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

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.IsBResize() &&
        (kidFrame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_BSIZE)) {
      // Tell our kid it's being block-dir resized too.  Bit of a
      // hack for framesets.
      kidReflowState.SetBResize(true);
    }

    WritingMode wm = aReflowState.GetWritingMode();
    WritingMode kidWM = kidReflowState.GetWritingMode();
    nsSize containerSize = aReflowState.ComputedPhysicalSize();

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

    kidReflowState.ApplyRelativePositioning(&kidPt, containerSize);

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

    // Complete the reflow and position and size the child frame
    FinishReflowChild(kidFrame, aPresContext, kidDesiredSize, &kidReflowState,
                      kidWM, kidPt, containerSize, 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.........