/* static */ void
nsMathMLFrame::GetAxisHeight(nsIRenderingContext& aRenderingContext,
                             nsIFontMetrics*      aFontMetrics,
                             nscoord&             aAxisHeight)
{
  // get the bounding metrics of the minus sign, the rendering context
  // is assumed to have been set with the font of the current style context
#ifdef NS_DEBUG
  nsCOMPtr<nsIFontMetrics> currFontMetrics;
  aRenderingContext.GetFontMetrics(*getter_AddRefs(currFontMetrics));
  NS_ASSERTION(currFontMetrics->Font().Equals(aFontMetrics->Font()),
	"unexpected state");
#endif
  nscoord xHeight;
  aFontMetrics->GetXHeight(xHeight);
  PRUnichar minus = 0x2212; // not '-', but official Unicode minus sign
  nsBoundingMetrics bm;
  nsresult rv = aRenderingContext.GetBoundingMetrics(&minus, PRUint32(1), bm);
  if (NS_SUCCEEDED(rv)) {
    aAxisHeight = bm.ascent - (bm.ascent + bm.descent)/2;
  }
  if (NS_FAILED(rv) || aAxisHeight <= 0 || aAxisHeight >= xHeight) {
    // fall-back to the other version
    GetAxisHeight(aFontMetrics, aAxisHeight);
  }
}

void
nsPageFrame::PaintHeaderFooter(nsIRenderingContext& aRenderingContext,
                               nsPoint aPt)
{
  nsPresContext* pc = PresContext();

  if (!mPD->mPrintSettings) {
    if (pc->Type() == nsPresContext::eContext_PrintPreview || pc->IsDynamic())
      mPD->mPrintSettings = pc->GetPrintSettings();
    if (!mPD->mPrintSettings)
      return;
  }

  nsRect rect(aPt.x, aPt.y, mRect.width - mPD->mShadowSize.width,
              mRect.height - mPD->mShadowSize.height);

  aRenderingContext.SetColor(NS_RGB(0,0,0));

  // Get the FontMetrics to determine width.height of strings
  nsCOMPtr<nsIFontMetrics> fontMet;
  pc->DeviceContext()->GetMetricsFor(*mPD->mHeadFootFont,
                                     pc->GetUserFontSet(),
                                     *getter_AddRefs(fontMet));

  aRenderingContext.SetFont(fontMet);

  nscoord ascent = 0;
  nscoord visibleHeight = 0;
  if (fontMet) {
    fontMet->GetHeight(visibleHeight);
    fontMet->GetMaxAscent(ascent);
  }

  // print document headers and footers
  nsXPIDLString headerLeft, headerCenter, headerRight;
  mPD->mPrintSettings->GetHeaderStrLeft(getter_Copies(headerLeft));
  mPD->mPrintSettings->GetHeaderStrCenter(getter_Copies(headerCenter));
  mPD->mPrintSettings->GetHeaderStrRight(getter_Copies(headerRight));
  DrawHeaderFooter(aRenderingContext, eHeader,
                   headerLeft, headerCenter, headerRight,
                   rect, ascent, visibleHeight);

  nsXPIDLString footerLeft, footerCenter, footerRight;
  mPD->mPrintSettings->GetFooterStrLeft(getter_Copies(footerLeft));
  mPD->mPrintSettings->GetFooterStrCenter(getter_Copies(footerCenter));
  mPD->mPrintSettings->GetFooterStrRight(getter_Copies(footerRight));
  DrawHeaderFooter(aRenderingContext, eFooter,
                   footerLeft, footerCenter, footerRight,
                   rect, ascent, visibleHeight);
}

