C++ nsRect::YMost方法代码示例

// Computes the area in which aRect1 and aRect2 overlap and fills 'this' with
// the result. Returns FALSE if the rectangles don't intersect.
PRBool nsRect::IntersectRect(const nsRect &aRect1, const nsRect &aRect2)
{
  nscoord  xmost1 = aRect1.XMost();
  nscoord  ymost1 = aRect1.YMost();
  nscoord  xmost2 = aRect2.XMost();
  nscoord  ymost2 = aRect2.YMost();
  nscoord  temp;

  x = PR_MAX(aRect1.x, aRect2.x);
  y = PR_MAX(aRect1.y, aRect2.y);

  // Compute the destination width
  temp = PR_MIN(xmost1, xmost2);
  if (temp <= x) {
    width = 0;
  } else {
    width = temp - x;
  }

  // Compute the destination height
  temp = PR_MIN(ymost1, ymost2);
  if (temp <= y) {
    height = 0;
  } else {
    height = temp - y;
  }

  return !IsEmpty();
}

static Maybe<nsRect>
EdgeInclusiveIntersection(const nsRect& aRect, const nsRect& aOtherRect)
{
    nscoord left = std::max(aRect.x, aOtherRect.x);
    nscoord top = std::max(aRect.y, aOtherRect.y);
    nscoord right = std::min(aRect.XMost(), aOtherRect.XMost());
    nscoord bottom = std::min(aRect.YMost(), aOtherRect.YMost());
    if (left > right || top > bottom) {
        return Nothing();
    }
    return Some(nsRect(left, top, right - left, bottom - top));
}

void nsRect::UnionRectIncludeEmpty(const nsRect &aRect1, const nsRect &aRect2)
{
  nscoord xmost1 = aRect1.XMost();
  nscoord xmost2 = aRect2.XMost();
  nscoord ymost1 = aRect1.YMost();
  nscoord ymost2 = aRect2.YMost();

  // Compute the origin
  x = PR_MIN(aRect1.x, aRect2.x);
  y = PR_MIN(aRect1.y, aRect2.y);

  // Compute the size
  width = PR_MAX(xmost1, xmost2) - x;
  height = PR_MAX(ymost1, ymost2) - y;
}

static float
ComputeDistanceFromRect(const nsPoint& aPoint, const nsRect& aRect)
{
  nscoord dx = std::max(0, std::max(aRect.x - aPoint.x, aPoint.x - aRect.XMost()));
  nscoord dy = std::max(0, std::max(aRect.y - aPoint.y, aPoint.y - aRect.YMost()));
  return float(NS_hypot(dx, dy));
}

// Find difference between rects as an nsMargin
nsMargin nsRect::operator-(const nsRect& aRect) const
{
  nsMargin margin;
  margin.left = aRect.x - x;
  margin.right = XMost() - aRect.XMost();
  margin.top = aRect.y - y;
  margin.bottom = YMost() - aRect.YMost();
  return margin;
}

void
DOMRect::SetLayoutRect(const nsRect& aLayoutRect)
{
  double scale = 65536.0;
  // Round to the nearest 1/scale units. We choose scale so it can be represented
  // exactly by machine floating point.
  double scaleInv = 1/scale;
  double t2pScaled = scale/nsPresContext::AppUnitsPerCSSPixel();
  double x = RoundFloat(aLayoutRect.x*t2pScaled)*scaleInv;
  double y = RoundFloat(aLayoutRect.y*t2pScaled)*scaleInv;
  SetRect(x, y, RoundFloat(aLayoutRect.XMost()*t2pScaled)*scaleInv - x,
          RoundFloat(aLayoutRect.YMost()*t2pScaled)*scaleInv - y);
}

void nsViewManager::InvalidateRectDifference(nsView *aView, const nsRect& aRect, const nsRect& aCutOut) {
  NS_ASSERTION(aView->GetViewManager() == this,
               "InvalidateRectDifference called on view we don't own");
  if (aRect.y < aCutOut.y) {
    InvalidateHorizontalBandDifference(aView, aRect, aCutOut, aRect.y, aCutOut.y, false);
  }
  if (aCutOut.y < aCutOut.YMost()) {
    InvalidateHorizontalBandDifference(aView, aRect, aCutOut, aCutOut.y, aCutOut.YMost(), true);
  }
  if (aCutOut.YMost() < aRect.YMost()) {
    InvalidateHorizontalBandDifference(aView, aRect, aCutOut, aCutOut.YMost(), aRect.YMost(), false);
  }
}

