src/third_party/WebKit/Source/core/rendering/RenderImage.cpp

   1 /*
   2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
   3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
   4  *           (C) 2000 Dirk Mueller (mueller@kde.org)
   5  *           (C) 2006 Allan Sandfeld Jensen (kde@carewolf.com)
   6  *           (C) 2006 Samuel Weinig (sam.weinig@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_didIncrementVisuallyNonEmptyPixelCount(false)
  61     , m_isGeneratedContent(false)
  62     , m_imageDevicePixelRatio(1.0f)
  63 {
  64     updateAltText();
  65     ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()->addRenderObject(this);
  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 }
 148
 149 void RenderImage::imageChanged(WrappedImagePtr newImage, const IntRect* rect)
 150 {
 151     if (documentBeingDestroyed())
 152         return;
 153
 154     if (hasBoxDecorations() || hasMask())
 155         RenderReplaced::imageChanged(newImage, rect);
 156
 157     if (!m_imageResource)
 158         return;
 159
 160     if (newImage != m_imageResource->imagePtr())
 161         return;
 162
 163     // Per the spec, we let the server-sent header override srcset/other sources of dpr.
 164     // https://github.com/igrigorik/http-client-hints/blob/master/draft-grigorik-http-client-hints-01.txt#L255
 165     if (m_imageResource->cachedImage() && m_imageResource->cachedImage()->hasDevicePixelRatioHeaderValue())
 166         m_imageDevicePixelRatio = 1 / m_imageResource->cachedImage()->devicePixelRatioHeaderValue();
 167
 168     if (!m_didIncrementVisuallyNonEmptyPixelCount) {
 169         // At a zoom level of 1 the image is guaranteed to have an integer size.
 170         view()->frameView()->incrementVisuallyNonEmptyPixelCount(flooredIntSize(m_imageResource->imageSize(1.0f)));
 171         m_didIncrementVisuallyNonEmptyPixelCount = true;
 172     }
 173
 174     bool imageSizeChanged = false;
 175
 176     // Set image dimensions, taking into account the size of the alt text.
 177     if (m_imageResource->errorOccurred() || !newImage)
 178         imageSizeChanged = setImageSizeForAltText(m_imageResource->cachedImage());
 179
 180     imageDimensionsChanged(imageSizeChanged, rect);
 181 }
 182
 183 bool RenderImage::updateIntrinsicSizeIfNeeded(const LayoutSize& newSize, bool imageSizeChanged)
 184 {
 185     if (newSize == intrinsicSize() && !imageSizeChanged)
 186         return false;
 187     if (m_imageResource->errorOccurred() || !m_imageResource->hasImage())
 188         return imageSizeChanged;
 189     setIntrinsicSize(newSize);
 190     return true;
 191 }
 192
 193 void RenderImage::updateInnerContentRect()
 194 {
 195     // Propagate container size to the image resource.
 196     LayoutRect containerRect = replacedContentRect();
 197     IntSize containerSize(containerRect.width(), containerRect.height());
 198     if (!containerSize.isEmpty())
 199         m_imageResource->setContainerSizeForRenderer(containerSize);
 200 }
 201
 202 void RenderImage::imageDimensionsChanged(bool imageSizeChanged, const IntRect* rect)
 203 {
 204     bool intrinsicSizeChanged = updateIntrinsicSizeIfNeeded(m_imageResource->intrinsicSize(style()->effectiveZoom()), imageSizeChanged);
 205
 206     // In the case of generated image content using :before/:after/content, we might not be
 207     // in the render tree yet. In that case, we just need to update our intrinsic size.
 208     // layout() will be called after we are inserted in the tree which will take care of
 209     // what we are doing here.
