renderimage.cpp

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            if (imageSizeChanged || width() != oldwidth || height() != oldheight) {
                shouldRepaint = false;
                if (!selfNeedsLayout())
                    setNeedsLayout(true);
            }

            setWidth(oldwidth);
            setHeight(oldheight);
        }
    }

    if (shouldRepaint) {
        IntRect repaintRect;
        if (rect) {
            // The image changed rect is in source image coordinates (pre-zooming),
            // so map from the bounds of the image to the contentsBox.
            repaintRect = enclosingIntRect(mapRect(*rect, FloatRect(FloatPoint(), imageSize(1.0f)), contentBoxRect()));
            // Guard against too-large changed rects.
            repaintRect.intersect(contentBoxRect());
        } else
            repaintRect = contentBoxRect();
        
        repaintRectangle(repaintRect);
    }
}

void RenderImage::resetAnimation()
{
    if (m_cachedImage) {
        image()->resetAnimation();
        if (!needsLayout())
            repaint();
    }
}

void RenderImage::paintReplaced(PaintInfo& paintInfo, int tx, int ty)
{
    int cWidth = contentWidth();
    int cHeight = contentHeight();
    int leftBorder = borderLeft();
    int topBorder = borderTop();
    int leftPad = paddingLeft();
    int topPad = paddingTop();

    if (document()->printing() && !view()->printImages())
        return;

    GraphicsContext* context = paintInfo.context;

    if (!hasImage() || errorOccurred()) {
        if (paintInfo.phase == PaintPhaseSelection)
            return;

        if (cWidth > 2 && cHeight > 2) {
            // Draw an outline rect where the image should be.
            context->setStrokeStyle(SolidStroke);
            context->setStrokeColor(Color::lightGray);
            context->setFillColor(Color::transparent);
            context->drawRect(IntRect(tx + leftBorder + leftPad, ty + topBorder + topPad, cWidth, cHeight));

            bool errorPictureDrawn = false;
            int imageX = 0;
            int imageY = 0;
            // When calculating the usable dimensions, exclude the pixels of
            // the ouline rect so the error image/alt text doesn't draw on it.
            int usableWidth = cWidth - 2;
            int usableHeight = cHeight - 2;

            if (errorOccurred() && !image()->isNull() && (usableWidth >= image()->width()) && (usableHeight >= image()->height())) {
                // Center the error image, accounting for border and padding.
                int centerX = (usableWidth - image()->width()) / 2;
                if (centerX < 0)
                    centerX = 0;
                int centerY = (usableHeight - image()->height()) / 2;
                if (centerY < 0)
                    centerY = 0;
                imageX = leftBorder + leftPad + centerX + 1;
                imageY = topBorder + topPad + centerY + 1;
                context->drawImage(image(), IntPoint(tx + imageX, ty + imageY));
                errorPictureDrawn = true;
            }

            if (!m_altText.isEmpty()) {
                String text = document()->displayStringModifiedByEncoding(m_altText);
                context->setFillColor(style()->color());
                int ax = tx + leftBorder + leftPad;
                int ay = ty + topBorder + topPad;
                const Font& font = style()->font();
                int ascent = font.ascent();

                // Only draw the alt text if it'll fit within the content box,
                // and only if it fits above the error image.
                TextRun textRun(text.characters(), text.length());
                int textWidth = font.width(textRun);
                if (errorPictureDrawn) {
                    if (usableWidth >= textWidth && font.height() <= imageY)
                        context->drawText(style()->font(), textRun, IntPoint(ax, ay + ascent));
                } else if (usableWidth >= textWidth && cHeight >= font.height())
                    context->drawText(style()->font(), textRun, IntPoint(ax, ay + ascent));
            }
        }
    } else if (hasImage() && cWidth > 0 && cHeight > 0) {
        Image* img = image(cWidth, cHeight);
        if (!img || img->isNull())
            return;

#if PLATFORM(MAC)
        if (style()->highlight() != nullAtom && !paintInfo.context->paintingDisabled())
            paintCustomHighlight(tx - x(), ty - y(), style()->highlight(), true);
#endif

        IntSize contentSize(cWidth, cHeight);
        bool useLowQualityScaling = RenderImageScaleObserver::shouldImagePaintAtLowQuality(this, contentSize);
        IntRect rect(IntPoint(tx + leftBorder + leftPad, ty + topBorder + topPad), contentSize);
        HTMLImageElement* imageElt = (node() && node()->hasTagName(imgTag)) ? static_cast<HTMLImageElement*>(node()) : 0;
        CompositeOperator compositeOperator = imageElt ? imageElt->compositeOperator() : CompositeSourceOver;
        context->drawImage(image(cWidth, cHeight), rect, compositeOperator, useLowQualityScaling);
    }
}

int RenderImage::minimumReplacedHeight() const
{
    return errorOccurred() ? intrinsicSize().height() : 0;
}

