/* -*- 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 CSS :first-letter pseudo-element */
#include "nsFirstLetterFrame.h"
#include "nsPresContext.h"
#include "nsPresContextInlines.h"
#include "mozilla/ComputedStyle.h"
#include "mozilla/PresShell.h"
#include "mozilla/PresShellInlines.h"
#include "mozilla/RestyleManager.h"
#include "mozilla/ServoStyleSet.h"
#include "mozilla/StaticPrefs_layout.h"
#include "nsIContent.h"
#include "nsLayoutUtils.h"
#include "nsLineLayout.h"
#include "nsGkAtoms.h"
#include "nsFrameManager.h"
#include "nsPlaceholderFrame.h"
#include "nsTextFrame.h"
#include "nsCSSFrameConstructor.h"
using namespace mozilla;
using namespace mozilla::layout;
nsFirstLetterFrame* NS_NewFirstLetterFrame(PresShell* aPresShell,
ComputedStyle* aStyle) {
return new (aPresShell)
nsFirstLetterFrame(aStyle, aPresShell->GetPresContext());
}
nsFirstLetterFrame* NS_NewFloatingFirstLetterFrame(PresShell* aPresShell,
ComputedStyle* aStyle) {
return new (aPresShell)
nsFloatingFirstLetterFrame(aStyle, aPresShell->GetPresContext());
}
NS_IMPL_FRAMEARENA_HELPERS(nsFirstLetterFrame)
NS_QUERYFRAME_HEAD(nsFirstLetterFrame)
NS_QUERYFRAME_ENTRY(nsFirstLetterFrame)
NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
NS_IMPL_FRAMEARENA_HELPERS(nsFloatingFirstLetterFrame)
NS_QUERYFRAME_HEAD(nsFloatingFirstLetterFrame)
NS_QUERYFRAME_ENTRY(nsFloatingFirstLetterFrame)
NS_QUERYFRAME_TAIL_INHERITING(nsFirstLetterFrame)
#ifdef DEBUG_FRAME_DUMP
nsresult nsFirstLetterFrame::GetFrameName(nsAString& aResult)
const {
return MakeFrameName(u
"Letter"_ns, aResult);
}
#endif
void nsFirstLetterFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsDisplayListSet& aLists) {
BuildDisplayListForInline(aBuilder, aLists);
}
void nsFirstLetterFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) {
RefPtr<ComputedStyle> newSC;
if (aPrevInFlow) {
// Get proper ComputedStyle for ourselves. We're creating the frame
// that represents everything *except* the first letter, so just create
// a ComputedStyle that inherits from our style parent, with no extra rules.
nsIFrame* styleParent =
CorrectStyleParentFrame(aParent, PseudoStyleType::firstLetter);
ComputedStyle* parentComputedStyle = styleParent->Style();
newSC = PresContext()->StyleSet()->ResolveStyleForFirstLetterContinuation(
parentComputedStyle);
SetComputedStyleWithoutNotification(newSC);
}
nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
}
void nsFirstLetterFrame::SetInitialChildList(ChildListID aListID,
nsFrameList&& aChildList) {
MOZ_ASSERT(aListID == FrameChildListID::Principal,
"Principal child list is the only "
"list that nsFirstLetterFrame should set via this function");
for (nsIFrame* f : aChildList) {
MOZ_ASSERT(f->GetParent() ==
this,
"Unexpected parent");
MOZ_ASSERT(f->IsTextFrame(),
"We should not have kids that are containers!");
nsLayoutUtils::MarkDescendantsDirty(f);
// Drops cached textruns
}
mFrames = std::move(aChildList);
}
nsresult nsFirstLetterFrame::GetChildFrameContainingOffset(
int32_t inContentOffset,
bool inHint, int32_t* outFrameContentOffset,
nsIFrame** outChildFrame) {
nsIFrame* kid = mFrames.FirstChild();
if (kid) {
return kid->GetChildFrameContainingOffset(
inContentOffset, inHint, outFrameContentOffset, outChildFrame);
}
return nsIFrame::GetChildFrameContainingOffset(
inContentOffset, inHint, outFrameContentOffset, outChildFrame);
}
// Needed for non-floating first-letter frames and for the continuations
// following the first-letter that we also use nsFirstLetterFrame for.
