C++ iterator::IsBlock方法代码示例

/*
 * Reconstruct the vertical margin before the line |aLine| in order to
 * do an incremental reflow that begins with |aLine| without reflowing
 * the line before it.  |aLine| may point to the fencepost at the end of
 * the line list, and it is used this way since we (for now, anyway)
 * always need to recover margins at the end of a block.
 *
 * The reconstruction involves walking backward through the line list to
 * find any collapsed margins preceding the line that would have been in
 * the reflow state's |mPrevBEndMargin| when we reflowed that line in
 * a full reflow (under the rule in CSS2 that all adjacent vertical
 * margins of blocks collapse).
 */
void
nsBlockReflowState::ReconstructMarginBefore(nsLineList::iterator aLine)
{
  mPrevBEndMargin.Zero();
  nsBlockFrame *block = mBlock;

  nsLineList::iterator firstLine = block->begin_lines();
  for (;;) {
    --aLine;
    if (aLine->IsBlock()) {
      mPrevBEndMargin = aLine->GetCarriedOutBEndMargin();
      break;
    }
    if (!aLine->IsEmpty()) {
      break;
    }
    if (aLine == firstLine) {
      // If the top margin was carried out (and thus already applied),
      // set it to zero.  Either way, we're done.
      if (!GetFlag(BRS_ISBSTARTMARGINROOT)) {
        mPrevBEndMargin.Zero();
      }
      break;
    }
  }
}

/**
 * Everything done in this function is done O(N) times for each pass of
 * reflow so it is O(N*M) where M is the number of incremental reflow
 * passes.  That's bad.  Don't do stuff here.
 *
 * When this function is called, |aLine| has just been slid by |aDeltaY|
 * and the purpose of RecoverStateFrom is to ensure that the
 * nsBlockReflowState is in the same state that it would have been in
 * had the line just been reflowed.
 *
 * Most of the state recovery that we have to do involves floats.
 */
void
nsBlockReflowState::RecoverStateFrom(nsLineList::iterator aLine,
                                     nscoord aDeltaY)
{
  // Make the line being recovered the current line
  mCurrentLine = aLine;

  // Place floats for this line into the space manager
  if (aLine->HasFloats() || aLine->IsBlock()) {
    // Undo border/padding translation since the nsFloatCache's
    // coordinates are relative to the frame not relative to the
    // border/padding.
    const nsMargin& bp = BorderPadding();
    mSpaceManager->Translate(-bp.left, -bp.top);

    RecoverFloats(aLine, aDeltaY);

#ifdef DEBUG
    if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisySpaceManager) {
      mSpaceManager->List(stdout);
    }
#endif
    // And then put the translation back again
    mSpaceManager->Translate(bp.left, bp.top);
  }
}

/*
 * Reconstruct the vertical margin before the line |aLine| in order to
 * do an incremental reflow that begins with |aLine| without reflowing
 * the line before it.  |aLine| may point to the fencepost at the end of
 * the line list, and it is used this way since we (for now, anyway)
 * always need to recover margins at the end of a block.
 *
 * The reconstruction involves walking backward through the line list to
 * find any collapsed margins preceding the line that would have been in
 * the reflow state's |mPrevBEndMargin| when we reflowed that line in
 * a full reflow (under the rule in CSS2 that all adjacent vertical
 * margins of blocks collapse).
 */
void
BlockReflowInput::ReconstructMarginBefore(nsLineList::iterator aLine)
{
  mPrevBEndMargin.Zero();
  nsBlockFrame *block = mBlock;

  nsLineList::iterator firstLine = block->LinesBegin();
  for (;;) {
    --aLine;
    if (aLine->IsBlock()) {
      mPrevBEndMargin = aLine->GetCarriedOutBEndMargin();
      break;
    }
    if (!aLine->IsEmpty()) {
      break;
    }
    if (aLine == firstLine) {
      // If the top margin was carried out (and thus already applied),
      // set it to zero.  Either way, we're done.
      if (!mFlags.mIsBStartMarginRoot) {
        mPrevBEndMargin.Zero();
      }
      break;
    }
  }
}