HTMLMapElement* RenderImage::imageMap()
{
    HTMLImageElement* i = node() && node()->hasTagName(imgTag) ? static_cast<HTMLImageElement*>(node()) : 0;
    return i ? i->document()->getImageMap(i->useMap()) : 0;
}

bool RenderImage::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int _x, int _y, int _tx, int _ty, HitTestAction hitTestAction)
{
    bool inside = RenderReplaced::nodeAtPoint(request, result, _x, _y, _tx, _ty, hitTestAction);

    if (inside && node()) {
        int tx = _tx + x();
        int ty = _ty + y();
        
        HTMLMapElement* map = imageMap();
        if (map) {
            // we're a client side image map
            inside = map->mapMouseEvent(_x - tx, _y - ty, IntSize(contentWidth(), contentHeight()), result);
            result.setInnerNonSharedNode(node());
        }
    }

    return inside;
}

void RenderImage::updateAltText()
{
    if (!node())
        return;

    if (node()->hasTagName(inputTag))
        m_altText = static_cast<HTMLInputElement*>(node())->altText();
    else if (node()->hasTagName(imgTag))
        m_altText = static_cast<HTMLImageElement*>(node())->altText();
#if ENABLE(WML)
    else if (node()->hasTagName(WMLNames::imgTag))
        m_altText = static_cast<WMLImageElement*>(node())->altText();
#endif
}

bool RenderImage::isWidthSpecified() const
{
    switch (style()->width().type()) {
        case Fixed:
        case Percent:
            return true;
        case Auto:
        case Relative: // FIXME: Shouldn't this case return true?
        case Static:
        case Intrinsic:
        case MinIntrinsic:
            return false;
    }
    ASSERT(false);
    return false;
}

bool RenderImage::isHeightSpecified() const
{
    switch (style()->height().type()) {
        case Fixed:
        case Percent:
            return true;
        case Auto:
        case Relative: // FIXME: Shouldn't this case return true?
        case Static:
        case Intrinsic:
        case MinIntrinsic:
            return false;
    }
    ASSERT(false);
    return false;
}

int RenderImage::calcReplacedWidth(bool includeMaxWidth) const
{
    if (imageHasRelativeWidth())
        if (RenderObject* cb = isPositioned() ? container() : containingBlock()) {
            if (cb->isBox())
                setImageContainerSize(IntSize(toRenderBox(cb)->availableWidth(), toRenderBox(cb)->availableHeight()));
        }

    int width;
    if (isWidthSpecified())
        width = calcReplacedWidthUsing(style()->width());
    else if (usesImageContainerSize())
        width = imageSize(style()->effectiveZoom()).width();
    else if (imageHasRelativeWidth())
        width = 0; // If the image is relatively-sized, set the width to 0 until there is a set container size.
    else
        width = calcAspectRatioWidth();

    int minW = calcReplacedWidthUsing(style()->minWidth());
    int maxW = !includeMaxWidth || style()->maxWidth().isUndefined() ? width : calcReplacedWidthUsing(style()->maxWidth());

    return max(minW, min(width, maxW));
}

int RenderImage::calcReplacedHeight() const
{
    int height;
    if (isHeightSpecified())
        height = calcReplacedHeightUsing(style()->height());
    else if (usesImageContainerSize())
        height = imageSize(style()->effectiveZoom()).height();
    else if (imageHasRelativeHeight())
        height = 0; // If the image is relatively-sized, set the height to 0 until there is a set container size.
    else
        height = calcAspectRatioHeight();

    int minH = calcReplacedHeightUsing(style()->minHeight());
    int maxH = style()->maxHeight().isUndefined() ? height : calcReplacedHeightUsing(style()->maxHeight());

    return max(minH, min(height, maxH));
}

int RenderImage::calcAspectRatioWidth() const
{
    IntSize size = intrinsicSize();
    if (!size.height())
        return 0;
    if (!hasImage() || errorOccurred())
        return size.width(); // Don't bother scaling.
    return RenderReplaced::calcReplacedHeight() * size.width() / size.height();
}

int RenderImage::calcAspectRatioHeight() const
{
    IntSize size = intrinsicSize();
    if (!size.width())
        return 0;
    if (!hasImage() || errorOccurred())
        return size.height(); // Don't bother scaling.
    return RenderReplaced::calcReplacedWidth() * size.height() / size.width();
}

void RenderImage::calcPrefWidths()
{
    ASSERT(prefWidthsDirty());

    int paddingAndBorders = paddingLeft() + paddingRight() + borderLeft() + borderRight();
    m_maxPrefWidth = calcReplacedWidth(false) + paddingAndBorders;

    if (style()->maxWidth().isFixed() && style()->maxWidth().value() != undefinedLength)
        m_maxPrefWidth = min(m_maxPrefWidth, style()->maxWidth().value() + (style()->boxSizing() == CONTENT_BOX ? paddingAndBorders : 0));

    if (style()->width().isPercent() || style()->height().isPercent() || 
        style()->maxWidth().isPercent() || style()->maxHeight().isPercent() ||
        style()->minWidth().isPercent() || style()->minHeight().isPercent())
        m_minPrefWidth = 0;
    else
        m_minPrefWidth = m_maxPrefWidth;

    setPrefWidthsDirty(false);
}

Image* RenderImage::nullImage()
{
    return Image::nullImage();
}

} // namespace WebCore