactly one child");
nsContainerFrame::SetInitialChildList(aListID, std::move(aChildList));
}
void nsColumnSetFrame::AppendFrames(ChildListID aListID,
nsFrameList&& aFrameList) {
MOZ_CRASH("unsupported operation");
}
void nsColumnSetFrame::InsertFrames(ChildListID aListID, nsIFrame* aPrevFrame,
const nsLineList::iterator* aPrevFrameLine,
nsFrameList&& aFrameList) {
MOZ_CRASH("unsupported operation");
}
void nsColumnSetFrame::RemoveFrame(DestroyContext&, ChildListID, nsIFrame*) {
MOZ_CRASH("unsupported operation");
}
#endif