Imported WebKit commit 7e538425aa020340619e927792f3d895061fb54b (http://svn.webkit.org/repository/webkit/trunk@116286)

1 files changed, 157 insertions, 0 deletions

diff --git a/Source/WebCore/css/CSSImageSetValue.cpp b/Source/WebCore/css/CSSImageSetValue.cpp
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+++ b/Source/WebCore/css/CSSImageSetValue.cpp
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+/*
+ * Copyright (C) 2012 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "CSSImageSetValue.h"
+
+#if ENABLE(CSS_IMAGE_SET)
+
+#include "CSSImageValue.h"
+#include "CSSPrimitiveValue.h"
+#include "CachedResourceLoader.h"
+#include "Document.h"
+#include "Page.h"
+#include "StyleCachedImageSet.h"
+#include "StylePendingImage.h"
+
+namespace WebCore {
+
+CSSImageSetValue::CSSImageSetValue()
+    : CSSValueList(ImageSetClass, CommaSeparator)
+    , m_accessedBestFitImage(false)
+    , m_scaleFactor(1)
+{
+}
+
+CSSImageSetValue::~CSSImageSetValue()
+{
+}
+
+void CSSImageSetValue::fillImageSet()
+{
+    size_t length = this->length();
+    size_t i = 0;
+    while (i < length) {
+        CSSValue* imageValue = item(i);
+        ASSERT(imageValue->isImageValue());
+        String imageURL = static_cast<CSSImageValue*>(imageValue)->url();
+
+        ++i;
+        ASSERT(i < length);
+        CSSValue* scaleFactorValue = item(i);
+        ASSERT(scaleFactorValue->isPrimitiveValue());
+        float scaleFactor = static_cast<CSSPrimitiveValue*>(scaleFactorValue)->getFloatValue();
+
+        ImageWithScale image;
+        image.imageURL = imageURL;
+        image.scaleFactor = scaleFactor;
+        m_imagesInSet.append(image);
+        ++i;
+    }
+
+    // Sort the images so that they are stored in order from lowest resolution to highest.
+    std::sort(m_imagesInSet.begin(), m_imagesInSet.end(), CSSImageSetValue::compareByScaleFactor);
+}
+
+CSSImageSetValue::ImageWithScale CSSImageSetValue::bestImageForScaleFactor()
+{
+    ImageWithScale image;
+    size_t numberOfImages = m_imagesInSet.size();
+    for (size_t i = 0; i < numberOfImages; ++i) {
+        image = m_imagesInSet.at(i);
+        if (image.scaleFactor >= m_scaleFactor)
+            return image;
+    }
+    return image;
+}
+
+StyleCachedImageSet* CSSImageSetValue::cachedImageSet(CachedResourceLoader* loader)
+{
+    ASSERT(loader);
+
+    Document* document = loader->document();
+    if (Page* page = document->page())
+        m_scaleFactor = page->deviceScaleFactor();
+    else
+        m_scaleFactor = 1;
+
+    if (!m_imagesInSet.size())
+        fillImageSet();
+
+    if (!m_accessedBestFitImage) {
+        // FIXME: In the future, we want to take much more than deviceScaleFactor into acount here. 
+        // All forms of scale should be included: Page::pageScaleFactor(), Frame::pageZoomFactor(),
+        // and any CSS transforms. https://bugs.webkit.org/show_bug.cgi?id=81698
+        ImageWithScale image = bestImageForScaleFactor();
+        ResourceRequest request(loader->document()->completeURL(image.imageURL));
+        if (CachedImage* cachedImage = loader->requestImage(request)) {
+            m_imageSet = StyleCachedImageSet::create(cachedImage, image.scaleFactor, this);
+            m_accessedBestFitImage = true;
+        }
+    }
+
+    return (m_imageSet && m_imageSet->isCachedImageSet()) ? static_cast<StyleCachedImageSet*>(m_imageSet.get()) : 0;
+}
+
+StyleImage* CSSImageSetValue::cachedOrPendingImageSet(Document* document)
+{
+    if (!m_imageSet)
+        m_imageSet = StylePendingImage::create(this);
+    else if (document && !m_imageSet->isPendingImage()) {
+        float deviceScaleFactor = 1;
+        if (Page* page = document->page())
+            deviceScaleFactor = page->deviceScaleFactor();
+
+        // If the deviceScaleFactor has changed, we may not have the best image loaded, so we have to re-assess.
+        if (deviceScaleFactor != m_scaleFactor) {
+            m_accessedBestFitImage = false;
+            m_imageSet = StylePendingImage::create(this);
+        }
+    }
+
+    return m_imageSet.get();
+}
+
+String CSSImageSetValue::customCssText() const
+{
+    return "-webkit-image-set(" + CSSValueList::customCssText() + ")";
+}
+
+CSSImageSetValue::CSSImageSetValue(const CSSImageSetValue& cloneFrom)
+    : CSSValueList(cloneFrom)
+    , m_accessedBestFitImage(false)
+    , m_scaleFactor(1)
+{
+    // Non-CSSValueList data is not accessible through CSS OM, no need to clone.
+}
+
+PassRefPtr<CSSImageSetValue> CSSImageSetValue::cloneForCSSOM() const
+{
+    return adoptRef(new CSSImageSetValue(*this));
+}
+
+} // namespace WebCore
+
+#endif // ENABLE(CSS_IMAGE_SET)