// Intersection. Returns TRUE if the receiver overlaps aRect and
// FALSE otherwise
PRBool nsRect::Intersects(const nsRect &aRect) const
{
  return (PRBool) ((x < aRect.XMost()) && (y < aRect.YMost()) &&
                   (aRect.x < XMost()) && (aRect.y < YMost()));
}

//Also Returns true if aRect is Empty
PRBool nsRect::Contains(const nsRect &aRect) const
{
  return aRect.IsEmpty() || 
          ((PRBool) ((aRect.x >= x) && (aRect.y >= y) &&
                    (aRect.XMost() <= XMost()) && (aRect.YMost() <= YMost())));
}

nsRect nsRegion::GetLargestRectangle (const nsRect& aContainingRect) const {
  nsRect bestRect;

  if (GetNumRects() <= 1) {
    bestRect = GetBounds();
    return bestRect;
  }

  AxisPartition xaxis, yaxis;

  // Step 1: Calculate the grid lines
  nsRegionRectIterator iter(*this);
  const nsRect *currentRect;
  while ((currentRect = iter.Next())) {
    xaxis.InsertCoord(currentRect->x);
    xaxis.InsertCoord(currentRect->XMost());
    yaxis.InsertCoord(currentRect->y);
    yaxis.InsertCoord(currentRect->YMost());
  }
  if (!aContainingRect.IsEmpty()) {
    xaxis.InsertCoord(aContainingRect.x);
    xaxis.InsertCoord(aContainingRect.XMost());
    yaxis.InsertCoord(aContainingRect.y);
    yaxis.InsertCoord(aContainingRect.YMost());
  }

  // Step 2: Fill out the grid with the areas
  // Note: due to the ordering of rectangles in the region, it is not always
  // possible to combine steps 2 and 3 so we don't try to be clever.
  int32_t matrixHeight = yaxis.GetNumStops() - 1;
  int32_t matrixWidth = xaxis.GetNumStops() - 1;
  int32_t matrixSize = matrixHeight * matrixWidth;
  nsTArray<SizePair> areas(matrixSize);
  areas.SetLength(matrixSize);

  iter.Reset();
  while ((currentRect = iter.Next())) {
    int32_t xstart = xaxis.IndexOf(currentRect->x);
    int32_t xend = xaxis.IndexOf(currentRect->XMost());
    int32_t y = yaxis.IndexOf(currentRect->y);
    int32_t yend = yaxis.IndexOf(currentRect->YMost());

    for (; y < yend; y++) {
      nscoord height = yaxis.StopSize(y);
      for (int32_t x = xstart; x < xend; x++) {
        nscoord width = xaxis.StopSize(x);
        int64_t size = width*int64_t(height);
        if (currentRect->Intersects(aContainingRect)) {
          areas[y*matrixWidth+x].mSizeContainingRect = size;
        }
        areas[y*matrixWidth+x].mSize = size;
      }
    }
  }

  // Step 3: Find the maximum submatrix sum that does not contain a rectangle
  {
    // First get the prefix sum array
    int32_t m = matrixHeight + 1;
    int32_t n = matrixWidth + 1;
    nsTArray<SizePair> pareas(m*n);
    pareas.SetLength(m*n);
    for (int32_t y = 1; y < m; y++) {
      for (int32_t x = 1; x < n; x++) {
        SizePair area = areas[(y-1)*matrixWidth+x-1];
        if (!area.mSize) {
          area = SizePair::VeryLargeNegative();
        }
        area = area + pareas[    y*n+x-1]
                    + pareas[(y-1)*n+x  ]
                    - pareas[(y-1)*n+x-1];
        pareas[y*n+x] = area;
      }
    }

    // No longer need the grid
    areas.SetLength(0);

