C++ nsHTMLReflowState::AvailableSize方法代码示例

void
nsTableOuterFrame::OuterBeginReflowChild(nsPresContext*           aPresContext,
                                         nsIFrame*                aChildFrame,
                                         const nsHTMLReflowState& aOuterRS,
                                         void*                    aChildRSSpace,
                                         nscoord                  aAvailISize)
{
  // work around pixel rounding errors, round down to ensure we don't exceed the avail height in
  WritingMode wm = aChildFrame->GetWritingMode();
  LogicalSize outerSize = aOuterRS.AvailableSize(wm);
  nscoord availBSize = outerSize.BSize(wm);
  if (NS_UNCONSTRAINEDSIZE != availBSize) {
    if (mCaptionFrames.FirstChild() == aChildFrame) {
      availBSize = NS_UNCONSTRAINEDSIZE;
    } else {
      LogicalMargin margin(wm);
      GetChildMargin(aPresContext, aOuterRS, aChildFrame,
                     outerSize.ISize(wm), margin);

      NS_ASSERTION(NS_UNCONSTRAINEDSIZE != margin.BStart(wm),
                   "No unconstrainedsize arithmetic, please");
      availBSize -= margin.BStart(wm);

      NS_ASSERTION(NS_UNCONSTRAINEDSIZE != margin.BEnd(wm),
                   "No unconstrainedsize arithmetic, please");
      availBSize -= margin.BEnd(wm);
    }
  }
  LogicalSize availSize(wm, aAvailISize, availBSize);
  // create and init the child reflow state, using placement new on
  // stack space allocated by the caller, so that the caller can destroy
  // it
  nsHTMLReflowState &childRS = * new (aChildRSSpace)
    nsHTMLReflowState(aPresContext, aOuterRS, aChildFrame, availSize,
                      -1, -1, nsHTMLReflowState::CALLER_WILL_INIT);
  InitChildReflowState(*aPresContext, childRS);

  // see if we need to reset top-of-page due to a caption
  if (childRS.mFlags.mIsTopOfPage &&
      mCaptionFrames.FirstChild() == aChildFrame) {
    uint8_t captionSide = GetCaptionSide();
    if (captionSide == NS_STYLE_CAPTION_SIDE_BOTTOM ||
        captionSide == NS_STYLE_CAPTION_SIDE_BOTTOM_OUTSIDE) {
      childRS.mFlags.mIsTopOfPage = false;
    }
  }
}

// get the margin and padding data. nsHTMLReflowState doesn't handle the
// case of auto margins
void
nsTableOuterFrame::GetChildMargin(nsPresContext*           aPresContext,
                                  const nsHTMLReflowState& aOuterRS,
                                  nsIFrame*                aChildFrame,
                                  nscoord                  aAvailISize,
                                  LogicalMargin&           aMargin)
{
  // construct a reflow state to compute margin and padding. Auto margins
  // will not be computed at this time.

  // create and init the child reflow state
  // XXX We really shouldn't construct a reflow state to do this.
  WritingMode wm = aChildFrame->GetWritingMode();
  LogicalSize availSize(wm, aAvailISize, aOuterRS.AvailableSize(wm).BSize(wm));
  nsHTMLReflowState childRS(aPresContext, aOuterRS, aChildFrame, availSize,
                            -1, -1, nsHTMLReflowState::CALLER_WILL_INIT);
  InitChildReflowState(*aPresContext, childRS);

  aMargin = childRS.ComputedLogicalMargin();
}

void
nsCanvasFrame::Reflow(nsPresContext*           aPresContext,
                      nsHTMLReflowMetrics&     aDesiredSize,
                      const nsHTMLReflowState& aReflowState,
                      nsReflowStatus&          aStatus)
{
  MarkInReflow();
  DO_GLOBAL_REFLOW_COUNT("nsCanvasFrame");
  DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
  NS_FRAME_TRACE_REFLOW_IN("nsCanvasFrame::Reflow");