/* virtual */
void nsFirstLetterFrame::AddInlineMinISize(
const IntrinsicSizeInput& aInput,
InlineMinISizeData* aData) {
DoInlineMinISize(aInput, aData);
}
// Needed for non-floating first-letter frames and for the continuations
// following the first-letter that we also use nsFirstLetterFrame for.
/* virtual */
void nsFirstLetterFrame::AddInlinePrefISize(
const IntrinsicSizeInput& aInput,
InlinePrefISizeData* aData) {
DoInlinePrefISize(aInput, aData);
}
// Needed for floating first-letter frames.
nscoord nsFirstLetterFrame::IntrinsicISize(
const IntrinsicSizeInput& aInput,
IntrinsicISizeType aType) {
return IntrinsicISizeFromInline(aInput, aType);
}
/* virtual */
nsIFrame::SizeComputationResult nsFirstLetterFrame::ComputeSize(
gfxContext* aRenderingContext, WritingMode aWM,
const LogicalSize& aCBSize,
nscoord aAvailableISize,
const LogicalSize& aMargin,
const LogicalSize& aBorderPadding,
const StyleSizeOverrides& aSizeOverrides,
ComputeSizeFlags aFlags) {
if (GetPrevInFlow()) {
// We're wrapping the text *after* the first letter, so behave like an
// inline frame.
return {LogicalSize(aWM, NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE),
AspectRatioUsage::None};
}
return nsContainerFrame::ComputeSize(aRenderingContext, aWM, aCBSize,
aAvailableISize, aMargin, aBorderPadding,
aSizeOverrides, aFlags);
}
bool nsFirstLetterFrame::UseTightBounds()
const {
int v = StaticPrefs::layout_css_floating_first_letter_tight_glyph_bounds();
// Check for the simple cases:
// pref value > 0: use legacy gecko behavior
// pref value = 0: use webkit/blink-like behavior
if (v > 0) {
return true;
}
if (v == 0) {
return false;
}
// Pref value < 0: use heuristics to determine whether the page is assuming
// webkit/blink-style behavior:
// If line-height is less than font-size, or there is a negative block-start
// or -end margin, use webkit/blink behavior.
if (nsTextFrame* textFrame = do_QueryFrame(mFrames.FirstChild())) {
RefPtr<nsFontMetrics> fm = textFrame->InflatedFontMetrics();
if (textFrame->ComputeLineHeight() < fm->EmHeight()) {
return false;
}
}
const auto wm = GetWritingMode();
const auto& bStart = StyleMargin()->GetMargin(LogicalSide::BStart, wm);
// Currently, we only check for margins with negative *length* values;
// negative percentages seem unlikely to be used/useful in this context.
if (bStart.ConvertsToLength() && bStart.ToLength() < 0) {
return false;
}
const auto& bEnd = StyleMargin()->GetMargin(LogicalSide::BEnd, wm);
if (bEnd.ConvertsToLength() && bEnd.ToLength() < 0) {
return false;
}
return true;
}
void nsFirstLetterFrame::Reflow(nsPresContext* aPresContext,
ReflowOutput& aMetrics,
const ReflowInput& aReflowInput,
nsReflowStatus& aReflowStatus) {
MarkInReflow();
DO_GLOBAL_REFLOW_COUNT(
"nsFirstLetterFrame");
MOZ_ASSERT(aReflowStatus.IsEmpty(),
"Caller should pass a fresh reflow status!");
// Grab overflow list
DrainOverflowFrames(aPresContext);
nsIFrame* kid = mFrames.FirstChild();
// Setup reflow input for our child
WritingMode wm = aReflowInput.GetWritingMode();
LogicalSize availSize = aReflowInput.AvailableSize();
const auto bp = aReflowInput.ComputedLogicalBorderPadding(wm);
NS_ASSERTION(availSize.ISize(wm) != NS_UNCONSTRAINEDSIZE,
"should no longer use unconstrained inline size");
availSize.ISize(wm) -= bp.IStartEnd(wm);
if (NS_UNCONSTRAINEDSIZE != availSize.BSize(wm)) {
availSize.BSize(wm) -= bp.BStartEnd(wm);
}
WritingMode lineWM = aMetrics.GetWritingMode();
ReflowOutput kidMetrics(lineWM);
// Reflow the child
if (!aReflowInput.mLineLayout) {
// When there is no lineLayout provided, we provide our own. The
// only time that the first-letter-frame is not reflowing in a
// line context is when its floating.
