C++ SVGInlineTextBox::measureCharacter方法代码示例

static float cummulatedWidthOrHeightOfTextChunk(SVGTextChunk& chunk, bool calcWidthOnly)
{
    float length = 0.0f;
    Vector<SVGChar>::iterator charIt = chunk.start;

    Vector<SVGInlineBoxCharacterRange>::iterator it = chunk.boxes.begin();
    Vector<SVGInlineBoxCharacterRange>::iterator end = chunk.boxes.end();

    for (; it != end; ++it) {
        SVGInlineBoxCharacterRange& range = *it;

        SVGInlineTextBox* box = static_cast<SVGInlineTextBox*>(range.box);
        RenderStyle* style = box->renderer()->style();

        for (int i = range.startOffset; i < range.endOffset; ++i) {
            ASSERT(charIt <= chunk.end);

            // Determine how many characters - starting from the current - can be measured at once.
            // Important for non-absolute positioned non-latin1 text (ie. Arabic) where ie. the width
            // of a string is not the sum of the boundaries of all contained glyphs.
            Vector<SVGChar>::iterator itSearch = charIt + 1;
            Vector<SVGChar>::iterator endSearch = charIt + range.endOffset - i;
            while (itSearch != endSearch) {
                // No need to check for 'isHidden()' here as this function is not called for text paths.
                if (itSearch->drawnSeperated)
                    break;

                itSearch++;
            }

            unsigned int positionOffset = itSearch - charIt;

            // Calculate width/height of subrange
            SVGInlineBoxCharacterRange subRange;
            subRange.box = range.box;
            subRange.startOffset = i;
            subRange.endOffset = i + positionOffset;

            if (calcWidthOnly)
                length += cummulatedWidthOfInlineBoxCharacterRange(subRange);
            else
                length += cummulatedHeightOfInlineBoxCharacterRange(subRange);

            // Calculate gap between the previous & current range
            // <text x="10 50 70">ABCD</text> - we need to take the gaps between A & B into account
            // so add "40" as width, and analogous for B & C, add "20" as width.
            if (itSearch > chunk.start && itSearch < chunk.end) {
                SVGChar& lastCharacter = *(itSearch - 1);
                SVGChar& currentCharacter = *itSearch;

                int charsConsumed = 0;
                float glyphWidth = 0.0f;
                float glyphHeight = 0.0f;
                String glyphName;
                String unicodeString;
                box->measureCharacter(style, i + positionOffset - 1, charsConsumed, glyphName, unicodeString, glyphWidth, glyphHeight);

                if (calcWidthOnly)
                    length += currentCharacter.x - lastCharacter.x - glyphWidth;
                else
                    length += currentCharacter.y - lastCharacter.y - glyphHeight;
            }

            // Advance processed characters
            i += positionOffset - 1;
            charIt = itSearch;
        }
    }

    ASSERT(charIt == chunk.end);
    return length;
}