  // Initialize OUT parameter
  aStatus = NS_FRAME_COMPLETE;

  nsCanvasFrame* prevCanvasFrame = static_cast<nsCanvasFrame*>
                                               (GetPrevInFlow());
  if (prevCanvasFrame) {
    AutoFrameListPtr overflow(aPresContext,
                              prevCanvasFrame->StealOverflowFrames());
    if (overflow) {
      NS_ASSERTION(overflow->OnlyChild(),
                   "must have doc root as canvas frame's only child");
      nsContainerFrame::ReparentFrameViewList(*overflow, prevCanvasFrame, this);
      // Prepend overflow to the our child list. There may already be
      // children placeholders for fixed-pos elements, which don't get
      // reflowed but must not be lost until the canvas frame is destroyed.
      mFrames.InsertFrames(this, nullptr, *overflow);
    }
  }

  // Set our size up front, since some parts of reflow depend on it
  // being already set.  Note that the computed height may be
  // unconstrained; that's ok.  Consumers should watch out for that.
  SetSize(nsSize(aReflowState.ComputedWidth(), aReflowState.ComputedHeight())); 

  // Reflow our one and only normal child frame. It's either the root
  // element's frame or a placeholder for that frame, if the root element
  // is abs-pos or fixed-pos. We may have additional children which
  // are placeholders for continuations of fixed-pos content, but those
  // don't need to be reflowed. The normal child is always comes before
  // the fixed-pos placeholders, because we insert it at the start
  // of the child list, above.
  nsHTMLReflowMetrics kidDesiredSize(aReflowState);
  if (mFrames.IsEmpty()) {
    // We have no child frame, so return an empty size
    aDesiredSize.Width() = aDesiredSize.Height() = 0;
  } else {
    nsIFrame* kidFrame = mFrames.FirstChild();
    bool kidDirty = (kidFrame->GetStateBits() & NS_FRAME_IS_DIRTY) != 0;

    nsHTMLReflowState
      kidReflowState(aPresContext, aReflowState, kidFrame,
                     aReflowState.AvailableSize(kidFrame->GetWritingMode()));

    if (aReflowState.IsVResize() &&
        (kidFrame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT)) {
      // Tell our kid it's being vertically resized too.  Bit of a
      // hack for framesets.
      kidReflowState.SetVResize(true);
    }

    WritingMode wm = aReflowState.GetWritingMode();
    WritingMode kidWM = kidReflowState.GetWritingMode();
    nscoord containerWidth = aReflowState.ComputedWidth();

    LogicalMargin margin = kidReflowState.ComputedLogicalMargin();
    LogicalPoint kidPt(kidWM, margin.IStart(kidWM), margin.BStart(kidWM));

    kidReflowState.ApplyRelativePositioning(&kidPt, containerWidth);

    // Reflow the frame
    ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
                kidWM, kidPt, containerWidth, 0, aStatus);

    // Complete the reflow and position and size the child frame
    FinishReflowChild(kidFrame, aPresContext, kidDesiredSize, &kidReflowState,
                      kidWM, kidPt, containerWidth, 0);

    if (!NS_FRAME_IS_FULLY_COMPLETE(aStatus)) {
      nsIFrame* nextFrame = kidFrame->GetNextInFlow();
      NS_ASSERTION(nextFrame || aStatus & NS_FRAME_REFLOW_NEXTINFLOW,
        "If it's incomplete and has no nif yet, it must flag a nif reflow.");
      if (!nextFrame) {
        nextFrame = aPresContext->PresShell()->FrameConstructor()->
          CreateContinuingFrame(aPresContext, kidFrame, this);
        SetOverflowFrames(nsFrameList(nextFrame, nextFrame));
        // Root overflow containers will be normal children of
        // the canvas frame, but that's ok because there
        // aren't any other frames we need to isolate them from
        // during reflow.
      }
      if (NS_FRAME_OVERFLOW_IS_INCOMPLETE(aStatus)) {
        nextFrame->AddStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
      }
    }

    // If the child frame was just inserted, then we're responsible for making sure
    // it repaints
    if (kidDirty) {
      // But we have a new child, which will affect our background, so
//.........这里部分代码省略.........

