src/third_party/WebKit/Source/core/paint/ImagePainter.cpp

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "config.h"
   6 #include "core/paint/ImagePainter.h"
   7
   8 #include "core/dom/Document.h"
   9 #include "core/dom/Element.h"
  10 #include "core/editing/FrameSelection.h"
  11 #include "core/frame/LocalFrame.h"
  12 #include "core/html/HTMLAreaElement.h"
  13 #include "core/html/HTMLImageElement.h"
  14 #include "core/inspector/InspectorInstrumentation.h"
  15 #include "core/page/Page.h"
  16 #include "core/paint/BoxPainter.h"
  17 #include "core/rendering/PaintInfo.h"
  18 #include "core/rendering/RenderImage.h"
  19 #include "core/rendering/RenderReplaced.h"
  20 #include "core/rendering/TextRunConstructor.h"
  21 #include "platform/geometry/LayoutPoint.h"
  22 #include "platform/graphics/GraphicsContextStateSaver.h"
  23 #include "platform/graphics/Path.h"
  24
  25 namespace blink {
  26
  27 void ImagePainter::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
  28 {
  29     m_renderImage.RenderReplaced::paint(paintInfo, paintOffset);
  30
  31     if (paintInfo.phase == PaintPhaseOutline)
  32         paintAreaElementFocusRing(paintInfo);
  33 }
  34
  35 void ImagePainter::paintAreaElementFocusRing(PaintInfo& paintInfo)
  36 {
  37     Document& document = m_renderImage.document();
  38
  39     if (document.printing() || !document.frame()->selection().isFocusedAndActive())
  40         return;
  41
  42     Element* focusedElement = document.focusedElement();
  43     if (!isHTMLAreaElement(focusedElement))
  44         return;
  45
  46     HTMLAreaElement& areaElement = toHTMLAreaElement(*focusedElement);
  47     if (areaElement.imageElement() != m_renderImage.node())
  48         return;
  49
  50     // Even if the theme handles focus ring drawing for entire elements, it won't do it for
  51     // an area within an image, so we don't call RenderTheme::supportsFocusRing here.
  52
  53     Path path = areaElement.computePath(&m_renderImage);
  54     if (path.isEmpty())
  55         return;
  56
  57     RenderStyle* areaElementStyle = areaElement.computedStyle();
  58     unsigned short outlineWidth = areaElementStyle->outlineWidth();
  59     if (!outlineWidth)
  60         return;
  61
  62     // FIXME: Clip path instead of context when Skia pathops is ready.
  63     // https://crbug.com/251206
  64     GraphicsContextStateSaver savedContext(*paintInfo.context);
  65     paintInfo.context->clip(m_renderImage.absoluteContentBox());
  66     paintInfo.context->drawFocusRing(path, outlineWidth,
  67         areaElementStyle->outlineOffset(),
  68         m_renderImage.resolveColor(areaElementStyle, CSSPropertyOutlineColor));
  69 }
  70
  71 void ImagePainter::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
  72 {
  73     LayoutUnit cWidth = m_renderImage.contentWidth();
  74     LayoutUnit cHeight = m_renderImage.contentHeight();
  75
  76     GraphicsContext* context = paintInfo.context;
  77
  78     if (!m_renderImage.imageResource()->hasImage() || m_renderImage.imageResource()->errorOccurred()) {
  79         if (paintInfo.phase == PaintPhaseSelection)
  80             return;
  81
  82         if (cWidth > 2 && cHeight > 2) {
  83             const int borderWidth = 1;
  84
  85             LayoutUnit leftBorder = m_renderImage.borderLeft();
  86             LayoutUnit topBorder = m_renderImage.borderTop();
  87             LayoutUnit leftPad = m_renderImage.paddingLeft();
  88             LayoutUnit topPad = m_renderImage.paddingTop();
  89
  90             // Draw an outline rect where the image should be.
  91             context->setStrokeStyle(SolidStroke);
  92             context->setStrokeColor(Color::lightGray);
  93             context->setFillColor(Color::transparent);
  94             context->drawRect(pixelSnappedIntRect(LayoutRect(paintOffset.x() + leftBorder + leftPad, paintOffset.y() + topBorder + topPad, cWidth, cHeight)));
  95
  96             bool errorPictureDrawn = false;
  97             LayoutSize imageOffset;
  98             // When calculating the usable dimensions, exclude the pixels of
  99             // the ouline rect so the error image/alt text doesn't draw on it.
 100             LayoutUnit usableWidth = cWidth - 2 * borderWidth;
 101             LayoutUnit usableHeight = cHeight - 2 * borderWidth;
 102
 103             RefPtr<Image> image = m_renderImage.imageResource()->image();
 104
 105             if (m_renderImage.imageResource()->errorOccurred() && !image->isNull() && usableWidth >= image->width() && usableHeight >= image->height()) {
 106                 float deviceScaleFactor = blink::deviceScaleFactor(m_renderImage.frame());
 107                 // Call brokenImage() explicitly to ensure we get the broken image icon at the appropriate resolution.
 108                 pair<Image*, float> brokenImageAndImageScaleFactor = ImageResource::brokenImage(deviceScaleFactor);
 109                 image = brokenImageAndImageScaleFactor.first;
 110                 IntSize imageSize = image->size();
 111                 imageSize.scale(1 / brokenImageAndImageScaleFactor.second);
 112                 // Center the error image, accounting for border and padding.
