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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2000 Dirk Mueller (mueller (at) kde.org)
      5  *           (C) 2006 Allan Sandfeld Jensen (kde (at) carewolf.com)
      6  *           (C) 2006 Samuel Weinig (sam.weinig (at) gmail.com)
      7  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
      8  * Copyright (C) 2010 Google Inc. All rights reserved.
      9  * Copyright (C) Research In Motion Limited 2011-2012. All rights reserved.
     10  *
     11  * This library is free software; you can redistribute it and/or
     12  * modify it under the terms of the GNU Library General Public
     13  * License as published by the Free Software Foundation; either
     14  * version 2 of the License, or (at your option) any later version.
     15  *
     16  * This library is distributed in the hope that it will be useful,
     17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     19  * Library General Public License for more details.
     20  *
     21  * You should have received a copy of the GNU Library General Public License
     22  * along with this library; see the file COPYING.LIB.  If not, write to
     23  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     24  * Boston, MA 02110-1301, USA.
     25  *
     26  */
     27 
     28 #include "config.h"
     29 #include "core/rendering/RenderImage.h"
     30 
     31 #include "HTMLNames.h"
     32 #include "core/editing/FrameSelection.h"
     33 #include "core/fetch/ImageResource.h"
     34 #include "core/fetch/ResourceLoadPriorityOptimizer.h"
     35 #include "core/fetch/ResourceLoader.h"
     36 #include "core/html/HTMLAreaElement.h"
     37 #include "core/html/HTMLImageElement.h"
     38 #include "core/html/HTMLInputElement.h"
     39 #include "core/html/HTMLMapElement.h"
     40 #include "core/inspector/InspectorInstrumentation.h"
     41 #include "core/frame/Frame.h"
     42 #include "core/rendering/HitTestResult.h"
     43 #include "core/rendering/LayoutRectRecorder.h"
     44 #include "core/rendering/PaintInfo.h"
     45 #include "core/rendering/RenderView.h"
     46 #include "core/svg/graphics/SVGImage.h"
     47 #include "platform/fonts/Font.h"
     48 #include "platform/fonts/FontCache.h"
     49 #include "platform/graphics/GraphicsContext.h"
     50 #include "platform/graphics/GraphicsContextStateSaver.h"
     51 
     52 using namespace std;
     53 
     54 namespace WebCore {
     55 
     56 using namespace HTMLNames;
     57 
     58 RenderImage::RenderImage(Element* element)
     59     : RenderReplaced(element, IntSize())
     60     , m_needsToSetSizeForAltText(false)
     61     , m_didIncrementVisuallyNonEmptyPixelCount(false)
     62     , m_isGeneratedContent(false)
     63     , m_imageDevicePixelRatio(1.0f)
     64 {
     65     updateAltText();
     66 }
     67 
     68 RenderImage* RenderImage::createAnonymous(Document* document)
     69 {
     70     RenderImage* image = new RenderImage(0);
     71     image->setDocumentForAnonymous(document);
     72     return image;
     73 }
     74 
     75 RenderImage::~RenderImage()
     76 {
     77     ASSERT(m_imageResource);
     78     m_imageResource->shutdown();
     79 }
     80 
     81 void RenderImage::setImageResource(PassOwnPtr<RenderImageResource> imageResource)
     82 {
     83     ASSERT(!m_imageResource);
     84     m_imageResource = imageResource;
     85     m_imageResource->initialize(this);
     86 }
     87 
     88 // If we'll be displaying either alt text or an image, add some padding.
     89 static const unsigned short paddingWidth = 4;
     90 static const unsigned short paddingHeight = 4;
     91 
     92 // Alt text is restricted to this maximum size, in pixels.  These are
     93 // signed integers because they are compared with other signed values.
     94 static const float maxAltTextWidth = 1024;
     95 static const int maxAltTextHeight = 256;
     96 
     97 IntSize RenderImage::imageSizeForError(ImageResource* newImage) const
     98 {
     99     ASSERT_ARG(newImage, newImage);
    100     ASSERT_ARG(newImage, newImage->imageForRenderer(this));
    101 
    102     IntSize imageSize;
    103     if (newImage->willPaintBrokenImage()) {
    104         float deviceScaleFactor = WebCore::deviceScaleFactor(frame());
    105         pair<Image*, float> brokenImageAndImageScaleFactor = ImageResource::brokenImage(deviceScaleFactor);
    106         imageSize = brokenImageAndImageScaleFactor.first->size();
    107         imageSize.scale(1 / brokenImageAndImageScaleFactor.second);
    108     } else
    109         imageSize = newImage->imageForRenderer(this)->size();
    110 
    111     // imageSize() returns 0 for the error image. We need the true size of the
    112     // error image, so we have to get it by grabbing image() directly.