 210     if (!containingBlock())
 211         return;
 212
 213     bool shouldRepaint = true;
 214     if (intrinsicSizeChanged) {
 215         if (!preferredLogicalWidthsDirty())
 216             setPreferredLogicalWidthsDirty();
 217
 218         bool hasOverrideSize = hasOverrideHeight() || hasOverrideWidth();
 219         if (!hasOverrideSize && !imageSizeChanged) {
 220             LogicalExtentComputedValues computedValues;
 221             computeLogicalWidth(computedValues);
 222             LayoutUnit newWidth = computedValues.m_extent;
 223             computeLogicalHeight(height(), 0, computedValues);
 224             LayoutUnit newHeight = computedValues.m_extent;
 225
 226             imageSizeChanged = width() != newWidth || height() != newHeight;
 227         }
 228
 229         // FIXME: We only need to recompute the containing block's preferred size
 230         // if the containing block's size depends on the image's size (i.e., the container uses shrink-to-fit sizing).
 231         // There's no easy way to detect that shrink-to-fit is needed, always force a layout.
 232         bool containingBlockNeedsToRecomputePreferredSize =
 233             style()->logicalWidth().isPercent()
 234             || style()->logicalMaxWidth().isPercent()
 235             || style()->logicalMinWidth().isPercent();
 236
 237         if (imageSizeChanged || hasOverrideSize || containingBlockNeedsToRecomputePreferredSize) {
 238             shouldRepaint = false;
 239             if (!selfNeedsLayout())
 240                 setNeedsLayout();
 241         }
 242     }
 243
 244     if (everHadLayout() && !selfNeedsLayout()) {
 245         // The inner content rectangle is calculated during layout, but may need an update now
 246         // (unless the box has already been scheduled for layout). In order to calculate it, we
 247         // may need values from the containing block, though, so make sure that we're not too
 248         // early. It may be that layout hasn't even taken place once yet.
 249         updateInnerContentRect();
 250     }
 251
 252     if (shouldRepaint) {
 253         LayoutRect repaintRect;
 254         if (rect) {
 255             // The image changed rect is in source image coordinates (pre-zooming),
 256             // so map from the bounds of the image to the contentsBox.
 257             repaintRect = enclosingIntRect(mapRect(*rect, FloatRect(FloatPoint(), m_imageResource->imageSize(1.0f)), contentBoxRect()));
 258             // Guard against too-large changed rects.
 259             repaintRect.intersect(contentBoxRect());
 260         } else
 261             repaintRect = contentBoxRect();
 262
 263         {
 264             // FIXME: We should not be allowing repaint during layout. crbug.com/339584
 265             AllowRepaintScope scoper(frameView());
 266             repaintRectangle(repaintRect);
 267         }
 268
 269         // Tell any potential compositing layers that the image needs updating.
 270         contentChanged(ImageChanged);
 271     }
 272 }
 273
 274 void RenderImage::notifyFinished(Resource* newImage)
 275 {
 276     if (!m_imageResource)
 277         return;
 278
 279     if (documentBeingDestroyed())
 280         return;
 281
 282     invalidateBackgroundObscurationStatus();
 283
 284     if (newImage == m_imageResource->cachedImage()) {
 285         // tell any potential compositing layers
 286         // that the image is done and they can reference it directly.
 287         contentChanged(ImageChanged);
 288     }
 289 }
 290
 291 void RenderImage::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 292 {
 293     LayoutUnit cWidth = contentWidth();
 294     LayoutUnit cHeight = contentHeight();
 295     LayoutUnit leftBorder = borderLeft();
 296     LayoutUnit topBorder = borderTop();
 297     LayoutUnit leftPad = paddingLeft();
 298     LayoutUnit topPad = paddingTop();
 299
 300     GraphicsContext* context = paintInfo.context;
 301
 302     if (!m_imageResource->hasImage() || m_imageResource->errorOccurred()) {
 303         if (paintInfo.phase == PaintPhaseSelection)
 304             return;
 305
 306         if (cWidth > 2 && cHeight > 2) {
 307             const int borderWidth = 1;
 308
 309             // Draw an outline rect where the image should be.