//------------------------------------------------------------------------------
void
nsPageFrame::PaintPageContent(nsIRenderingContext& aRenderingContext,
                              const nsRect&        aDirtyRect,
                              nsPoint              aPt) {
  nsIFrame* pageContentFrame  = mFrames.FirstChild();
  nsRect rect = aDirtyRect;
  float scale = PresContext()->GetPageScale();
  aRenderingContext.PushState();
  nsPoint framePos = aPt + pageContentFrame->GetOffsetTo(this);
  aRenderingContext.Translate(framePos.x, framePos.y);
  // aPt translates to coords relative to this, then margins translate to
  // pageContentFrame's coords
  rect -= framePos;
  aRenderingContext.Scale(scale, scale);
  rect.ScaleRoundOut(1.0f / scale);
  // Make sure we don't draw where we aren't supposed to draw, especially
  // when printing selection
  nsRect clipRect(nsPoint(0, 0), pageContentFrame->GetSize());
  // Note: this computation matches how we compute maxSize.height
  // in nsPageFrame::Reflow
  nscoord expectedPageContentHeight = 
    NSToCoordCeil((GetSize().height - mPD->mReflowMargin.TopBottom()) / scale);
  if (clipRect.height > expectedPageContentHeight) {
    // We're doing print-selection, with one long page-content frame.
    // Clip to the appropriate page-content slice for the current page.
    NS_ASSERTION(mPageNum > 0, "page num should be positive");
    // Note: The pageContentFrame's y-position has been set such that a zero
    // y-value matches the top edge of the current page.  So, to clip to the
    // current page's content (in coordinates *relative* to the page content
    // frame), we just negate its y-position and add the top margin.
    clipRect.y = NSToCoordCeil((-pageContentFrame->GetRect().y + 
                                mPD->mReflowMargin.top) / scale);
    clipRect.height = expectedPageContentHeight;
    NS_ASSERTION(clipRect.y < pageContentFrame->GetSize().height,
                 "Should be clipping to region inside the page content bounds");
  }
  aRenderingContext.SetClipRect(clipRect, nsClipCombine_kIntersect);

  nsRect backgroundRect = nsRect(nsPoint(0, 0), pageContentFrame->GetSize());
  nsCSSRendering::PaintBackground(PresContext(), aRenderingContext, this,
                                  rect, backgroundRect,
                                  nsCSSRendering::PAINTBG_SYNC_DECODE_IMAGES);

  nsLayoutUtils::PaintFrame(&aRenderingContext, pageContentFrame,
                            nsRegion(rect), NS_RGBA(0,0,0,0),
                            nsLayoutUtils::PAINT_SYNC_DECODE_IMAGES);

  aRenderingContext.PopState();
}

NS_IMETHODIMP nsScrollPortView::Paint(nsIRenderingContext& aRC, const nsIRegion& aRegion,
                                      PRUint32 aPaintFlags, PRBool &aResult)
{
  aRC.PushState();
  nsRect bounds;
  GetDimensions(bounds);
  bounds.x = bounds.y = 0;
  aRC.SetClipRect(bounds, nsClipCombine_kIntersect);

  nsresult rv = nsView::Paint(aRC, aRegion, aPaintFlags, aResult);

  aRC.PopState();
    
  return rv;
}

static void
PaintCheckMark(nsIRenderingContext& aRenderingContext,
               const nsRect& aRect)
{
  // Points come from the coordinates on a 7X7 unit box centered at 0,0
  const PRInt32 checkPolygonX[] = { -3, -1,  3,  3, -1, -3 };
  const PRInt32 checkPolygonY[] = { -1,  1, -3, -1,  3,  1 };
  const PRInt32 checkNumPoints = sizeof(checkPolygonX) / sizeof(PRInt32);
  const PRInt32 checkSize      = 9; // This is value is determined by adding 2
                                    // units to pad the 7x7 unit checkmark

  // Scale the checkmark based on the smallest dimension
  nscoord paintScale = PR_MIN(aRect.width, aRect.height) / checkSize;
  nsPoint paintCenter(aRect.x + aRect.width  / 2,
                      aRect.y + aRect.height / 2);

  nsPoint paintPolygon[checkNumPoints];
  // Convert checkmark for screen rendering
  for (PRInt32 polyIndex = 0; polyIndex < checkNumPoints; polyIndex++) {
    paintPolygon[polyIndex] = paintCenter +
                              nsPoint(checkPolygonX[polyIndex] * paintScale,
                                      checkPolygonY[polyIndex] * paintScale);
  }

  aRenderingContext.FillPolygon(paintPolygon, checkNumPoints);
}

void
nsTextBoxFrame::PaintTitle(nsIRenderingContext& aRenderingContext,
                           const nsRect&        aDirtyRect,
                           nsPoint              aPt)
{
    if (mTitle.IsEmpty())
        return;

    nsRect textRect(CalcTextRect(aRenderingContext, aPt));