    113     return IntSize(paddingWidth + imageSize.width() * style()->effectiveZoom(), paddingHeight + imageSize.height() * style()->effectiveZoom());
    114 }
    115 
    116 // Sets the image height and width to fit the alt text.  Returns true if the
    117 // image size changed.
    118 bool RenderImage::setImageSizeForAltText(ImageResource* newImage /* = 0 */)
    119 {
    120     IntSize imageSize;
    121     if (newImage && newImage->imageForRenderer(this))
    122         imageSize = imageSizeForError(newImage);
    123     else if (!m_altText.isEmpty() || newImage) {
    124         // If we'll be displaying either text or an image, add a little padding.
    125         imageSize = IntSize(paddingWidth, paddingHeight);
    126     }
    127 
    128     // we have an alt and the user meant it (its not a text we invented)
    129     if (!m_altText.isEmpty()) {
    130         FontCachePurgePreventer fontCachePurgePreventer;
    131 
    132         const Font& font = style()->font();
    133         IntSize paddedTextSize(paddingWidth + min(ceilf(font.width(RenderBlockFlow::constructTextRun(this, font, m_altText, style()))), maxAltTextWidth), paddingHeight + min(font.fontMetrics().height(), maxAltTextHeight));
    134         imageSize = imageSize.expandedTo(paddedTextSize);
    135     }
    136 
    137     if (imageSize == intrinsicSize())
    138         return false;
    139 
    140     setIntrinsicSize(imageSize);
    141     return true;
    142 }
    143 
    144 void RenderImage::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
    145 {
    146     RenderReplaced::styleDidChange(diff, oldStyle);
    147     if (m_needsToSetSizeForAltText) {
    148         if (!m_altText.isEmpty() && setImageSizeForAltText(m_imageResource->cachedImage()))
    149             imageDimensionsChanged(true /* imageSizeChanged */);
    150         m_needsToSetSizeForAltText = false;
    151     }
    152 }
    153 
    154 void RenderImage::imageChanged(WrappedImagePtr newImage, const IntRect* rect)
    155 {
    156     if (documentBeingDestroyed())
    157         return;
    158 
    159     if (hasBoxDecorations() || hasMask())
    160         RenderReplaced::imageChanged(newImage, rect);
    161 
    162     if (!m_imageResource)
    163         return;
    164 
    165     if (newImage != m_imageResource->imagePtr())
    166         return;
    167 
    168     // Per the spec, we let the server-sent header override srcset/other sources of dpr.
    169     // https://github.com/igrigorik/http-client-hints/blob/master/draft-grigorik-http-client-hints-01.txt#L255
    170     if (m_imageResource->cachedImage() && m_imageResource->cachedImage()->hasDevicePixelRatioHeaderValue())
    171         m_imageDevicePixelRatio = 1 / m_imageResource->cachedImage()->devicePixelRatioHeaderValue();
    172 
    173     if (!m_didIncrementVisuallyNonEmptyPixelCount) {
    174         // At a zoom level of 1 the image is guaranteed to have an integer size.
    175         view()->frameView()->incrementVisuallyNonEmptyPixelCount(flooredIntSize(m_imageResource->imageSize(1.0f)));
    176         m_didIncrementVisuallyNonEmptyPixelCount = true;
    177     }
    178 
    179     bool imageSizeChanged = false;
    180 
    181     // Set image dimensions, taking into account the size of the alt text.
    182     if (m_imageResource->errorOccurred() || !newImage) {
    183         if (!m_altText.isEmpty() && document().hasPendingStyleRecalc()) {
    184             ASSERT(node());
    185             if (node()) {
    186                 m_needsToSetSizeForAltText = true;
    187                 node()->setNeedsStyleRecalc(LocalStyleChange, StyleChangeFromRenderer);
    188             }
    189             return;
    190         }
    191         imageSizeChanged = setImageSizeForAltText(m_imageResource->cachedImage());
    192     }
    193 
    194     imageDimensionsChanged(imageSizeChanged, rect);
    195 }
    196 
    197 bool RenderImage::updateIntrinsicSizeIfNeeded(const LayoutSize& newSize, bool imageSizeChanged)
    198 {
    199     if (newSize == intrinsicSize() && !imageSizeChanged)
    200         return false;
    201     if (m_imageResource->errorOccurred() || !m_imageResource->hasImage())
    202         return imageSizeChanged;
    203     setIntrinsicSize(newSize);
    204     return true;
    205 }
    206 
    207 void RenderImage::updateInnerContentRect()
    208 {
    209     // Propagate container size to the image resource.