void
ViewportFrame::Reflow(nsPresContext*           aPresContext,
                      nsHTMLReflowMetrics&     aDesiredSize,
                      const nsHTMLReflowState& aReflowState,
                      nsReflowStatus&          aStatus)
{
  MarkInReflow();
  DO_GLOBAL_REFLOW_COUNT("ViewportFrame");
  DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
  NS_FRAME_TRACE_REFLOW_IN("ViewportFrame::Reflow");

  // Initialize OUT parameters
  aStatus = NS_FRAME_COMPLETE;

  // Because |Reflow| sets ComputedBSize() on the child to our
  // ComputedBSize().
  AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);

  // Set our size up front, since some parts of reflow depend on it
  // being already set.  Note that the computed height may be
  // unconstrained; that's ok.  Consumers should watch out for that.
  SetSize(nsSize(aReflowState.ComputedWidth(), aReflowState.ComputedHeight()));

  // Reflow the main content first so that the placeholders of the
  // fixed-position frames will be in the right places on an initial
  // reflow.
  nscoord kidBSize = 0;
  WritingMode wm = aReflowState.GetWritingMode();

  if (mFrames.NotEmpty()) {
    // Deal with a non-incremental reflow or an incremental reflow
    // targeted at our one-and-only principal child frame.
    if (aReflowState.ShouldReflowAllKids() ||
        aReflowState.IsVResize() ||
        NS_SUBTREE_DIRTY(mFrames.FirstChild())) {
      // Reflow our one-and-only principal child frame
      nsIFrame*           kidFrame = mFrames.FirstChild();
      nsHTMLReflowMetrics kidDesiredSize(aReflowState);
      WritingMode         wm = kidFrame->GetWritingMode();
      LogicalSize         availableSpace = aReflowState.AvailableSize(wm);
      nsHTMLReflowState   kidReflowState(aPresContext, aReflowState,
                                         kidFrame, availableSpace);

      // Reflow the frame
      kidReflowState.SetComputedBSize(aReflowState.ComputedBSize());
      ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
                  0, 0, 0, aStatus);
      kidBSize = kidDesiredSize.BSize(wm);

      FinishReflowChild(kidFrame, aPresContext, kidDesiredSize, nullptr, 0, 0, 0);
    } else {
      kidBSize = LogicalSize(wm, mFrames.FirstChild()->GetSize()).BSize(wm);
    }
  }

  NS_ASSERTION(aReflowState.AvailableISize() != NS_UNCONSTRAINEDSIZE,
               "shouldn't happen anymore");

  // Return the max size as our desired size
  LogicalSize maxSize(wm, aReflowState.AvailableISize(),
                      // Being flowed initially at an unconstrained block size
                      // means we should return our child's intrinsic size.
                      aReflowState.ComputedBSize() != NS_UNCONSTRAINEDSIZE
                        ? aReflowState.ComputedBSize()
                        : kidBSize);
  aDesiredSize.SetSize(wm, maxSize);
  aDesiredSize.SetOverflowAreasToDesiredBounds();

  if (HasAbsolutelyPositionedChildren()) {
    // Make a copy of the reflow state and change the computed width and height
    // to reflect the available space for the fixed items
    nsHTMLReflowState reflowState(aReflowState);

    if (reflowState.AvailableBSize() == NS_UNCONSTRAINEDSIZE) {
      // We have an intrinsic-height document with abs-pos/fixed-pos children.
      // Set the available height and mComputedHeight to our chosen height.
      reflowState.AvailableBSize() = maxSize.BSize(wm);
      // Not having border/padding simplifies things
      NS_ASSERTION(reflowState.ComputedPhysicalBorderPadding() == nsMargin(0,0,0,0),
                   "Viewports can't have border/padding");
      reflowState.SetComputedBSize(maxSize.BSize(wm));
    }

    nsRect rect = AdjustReflowStateAsContainingBlock(&reflowState);
    nsOverflowAreas* overflowAreas = &aDesiredSize.mOverflowAreas;
    nsIScrollableFrame* rootScrollFrame =
                    aPresContext->PresShell()->GetRootScrollFrameAsScrollable();
    if (rootScrollFrame && !rootScrollFrame->IsIgnoringViewportClipping()) {
      overflowAreas = nullptr;
    }
    AbsPosReflowFlags flags =
      AbsPosReflowFlags::eCBWidthAndHeightChanged; // XXX could be optimized
    GetAbsoluteContainingBlock()->Reflow(this, aPresContext, reflowState, aStatus,
                                         rect, flags, overflowAreas);
  }

  if (mFrames.NotEmpty()) {
    ConsiderChildOverflow(aDesiredSize.mOverflowAreas, mFrames.FirstChild());
  }