    // Paint the text shadow before doing any foreground stuff
    const nsStyleText* textStyle = GetStyleText();
    if (textStyle->mTextShadow) {
      // Text shadow happens with the last value being painted at the back,
      // ie. it is painted first.
      for (PRUint32 i = textStyle->mTextShadow->Length(); i > 0; --i) {
        PaintOneShadow(aRenderingContext.ThebesContext(),
                       textRect,
                       textStyle->mTextShadow->ShadowAt(i - 1),
                       GetStyleColor()->mColor,
                       aDirtyRect);
      }
    }

    DrawText(aRenderingContext, textRect, nsnull);
}

NS_IMETHODIMP
nsMathMLmsqrtFrame::Paint(nsPresContext*      aPresContext,
                          nsIRenderingContext& aRenderingContext,
                          const nsRect&        aDirtyRect,
                          nsFramePaintLayer    aWhichLayer,
                          PRUint32             aFlags)
{
  /////////////
  // paint the content we are square-rooting
  nsresult rv = nsMathMLContainerFrame::Paint(aPresContext, aRenderingContext, 
                                              aDirtyRect, aWhichLayer);
  /////////////
  // paint the sqrt symbol
  if (!NS_MATHML_HAS_ERROR(mPresentationData.flags)) {
    mSqrChar.Paint(aPresContext, aRenderingContext,
                   aDirtyRect, aWhichLayer, this);

    if (NS_FRAME_PAINT_LAYER_FOREGROUND == aWhichLayer &&
        mStyleContext->GetStyleVisibility()->IsVisible() &&
        !mBarRect.IsEmpty()) {
      // paint the overline bar
      const nsStyleColor* color = GetStyleColor();
      aRenderingContext.SetColor(color->mColor);
      aRenderingContext.FillRect(mBarRect);
    }

#if defined(NS_DEBUG) && defined(SHOW_BOUNDING_BOX)
    // for visual debug
    if (NS_MATHML_PAINT_BOUNDING_METRICS(mPresentationData.flags)) {
      nsRect rect;
      mSqrChar.GetRect(rect);

      nsBoundingMetrics bm;
      mSqrChar.GetBoundingMetrics(bm);

      aRenderingContext.SetColor(NS_RGB(255,0,0));
      nscoord x = rect.x + bm.leftBearing;
      nscoord y = rect.y;
      nscoord w = bm.rightBearing - bm.leftBearing;
      nscoord h = bm.ascent + bm.descent;
      aRenderingContext.DrawRect(x,y,w,h);
    }
#endif
  }

  return rv;
}

void RectArea::Draw(nsIFrame* aFrame, nsIRenderingContext& aRC)
{
  if (mHasFocus) {
    if (mNumCoords >= 4) {
      nscoord x1 = nsPresContext::CSSPixelsToAppUnits(mCoords[0]);
      nscoord y1 = nsPresContext::CSSPixelsToAppUnits(mCoords[1]);
      nscoord x2 = nsPresContext::CSSPixelsToAppUnits(mCoords[2]);
      nscoord y2 = nsPresContext::CSSPixelsToAppUnits(mCoords[3]);
      NS_ASSERTION(x1 <= x2 && y1 <= y2,
                   "Someone screwed up RectArea::ParseCoords");
      aRC.DrawLine(x1, y1, x1, y2);
      aRC.DrawLine(x1, y2, x2, y2);
      aRC.DrawLine(x1, y1, x2, y1);
      aRC.DrawLine(x2, y1, x2, y2);
    }
  }
}