    210     LayoutRect containerRect = replacedContentRect();
    211     IntSize containerSize(containerRect.width(), containerRect.height());
    212     if (!containerSize.isEmpty())
    213         m_imageResource->setContainerSizeForRenderer(containerSize);
    214 }
    215 
    216 void RenderImage::imageDimensionsChanged(bool imageSizeChanged, const IntRect* rect)
    217 {
    218     bool intrinsicSizeChanged = updateIntrinsicSizeIfNeeded(m_imageResource->intrinsicSize(style()->effectiveZoom()), imageSizeChanged);
    219 
    220     // In the case of generated image content using :before/:after/content, we might not be
    221     // in the render tree yet. In that case, we just need to update our intrinsic size.
    222     // layout() will be called after we are inserted in the tree which will take care of
    223     // what we are doing here.
    224     if (!containingBlock())
    225         return;
    226 
    227     bool shouldRepaint = true;
    228     if (intrinsicSizeChanged) {
    229         if (!preferredLogicalWidthsDirty())
    230             setPreferredLogicalWidthsDirty();
    231 
    232         bool hasOverrideSize = hasOverrideHeight() || hasOverrideWidth();
    233         if (!hasOverrideSize && !imageSizeChanged) {
    234             LogicalExtentComputedValues computedValues;
    235             computeLogicalWidthInRegion(computedValues);
    236             LayoutUnit newWidth = computedValues.m_extent;
    237             computeLogicalHeight(height(), 0, computedValues);
    238             LayoutUnit newHeight = computedValues.m_extent;
    239 
    240             imageSizeChanged = width() != newWidth || height() != newHeight;
    241         }
    242 
    243         // FIXME: We only need to recompute the containing block's preferred size
    244         // if the containing block's size depends on the image's size (i.e., the container uses shrink-to-fit sizing).
    245         // There's no easy way to detect that shrink-to-fit is needed, always force a layout.
    246         bool containingBlockNeedsToRecomputePreferredSize =
    247             style()->logicalWidth().isPercent()
    248             || style()->logicalMaxWidth().isPercent()
    249             || style()->logicalMinWidth().isPercent();
    250 
    251         if (imageSizeChanged || hasOverrideSize || containingBlockNeedsToRecomputePreferredSize) {
    252             shouldRepaint = false;
    253             if (!selfNeedsLayout())
    254                 setNeedsLayout();
    255         }
    256     }
    257 
    258     if (everHadLayout() && !selfNeedsLayout()) {
    259         // The inner content rectangle is calculated during layout, but may need an update now
    260         // (unless the box has already been scheduled for layout). In order to calculate it, we
    261         // may need values from the containing block, though, so make sure that we're not too
    262         // early. It may be that layout hasn't even taken place once yet.
    263         updateInnerContentRect();
    264     }
    265 
    266     if (shouldRepaint) {
    267         LayoutRect repaintRect;
    268         if (rect) {
    269             // The image changed rect is in source image coordinates (pre-zooming),
    270             // so map from the bounds of the image to the contentsBox.
    271             repaintRect = enclosingIntRect(mapRect(*rect, FloatRect(FloatPoint(), m_imageResource->imageSize(1.0f)), contentBoxRect()));
    272             // Guard against too-large changed rects.
    273             repaintRect.intersect(contentBoxRect());
    274         } else
    275             repaintRect = contentBoxRect();
    276 
    277         repaintRectangle(repaintRect);
    278 
    279         // Tell any potential compositing layers that the image needs updating.
    280         contentChanged(ImageChanged);
    281     }
    282 }
    283 
    284 void RenderImage::notifyFinished(Resource* newImage)
    285 {
    286     if (!m_imageResource)
    287         return;
    288 
    289     if (documentBeingDestroyed())
    290         return;
    291 
    292     invalidateBackgroundObscurationStatus();
    293 
    294     if (newImage == m_imageResource->cachedImage()) {
    295         // tell any potential compositing layers
    296         // that the image is done and they can reference it directly.