    SizePair bestArea;
    struct {
      int32_t left, top, right, bottom;
    } bestRectIndices = { 0, 0, 0, 0 };
    for (int32_t m1 = 0; m1 < m; m1++) {
      for (int32_t m2 = m1+1; m2 < m; m2++) {
        nsTArray<SizePair> B;
        B.SetLength(n);
        for (int32_t i = 0; i < n; i++) {
          B[i] = pareas[m2*n+i] - pareas[m1*n+i];
        }
        int32_t minIdx, maxIdx;
        SizePair area = MaxSum1D(B, n, &minIdx, &maxIdx);
        if (area > bestArea) {
          bestRectIndices.left = minIdx;
          bestRectIndices.top = m1;
          bestRectIndices.right = maxIdx;
          bestRectIndices.bottom = m2;
          bestArea = area;
        }
      }
    }
//.........这里部分代码省略.........

// Draw a header or footer string
// @param aRenderingContext - rendering context to draw into
// @param aHeaderFooter - indicates whether it is a header or footer
// @param aJust - indicates where the string is located within the header/footer
// @param aStr - the string to be drawn
// @param aRect - the rect of the page
// @param aHeight - the height of the font
// @param aAscent - the ascent of the font
// @param aWidth - available width for the string
void
nsPageFrame::DrawHeaderFooter(nsIRenderingContext& aRenderingContext,
                              nsHeaderFooterEnum   aHeaderFooter,
                              PRInt32              aJust,
                              const nsString&      aStr,
                              const nsRect&        aRect,
                              nscoord              aAscent,
                              nscoord              aHeight,
                              nscoord              aWidth)
{

  nscoord contentWidth = aWidth - (mPD->mEdgePaperMargin.left + mPD->mEdgePaperMargin.right);

  if ((aHeaderFooter == eHeader && aHeight < mPD->mReflowMargin.top) ||
      (aHeaderFooter == eFooter && aHeight < mPD->mReflowMargin.bottom)) {
    nsAutoString str;
    ProcessSpecialCodes(aStr, str);

    PRInt32 indx;
    PRInt32 textWidth = 0;
    const PRUnichar* text = str.get();

    PRInt32 len = (PRInt32)str.Length();
    if (len == 0) {
      return; // bail is empty string
    }
    // find how much text fits, the "position" is the size of the available area
    if (nsLayoutUtils::BinarySearchForPosition(&aRenderingContext, text, 0, 0, 0, len,
                                PRInt32(contentWidth), indx, textWidth)) {
      if (indx < len-1 ) {
        // we can't fit in all the text
        if (indx > 3) {
          // But we can fit in at least 4 chars.  Show all but 3 of them, then
          // an ellipsis.
          // XXXbz for non-plane0 text, this may be cutting things in the
          // middle of a codepoint!  Also, we have no guarantees that the three
          // dots will fit in the space the three chars we removed took up with
          // these font metrics!
          str.Truncate(indx-3);
          str.AppendLiteral("...");
        } else {
          // We can only fit 3 or fewer chars.  Just show nothing
          str.Truncate();
        }
      }
    } else { 
      return; // bail if couldn't find the correct length
    }
    
    if (HasRTLChars(str)) {
      PresContext()->SetBidiEnabled();
    }

    // cacl the x and y positions of the text
    nscoord x = GetXPosition(aRenderingContext, aRect, aJust, str);
    nscoord y;
    if (aHeaderFooter == eHeader) {
      y = aRect.y + mPD->mExtraMargin.top + mPD->mEdgePaperMargin.top;
    } else {
      y = aRect.YMost() - aHeight - mPD->mExtraMargin.bottom - mPD->mEdgePaperMargin.bottom;
    }

    // set up new clip and draw the text
    aRenderingContext.PushState();
    aRenderingContext.SetColor(NS_RGB(0,0,0));
    aRenderingContext.SetClipRect(aRect, nsClipCombine_kIntersect);
    nsLayoutUtils::DrawString(this, &aRenderingContext, str.get(), str.Length(), nsPoint(x, y + aAscent));
    aRenderingContext.PopState();
  }
}