C++ nsIRenderingContext::ThebesContext方法代码示例

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);
}

void
nsTextBoxFrame::DrawText(nsIRenderingContext& aRenderingContext,
                         const nsRect&        aTextRect,
                         const nscolor*       aOverrideColor)
{
    nsPresContext* presContext = PresContext();

    // paint the title
    nscolor overColor;
    nscolor underColor;
    nscolor strikeColor;
    nsStyleContext* context = mStyleContext;
  
    PRUint8 decorations = NS_STYLE_TEXT_DECORATION_NONE; // Begin with no decorations
    PRUint8 decorMask = NS_STYLE_TEXT_DECORATION_UNDERLINE | NS_STYLE_TEXT_DECORATION_OVERLINE |
                        NS_STYLE_TEXT_DECORATION_LINE_THROUGH; // A mask of all possible decorations.
    PRBool hasDecorations = context->HasTextDecorations();

    do {  // find decoration colors
      const nsStyleTextReset* styleText = context->GetStyleTextReset();
      
      if (decorMask & styleText->mTextDecoration) {  // a decoration defined here
        nscolor color = aOverrideColor ? *aOverrideColor : context->GetStyleColor()->mColor;
    
        if (NS_STYLE_TEXT_DECORATION_UNDERLINE & decorMask & styleText->mTextDecoration) {
          underColor = color;
          decorMask &= ~NS_STYLE_TEXT_DECORATION_UNDERLINE;
          decorations |= NS_STYLE_TEXT_DECORATION_UNDERLINE;
        }
        if (NS_STYLE_TEXT_DECORATION_OVERLINE & decorMask & styleText->mTextDecoration) {
          overColor = color;
          decorMask &= ~NS_STYLE_TEXT_DECORATION_OVERLINE;
          decorations |= NS_STYLE_TEXT_DECORATION_OVERLINE;
        }
        if (NS_STYLE_TEXT_DECORATION_LINE_THROUGH & decorMask & styleText->mTextDecoration) {
          strikeColor = color;
          decorMask &= ~NS_STYLE_TEXT_DECORATION_LINE_THROUGH;
          decorations |= NS_STYLE_TEXT_DECORATION_LINE_THROUGH;
        }
      }
      if (0 != decorMask) {
        context = context->GetParent();
        if (context) {
          hasDecorations = context->HasTextDecorations();
        }
      }
    } while (context && hasDecorations && (0 != decorMask));

    nsCOMPtr<nsIFontMetrics> fontMet;
    nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fontMet));

    nscoord offset;
    nscoord size;
    nscoord ascent;
    fontMet->GetMaxAscent(ascent);

    nscoord baseline =
      presContext->RoundAppUnitsToNearestDevPixels(aTextRect.y + ascent);
    nsRefPtr<gfxContext> ctx = aRenderingContext.ThebesContext();
    gfxPoint pt(presContext->AppUnitsToGfxUnits(aTextRect.x),
                presContext->AppUnitsToGfxUnits(aTextRect.y));
    gfxFloat width = presContext->AppUnitsToGfxUnits(aTextRect.width);
    gfxFloat ascentPixel = presContext->AppUnitsToGfxUnits(ascent);

    // Underlines are drawn before overlines, and both before the text
    // itself, per http://www.w3.org/TR/CSS21/zindex.html point 7.2.1.4.1.1.
    // (We don't apply this rule to the access-key underline because we only
    // find out where that is as a side effect of drawing the text, in the
    // general case -- see below.)
    if (decorations & (NS_FONT_DECORATION_OVERLINE |
                       NS_FONT_DECORATION_UNDERLINE)) {
      fontMet->GetUnderline(offset, size);
      gfxFloat offsetPixel = presContext->AppUnitsToGfxUnits(offset);
      gfxFloat sizePixel = presContext->AppUnitsToGfxUnits(size);
      if (decorations & NS_FONT_DECORATION_UNDERLINE) {
        nsCSSRendering::PaintDecorationLine(ctx, underColor,
                          pt, gfxSize(width, sizePixel),
                          ascentPixel, offsetPixel,
                          NS_STYLE_TEXT_DECORATION_UNDERLINE,
                          nsCSSRendering::DECORATION_STYLE_SOLID);
      }
      if (decorations & NS_FONT_DECORATION_OVERLINE) {
        nsCSSRendering::PaintDecorationLine(ctx, overColor,
                          pt, gfxSize(width, sizePixel),
                          ascentPixel, ascentPixel,
                          NS_STYLE_TEXT_DECORATION_OVERLINE,
                          nsCSSRendering::DECORATION_STYLE_SOLID);
      }
    }

    aRenderingContext.SetFont(fontMet);

    CalculateUnderline(aRenderingContext);

    aRenderingContext.SetColor(aOverrideColor ? *aOverrideColor : GetStyleColor()->mColor);

#ifdef IBMBIDI
    nsresult rv = NS_ERROR_FAILURE;

    if (mState & NS_FRAME_IS_BIDI) {
//.........这里部分代码省略.........