/**
 * Everything done in this function is done O(N) times for each pass of
 * reflow so it is O(N*M) where M is the number of incremental reflow
 * passes.  That's bad.  Don't do stuff here.
 *
 * When this function is called, |aLine| has just been slid by |aDeltaBCoord|
 * and the purpose of RecoverStateFrom is to ensure that the
 * nsBlockReflowState is in the same state that it would have been in
 * had the line just been reflowed.
 *
 * Most of the state recovery that we have to do involves floats.
 */
void
nsBlockReflowState::RecoverStateFrom(nsLineList::iterator aLine,
                                     nscoord aDeltaBCoord)
{
  // Make the line being recovered the current line
  mCurrentLine = aLine;

  // Place floats for this line into the float manager
  if (aLine->HasFloats() || aLine->IsBlock()) {
    RecoverFloats(aLine, aDeltaBCoord);

#ifdef DEBUG
    if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisyFloatManager) {
      mFloatManager->List(stdout);
    }
#endif
  }
}

/**
 * Restore information about floats into the float manager for an
 * incremental reflow, and simultaneously push the floats by
 * |aDeltaBCoord|, which is the amount |aLine| was pushed relative to its
 * parent.  The recovery of state is one of the things that makes
 * incremental reflow O(N^2) and this state should really be kept
 * around, attached to the frame tree.
 */
void
nsBlockReflowState::RecoverFloats(nsLineList::iterator aLine,
                                  nscoord aDeltaBCoord)
{
  WritingMode wm = mReflowState.GetWritingMode();
  if (aLine->HasFloats()) {
    // Place the floats into the space-manager again. Also slide
    // them, just like the regular frames on the line.
    nsFloatCache* fc = aLine->GetFirstFloat();
    while (fc) {
      nsIFrame* floatFrame = fc->mFloat;
      if (aDeltaBCoord != 0) {
        floatFrame->MovePositionBy(nsPoint(0, aDeltaBCoord));
        nsContainerFrame::PositionFrameView(floatFrame);
        nsContainerFrame::PositionChildViews(floatFrame);
      }
#ifdef DEBUG
      if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisyFloatManager) {
        nscoord tI, tB;
        mFloatManager->GetTranslation(tI, tB);
        nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
        printf("RecoverFloats: tIB=%d,%d (%d,%d) ",
               tI, tB, mFloatManagerI, mFloatManagerB);
        nsFrame::ListTag(stdout, floatFrame);
        LogicalRect region = nsFloatManager::GetRegionFor(wm, floatFrame,
                                                          ContainerSize());
        printf(" aDeltaBCoord=%d region={%d,%d,%d,%d}\n",
               aDeltaBCoord, region.IStart(wm), region.BStart(wm),
               region.ISize(wm), region.BSize(wm));
      }
#endif
      mFloatManager->AddFloat(floatFrame,
                              nsFloatManager::GetRegionFor(wm, floatFrame,
                                                           ContainerSize()),
                              wm, ContainerSize());
      fc = fc->Next();
    }
  } else if (aLine->IsBlock()) {
    nsBlockFrame::RecoverFloatsFor(aLine->mFirstChild, *mFloatManager, wm,
                                   ContainerSize());
  }
}

/**
 * Restore information about floats into the float manager for an
 * incremental reflow, and simultaneously push the floats by
 * |aDeltaY|, which is the amount |aLine| was pushed relative to its
 * parent.  The recovery of state is one of the things that makes
 * incremental reflow O(N^2) and this state should really be kept
 * around, attached to the frame tree.
 */
void
nsBlockReflowState::RecoverFloats(nsLineList::iterator aLine,
                                  nscoord aDeltaY)
{
  if (aLine->HasFloats()) {
    // Place the floats into the space-manager again. Also slide
    // them, just like the regular frames on the line.
    nsFloatCache* fc = aLine->GetFirstFloat();
    while (fc) {
      nsIFrame* floatFrame = fc->mFloat;
      if (aDeltaY != 0) {
        nsPoint p = floatFrame->GetPosition();
        floatFrame->SetPosition(nsPoint(p.x, p.y + aDeltaY));
        nsContainerFrame::PositionFrameView(floatFrame);
        nsContainerFrame::PositionChildViews(floatFrame);
      }
#ifdef DEBUG
      if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisyFloatManager) {
        nscoord tx, ty;
        mFloatManager->GetTranslation(tx, ty);
        nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
        printf("RecoverFloats: txy=%d,%d (%d,%d) ",
               tx, ty, mFloatManagerX, mFloatManagerY);
        nsFrame::ListTag(stdout, floatFrame);
        nsRect region = nsFloatManager::GetRegionFor(floatFrame);
        printf(" aDeltaY=%d region={%d,%d,%d,%d}\n",
               aDeltaY, region.x, region.y, region.width, region.height);
      }
#endif
      mFloatManager->AddFloat(floatFrame,
                              nsFloatManager::GetRegionFor(floatFrame));
      fc = fc->Next();
    }
  } else if (aLine->IsBlock()) {
    nsBlockFrame::RecoverFloatsFor(aLine->mFirstChild, *mFloatManager);
  }
}