//------------------------------------------------------------------------------
void
nsPageFrame::PaintPageContent(nsIRenderingContext& aRenderingContext,
                              const nsRect&        aDirtyRect,
                              nsPoint              aPt) {
  nsIFrame* pageContentFrame  = mFrames.FirstChild();
  nsRect rect = aDirtyRect;
  float scale = PresContext()->GetPageScale();
  aRenderingContext.PushState();
  nsPoint framePos = aPt + pageContentFrame->GetOffsetTo(this);
  aRenderingContext.Translate(framePos.x, framePos.y);
  // aPt translates to coords relative to this, then margins translate to
  // pageContentFrame's coords
  rect -= framePos;
  aRenderingContext.Scale(scale, scale);
  rect.ScaleRoundOut(1.0f / scale);
  // Make sure we don't draw where we aren't supposed to draw, especially
  // when printing selection
  nsRect clipRect(nsPoint(0, 0), pageContentFrame->GetSize());
  // Note: this computation matches how we compute maxSize.height
  // in nsPageFrame::Reflow
  nscoord expectedPageContentHeight = 
    NSToCoordCeil((GetSize().height - mPD->mReflowMargin.TopBottom()) / scale);
  if (clipRect.height > expectedPageContentHeight) {
    // We're doing print-selection, with one long page-content frame.
    // Clip to the appropriate page-content slice for the current page.
    NS_ASSERTION(mPageNum > 0, "page num should be positive");
    clipRect.y =  expectedPageContentHeight * (mPageNum - 1);
    clipRect.height = expectedPageContentHeight;
    NS_ASSERTION(clipRect.y < pageContentFrame->GetSize().height,
                 "Should be clipping to region inside the page content bounds");
  }
  aRenderingContext.SetClipRect(clipRect, nsClipCombine_kIntersect);

  const nsStyleBorder* border = GetStyleBorder();
  const nsStylePadding* padding = GetStylePadding();
  nsRect backgroundRect = nsRect(nsPoint(0, 0), pageContentFrame->GetSize());
  nsCSSRendering::PaintBackground(PresContext(), aRenderingContext, this,
                                  rect, backgroundRect, *border, *padding,
                                  PR_TRUE);

  nsLayoutUtils::PaintFrame(&aRenderingContext, pageContentFrame,
                            nsRegion(rect), NS_RGBA(0,0,0,0));

  aRenderingContext.PopState();
}

//------------------------------------------------------------------------------
void
nsSimplePageSequenceFrame::PaintPageSequence(nsIRenderingContext& aRenderingContext,
                                             const nsRect&        aDirtyRect,
                                             nsPoint              aPt) {
  nsRect rect = aDirtyRect;
  float scale = PresContext()->GetPrintPreviewScale();
  aRenderingContext.PushState();
  nsPoint framePos = aPt;
  aRenderingContext.Translate(framePos.x, framePos.y);
  rect -= framePos;
  aRenderingContext.Scale(scale, scale);
  rect.ScaleRoundOut(1.0f / scale);

  // Now the rect and the rendering coordinates are are relative to this frame.
  // Loop over the pages and paint them.
  nsIFrame* child = GetFirstChild(nsnull);
  while (child) {
    nsPoint pt = child->GetPosition();
    // The rendering context has to be translated before each call to PaintFrame
    aRenderingContext.PushState();
    aRenderingContext.Translate(pt.x, pt.y);
    nsLayoutUtils::PaintFrame(&aRenderingContext, child,
                              nsRegion(rect - pt), NS_RGBA(0,0,0,0));
    aRenderingContext.PopState();
    child = child->GetNextSibling();
  }

  aRenderingContext.PopState();
}

void
nsHTMLContainerFrame::PaintDecorationsAndChildren(
                                       nsPresContext*      aPresContext,
                                       nsIRenderingContext& aRenderingContext,
                                       const nsRect&        aDirtyRect,
                                       nsFramePaintLayer    aWhichLayer,
                                       PRBool               aIsBlock,
                                       PRUint32             aFlags)
{
  // Do standards mode painting of 'text-decoration's: under+overline
  // behind children, line-through in front.  For Quirks mode, see
  // nsTextFrame::PaintTextDecorations.  (See bug 1777.)
  nscolor underColor, overColor, strikeColor;
  PRUint8 decorations = NS_STYLE_TEXT_DECORATION_NONE;
  nsCOMPtr<nsIFontMetrics> fm;
  PRBool isVisible;

