C++ SVGSVGElement::UpdateHasChildrenOnlyTransform方法代码示例

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

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

  aStatus = NS_FRAME_COMPLETE;

  aDesiredSize.Width()  = aReflowState.ComputedWidth() +
                          aReflowState.ComputedPhysicalBorderPadding().LeftRight();
  aDesiredSize.Height() = aReflowState.ComputedHeight() +
                          aReflowState.ComputedPhysicalBorderPadding().TopBottom();

  NS_ASSERTION(!GetPrevInFlow(), "SVG can't currently be broken across pages.");

  SVGSVGElement *svgElem = static_cast<SVGSVGElement*>(mContent);

  nsSVGOuterSVGAnonChildFrame *anonKid =
    static_cast<nsSVGOuterSVGAnonChildFrame*>(GetFirstPrincipalChild());

  if (mState & NS_FRAME_FIRST_REFLOW) {
    // Initialize
    svgElem->UpdateHasChildrenOnlyTransform();
  }

  // If our SVG viewport has changed, update our content and notify.
  // http://www.w3.org/TR/SVG11/coords.html#ViewportSpace

  svgFloatSize newViewportSize(
    nsPresContext::AppUnitsToFloatCSSPixels(aReflowState.ComputedWidth()),
    nsPresContext::AppUnitsToFloatCSSPixels(aReflowState.ComputedHeight()));

  svgFloatSize oldViewportSize = svgElem->GetViewportSize();

  uint32_t changeBits = 0;
  if (newViewportSize != oldViewportSize) {
    // When our viewport size changes, we may need to update the overflow rects
    // of our child frames. This is the case if:
    //
    //  * We have a real/synthetic viewBox (a children-only transform), since
    //    the viewBox transform will change as the viewport dimensions change.
    //
    //  * We do not have a real/synthetic viewBox, but the last time we
    //    reflowed (or the last time UpdateOverflow() was called) we did.
    //
    // We only handle the former case here, in which case we mark all our child
    // frames as dirty so that we reflow them below and update their overflow
    // rects.
    //
    // In the latter case, updating of overflow rects is handled for removal of
    // real viewBox (the viewBox attribute) in AttributeChanged. Synthetic
    // viewBox "removal" (e.g. a document references the same SVG via both an
    // <svg:image> and then as a CSS background image (a synthetic viewBox is
    // used when painting the former, but not when painting the latter)) is
    // handled in SVGSVGElement::FlushImageTransformInvalidation.
    //
    if (svgElem->HasViewBoxOrSyntheticViewBox()) {
      nsIFrame* anonChild = GetFirstPrincipalChild();
      anonChild->AddStateBits(NS_FRAME_IS_DIRTY);
      for (nsIFrame* child = anonChild->GetFirstPrincipalChild(); child;
           child = child->GetNextSibling()) {
        child->AddStateBits(NS_FRAME_IS_DIRTY);
      }
    }
    changeBits |= COORD_CONTEXT_CHANGED;
    svgElem->SetViewportSize(newViewportSize);
  }
  if (mFullZoom != PresContext()->GetFullZoom()) {
    changeBits |= FULL_ZOOM_CHANGED;
    mFullZoom = PresContext()->GetFullZoom();
  }
  if (changeBits) {
    NotifyViewportOrTransformChanged(changeBits);
  }
  mViewportInitialized = true;

  // Now that we've marked the necessary children as dirty, call
  // ReflowSVG() or ReflowSVGNonDisplayText() on them, depending
  // on whether we are non-display.
  mCallingReflowSVG = true;
  if (GetStateBits() & NS_FRAME_IS_NONDISPLAY) {
    ReflowSVGNonDisplayText(this);
  } else {
    // Update the mRects and visual overflow rects of all our descendants,
    // including our anonymous wrapper kid:
    anonKid->AddStateBits(mState & NS_FRAME_IS_DIRTY);
    anonKid->ReflowSVG();
    NS_ABORT_IF_FALSE(!anonKid->GetNextSibling(),
      "We should have one anonymous child frame wrapping our real children");
  }
  mCallingReflowSVG = false;

//.........这里部分代码省略.........