//.........这里部分代码省略.........

void
nsVideoFrame::Reflow(nsPresContext*           aPresContext,
                     nsHTMLReflowMetrics&     aMetrics,
                     const nsHTMLReflowState& aReflowState,
                     nsReflowStatus&          aStatus)
{
  MarkInReflow();
  DO_GLOBAL_REFLOW_COUNT("nsVideoFrame");
  DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aStatus);
  NS_FRAME_TRACE(NS_FRAME_TRACE_CALLS,
                  ("enter nsVideoFrame::Reflow: availSize=%d,%d",
                  aReflowState.AvailableWidth(), aReflowState.AvailableHeight()));

  NS_PRECONDITION(mState & NS_FRAME_IN_REFLOW, "frame is not in reflow");

  aStatus = NS_FRAME_COMPLETE;

  aMetrics.Width() = aReflowState.ComputedWidth();
  aMetrics.Height() = aReflowState.ComputedHeight();

  // stash this away so we can compute our inner area later
  mBorderPadding   = aReflowState.ComputedPhysicalBorderPadding();

  aMetrics.Width() += mBorderPadding.left + mBorderPadding.right;
  aMetrics.Height() += mBorderPadding.top + mBorderPadding.bottom;

  // Reflow the child frames. We may have up to two, an image frame
  // which is the poster, and a box frame, which is the video controls.
  for (nsIFrame* child : mFrames) {
    if (child->GetContent() == mPosterImage) {
      // Reflow the poster frame.
      nsImageFrame* imageFrame = static_cast<nsImageFrame*>(child);
      nsHTMLReflowMetrics kidDesiredSize(aReflowState);
      WritingMode wm = imageFrame->GetWritingMode();
      LogicalSize availableSize = aReflowState.AvailableSize(wm);
      LogicalSize cbSize = aMetrics.Size(aMetrics.GetWritingMode()).
                             ConvertTo(wm, aMetrics.GetWritingMode());
      nsHTMLReflowState kidReflowState(aPresContext,
                                       aReflowState,
                                       imageFrame,
                                       availableSize,
                                       &cbSize);

      nsRect posterRenderRect;
      if (ShouldDisplayPoster()) {
        posterRenderRect =
          nsRect(nsPoint(mBorderPadding.left, mBorderPadding.top),
                 nsSize(aReflowState.ComputedWidth(),
                        aReflowState.ComputedHeight()));
      }
      kidReflowState.SetComputedWidth(posterRenderRect.width);
      kidReflowState.SetComputedHeight(posterRenderRect.height);
      ReflowChild(imageFrame, aPresContext, kidDesiredSize, kidReflowState,
                  posterRenderRect.x, posterRenderRect.y, 0, aStatus);
      FinishReflowChild(imageFrame, aPresContext,
                        kidDesiredSize, &kidReflowState,
                        posterRenderRect.x, posterRenderRect.y, 0);
    } else if (child->GetContent() == mVideoControls) {
      // Reflow the video controls frame.
      nsBoxLayoutState boxState(PresContext(), aReflowState.rendContext);
      nsSize size = child->GetSize();
      nsBoxFrame::LayoutChildAt(boxState,
                                child,
                                nsRect(mBorderPadding.left,
                                       mBorderPadding.top,
                                       aReflowState.ComputedWidth(),
                                       aReflowState.ComputedHeight()));
      if (child->GetSize() != size) {
        RefPtr<nsRunnable> event = new DispatchResizeToControls(child->GetContent());
        nsContentUtils::AddScriptRunner(event);
      }
    } else if (child->GetContent() == mCaptionDiv) {
      // Reflow to caption div
      nsHTMLReflowMetrics kidDesiredSize(aReflowState);
      WritingMode wm = child->GetWritingMode();
      LogicalSize availableSize = aReflowState.AvailableSize(wm);
      LogicalSize cbSize = aMetrics.Size(aMetrics.GetWritingMode()).
                             ConvertTo(wm, aMetrics.GetWritingMode());
      nsHTMLReflowState kidReflowState(aPresContext,
                                       aReflowState,
                                       child,
                                       availableSize,
                                       &cbSize);
      nsSize size(aReflowState.ComputedWidth(), aReflowState.ComputedHeight());
      size.width -= kidReflowState.ComputedPhysicalBorderPadding().LeftRight();
      size.height -= kidReflowState.ComputedPhysicalBorderPadding().TopBottom();