    297         contentChanged(ImageChanged);
    298     }
    299 }
    300 
    301 void RenderImage::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
    302 {
    303     LayoutUnit cWidth = contentWidth();
    304     LayoutUnit cHeight = contentHeight();
    305     LayoutUnit leftBorder = borderLeft();
    306     LayoutUnit topBorder = borderTop();
    307     LayoutUnit leftPad = paddingLeft();
    308     LayoutUnit topPad = paddingTop();
    309 
    310     GraphicsContext* context = paintInfo.context;
    311 
    312     if (!m_imageResource->hasImage() || m_imageResource->errorOccurred()) {
    313         if (paintInfo.phase == PaintPhaseSelection)
    314             return;
    315 
    316         if (cWidth > 2 && cHeight > 2) {
    317             const int borderWidth = 1;
    318 
    319             // Draw an outline rect where the image should be.
    320             context->setStrokeStyle(SolidStroke);
    321             context->setStrokeColor(Color::lightGray);
    322             context->setFillColor(Color::transparent);
    323             context->drawRect(pixelSnappedIntRect(LayoutRect(paintOffset.x() + leftBorder + leftPad, paintOffset.y() + topBorder + topPad, cWidth, cHeight)));
    324 
    325             bool errorPictureDrawn = false;
    326             LayoutSize imageOffset;
    327             // When calculating the usable dimensions, exclude the pixels of
    328             // the ouline rect so the error image/alt text doesn't draw on it.
    329             LayoutUnit usableWidth = cWidth - 2 * borderWidth;
    330             LayoutUnit usableHeight = cHeight - 2 * borderWidth;
    331 
    332             RefPtr<Image> image = m_imageResource->image();
    333 
    334             if (m_imageResource->errorOccurred() && !image->isNull() && usableWidth >= image->width() && usableHeight >= image->height()) {
    335                 float deviceScaleFactor = WebCore::deviceScaleFactor(frame());
    336                 // Call brokenImage() explicitly to ensure we get the broken image icon at the appropriate resolution.
    337                 pair<Image*, float> brokenImageAndImageScaleFactor = ImageResource::brokenImage(deviceScaleFactor);
    338                 image = brokenImageAndImageScaleFactor.first;
    339                 IntSize imageSize = image->size();
    340                 imageSize.scale(1 / brokenImageAndImageScaleFactor.second);
    341                 // Center the error image, accounting for border and padding.
    342                 LayoutUnit centerX = (usableWidth - imageSize.width()) / 2;
    343                 if (centerX < 0)
    344                     centerX = 0;
    345                 LayoutUnit centerY = (usableHeight - imageSize.height()) / 2;
    346                 if (centerY < 0)
    347                     centerY = 0;
    348                 imageOffset = LayoutSize(leftBorder + leftPad + centerX + borderWidth, topBorder + topPad + centerY + borderWidth);
    349                 context->drawImage(image.get(), pixelSnappedIntRect(LayoutRect(paintOffset + imageOffset, imageSize)), CompositeSourceOver, shouldRespectImageOrientation());
    350                 errorPictureDrawn = true;
    351             }
    352 
    353             if (!m_altText.isEmpty()) {
    354                 const Font& font = style()->font();
    355                 const FontMetrics& fontMetrics = font.fontMetrics();
    356                 LayoutUnit ascent = fontMetrics.ascent();
    357                 LayoutPoint textRectOrigin = paintOffset;
    358                 textRectOrigin.move(leftBorder + leftPad + (paddingWidth / 2) - borderWidth, topBorder + topPad + (paddingHeight / 2) - borderWidth);
    359                 LayoutPoint textOrigin(textRectOrigin.x(), textRectOrigin.y() + ascent);
    360 
    361                 // Only draw the alt text if it'll fit within the content box,
    362                 // and only if it fits above the error image.
