Home | History | Annotate | Download | only in css 
      1 /*
      2  * Copyright (C) 2006 Rob Buis <buis (at) kde.org>
      3  *           (C) 2008 Nikolas Zimmermann <zimmermann (at) kde.org>
      4  * Copyright (C) 2008 Apple Inc. All rights reserved.
      5  *
      6  * This library is free software; you can redistribute it and/or
      7  * modify it under the terms of the GNU Library General Public
      8  * License as published by the Free Software Foundation; either
      9  * version 2 of the License, or (at your option) any later version.
     10  *
     11  * This library is distributed in the hope that it will be useful,
     12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14  * Library General Public License for more details.
     15  *
     16  * You should have received a copy of the GNU Library General Public License
     17  * along with this library; see the file COPYING.LIB.  If not, write to
     18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     19  * Boston, MA 02110-1301, USA.
     20  */
     21 
     22 #include "config.h"
     23 #include "core/css/CSSCursorImageValue.h"
     24 
     25 #include "core/SVGNames.h"
     26 #include "core/css/CSSImageSetValue.h"
     27 #include "core/fetch/ImageResource.h"
     28 #include "core/fetch/ResourceFetcher.h"
     29 #include "core/rendering/style/StyleFetchedImage.h"
     30 #include "core/rendering/style/StyleFetchedImageSet.h"
     31 #include "core/rendering/style/StyleImage.h"
     32 #include "core/rendering/style/StylePendingImage.h"
     33 #include "core/svg/SVGCursorElement.h"
     34 #include "core/svg/SVGLengthContext.h"
     35 #include "core/svg/SVGURIReference.h"
     36 #include "wtf/MathExtras.h"
     37 #include "wtf/text/StringBuilder.h"
     38 #include "wtf/text/WTFString.h"
     39 
     40 namespace blink {
     41 
     42 static inline SVGCursorElement* resourceReferencedByCursorElement(const String& url, TreeScope& treeScope)
     43 {
     44     Element* element = SVGURIReference::targetElementFromIRIString(url, treeScope);
     45     return isSVGCursorElement(element) ? toSVGCursorElement(element) : 0;
     46 }
     47 
     48 CSSCursorImageValue::CSSCursorImageValue(PassRefPtrWillBeRawPtr<CSSValue> imageValue, bool hasHotSpot, const IntPoint& hotSpot)
     49     : CSSValue(CursorImageClass)
     50     , m_imageValue(imageValue)
     51     , m_hasHotSpot(hasHotSpot)
     52     , m_hotSpot(hotSpot)
     53     , m_accessedImage(false)
     54 {
     55 }
     56 
     57 CSSCursorImageValue::~CSSCursorImageValue()
     58 {
     59     // The below teardown is all handled by weak pointer processing in oilpan.
     60 #if !ENABLE(OILPAN)
     61     if (!isSVGCursor())
     62         return;
     63 
     64     HashSet<SVGElement*>::const_iterator it = m_referencedElements.begin();
     65     HashSet<SVGElement*>::const_iterator end = m_referencedElements.end();
     66     String url = toCSSImageValue(m_imageValue.get())->url();
     67 
     68     for (; it != end; ++it) {
     69         SVGElement* referencedElement = *it;
     70         referencedElement->cursorImageValueRemoved();
     71         if (SVGCursorElement* cursorElement = resourceReferencedByCursorElement(url, referencedElement->treeScope()))
     72             cursorElement->removeClient(referencedElement);
     73     }
     74 #endif
     75 }
     76 
     77 String CSSCursorImageValue::customCSSText() const
     78 {
     79     StringBuilder result;
     80     result.append(m_imageValue->cssText());
     81     if (m_hasHotSpot) {
     82         result.append(' ');
     83         result.appendNumber(m_hotSpot.x());
     84         result.append(' ');
     85         result.appendNumber(m_hotSpot.y());
     86     }
     87     return result.toString();
     88 }
     89 
     90 bool CSSCursorImageValue::updateIfSVGCursorIsUsed(Element* element)
     91 {
     92     if (!element || !element->isSVGElement())
     93         return false;
     94 
     95     if (!isSVGCursor())
     96         return false;
     97 
     98     String url = toCSSImageValue(m_imageValue.get())->url();
     99     if (SVGCursorElement* cursorElement = resourceReferencedByCursorElement(url, element->treeScope())) {
    100         // FIXME: This will override hot spot specified in CSS, which is probably incorrect.