/**
 * Restore information about floats into the space manager for an
 * incremental reflow, and simultaneously push the floats by
 * |aDeltaY|, which is the amount |aLine| was pushed relative to its
 * parent.  The recovery of state is one of the things that makes
 * incremental reflow O(N^2) and this state should really be kept
 * around, attached to the frame tree.
 */
void
nsBlockReflowState::RecoverFloats(nsLineList::iterator aLine,
                                  nscoord aDeltaY)
{
  if (aLine->HasFloats()) {
    // Place the floats into the space-manager again. Also slide
    // them, just like the regular frames on the line.
    nsFloatCache* fc = aLine->GetFirstFloat();
    while (fc) {
      nsIFrame* floatFrame = fc->mPlaceholder->GetOutOfFlowFrame();
      if (aDeltaY != 0) {
        fc->mRegion.y += aDeltaY;
        nsPoint p = floatFrame->GetPosition();
        floatFrame->SetPosition(nsPoint(p.x, p.y + aDeltaY));
        nsContainerFrame::PositionFrameView(floatFrame);
        nsContainerFrame::PositionChildViews(floatFrame);
      }
#ifdef DEBUG
      if (nsBlockFrame::gNoisyReflow || nsBlockFrame::gNoisySpaceManager) {
        nscoord tx, ty;
        mSpaceManager->GetTranslation(tx, ty);
        nsFrame::IndentBy(stdout, nsBlockFrame::gNoiseIndent);
        printf("RecoverFloats: txy=%d,%d (%d,%d) ",
               tx, ty, mSpaceManagerX, mSpaceManagerY);
        nsFrame::ListTag(stdout, floatFrame);
        printf(" aDeltaY=%d region={%d,%d,%d,%d}\n",
               aDeltaY, fc->mRegion.x, fc->mRegion.y,
               fc->mRegion.width, fc->mRegion.height);
      }
#endif
      mSpaceManager->AddRectRegion(floatFrame, fc->mRegion);
      fc = fc->Next();
    }
  } else if (aLine->IsBlock()) {
    nsBlockFrame *kid = nsnull;
    aLine->mFirstChild->QueryInterface(kBlockFrameCID, (void**)&kid);
    // don't recover any state inside a block that has its own space
    // manager (we don't currently have any blocks like this, though,
    // thanks to our use of extra frames for 'overflow')
    if (kid && !nsBlockFrame::BlockNeedsSpaceManager(kid)) {
      nscoord tx = kid->mRect.x, ty = kid->mRect.y;

      // If the element is relatively positioned, then adjust x and y
      // accordingly so that we consider relatively positioned frames
      // at their original position.
      if (NS_STYLE_POSITION_RELATIVE == kid->GetStyleDisplay()->mPosition) {
        nsPoint *offsets = static_cast<nsPoint*>
                                      (mPresContext->PropertyTable()->GetProperty(kid,
                                       nsGkAtoms::computedOffsetProperty));

        if (offsets) {
          tx -= offsets->x;
          ty -= offsets->y;
        }
      }
 
      mSpaceManager->Translate(tx, ty);
      for (nsBlockFrame::line_iterator line = kid->begin_lines(),
                                   line_end = kid->end_lines();
           line != line_end;
           ++line)
        // Pass 0, not the real DeltaY, since these floats aren't
        // moving relative to their parent block, only relative to
        // the space manager.
        RecoverFloats(line, 0);
      mSpaceManager->Translate(-tx, -ty);
    }
  }
}