WritingMode kidWritingMode = WritingModeForLine(wm, kid);
LogicalSize kidAvailSize = availSize.ConvertTo(kidWritingMode, wm);
ReflowInput rs(aPresContext, aReflowInput, kid, kidAvailSize);
nsLineLayout ll(aPresContext, nullptr, aReflowInput, nullptr, nullptr);
// This frame does not get constructed for an empty inline frame, so
// `CollapseEmptyInlineFramesInLine` should not matter.
ll.BeginLineReflow(
bp.IStart(wm), bp.BStart(wm), availSize.ISize(wm), NS_UNCONSTRAINEDSIZE,
false,
true, kidWritingMode,
nsSize(aReflowInput.AvailableWidth(), aReflowInput.AvailableHeight()));
rs.mLineLayout = ≪
ll.SetInFirstLetter(
true);
ll.SetFirstLetterStyleOK(
true);
kid->Reflow(aPresContext, kidMetrics, rs, aReflowStatus);
ll.EndLineReflow();
ll.SetInFirstLetter(
false);
// In the floating first-letter case, we need to set this ourselves;
// nsLineLayout::BeginSpan will set it in the other case
mBaseline = kidMetrics.BlockStartAscent();
// Place and size the child and update the output metrics
LogicalSize convertedSize = kidMetrics.Size(wm);
const bool tightBounds = UseTightBounds();
const nscoord shift =
tightBounds ? 0
// Shift by half of the difference between the line-height
// we're going to use and current height of the kid frame.
: (rs.GetLineHeight() - convertedSize.BSize(wm)) / 2;
kid->SetRect(nsRect(bp.IStart(wm), bp.BStart(wm) + shift,
convertedSize.ISize(wm), convertedSize.BSize(wm)));
kid->FinishAndStoreOverflow(&kidMetrics, rs.mStyleDisplay);
kid->DidReflow(aPresContext, nullptr);
if (!tightBounds) {
// Adjust size to account for line-height.
convertedSize.BSize(wm) = rs.GetLineHeight();
}
convertedSize.ISize(wm) += bp.IStartEnd(wm);
convertedSize.BSize(wm) += bp.BStartEnd(wm);
aMetrics.SetSize(wm, convertedSize);
aMetrics.SetBlockStartAscent(kidMetrics.BlockStartAscent() + bp.BStart(wm));
// Ensure that the overflow rect contains the child textframe's
// overflow rect.
// Note that if this is floating, the overline/underline drawable
// area is in the overflow rect of the child textframe.
aMetrics.UnionOverflowAreasWithDesiredBounds();
ConsiderChildOverflow(aMetrics.mOverflowAreas, kid);
FinishAndStoreOverflow(&aMetrics, aReflowInput.mStyleDisplay);
}
else {
// Pretend we are a span and reflow the child frame
nsLineLayout* ll = aReflowInput.mLineLayout;
bool pushedFrame;
ll->SetInFirstLetter(Style()->GetPseudoType() ==
PseudoStyleType::firstLetter);
ll->BeginSpan(
this, &aReflowInput, bp.IStart(wm), availSize.ISize(wm),
&mBaseline);
ll->ReflowFrame(kid, aReflowStatus, &kidMetrics, pushedFrame);
NS_ASSERTION(lineWM.IsVertical() == wm.IsVertical(),
"we're assuming we can mix sizes between lineWM and wm "
"since we shouldn't have orthogonal writing modes within "
"a line.");
aMetrics.ISize(lineWM) = ll->EndSpan(
this) + bp.IStartEnd(wm);
ll->SetInFirstLetter(
false);
if (mComputedStyle->StyleTextReset()->mInitialLetter.size != 0.0f) {
aMetrics.SetBlockStartAscent(kidMetrics.BlockStartAscent() +
bp.BStart(wm));
aMetrics.BSize(lineWM) = kidMetrics.BSize(lineWM) + bp.BStartEnd(wm);
}
else {
nsLayoutUtils::SetBSizeFromFontMetrics(
this, aMetrics, bp, lineWM, wm);
}
}
if (!aReflowStatus.IsInlineBreakBefore()) {
// Create a continuation or remove existing continuations based on
// the reflow completion status.