    363                 TextRun textRun = RenderBlockFlow::constructTextRun(this, font, m_altText, style(), TextRun::AllowTrailingExpansion | TextRun::ForbidLeadingExpansion, DefaultTextRunFlags | RespectDirection);
    364                 LayoutUnit textWidth = font.width(textRun);
    365                 TextRunPaintInfo textRunPaintInfo(textRun);
    366                 textRunPaintInfo.bounds = FloatRect(textRectOrigin, FloatSize(textWidth, fontMetrics.height()));
    367                 context->setFillColor(resolveColor(CSSPropertyColor));
    368                 if (errorPictureDrawn) {
    369                     if (usableWidth >= textWidth && fontMetrics.height() <= imageOffset.height())
    370                         context->drawText(font, textRunPaintInfo, textOrigin);
    371                 } else if (usableWidth >= textWidth && usableHeight >= fontMetrics.height())
    372                     context->drawText(font, textRunPaintInfo, textOrigin);
    373             }
    374         }
    375     } else if (m_imageResource->hasImage() && cWidth > 0 && cHeight > 0) {
    376         RefPtr<Image> img = m_imageResource->image(cWidth, cHeight);
    377         if (!img || img->isNull())
    378             return;
    379 
    380         LayoutRect contentRect = contentBoxRect();
    381         contentRect.moveBy(paintOffset);
    382         LayoutRect paintRect = replacedContentRect();
    383         paintRect.moveBy(paintOffset);
    384         bool clip = !contentRect.contains(paintRect);
    385         if (clip) {
    386             context->save();
    387             context->clip(contentRect);
    388         }
    389 
    390         paintIntoRect(context, paintRect);
    391 
    392         if (clip)
    393             context->restore();
    394     }
    395 }
    396 
    397 void RenderImage::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
    398 {
    399     RenderReplaced::paint(paintInfo, paintOffset);
    400 
    401     if (paintInfo.phase == PaintPhaseOutline)
    402         paintAreaElementFocusRing(paintInfo);
    403 }
    404 
    405 void RenderImage::paintAreaElementFocusRing(PaintInfo& paintInfo)
    406 {
    407     Document& document = this->document();
    408 
    409     if (document.printing() || !document.frame()->selection().isFocusedAndActive())
    410         return;
    411 
    412     if (paintInfo.context->paintingDisabled() && !paintInfo.context->updatingControlTints())
    413         return;
    414 
    415     Element* focusedElement = document.focusedElement();
    416     if (!focusedElement || !isHTMLAreaElement(focusedElement))
    417         return;
    418 
    419     HTMLAreaElement* areaElement = toHTMLAreaElement(focusedElement);
    420     if (areaElement->imageElement() != node())
    421         return;
    422 
    423     // Even if the theme handles focus ring drawing for entire elements, it won't do it for
    424     // an area within an image, so we don't call RenderTheme::supportsFocusRing here.
    425 
    426     Path path = areaElement->computePath(this);
    427     if (path.isEmpty())
    428         return;
    429 
    430     RenderStyle* areaElementStyle = areaElement->computedStyle();
    431     unsigned short outlineWidth = areaElementStyle->outlineWidth();
    432     if (!outlineWidth)
    433         return;
    434 
    435     // FIXME: Clip path instead of context when Skia pathops is ready.
    436     // https://crbug.com/251206
    437     GraphicsContextStateSaver savedContext(*paintInfo.context);
    438     paintInfo.context->clip(absoluteContentBox());
    439     paintInfo.context->drawFocusRing(path, outlineWidth,
    440         areaElementStyle->outlineOffset(),
    441         resolveColor(areaElementStyle, CSSPropertyOutlineColor));
    442 }
    443 
    444 void RenderImage::areaElementFocusChanged(HTMLAreaElement* areaElement)
    445 {
    446     ASSERT(areaElement->imageElement() == node());
    447 
    448     Path path = areaElement->computePath(this);
    449     if (path.isEmpty())
    450         return;
    451 
    452     RenderStyle* areaElementStyle = areaElement->computedStyle();
    453     unsigned short outlineWidth = areaElementStyle->outlineWidth();
    454 
    455     IntRect repaintRect = enclosingIntRect(path.boundingRect());
    456     repaintRect.moveBy(-absoluteContentBox().location());
    457     repaintRect.inflate(outlineWidth);
    458 
    459     repaintRectangle(repaintRect);
    460 }
    461 