 310             context->setStrokeStyle(SolidStroke);
 311             context->setStrokeColor(Color::lightGray);
 312             context->setFillColor(Color::transparent);
 313             context->drawRect(pixelSnappedIntRect(LayoutRect(paintOffset.x() + leftBorder + leftPad, paintOffset.y() + topBorder + topPad, cWidth, cHeight)));
 314
 315             bool errorPictureDrawn = false;
 316             LayoutSize imageOffset;
 317             // When calculating the usable dimensions, exclude the pixels of
 318             // the ouline rect so the error image/alt text doesn't draw on it.
 319             LayoutUnit usableWidth = cWidth - 2 * borderWidth;
 320             LayoutUnit usableHeight = cHeight - 2 * borderWidth;
 321
 322             RefPtr<Image> image = m_imageResource->image();
 323
 324             if (m_imageResource->errorOccurred() && !image->isNull() && usableWidth >= image->width() && usableHeight >= image->height()) {
 325                 float deviceScaleFactor = WebCore::deviceScaleFactor(frame());
 326                 // Call brokenImage() explicitly to ensure we get the broken image icon at the appropriate resolution.
 327                 pair<Image*, float> brokenImageAndImageScaleFactor = ImageResource::brokenImage(deviceScaleFactor);
 328                 image = brokenImageAndImageScaleFactor.first;
 329                 IntSize imageSize = image->size();
 330                 imageSize.scale(1 / brokenImageAndImageScaleFactor.second);
 331                 // Center the error image, accounting for border and padding.
 332                 LayoutUnit centerX = (usableWidth - imageSize.width()) / 2;
 333                 if (centerX < 0)
 334                     centerX = 0;
 335                 LayoutUnit centerY = (usableHeight - imageSize.height()) / 2;
 336                 if (centerY < 0)
 337                     centerY = 0;
 338                 imageOffset = LayoutSize(leftBorder + leftPad + centerX + borderWidth, topBorder + topPad + centerY + borderWidth);
 339                 context->drawImage(image.get(), pixelSnappedIntRect(LayoutRect(paintOffset + imageOffset, imageSize)), CompositeSourceOver, shouldRespectImageOrientation());
 340                 errorPictureDrawn = true;
 341             }
 342
 343             if (!m_altText.isEmpty()) {
 344                 const Font& font = style()->font();
 345                 const FontMetrics& fontMetrics = font.fontMetrics();
 346                 LayoutUnit ascent = fontMetrics.ascent();
 347                 LayoutPoint textRectOrigin = paintOffset;
 348                 textRectOrigin.move(leftBorder + leftPad + (paddingWidth / 2) - borderWidth, topBorder + topPad + (paddingHeight / 2) - borderWidth);
 349                 LayoutPoint textOrigin(textRectOrigin.x(), textRectOrigin.y() + ascent);
 350
 351                 // Only draw the alt text if it'll fit within the content box,
 352                 // and only if it fits above the error image.
 353                 TextRun textRun = RenderBlockFlow::constructTextRun(this, font, m_altText, style(), TextRun::AllowTrailingExpansion | TextRun::ForbidLeadingExpansion, DefaultTextRunFlags | RespectDirection);
 354                 LayoutUnit textWidth = font.width(textRun);
 355                 TextRunPaintInfo textRunPaintInfo(textRun);
 356                 textRunPaintInfo.bounds = FloatRect(textRectOrigin, FloatSize(textWidth, fontMetrics.height()));
 357                 context->setFillColor(resolveColor(CSSPropertyColor));
 358                 if (textRun.direction() == RTL) {
 359                     int availableWidth = cWidth - static_cast<int>(paddingWidth);
 360                     textOrigin.move(availableWidth - ceilf(textWidth), 0);
 361                 }
 362                 if (errorPictureDrawn) {
 363                     if (usableWidth >= textWidth && fontMetrics.height() <= imageOffset.height())