if (aReflowStatus.IsComplete()) {
if (aReflowInput.mLineLayout) {
aReflowInput.mLineLayout->SetFirstLetterStyleOK(
false);
}
if (nsIFrame* kidNextInFlow = kid->GetNextInFlow()) {
DestroyContext context(PresShell());
// Remove all of the childs next-in-flows
kidNextInFlow->GetParent()->DeleteNextInFlowChild(context,
kidNextInFlow,
true);
}
}
else {
// Create a continuation for the child frame if it doesn't already
// have one.
if (!IsFloating()) {
CreateNextInFlow(kid);
// And then push it to our overflow list
nsFrameList overflow = mFrames.TakeFramesAfter(kid);
if (overflow.NotEmpty()) {
SetOverflowFrames(std::move(overflow));
}
}
else if (!kid->GetNextInFlow()) {
// For floating first letter frames (if a continuation wasn't already
// created for us) we need to put the continuation with the rest of the
// text that the first letter frame was made out of.
nsIFrame* continuation;
CreateContinuationForFloatingParent(kid, &continuation,
true);
}
}
}
}
/* virtual */
bool nsFirstLetterFrame::CanContinueTextRun()
const {
// We can continue a text run through a first-letter frame.
return true;
}
void nsFirstLetterFrame::CreateContinuationForFloatingParent(
nsIFrame* aChild, nsIFrame** aContinuation,
bool aIsFluid) {
NS_ASSERTION(IsFloating(),
"can only call this on floating first letter frames");
MOZ_ASSERT(aContinuation,
"bad args");
*aContinuation = nullptr;
mozilla::PresShell* presShell = PresShell();
nsPlaceholderFrame* placeholderFrame = GetPlaceholderFrame();
nsContainerFrame* parent = placeholderFrame->GetParent();
nsIFrame* continuation = presShell->FrameConstructor()->CreateContinuingFrame(
aChild, parent, aIsFluid);
// The continuation will have gotten the first letter style from its
// prev continuation, so we need to repair the ComputedStyle so it
// doesn't have the first letter styling.
//
// Note that getting parent frame's ComputedStyle is different from getting
// this frame's ComputedStyle's parent in the presence of ::first-line,
// which we do want the continuation to inherit from.
ComputedStyle* parentSC = parent->Style();
RefPtr<ComputedStyle> newSC =
presShell->StyleSet()->ResolveStyleForFirstLetterContinuation(parentSC);
continuation->SetComputedStyle(newSC);
nsLayoutUtils::MarkDescendantsDirty(continuation);
// XXX Bidi may not be involved but we have to use the list name
// FrameChildListID::NoReflowPrincipal because this is just like creating a
// continuation except we have to insert it in a different place and we don't
// want a reflow command to try to be issued.
parent->InsertFrames(FrameChildListID::NoReflowPrincipal, placeholderFrame,
nullptr, nsFrameList(continuation, continuation));
*aContinuation = continuation;
}
nsTextFrame* nsFirstLetterFrame::CreateContinuationForFramesAfter(
nsTextFrame* aFrame) {
auto* presShell = PresShell();
auto* parent = GetParent();
auto* letterContinuation =
static_cast<nsFirstLetterFrame*>(
presShell->FrameConstructor()->CreateContinuingFrame(
this, parent,
true));
parent->InsertFrames(FrameChildListID::NoReflowPrincipal,
this, nullptr,
nsFrameList(letterContinuation, letterContinuation));
nsTextFrame* next;
auto list = mFrames.TakeFramesAfter(aFrame);
if (list.NotEmpty()) {
// If we already have additional frames, just move them to the continuation.
next =
static_cast<nsTextFrame*>(list.FirstChild());
for (
auto* frame : list) {
frame->SetParent(letterContinuation);
}
// If the first frame of the list was not a fluid continuation, we need to
// insert one there to accept the overflowing text without disrupting the
// existing fixed continuation.