      kidReflowState.SetComputedWidth(std::max(size.width, 0));
      kidReflowState.SetComputedHeight(std::max(size.height, 0));

      ReflowChild(child, aPresContext, kidDesiredSize, kidReflowState,
                  mBorderPadding.left, mBorderPadding.top, 0, aStatus);
      FinishReflowChild(child, aPresContext,
                        kidDesiredSize, &kidReflowState,
                        mBorderPadding.left, mBorderPadding.top, 0);
    }
  }
  aMetrics.SetOverflowAreasToDesiredBounds();

  FinishAndStoreOverflow(&aMetrics);
//.........这里部分代码省略.........

void
nsFirstLetterFrame::Reflow(nsPresContext*          aPresContext,
                           nsHTMLReflowMetrics&     aMetrics,
                           const nsHTMLReflowState& aReflowState,
                           nsReflowStatus&          aReflowStatus)
{
  MarkInReflow();
  DO_GLOBAL_REFLOW_COUNT("nsFirstLetterFrame");
  DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aReflowStatus);

  // Grab overflow list
  DrainOverflowFrames(aPresContext);

  nsIFrame* kid = mFrames.FirstChild();

  // Setup reflow state for our child
  WritingMode wm = aReflowState.GetWritingMode();
  LogicalSize availSize = aReflowState.AvailableSize();
  const LogicalMargin& bp = aReflowState.ComputedLogicalBorderPadding();
  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();
  nsHTMLReflowMetrics kidMetrics(lineWM);

  // Reflow the child
  if (!aReflowState.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 = GetWritingMode(kid);
    LogicalSize kidAvailSize = availSize.ConvertTo(kidWritingMode, wm);
    nsHTMLReflowState rs(aPresContext, aReflowState, kid, kidAvailSize);
    nsLineLayout ll(aPresContext, nullptr, &aReflowState, nullptr, nullptr);

    ll.BeginLineReflow(bp.IStart(wm), bp.BStart(wm),
                       availSize.ISize(wm), NS_UNCONSTRAINEDSIZE,
                       false, true, kidWritingMode,
                       nsSize(aReflowState.AvailableWidth(),
                              aReflowState.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(lineWM).ConvertTo(wm, lineWM);
    kid->SetRect(nsRect(bp.IStart(wm), bp.BStart(wm),
                        convertedSize.ISize(wm), convertedSize.BSize(wm)));
    kid->FinishAndStoreOverflow(&kidMetrics);
    kid->DidReflow(aPresContext, nullptr, nsDidReflowStatus::FINISHED);

    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);
  }
  else {
    // Pretend we are a span and reflow the child frame
    nsLineLayout* ll = aReflowState.mLineLayout;
    bool          pushedFrame;

    ll->SetInFirstLetter(
      mStyleContext->GetPseudo() == nsCSSPseudoElements::firstLetter);
    ll->BeginSpan(this, &aReflowState, 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);

    nsLayoutUtils::SetBSizeFromFontMetrics(this, aMetrics, bp, lineWM, wm);
  }

  if (!NS_INLINE_IS_BREAK_BEFORE(aReflowStatus)) {
//.........这里部分代码省略.........