  if (eCompatibility_NavQuirks != aPresContext->CompatibilityMode() && 
      NS_FRAME_PAINT_LAYER_FOREGROUND == aWhichLayer &&
      NS_SUCCEEDED(IsVisibleForPainting(aPresContext, aRenderingContext,
                                        PR_TRUE, &isVisible)) &&
      isVisible) {
    GetTextDecorations(aPresContext, aIsBlock, decorations, underColor, 
                       overColor, strikeColor);
    if (decorations & (NS_STYLE_TEXT_DECORATION_UNDERLINE |
                       NS_STYLE_TEXT_DECORATION_OVERLINE |
                       NS_STYLE_TEXT_DECORATION_LINE_THROUGH)) {
      const nsStyleFont* font = GetStyleFont();
      NS_ASSERTION(font->mFont.decorations == NS_FONT_DECORATION_NONE,
                   "fonts on style structs shouldn't have decorations");

      // XXX This is relatively slow and shouldn't need to be used here.
      nsCOMPtr<nsIDeviceContext> deviceContext;
      aRenderingContext.GetDeviceContext(*getter_AddRefs(deviceContext));
      nsCOMPtr<nsIFontMetrics> normalFont;
      const nsStyleVisibility* visibility = GetStyleVisibility();      
      deviceContext->GetMetricsFor(font->mFont, visibility->mLangGroup, *getter_AddRefs(fm));
    }
    if (decorations & NS_STYLE_TEXT_DECORATION_UNDERLINE) {
      PaintTextDecorations(aRenderingContext, fm,
                           NS_STYLE_TEXT_DECORATION_UNDERLINE, underColor);
    }
    if (decorations & NS_STYLE_TEXT_DECORATION_OVERLINE) {
      PaintTextDecorations(aRenderingContext, fm,
                           NS_STYLE_TEXT_DECORATION_OVERLINE, overColor);
    }
  }

  PaintChildren(aPresContext, aRenderingContext, aDirtyRect,
                aWhichLayer, aFlags);

  if (decorations & NS_STYLE_TEXT_DECORATION_LINE_THROUGH) {
    PaintTextDecorations(aRenderingContext, fm,
                         NS_STYLE_TEXT_DECORATION_LINE_THROUGH, strikeColor);
  }
}

void
nsTextBoxFrame::CalculateUnderline(nsIRenderingContext& aRenderingContext)
{
    if (mAccessKeyInfo && mAccessKeyInfo->mAccesskeyIndex != kNotFound) {
         // Calculate all fields of mAccessKeyInfo which
         // are the same for both BiDi and non-BiDi frames.
         const PRUnichar *titleString = mCroppedTitle.get();
         aRenderingContext.SetTextRunRTL(PR_FALSE);
         aRenderingContext.GetWidth(titleString[mAccessKeyInfo->mAccesskeyIndex],
                                    mAccessKeyInfo->mAccessWidth);

         nscoord offset, baseline;
         nsIFontMetrics *metrics;
         aRenderingContext.GetFontMetrics(metrics);
         metrics->GetUnderline(offset, mAccessKeyInfo->mAccessUnderlineSize);
         metrics->GetMaxAscent(baseline);
         NS_RELEASE(metrics);
         mAccessKeyInfo->mAccessOffset = baseline - offset;
    }
}

/*virtual*/ void
nsHTMLContainerFrame::PaintTextDecorationLines(
                   nsIRenderingContext& aRenderingContext, 
                   nscolor aColor, 
                   nscoord aOffset, 
                   nscoord aAscent, 
                   nscoord aSize) 
{
  nsMargin bp;
  CalcBorderPadding(bp);
  PRIntn skip = GetSkipSides();
  NS_FOR_CSS_SIDES(side) {
    if (skip & (1 << side)) {
      bp.side(side) = 0;
    }
  }
  aRenderingContext.SetColor(aColor);
  nscoord innerWidth = mRect.width - bp.left - bp.right;
  aRenderingContext.FillRect(bp.left, 
                             bp.top + aAscent - aOffset, innerWidth, aSize);
}