 364                         context->drawBidiText(font, textRunPaintInfo, textOrigin);
 365                 } else if (usableWidth >= textWidth && usableHeight >= fontMetrics.height()) {
 366                     context->drawBidiText(font, textRunPaintInfo, textOrigin);
 367                 }
 368             }
 369         }
 370     } else if (m_imageResource->hasImage() && cWidth > 0 && cHeight > 0) {
 371         RefPtr<Image> img = m_imageResource->image(cWidth, cHeight);
 372         if (!img || img->isNull())
 373             return;
 374
 375         LayoutRect contentRect = contentBoxRect();
 376         contentRect.moveBy(paintOffset);
 377         LayoutRect paintRect = replacedContentRect();
 378         paintRect.moveBy(paintOffset);
 379         bool clip = !contentRect.contains(paintRect);
 380         if (clip) {
 381             context->save();
 382             context->clip(contentRect);
 383         }
 384
 385         paintIntoRect(context, paintRect);
 386
 387         if (clip)
 388             context->restore();
 389     }
 390 }
 391
 392 void RenderImage::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 393 {
 394     RenderReplaced::paint(paintInfo, paintOffset);
 395
 396     if (paintInfo.phase == PaintPhaseOutline)
 397         paintAreaElementFocusRing(paintInfo);
 398 }
 399
 400 void RenderImage::paintAreaElementFocusRing(PaintInfo& paintInfo)
 401 {
 402     Document& document = this->document();
 403
 404     if (document.printing() || !document.frame()->selection().isFocusedAndActive())
 405         return;
 406
 407     if (paintInfo.context->paintingDisabled() && !paintInfo.context->updatingControlTints())
 408         return;
 409
 410     Element* focusedElement = document.focusedElement();
 411     if (!focusedElement || !focusedElement->hasTagName(areaTag))
 412         return;
 413
 414     HTMLAreaElement* areaElement = toHTMLAreaElement(focusedElement);
 415     if (areaElement->imageElement() != node())
 416         return;
 417
 418     // Even if the theme handles focus ring drawing for entire elements, it won't do it for
 419     // an area within an image, so we don't call RenderTheme::supportsFocusRing here.
 420
 421     Path path = areaElement->computePath(this);
 422     if (path.isEmpty())
 423         return;
 424
 425     RenderStyle* areaElementStyle = areaElement->computedStyle();
 426     unsigned short outlineWidth = areaElementStyle->outlineWidth();
 427     if (!outlineWidth)
 428         return;
 429
 430     // FIXME: Clip path instead of context when Skia pathops is ready.
 431     // https://crbug.com/251206
 432     GraphicsContextStateSaver savedContext(*paintInfo.context);
 433     paintInfo.context->clip(absoluteContentBox());
 434     paintInfo.context->drawFocusRing(path, outlineWidth,
 435         areaElementStyle->outlineOffset(),
 436         resolveColor(areaElementStyle, CSSPropertyOutlineColor));
 437 }
 438
 439 void RenderImage::areaElementFocusChanged(HTMLAreaElement* areaElement)
 440 {
 441     ASSERT(areaElement->imageElement() == node());
 442
 443     Path path = areaElement->computePath(this);
 444     if (path.isEmpty())
 445         return;
 446
 447     RenderStyle* areaElementStyle = areaElement->computedStyle();
 448     unsigned short outlineWidth = areaElementStyle->outlineWidth();
 449
 450     IntRect repaintRect = enclosingIntRect(path.boundingRect());
 451     repaintRect.moveBy(-absoluteContentBox().location());
 452     repaintRect.inflate(outlineWidth);
 453
 454     repaintRectangle(repaintRect);
 455 }
 456
 457 void RenderImage::paintIntoRect(GraphicsContext* context, const LayoutRect& rect)
 458 {
 459     IntRect alignedRect = pixelSnappedIntRect(rect);
 460     if (!m_imageResource->hasImage() || m_imageResource->errorOccurred() || alignedRect.width() <= 0 || alignedRect.height() <= 0)
 461         return;
 462
 463     RefPtr<Image> img = m_imageResource->image(alignedRect.width(), alignedRect.height());