 113                 LayoutUnit centerX = (usableWidth - imageSize.width()) / 2;
 114                 if (centerX < 0)
 115                     centerX = 0;
 116                 LayoutUnit centerY = (usableHeight - imageSize.height()) / 2;
 117                 if (centerY < 0)
 118                     centerY = 0;
 119                 imageOffset = LayoutSize(leftBorder + leftPad + centerX + borderWidth, topBorder + topPad + centerY + borderWidth);
 120                 context->drawImage(image.get(), pixelSnappedIntRect(LayoutRect(paintOffset + imageOffset, imageSize)), CompositeSourceOver, m_renderImage.shouldRespectImageOrientation());
 121                 errorPictureDrawn = true;
 122             }
 123
 124             if (!m_renderImage.altText().isEmpty()) {
 125                 const Font& font = m_renderImage.style()->font();
 126                 const FontMetrics& fontMetrics = font.fontMetrics();
 127                 LayoutUnit ascent = fontMetrics.ascent();
 128                 LayoutPoint textRectOrigin = paintOffset;
 129                 textRectOrigin.move(leftBorder + leftPad + (RenderImage::paddingWidth / 2) - borderWidth, topBorder + topPad + (RenderImage::paddingHeight / 2) - borderWidth);
 130                 LayoutPoint textOrigin(textRectOrigin.x(), textRectOrigin.y() + ascent);
 131
 132                 // Only draw the alt text if it'll fit within the content box,
 133                 // and only if it fits above the error image.
 134                 TextRun textRun = constructTextRun(&m_renderImage, font, m_renderImage.altText(), m_renderImage.style(), TextRun::AllowTrailingExpansion | TextRun::ForbidLeadingExpansion, DefaultTextRunFlags | RespectDirection);
 135                 float textWidth = font.width(textRun);
 136                 TextRunPaintInfo textRunPaintInfo(textRun);
 137                 textRunPaintInfo.bounds = FloatRect(textRectOrigin, FloatSize(textWidth, fontMetrics.height()));
 138                 context->setFillColor(m_renderImage.resolveColor(CSSPropertyColor));
 139                 if (textRun.direction() == RTL) {
 140                     int availableWidth = cWidth - static_cast<int>(RenderImage::paddingWidth);
 141                     textOrigin.move(availableWidth - ceilf(textWidth), 0);
 142                 }
 143                 if (errorPictureDrawn) {
 144                     if (usableWidth >= textWidth && fontMetrics.height() <= imageOffset.height())
 145                         context->drawBidiText(font, textRunPaintInfo, textOrigin);
 146                 } else if (usableWidth >= textWidth && usableHeight >= fontMetrics.height()) {
 147                     context->drawBidiText(font, textRunPaintInfo, textOrigin);
 148                 }
 149             }
 150         }
 151     } else if (m_renderImage.imageResource()->hasImage() && cWidth > 0 && cHeight > 0) {
 152         LayoutRect contentRect = m_renderImage.contentBoxRect();
 153         contentRect.moveBy(paintOffset);
 154         LayoutRect paintRect = m_renderImage.replacedContentRect();
 155         paintRect.moveBy(paintOffset);
 156         bool clip = !contentRect.contains(paintRect);
 157         if (clip) {
 158             context->save();
 159             context->clip(contentRect);
 160         }
 161
 162         paintIntoRect(context, paintRect);
 163
 164         if (clip)
 165             context->restore();
 166     }
 167 }
 168
 169 void ImagePainter::paintIntoRect(GraphicsContext* context, const LayoutRect& rect)
 170 {
 171     IntRect alignedRect = pixelSnappedIntRect(rect);
 172     if (!m_renderImage.imageResource()->hasImage() || m_renderImage.imageResource()->errorOccurred() || alignedRect.width() <= 0 || alignedRect.height() <= 0)
 173         return;
 174
 175     RefPtr<Image> img = m_renderImage.imageResource()->image(alignedRect.width(), alignedRect.height());
 176     if (!img || img->isNull())
 177         return;
 178
 179     HTMLImageElement* imageElt = isHTMLImageElement(m_renderImage.node()) ? toHTMLImageElement(m_renderImage.node()) : 0;
 180     CompositeOperator compositeOperator = imageElt ? imageElt->compositeOperator() : CompositeSourceOver;
 181     Image* image = img.get();
 182     InterpolationQuality interpolationQuality = BoxPainter::chooseInterpolationQuality(m_renderImage, context, image, image, alignedRect.size());
 183
 184     TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "PaintImage", "data", InspectorPaintImageEvent::data(m_renderImage));
 185     // FIXME(361045): remove InspectorInstrumentation calls once DevTools Timeline migrates to tracing.
 186     InspectorInstrumentation::willPaintImage(&m_renderImage);
 187     InterpolationQuality previousInterpolationQuality = context->imageInterpolationQuality();
 188     context->setImageInterpolationQuality(interpolationQuality);
 189     context->drawImage(image, alignedRect, compositeOperator, m_renderImage.shouldRespectImageOrientation());
 190     context->setImageInterpolationQuality(previousInterpolationQuality);
 191     InspectorInstrumentation::didPaintImage(&m_renderImage);
 192 }
 193
 194 } // namespace blink