NS_IMETHODIMP
nsPlaceholderFrame::Paint(nsPresContext*      aPresContext,
                          nsIRenderingContext& aRenderingContext,
                          const nsRect&        aDirtyRect,
                          nsFramePaintLayer    aWhichLayer,
                          PRUint32             aFlags)
{
  if ((NS_FRAME_PAINT_LAYER_DEBUG == aWhichLayer) && GetShowFrameBorders()) {
    float p2t;
    p2t = aPresContext->PixelsToTwips();
    aRenderingContext.SetColor(NS_RGB(0, 255, 255));
    nscoord x = NSIntPixelsToTwips(-5, p2t);
    aRenderingContext.FillRect(x, 0, NSIntPixelsToTwips(13, p2t),
                               NSIntPixelsToTwips(3, p2t));
    nscoord y = NSIntPixelsToTwips(-10, p2t);
    aRenderingContext.FillRect(0, y, NSIntPixelsToTwips(3, p2t),
                               NSIntPixelsToTwips(10, p2t));
  }
  DO_GLOBAL_REFLOW_COUNT_DSP("nsPlaceholderFrame", &aRenderingContext);
  return NS_OK;
}

void nsComboboxControlFrame::PaintFocus(nsIRenderingContext& aRenderingContext,
                                        nsPoint aPt)
{
  /* Do we need to do anything? */
  if (mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::disabled) ||
      mFocused != this)
    return;

  aRenderingContext.PushState();
  nsRect clipRect = mDisplayFrame->GetRect() + aPt;
  aRenderingContext.SetClipRect(clipRect, nsClipCombine_kIntersect);

  // REVIEW: Why does the old code paint mDisplayFrame again? We've
  // already painted it in the children above. So clipping it here won't do
  // us much good.

  /////////////////////
  // draw focus

  aRenderingContext.SetLineStyle(nsLineStyle_kDotted);
  aRenderingContext.SetColor(GetStyleColor()->mColor);

  //aRenderingContext.DrawRect(clipRect);

  nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
  clipRect.width -= onePixel;
  clipRect.height -= onePixel;
  aRenderingContext.DrawLine(clipRect.x, clipRect.y, 
                             clipRect.x+clipRect.width, clipRect.y);
  aRenderingContext.DrawLine(clipRect.x+clipRect.width, clipRect.y, 
                             clipRect.x+clipRect.width, clipRect.y+clipRect.height);
  aRenderingContext.DrawLine(clipRect.x+clipRect.width, clipRect.y+clipRect.height, 
                             clipRect.x, clipRect.y+clipRect.height);
  aRenderingContext.DrawLine(clipRect.x, clipRect.y+clipRect.height, 
                             clipRect.x, clipRect.y);
  aRenderingContext.DrawLine(clipRect.x, clipRect.y+clipRect.height, 
                             clipRect.x, clipRect.y);

  aRenderingContext.PopState();
}

nsresult
nsTableCellFrame::DecorateForSelection(nsPresContext* aPresContext,
                                       nsIRenderingContext& aRenderingContext,
                                       const nsStyleBackground *aStyleColor)
{
  PRInt16 displaySelection;
  displaySelection = DisplaySelection(aPresContext);
  if (displaySelection) {
    PRBool isSelected =
      (GetStateBits() & NS_FRAME_SELECTED_CONTENT) == NS_FRAME_SELECTED_CONTENT;
    if (isSelected) {
      nsIFrameSelection *frameSelection =
        aPresContext->PresShell()->FrameSelection();

      PRBool tableCellSelectionMode;
      nsresult result =
        frameSelection->GetTableCellSelection(&tableCellSelectionMode);
      if (NS_SUCCEEDED(result) && tableCellSelectionMode) {
        nscolor       bordercolor;
        if (displaySelection == nsISelectionController::SELECTION_DISABLED) {
          bordercolor = NS_RGB(176,176,176);// disabled color
        }
        else {
          aPresContext->LookAndFeel()->
            GetColor(nsILookAndFeel::eColor_TextSelectBackground,
                     bordercolor);
        }
        PRInt16 t2p = (PRInt16) aPresContext->PixelsToTwips();
        if ((mRect.width >(3*t2p)) && (mRect.height > (3*t2p)))
        {
          //compare bordercolor to ((nsStyleColor *)myColor)->mBackgroundColor)
          bordercolor = EnsureDifferentColors(bordercolor, aStyleColor->mBackgroundColor);
          //outerrounded
          aRenderingContext.SetColor(bordercolor);
          aRenderingContext.DrawLine(t2p, 0, mRect.width, 0);
          aRenderingContext.DrawLine(0, t2p, 0, mRect.height);
          aRenderingContext.DrawLine(t2p, mRect.height, mRect.width, mRect.height);
          aRenderingContext.DrawLine(mRect.width, t2p, mRect.width, mRect.height);
          //middle
          aRenderingContext.DrawRect(t2p, t2p, mRect.width-t2p, mRect.height-t2p);
          //shading
          aRenderingContext.DrawLine(2*t2p, mRect.height-2*t2p, mRect.width-t2p, mRect.height- (2*t2p));
          aRenderingContext.DrawLine(mRect.width - (2*t2p), 2*t2p, mRect.width - (2*t2p), mRect.height-t2p);
        }
      }
    }
  }
  return NS_OK;
}