 464     if (!img || img->isNull())
 465         return;
 466
 467     HTMLImageElement* imageElt = (node() && node()->hasTagName(imgTag)) ? toHTMLImageElement(node()) : 0;
 468     CompositeOperator compositeOperator = imageElt ? imageElt->compositeOperator() : CompositeSourceOver;
 469     Image* image = m_imageResource->image().get();
 470     bool useLowQualityScaling = shouldPaintAtLowQuality(context, image, image, alignedRect.size());
 471
 472     InspectorInstrumentation::willPaintImage(this);
 473     context->drawImage(m_imageResource->image(alignedRect.width(), alignedRect.height()).get(), alignedRect, compositeOperator, shouldRespectImageOrientation(), useLowQualityScaling);
 474     InspectorInstrumentation::didPaintImage(this);
 475 }
 476
 477 bool RenderImage::boxShadowShouldBeAppliedToBackground(BackgroundBleedAvoidance bleedAvoidance, InlineFlowBox*) const
 478 {
 479     if (!RenderBoxModelObject::boxShadowShouldBeAppliedToBackground(bleedAvoidance))
 480         return false;
 481
 482     return !const_cast<RenderImage*>(this)->backgroundIsKnownToBeObscured();
 483 }
 484
 485 bool RenderImage::foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, unsigned) const
 486 {
 487     if (!m_imageResource->hasImage() || m_imageResource->errorOccurred())
 488         return false;
 489     if (m_imageResource->cachedImage() && !m_imageResource->cachedImage()->isLoaded())
 490         return false;
 491     if (!contentBoxRect().contains(localRect))
 492         return false;
 493     EFillBox backgroundClip = style()->backgroundClip();
 494     // Background paints under borders.
 495     if (backgroundClip == BorderFillBox && style()->hasBorder() && !borderObscuresBackground())
 496         return false;
 497     // Background shows in padding area.
 498     if ((backgroundClip == BorderFillBox || backgroundClip == PaddingFillBox) && style()->hasPadding())
 499         return false;
 500     // Object-position may leave parts of the content box empty, regardless of the value of object-fit.
 501     if (style()->objectPosition() != RenderStyle::initialObjectPosition())
 502         return false;
 503     // Object-fit may leave parts of the content box empty.
 504     ObjectFit objectFit = style()->objectFit();
 505     if (objectFit != ObjectFitFill && objectFit != ObjectFitCover)
 506         return false;
 507     // Check for image with alpha.
 508     return m_imageResource->cachedImage() && m_imageResource->cachedImage()->currentFrameKnownToBeOpaque(this);
 509 }
 510
 511 bool RenderImage::computeBackgroundIsKnownToBeObscured()
 512 {
 513     if (!hasBackground())
 514         return false;
 515     return foregroundIsKnownToBeOpaqueInRect(backgroundPaintedExtent(), 0);
 516 }
 517
 518 LayoutUnit RenderImage::minimumReplacedHeight() const
 519 {
 520     return m_imageResource->errorOccurred() ? intrinsicSize().height() : LayoutUnit();
 521 }
 522
 523 HTMLMapElement* RenderImage::imageMap() const
 524 {
 525     HTMLImageElement* i = node() && node()->hasTagName(imgTag) ? toHTMLImageElement(node()) : 0;
 526     return i ? i->treeScope().getImageMap(i->fastGetAttribute(usemapAttr)) : 0;
 527 }
 528
 529 bool RenderImage::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction hitTestAction)
 530 {
 531     HitTestResult tempResult(result.hitTestLocation());
 532     bool inside = RenderReplaced::nodeAtPoint(request, tempResult, locationInContainer, accumulatedOffset, hitTestAction);
 533
 534     if (tempResult.innerNode() && node()) {
 535         if (HTMLMapElement* map = imageMap()) {
 536             LayoutRect contentBox = contentBoxRect();
 537             float scaleFactor = 1 / style()->effectiveZoom();
 538             LayoutPoint mapLocation = locationInContainer.point() - toLayoutSize(accumulatedOffset) - locationOffset() - toLayoutSize(contentBox.location());
 539             mapLocation.scale(scaleFactor, scaleFactor);
 540