if (!next->HasAnyStateBits(NS_FRAME_IS_FLUID_CONTINUATION)) {
next =
static_cast<nsTextFrame*>(
presShell->FrameConstructor()->CreateContinuingFrame(
aFrame, letterContinuation));
list.InsertFrame(letterContinuation, nullptr, next);
}
letterContinuation->SetInitialChildList(FrameChildListID::Principal,
std::move(list));
}
else {
// We don't have extra frames already, so create a new text continuation.
next =
static_cast<nsTextFrame*>(
presShell->FrameConstructor()->CreateContinuingFrame(
aFrame, letterContinuation));
letterContinuation->SetInitialChildList(FrameChildListID::Principal,
nsFrameList(next, next));
}
// Update the computed style of the continuation text frame(s) that are
// no longer supposed to be first-letter style.
ComputedStyle* parentSC = letterContinuation->Style();
RefPtr<ComputedStyle> newSC =
presShell->StyleSet()->ResolveStyleForFirstLetterContinuation(parentSC);
for (
auto* frame : letterContinuation->PrincipalChildList()) {
frame->SetComputedStyle(newSC);
}
return next;
}
void nsFirstLetterFrame::DrainOverflowFrames(nsPresContext* aPresContext) {
// Check for an overflow list with our prev-in-flow
nsFirstLetterFrame* prevInFlow = (nsFirstLetterFrame*)GetPrevInFlow();
if (prevInFlow) {
AutoFrameListPtr overflowFrames(aPresContext,
prevInFlow->StealOverflowFrames());
if (overflowFrames) {
NS_ASSERTION(mFrames.IsEmpty(),
"bad overflow list");
// When pushing and pulling frames we need to check for whether any
// views need to be reparented.
nsContainerFrame::ReparentFrameViewList(*overflowFrames, prevInFlow,
this);
mFrames.InsertFrames(
this, nullptr, std::move(*overflowFrames));
}
}
// It's also possible that we have an overflow list for ourselves
AutoFrameListPtr overflowFrames(aPresContext, StealOverflowFrames());
if (overflowFrames) {
NS_ASSERTION(mFrames.NotEmpty(),
"overflow list w/o frames");
mFrames.AppendFrames(nullptr, std::move(*overflowFrames));
}
// Now repair our first frames ComputedStyle (since we only reflow
// one frame there is no point in doing any other ones until they
// are reflowed)
nsIFrame* kid = mFrames.FirstChild();
if (kid) {
nsIContent* kidContent = kid->GetContent();
if (kidContent) {
NS_ASSERTION(kidContent->IsText(),
"should contain only text nodes");
ComputedStyle* parentSC;
if (prevInFlow) {
// This is for the rest of the content not in the first-letter.
nsIFrame* styleParent =
CorrectStyleParentFrame(GetParent(), PseudoStyleType::firstLetter);
parentSC = styleParent->Style();
}
else {
// And this for the first-letter style.
parentSC = mComputedStyle;
}
RefPtr<ComputedStyle> sc =
aPresContext->StyleSet()->ResolveStyleForText(kidContent, parentSC);
kid->SetComputedStyle(sc);
nsLayoutUtils::MarkDescendantsDirty(kid);
}
}
}
Maybe<nscoord> nsFirstLetterFrame::GetNaturalBaselineBOffset(
WritingMode aWM, BaselineSharingGroup aBaselineGroup,
BaselineExportContext)
const {
if (aBaselineGroup == BaselineSharingGroup::Last) {
return Nothing{};
}
return Some(mBaseline);
}
LogicalSides nsFirstLetterFrame::GetLogicalSkipSides()
const {
if (GetPrevContinuation()) {
// We shouldn't get calls to GetLogicalSkipSides for later continuations
// since they have separate ComputedStyles with initial values for all the
// properties that could trigger a call to GetLogicalSkipSides. Then again,
// it's not really an error to call GetLogicalSkipSides on any frame, so
// that's why we handle it properly.
return LogicalSides(mWritingMode, LogicalSides::All);
}
return LogicalSides(mWritingMode);
// first continuation displays all sides
}
