DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (d38398e5144e)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */

/*
 * base class for rendering objects that can be split across lines,
 * columns, or pages
 */

#include "nsSplittableFrame.h"
#include "nsContainerFrame.h"
#include "nsIFrameInlines.h"

using namespace mozilla;

void
nsSplittableFrame::Init(nsIContent*       aContent,
                        nsContainerFrame* aParent,
                        nsIFrame*         aPrevInFlow)
{
  nsFrame::Init(aContent, aParent, aPrevInFlow);

  if (aPrevInFlow) {
    // Hook the frame into the flow
    SetPrevInFlow(aPrevInFlow);
    aPrevInFlow->SetNextInFlow(this);
  }
}

void
nsSplittableFrame::DestroyFrom(nsIFrame* aDestructRoot)
{
  // Disconnect from the flow list
  if (mPrevContinuation || mNextContinuation) {
    RemoveFromFlow(this);
  }

  // Let the base class destroy the frame
  nsFrame::DestroyFrom(aDestructRoot);
}

nsSplittableType
nsSplittableFrame::GetSplittableType() const
{
  return NS_FRAME_SPLITTABLE;
}

nsIFrame* nsSplittableFrame::GetPrevContinuation() const
{
  return mPrevContinuation;
}

void
nsSplittableFrame::SetPrevContinuation(nsIFrame* aFrame)
{
  NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "setting a prev continuation with incorrect type!");
  NS_ASSERTION (!IsInPrevContinuationChain(aFrame, this), "creating a loop in continuation chain!");
  mPrevContinuation = aFrame;
  RemoveStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
}

nsIFrame* nsSplittableFrame::GetNextContinuation() const
{
  return mNextContinuation;
}

void
nsSplittableFrame::SetNextContinuation(nsIFrame* aFrame)
{
  NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(),  "setting a next continuation with incorrect type!");
  NS_ASSERTION (!IsInNextContinuationChain(aFrame, this), "creating a loop in continuation chain!");
  mNextContinuation = aFrame;
  if (aFrame)
    aFrame->RemoveStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
}

nsIFrame*
nsSplittableFrame::FirstContinuation() const
{
  nsSplittableFrame* firstContinuation = const_cast<nsSplittableFrame*>(this);
  while (firstContinuation->mPrevContinuation)  {
    firstContinuation = static_cast<nsSplittableFrame*>(firstContinuation->mPrevContinuation);
  }
  MOZ_ASSERT(firstContinuation, "post-condition failed");
  return firstContinuation;
}

nsIFrame*
nsSplittableFrame::LastContinuation() const
{
  nsSplittableFrame* lastContinuation = const_cast<nsSplittableFrame*>(this);
  while (lastContinuation->mNextContinuation)  {
    lastContinuation = static_cast<nsSplittableFrame*>(lastContinuation->mNextContinuation);
  }
  MOZ_ASSERT(lastContinuation, "post-condition failed");
  return lastContinuation;
}

#ifdef DEBUG
bool nsSplittableFrame::IsInPrevContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2)
{
  int32_t iterations = 0;
  while (aFrame1 && iterations < 10) {
    // Bail out after 10 iterations so we don't bog down debug builds too much
    if (aFrame1 == aFrame2)
      return true;
    aFrame1 = aFrame1->GetPrevContinuation();
    ++iterations;
  }
  return false;
}

bool nsSplittableFrame::IsInNextContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2)
{
  int32_t iterations = 0;
  while (aFrame1 && iterations < 10) {
    // Bail out after 10 iterations so we don't bog down debug builds too much
    if (aFrame1 == aFrame2)
      return true;
    aFrame1 = aFrame1->GetNextContinuation();
    ++iterations;
  }
  return false;
}
#endif

nsIFrame* nsSplittableFrame::GetPrevInFlow() const
{
  return (GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ? mPrevContinuation : nullptr;
}

void
nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
{
  NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "setting a prev in flow with incorrect type!");
  NS_ASSERTION (!IsInPrevContinuationChain(aFrame, this), "creating a loop in continuation chain!");
  mPrevContinuation = aFrame;
  AddStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
}

nsIFrame* nsSplittableFrame::GetNextInFlow() const
{
  return mNextContinuation && (mNextContinuation->GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ? 
    mNextContinuation : nullptr;
}

void
nsSplittableFrame::SetNextInFlow(nsIFrame* aFrame)
{
  NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(),  "setting a next in flow with incorrect type!");
  NS_ASSERTION (!IsInNextContinuationChain(aFrame, this), "creating a loop in continuation chain!");
  mNextContinuation = aFrame;
  if (aFrame)
    aFrame->AddStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
}

nsIFrame*
nsSplittableFrame::FirstInFlow() const
{
  nsSplittableFrame* firstInFlow = const_cast<nsSplittableFrame*>(this);
  while (nsIFrame* prev = firstInFlow->GetPrevInFlow())  {
    firstInFlow = static_cast<nsSplittableFrame*>(prev);
  }
  MOZ_ASSERT(firstInFlow, "post-condition failed");
  return firstInFlow;
}

nsIFrame*
nsSplittableFrame::LastInFlow() const
{
  nsSplittableFrame* lastInFlow = const_cast<nsSplittableFrame*>(this);
  while (nsIFrame* next = lastInFlow->GetNextInFlow())  {
    lastInFlow = static_cast<nsSplittableFrame*>(next);
  }
  MOZ_ASSERT(lastInFlow, "post-condition failed");
  return lastInFlow;
}