 541             if (map->mapMouseEvent(mapLocation, contentBox.size(), tempResult))
 542                 tempResult.setInnerNonSharedNode(node());
 543         }
 544     }
 545
 546     if (!inside && result.isRectBasedTest())
 547         result.append(tempResult);
 548     if (inside)
 549         result = tempResult;
 550     return inside;
 551 }
 552
 553 void RenderImage::updateAltText()
 554 {
 555     if (!node())
 556         return;
 557
 558     if (node()->hasTagName(inputTag))
 559         m_altText = toHTMLInputElement(node())->altText();
 560     else if (node()->hasTagName(imgTag))
 561         m_altText = toHTMLImageElement(node())->altText();
 562 }
 563
 564 void RenderImage::layout()
 565 {
 566     LayoutRectRecorder recorder(*this);
 567     RenderReplaced::layout();
 568     updateInnerContentRect();
 569 }
 570
 571 bool RenderImage::updateImageLoadingPriorities()
 572 {
 573     if (!m_imageResource || !m_imageResource->cachedImage() || m_imageResource->cachedImage()->isLoaded())
 574         return false;
 575
 576     LayoutRect viewBounds = viewRect();
 577     LayoutRect objectBounds = absoluteContentBox();
 578
 579     // The object bounds might be empty right now, so intersects will fail since it doesn't deal
 580     // with empty rects. Use LayoutRect::contains in that case.
 581     bool isVisible;
 582     if (!objectBounds.isEmpty())
 583         isVisible =  viewBounds.intersects(objectBounds);
 584     else
 585         isVisible = viewBounds.contains(objectBounds);
 586
 587     ResourceLoadPriorityOptimizer::VisibilityStatus status = isVisible ?
 588         ResourceLoadPriorityOptimizer::Visible : ResourceLoadPriorityOptimizer::NotVisible;
 589
 590     ResourceLoadPriorityOptimizer::resourceLoadPriorityOptimizer()->notifyImageResourceVisibility(m_imageResource->cachedImage(), status);
 591
 592     return true;
 593 }
 594
 595 void RenderImage::computeIntrinsicRatioInformation(FloatSize& intrinsicSize, double& intrinsicRatio, bool& isPercentageIntrinsicSize) const
 596 {
 597     RenderReplaced::computeIntrinsicRatioInformation(intrinsicSize, intrinsicRatio, isPercentageIntrinsicSize);
 598
 599     // Our intrinsicSize is empty if we're rendering generated images with relative width/height. Figure out the right intrinsic size to use.
 600     if (intrinsicSize.isEmpty() && (m_imageResource->imageHasRelativeWidth() || m_imageResource->imageHasRelativeHeight())) {
 601         RenderObject* containingBlock = isOutOfFlowPositioned() ? container() : this->containingBlock();
 602         if (containingBlock->isBox()) {
 603             RenderBox* box = toRenderBox(containingBlock);
 604             intrinsicSize.setWidth(box->availableLogicalWidth());
 605             intrinsicSize.setHeight(box->availableLogicalHeight(IncludeMarginBorderPadding));
 606         }
 607     }
 608     // Don't compute an intrinsic ratio to preserve historical WebKit behavior if we're painting alt text and/or a broken image.
 609     // Video is excluded from this behavior because video elements have a default aspect ratio that a failed poster image load should not override.
 610     if (m_imageResource && m_imageResource->errorOccurred() && !isVideo()) {
 611         intrinsicRatio = 1;
 612         return;
 613     }
 614 }
 615
 616 bool RenderImage::needsPreferredWidthsRecalculation() const
 617 {
 618     if (RenderReplaced::needsPreferredWidthsRecalculation())
 619         return true;
 620     return embeddedContentBox();
 621 }
 622
 623 RenderBox* RenderImage::embeddedContentBox() const
 624 {
 625     if (!m_imageResource)
 626         return 0;
 627
 628     ImageResource* cachedImage = m_imageResource->cachedImage();
 629     if (cachedImage && cachedImage->image() && cachedImage->image()->isSVGImage())
 630         return toSVGImage(cachedImage->image())->embeddedContentBox();
 631
 632     return 0;
 633 }
 634
 635 } // namespace WebCore