    462 void RenderImage::paintIntoRect(GraphicsContext* context, const LayoutRect& rect)
    463 {
    464     IntRect alignedRect = pixelSnappedIntRect(rect);
    465     if (!m_imageResource->hasImage() || m_imageResource->errorOccurred() || alignedRect.width() <= 0 || alignedRect.height() <= 0)
    466         return;
    467 
    468     RefPtr<Image> img = m_imageResource->image(alignedRect.width(), alignedRect.height());
    469     if (!img || img->isNull())
    470         return;
    471 
    472     HTMLImageElement* imageElt = (node() && node()->hasTagName(imgTag)) ? toHTMLImageElement(node()) : 0;
    473     CompositeOperator compositeOperator = imageElt ? imageElt->compositeOperator() : CompositeSourceOver;
    474     Image* image = m_imageResource->image().get();
    475     bool useLowQualityScaling = shouldPaintAtLowQuality(context, image, image, alignedRect.size());
    476 
    477     InspectorInstrumentation::willPaintImage(this);
    478     context->drawImage(m_imageResource->image(alignedRect.width(), alignedRect.height()).get(), alignedRect, compositeOperator, shouldRespectImageOrientation(), useLowQualityScaling);
    479     InspectorInstrumentation::didPaintImage(this);
    480 }
    481 
    482 bool RenderImage::boxShadowShouldBeAppliedToBackground(BackgroundBleedAvoidance bleedAvoidance, InlineFlowBox*) const
    483 {
    484     if (!RenderBoxModelObject::boxShadowShouldBeAppliedToBackground(bleedAvoidance))
    485         return false;
    486 
    487     return !const_cast<RenderImage*>(this)->backgroundIsKnownToBeObscured();
    488 }
    489 
    490 bool RenderImage::foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, unsigned) const
    491 {
    492     if (!m_imageResource->hasImage() || m_imageResource->errorOccurred())
    493         return false;
    494     if (m_imageResource->cachedImage() && !m_imageResource->cachedImage()->isLoaded())
    495         return false;
    496     if (!contentBoxRect().contains(localRect))
    497         return false;
    498     EFillBox backgroundClip = style()->backgroundClip();
    499     // Background paints under borders.
    500     if (backgroundClip == BorderFillBox && style()->hasBorder() && !borderObscuresBackground())
    501         return false;
    502     // Background shows in padding area.
    503     if ((backgroundClip == BorderFillBox || backgroundClip == PaddingFillBox) && style()->hasPadding())
    504         return false;
    505     // Object-position may leave parts of the content box empty, regardless of the value of object-fit.
    506     if (style()->objectPosition() != RenderStyle::initialObjectPosition())
    507         return false;
    508     // Object-fit may leave parts of the content box empty.
    509     ObjectFit objectFit = style()->objectFit();
    510     if (objectFit != ObjectFitFill && objectFit != ObjectFitCover)
    511         return false;
    512     // Check for image with alpha.
    513     return m_imageResource->cachedImage() && m_imageResource->cachedImage()->currentFrameKnownToBeOpaque(this);
    514 }
    515 
    516 bool RenderImage::computeBackgroundIsKnownToBeObscured()
    517 {
    518     if (!hasBackground())
    519         return false;
    520     return foregroundIsKnownToBeOpaqueInRect(backgroundPaintedExtent(), 0);
    521 }
    522 
    523 LayoutUnit RenderImage::minimumReplacedHeight() const
    524 {
    525     return m_imageResource->errorOccurred() ? intrinsicSize().height() : LayoutUnit();
    526 }
    527 
    528 HTMLMapElement* RenderImage::imageMap() const
    529 {
    530     HTMLImageElement* i = node() && node()->hasTagName(imgTag) ? toHTMLImageElement(node()) : 0;
    531     return i ? i->treeScope().getImageMap(i->fastGetAttribute(usemapAttr)) : 0;
    532 }
    533 
    534 bool RenderImage::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction hitTestAction)
    535 {
    536     HitTestResult tempResult(result.hitTestLocation());
    537     bool inside = RenderReplaced::nodeAtPoint(request, tempResult, locationInContainer, accumulatedOffset, hitTestAction);
    538 
    539     if (tempResult.innerNode() && node()) {
    540         if (HTMLMapElement* map = imageMap()) {
    541             LayoutRect contentBox = contentBoxRect();
    542             float scaleFactor = 1 / style()->effectiveZoom();
    543             LayoutPoint mapLocation = locationInContainer.point() - toLayoutSize(accumulatedOffset) - locationOffset() - toLayoutSize(contentBox.location());
    544             mapLocation.scale(scaleFactor, scaleFactor);
    545 