/* static */ void
nsMathMLFrame::GetRuleThickness(nsIRenderingContext& aRenderingContext,
                                nsIFontMetrics*      aFontMetrics,
                                nscoord&             aRuleThickness)
{
  // get the bounding metrics of the overbar char, the rendering context
  // is assumed to have been set with the font of the current style context
#ifdef NS_DEBUG
  nsCOMPtr<nsIFontMetrics> currFontMetrics;
  aRenderingContext.GetFontMetrics(*getter_AddRefs(currFontMetrics));
  NS_ASSERTION(currFontMetrics->Font().Equals(aFontMetrics->Font()),
      "unexpected state");
#endif
  nscoord xHeight;
  aFontMetrics->GetXHeight(xHeight);
  PRUnichar overBar = 0x00AF;
  nsBoundingMetrics bm;
  nsresult rv = aRenderingContext.GetBoundingMetrics(&overBar, PRUint32(1), bm);
  if (NS_SUCCEEDED(rv)) {
    aRuleThickness = bm.ascent + bm.descent;
  }
  if (NS_FAILED(rv) || aRuleThickness <= 0 || aRuleThickness >= xHeight) {
    // fall-back to the other version
    GetRuleThickness(aFontMetrics, aRuleThickness);
  }

#if 0
  nscoord oldRuleThickness;
  GetRuleThickness(aFontMetrics, oldRuleThickness);

  PRUnichar sqrt = 0xE063; // a sqrt glyph from TeX's CMEX font
  rv = aRenderingContext.GetBoundingMetrics(&sqrt, PRUint32(1), bm);
  nscoord sqrtrule = bm.ascent; // according to TeX, the ascent should be the rule

  printf("xheight:%4d rule:%4d oldrule:%4d  sqrtrule:%4d\n",
          xHeight, aRuleThickness, oldRuleThickness, sqrtrule);
#endif
}

//------------------------------------------------------------
void
nsGfxCheckboxControlFrame::PaintCheckBox(nsIRenderingContext& aRenderingContext,
                                         nsPoint aPt,
                                         const nsRect& aDirtyRect)
{
  // REVIEW: moved the mAppearance test out so we avoid constructing
  // a display item if it's not needed
  nsRect checkRect(aPt, mRect.Size());
  checkRect.Deflate(GetUsedBorderAndPadding());

  const nsStyleColor* color = GetStyleColor();
  aRenderingContext.SetColor(color->mColor);

  PaintCheckMark(aRenderingContext, checkRect);
}

void
nsVideoFrame::PaintVideo(nsIRenderingContext& aRenderingContext,
                         const nsRect& aDirtyRect, nsPoint aPt) 
{
  nsRect area = GetContentRect() - GetPosition() + aPt;
  nsHTMLVideoElement* element = static_cast<nsHTMLVideoElement*>(GetContent());
  nsIntSize videoSize = element->GetVideoSize(nsIntSize(0, 0));
  if (videoSize.width <= 0 || videoSize.height <= 0 || area.IsEmpty())
    return;

  gfxContext* ctx = static_cast<gfxContext*>(aRenderingContext.GetNativeGraphicData(nsIRenderingContext::NATIVE_THEBES_CONTEXT));
  nsPresContext* presContext = PresContext();
  gfxRect r = gfxRect(presContext->AppUnitsToGfxUnits(area.x), 
                      presContext->AppUnitsToGfxUnits(area.y), 
                      presContext->AppUnitsToGfxUnits(area.width), 
                      presContext->AppUnitsToGfxUnits(area.height));

