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

void
nsSVGInnerSVGFrame::NotifySVGChanged(uint32_t aFlags)
{
  NS_ABORT_IF_FALSE(aFlags & (TRANSFORM_CHANGED | COORD_CONTEXT_CHANGED),
                    "Invalidation logic may need adjusting");

  if (aFlags & COORD_CONTEXT_CHANGED) {

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

    bool xOrYIsPercentage =
      svg->mLengthAttributes[SVGSVGElement::ATTR_X].IsPercentage() ||
      svg->mLengthAttributes[SVGSVGElement::ATTR_Y].IsPercentage();
    bool widthOrHeightIsPercentage =
      svg->mLengthAttributes[SVGSVGElement::ATTR_WIDTH].IsPercentage() ||
      svg->mLengthAttributes[SVGSVGElement::ATTR_HEIGHT].IsPercentage();

    if (xOrYIsPercentage || widthOrHeightIsPercentage) {
      // Ancestor changes can't affect how we render from the perspective of
      // any rendering observers that we may have, so we don't need to
      // invalidate them. We also don't need to invalidate ourself, since our
      // changed ancestor will have invalidated its entire area, which includes
      // our area.
      // For perf reasons we call this before calling NotifySVGChanged() below.
      nsSVGUtils::ScheduleReflowSVG(this);
    }

    // Coordinate context changes affect mCanvasTM if we have a
    // percentage 'x' or 'y', or if we have a percentage 'width' or 'height' AND
    // a 'viewBox'.

    if (!(aFlags & TRANSFORM_CHANGED) &&
        (xOrYIsPercentage ||
         (widthOrHeightIsPercentage && svg->HasViewBoxRect()))) {
      aFlags |= TRANSFORM_CHANGED;
    }

    if (svg->HasViewBoxRect() || !widthOrHeightIsPercentage) {
      // Remove COORD_CONTEXT_CHANGED, since we establish the coordinate
      // context for our descendants and this notification won't change its
      // dimensions:
      aFlags &= ~COORD_CONTEXT_CHANGED;

      if (!aFlags) {
        return; // No notification flags left
      }
    }
  }

  if (aFlags & TRANSFORM_CHANGED) {
    // make sure our cached transform matrix gets (lazily) updated
    mCanvasTM = nullptr;
  }

  nsSVGInnerSVGFrameBase::NotifySVGChanged(aFlags);
}

void
nsSVGOuterSVGFrame::NotifyViewportOrTransformChanged(uint32_t aFlags)
{
  NS_ABORT_IF_FALSE(aFlags &&
                    !(aFlags & ~(COORD_CONTEXT_CHANGED | TRANSFORM_CHANGED |
                                 FULL_ZOOM_CHANGED)),
                    "Unexpected aFlags value");

  // No point in doing anything when were not init'ed yet:
  if (!mViewportInitialized) {
    return;
  }

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

  if (aFlags & COORD_CONTEXT_CHANGED) {
    if (content->HasViewBoxRect()) {
      // Percentage lengths on children resolve against the viewBox rect so we
      // don't need to notify them of the viewport change, but the viewBox
      // transform will have changed, so we need to notify them of that instead.
      aFlags = TRANSFORM_CHANGED;
    }
    else if (content->ShouldSynthesizeViewBox()) {
      // In the case of a synthesized viewBox, the synthetic viewBox's rect
      // changes as the viewport changes. As a result we need to maintain the
      // COORD_CONTEXT_CHANGED flag.
      aFlags |= TRANSFORM_CHANGED;
    }
    else if (mCanvasTM && mCanvasTM->IsSingular()) {
      // A width/height of zero will result in us having a singular mCanvasTM
      // even when we don't have a viewBox. So we also want to recompute our
      // mCanvasTM for this width/height change even though we don't have a
      // viewBox.
      aFlags |= TRANSFORM_CHANGED;
    }
  }

  bool haveNonFulLZoomTransformChange = (aFlags & TRANSFORM_CHANGED);

  if (aFlags & FULL_ZOOM_CHANGED) {
    // Convert FULL_ZOOM_CHANGED to TRANSFORM_CHANGED:
    aFlags = (aFlags & ~FULL_ZOOM_CHANGED) | TRANSFORM_CHANGED;
  }

  if (aFlags & TRANSFORM_CHANGED) {
    // Make sure our canvas transform matrix gets (lazily) recalculated:
    mCanvasTM = nullptr;

    if (haveNonFulLZoomTransformChange &&
        !(mState & NS_FRAME_IS_NONDISPLAY)) {
      uint32_t flags = (mState & NS_FRAME_IN_REFLOW) ?
                         SVGSVGElement::eDuringReflow : 0;
      content->ChildrenOnlyTransformChanged(flags);
    }
  }

  nsSVGUtils::NotifyChildrenOfSVGChange(GetFirstPrincipalChild(), aFlags);
}