    546             if (map->mapMouseEvent(mapLocation, contentBox.size(), tempResult))
    547                 tempResult.setInnerNonSharedNode(node());
    548         }
    549     }
    550 
    551     if (!inside && result.isRectBasedTest())
    552         result.append(tempResult);
    553     if (inside)
    554         result = tempResult;
    555     return inside;
    556 }
    557 
    558 void RenderImage::updateAltText()
    559 {
    560     if (!node())
    561         return;
    562 
    563     if (node()->hasTagName(inputTag))
    564         m_altText = toHTMLInputElement(node())->altText();
    565     else if (node()->hasTagName(imgTag))
    566         m_altText = toHTMLImageElement(node())->altText();
    567 }
    568 
    569 void RenderImage::layout()
    570 {
    571     LayoutRectRecorder recorder(*this);
    572     RenderReplaced::layout();
    573     updateInnerContentRect();
    574 }
    575 
    576 void RenderImage::didLayout(ResourceLoadPriorityOptimizer& optimizer)
    577 {
    578     RenderReplaced::didLayout(optimizer);
    579     updateImageLoadingPriority(optimizer);
    580 }
    581 
    582 void RenderImage::didScroll(ResourceLoadPriorityOptimizer& optimizer)
    583 {
    584     RenderReplaced::didScroll(optimizer);
    585     updateImageLoadingPriority(optimizer);
    586 }
    587 
    588 void RenderImage::updateImageLoadingPriority(ResourceLoadPriorityOptimizer& optimizer)
    589 {
    590     if (!m_imageResource || !m_imageResource->cachedImage() || m_imageResource->cachedImage()->isLoaded())
    591         return;
    592 
    593     LayoutRect viewBounds = viewRect();
    594     LayoutRect objectBounds = absoluteContentBox();
    595 
    596     // The object bounds might be empty right now, so intersects will fail since it doesn't deal
    597     // with empty rects. Use LayoutRect::contains in that case.
    598     bool isVisible;
    599     if (!objectBounds.isEmpty())
    600         isVisible =  viewBounds.intersects(objectBounds);
    601     else
    602         isVisible = viewBounds.contains(objectBounds);
    603 
    604     ResourceLoadPriorityOptimizer::VisibilityStatus status = isVisible ?
    605         ResourceLoadPriorityOptimizer::Visible : ResourceLoadPriorityOptimizer::NotVisible;
    606 
    607     optimizer.notifyImageResourceVisibility(m_imageResource->cachedImage(), status);
    608 }
    609 
    610 void RenderImage::computeIntrinsicRatioInformation(FloatSize& intrinsicSize, double& intrinsicRatio, bool& isPercentageIntrinsicSize) const
    611 {
    612     RenderReplaced::computeIntrinsicRatioInformation(intrinsicSize, intrinsicRatio, isPercentageIntrinsicSize);
    613 
    614     // Our intrinsicSize is empty if we're rendering generated images with relative width/height. Figure out the right intrinsic size to use.
    615     if (intrinsicSize.isEmpty() && (m_imageResource->imageHasRelativeWidth() || m_imageResource->imageHasRelativeHeight())) {
    616         RenderObject* containingBlock = isOutOfFlowPositioned() ? container() : this->containingBlock();
    617         if (containingBlock->isBox()) {
    618             RenderBox* box = toRenderBox(containingBlock);
    619             intrinsicSize.setWidth(box->availableLogicalWidth());
    620             intrinsicSize.setHeight(box->availableLogicalHeight(IncludeMarginBorderPadding));
    621         }
    622     }
    623     // Don't compute an intrinsic ratio to preserve historical WebKit behavior if we're painting alt text and/or a broken image.
    624     // Video is excluded from this behavior because video elements have a default aspect ratio that a failed poster image load should not override.
    625     if (m_imageResource && m_imageResource->errorOccurred() && !isVideo()) {
    626         intrinsicRatio = 1;
    627         return;
    628     }
    629 }
    630 
    631 bool RenderImage::needsPreferredWidthsRecalculation() const
    632 {
    633     if (RenderReplaced::needsPreferredWidthsRecalculation())
    634         return true;
    635     return embeddedContentBox();
    636 }
    637 
    638 RenderBox* RenderImage::embeddedContentBox() const
    639 {
    640     if (!m_imageResource)
    641         return 0;
    642 
    643     ImageResource* cachedImage = m_imageResource->cachedImage();
    644     if (cachedImage && cachedImage->image() && cachedImage->image()->isSVGImage())
    645         return toSVGImage(cachedImage->image())->embeddedContentBox();
    646 
    647     return 0;
    648 }
    649 
    650 } // namespace WebCore
    651