  r = CorrectForAspectRatio(r, videoSize);
  element->Paint(ctx, nsLayoutUtils::GetGraphicsFilterForFrame(this), r);
}

nsresult
nsMathMLmfracFrame::PlaceInternal(nsIRenderingContext& aRenderingContext,
                                  PRBool               aPlaceOrigin,
                                  nsHTMLReflowMetrics& aDesiredSize,
                                  PRBool               aWidthOnly)
{
  ////////////////////////////////////
  // Get the children's desired sizes
  nsBoundingMetrics bmNum, bmDen;
  nsHTMLReflowMetrics sizeNum;
  nsHTMLReflowMetrics sizeDen;
  nsIFrame* frameDen = nsnull;
  nsIFrame* frameNum = mFrames.FirstChild();
  if (frameNum) 
    frameDen = frameNum->GetNextSibling();
  if (!frameNum || !frameDen || frameDen->GetNextSibling()) {
    // report an error, encourage people to get their markups in order
    return ReflowError(aRenderingContext, aDesiredSize);
  }
  GetReflowAndBoundingMetricsFor(frameNum, sizeNum, bmNum);
  GetReflowAndBoundingMetricsFor(frameDen, sizeDen, bmDen);

  nsPresContext* presContext = PresContext();
  nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);

  aRenderingContext.SetFont(GetStyleFont()->mFont,
                            presContext->GetUserFontSet());
  nsCOMPtr<nsIFontMetrics> fm;
  aRenderingContext.GetFontMetrics(*getter_AddRefs(fm));

  nscoord defaultRuleThickness, axisHeight;
  GetRuleThickness(aRenderingContext, fm, defaultRuleThickness);
  GetAxisHeight(aRenderingContext, fm, axisHeight);

  nsEmbellishData coreData;
  GetEmbellishDataFrom(mEmbellishData.coreFrame, coreData);

  // see if the linethickness attribute is there 
  nsAutoString value;
  GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::linethickness_,
               value);

  mLineThickness = CalcLineThickness(presContext, mStyleContext, value,
                                     onePixel, defaultRuleThickness);

  if (!mIsBevelled) {
    mLineRect.height = mLineThickness;
    
    // by default, leave at least one-pixel padding at either end, or use
    // lspace & rspace that may come from <mo> if we are an embellished
    // container (we fetch values from the core since they may use units that
    // depend on style data, and style changes could have occurred in the
    // core since our last visit there)
    nscoord leftSpace = NS_MAX(onePixel, coreData.leftSpace);
    nscoord rightSpace = NS_MAX(onePixel, coreData.rightSpace);

    //////////////////
    // Get shifts
    nscoord numShift = 0;
    nscoord denShift = 0;

    // Rule 15b, App. G, TeXbook
    nscoord numShift1, numShift2, numShift3;
    nscoord denShift1, denShift2;

    GetNumeratorShifts(fm, numShift1, numShift2, numShift3);
    GetDenominatorShifts(fm, denShift1, denShift2);
    if (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) {
      // C > T
      numShift = numShift1;
      denShift = denShift1;
    }
    else {
      numShift = (0 < mLineRect.height) ? numShift2 : numShift3;
      denShift = denShift2;
    }

    nscoord minClearance = 0;
    nscoord actualClearance = 0;

    nscoord actualRuleThickness =  mLineThickness;

    if (0 == actualRuleThickness) {
      // Rule 15c, App. G, TeXbook

      // min clearance between numerator and denominator
      minClearance = (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) ?
        7 * defaultRuleThickness : 3 * defaultRuleThickness;
      actualClearance =
        (numShift - bmNum.descent) - (bmDen.ascent - denShift);
      // actualClearance should be >= minClearance
      if (actualClearance < minClearance) {
        nscoord halfGap = (minClearance - actualClearance)/2;
        numShift += halfGap;
        denShift += halfGap;
      }
    }
    else {
    // Rule 15d, App. G, TeXbook

//.........这里部分代码省略.........