// Remove this frame from the flow. Connects prev in flow and next in flow
void
nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
{
  nsIFrame* prevContinuation = aFrame->GetPrevContinuation();
  nsIFrame* nextContinuation = aFrame->GetNextContinuation();

  // The new continuation is fluid only if the continuation on both sides
  // of the removed frame was fluid
  if (aFrame->GetPrevInFlow() && aFrame->GetNextInFlow()) {
    if (prevContinuation) {
      prevContinuation->SetNextInFlow(nextContinuation);
    }
    if (nextContinuation) {
      nextContinuation->SetPrevInFlow(prevContinuation);
    }
  } else {
    if (prevContinuation) {
      prevContinuation->SetNextContinuation(nextContinuation);
    }
    if (nextContinuation) {
      nextContinuation->SetPrevContinuation(prevContinuation);
    }
  }

  aFrame->SetPrevInFlow(nullptr);
  aFrame->SetNextInFlow(nullptr);
}

nscoord
nsSplittableFrame::ConsumedBSize(WritingMode aWM) const
{
  nscoord bSize = 0;
  for (nsIFrame* prev = GetPrevInFlow(); prev; prev = prev->GetPrevInFlow()) {
    bSize += prev->ContentBSize(aWM);
  }
  return bSize;
}

nscoord
nsSplittableFrame::GetEffectiveComputedBSize(const ReflowInput& aReflowInput,
                                              nscoord aConsumedBSize) const
{
  nscoord bSize = aReflowInput.ComputedBSize();
  if (bSize == NS_INTRINSICSIZE) {
    return NS_INTRINSICSIZE;
  }

  if (aConsumedBSize == NS_INTRINSICSIZE) {
    aConsumedBSize = ConsumedBSize(aReflowInput.GetWritingMode());
  }

  bSize -= aConsumedBSize;

  // We may have stretched the frame beyond its computed height. Oh well.
  return std::max(0, bSize);
}

nsIFrame::LogicalSides
nsSplittableFrame::GetLogicalSkipSides(const ReflowInput* aReflowInput) const
{
  if (IS_TRUE_OVERFLOW_CONTAINER(this)) {
    return LogicalSides(eLogicalSideBitsBBoth);
  }

  if (MOZ_UNLIKELY(StyleBorder()->mBoxDecorationBreak ==
                     StyleBoxDecorationBreak::Clone)) {
    return LogicalSides();
  }

  LogicalSides skip;
  if (GetPrevInFlow()) {
    skip |= eLogicalSideBitsBStart;
  }

  if (aReflowInput) {
    // We're in the midst of reflow right now, so it's possible that we haven't
    // created a nif yet. If our content height is going to exceed our available
    // height, though, then we're going to need a next-in-flow, it just hasn't
    // been created yet.

    if (NS_UNCONSTRAINEDSIZE != aReflowInput->AvailableBSize()) {
      nscoord effectiveCH = this->GetEffectiveComputedBSize(*aReflowInput);
      if (effectiveCH != NS_INTRINSICSIZE &&
          effectiveCH > aReflowInput->AvailableBSize()) {
        // Our content height is going to exceed our available height, so we're
        // going to need a next-in-flow.
        skip |= eLogicalSideBitsBEnd;
      }
    }
  } else {
    nsIFrame* nif = GetNextInFlow();
    if (nif && !IS_TRUE_OVERFLOW_CONTAINER(nif)) {
      skip |= eLogicalSideBitsBEnd;
    }
  }

 return skip;
}

LogicalSides
nsSplittableFrame::PreReflowBlockLevelLogicalSkipSides() const
{
  if (MOZ_UNLIKELY(IS_TRUE_OVERFLOW_CONTAINER(this))) {
    return LogicalSides(mozilla::eLogicalSideBitsBBoth);
  }
  if (MOZ_LIKELY(StyleBorder()->mBoxDecorationBreak !=
                   StyleBoxDecorationBreak::Clone) &&
      GetPrevInFlow()) {
    return LogicalSides(mozilla::eLogicalSideBitsBStart);
  }
  return LogicalSides();
}

#ifdef DEBUG
void
nsSplittableFrame::DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, int32_t aIndent)
{
  nsFrame::DumpBaseRegressionData(aPresContext, out, aIndent);
  if (nullptr != mNextContinuation) {
    IndentBy(out, aIndent);
    fprintf(out, "<next-continuation va=\"%p\"/>\n", (void*)mNextContinuation);
  }
  if (nullptr != mPrevContinuation) {
    IndentBy(out, aIndent);
    fprintf(out, "<prev-continuation va=\"%p\"/>\n", (void*)mPrevContinuation);
  }

}
#endif