    101         SVGLengthContext lengthContext(0);
    102         m_hasHotSpot = true;
    103         float x = roundf(cursorElement->x()->currentValue()->value(lengthContext));
    104         m_hotSpot.setX(static_cast<int>(x));
    105 
    106         float y = roundf(cursorElement->y()->currentValue()->value(lengthContext));
    107         m_hotSpot.setY(static_cast<int>(y));
    108 
    109         if (cachedImageURL() != element->document().completeURL(cursorElement->href()->currentValue()->value()))
    110             clearImageResource();
    111 
    112         SVGElement* svgElement = toSVGElement(element);
    113 #if !ENABLE(OILPAN)
    114         m_referencedElements.add(svgElement);
    115 #endif
    116         svgElement->setCursorImageValue(this);
    117         cursorElement->addClient(svgElement);
    118         return true;
    119     }
    120 
    121     return false;
    122 }
    123 
    124 StyleImage* CSSCursorImageValue::cachedImage(ResourceFetcher* loader, float deviceScaleFactor)
    125 {
    126     if (m_imageValue->isImageSetValue())
    127         return toCSSImageSetValue(m_imageValue.get())->cachedImageSet(loader, deviceScaleFactor);
    128 
    129     if (!m_accessedImage) {
    130         m_accessedImage = true;
    131 
    132         // For SVG images we need to lazily substitute in the correct URL. Rather than attempt
    133         // to change the URL of the CSSImageValue (which would then change behavior like cssText),
    134         // we create an alternate CSSImageValue to use.
    135         if (isSVGCursor() && loader && loader->document()) {
    136             RefPtrWillBeRawPtr<CSSImageValue> imageValue = toCSSImageValue(m_imageValue.get());
    137             // FIXME: This will fail if the <cursor> element is in a shadow DOM (bug 59827)
    138             if (SVGCursorElement* cursorElement = resourceReferencedByCursorElement(imageValue->url(), *loader->document())) {
    139                 RefPtrWillBeRawPtr<CSSImageValue> svgImageValue = CSSImageValue::create(loader->document()->completeURL(cursorElement->href()->currentValue()->value()));
    140                 svgImageValue->setReferrer(imageValue->referrer());
    141                 StyleFetchedImage* cachedImage = svgImageValue->cachedImage(loader);
    142                 m_image = cachedImage;
    143                 return cachedImage;
    144             }
    145         }
    146 
    147         if (m_imageValue->isImageValue())
    148             m_image = toCSSImageValue(m_imageValue.get())->cachedImage(loader);
    149     }
    150 
    151     if (m_image && m_image->isImageResource())
    152         return toStyleFetchedImage(m_image);
    153     return 0;
    154 }
    155 
    156 StyleImage* CSSCursorImageValue::cachedOrPendingImage(float deviceScaleFactor)
    157 {
    158     // Need to delegate completely so that changes in device scale factor can be handled appropriately.
    159     if (m_imageValue->isImageSetValue())
    160         return toCSSImageSetValue(m_imageValue.get())->cachedOrPendingImageSet(deviceScaleFactor);
    161 
    162     if (!m_image)
    163         m_image = StylePendingImage::create(this);
    164 
    165     return m_image.get();
    166 }
    167 
    168 bool CSSCursorImageValue::isSVGCursor() const
    169 {
    170     if (m_imageValue->isImageValue()) {
    171         RefPtrWillBeRawPtr<CSSImageValue> imageValue = toCSSImageValue(m_imageValue.get());
    172         KURL kurl(ParsedURLString, imageValue->url());
    173         return kurl.hasFragmentIdentifier();
    174     }
    175     return false;
    176 }
    177 
    178 String CSSCursorImageValue::cachedImageURL()
    179 {
    180     if (!m_image || !m_image->isImageResource())
    181         return String();
    182     return toStyleFetchedImage(m_image)->cachedImage()->url().string();
    183 }
    184 
    185 void CSSCursorImageValue::clearImageResource()
    186 {
    187     m_image = nullptr;
    188     m_accessedImage = false;
    189 }
    190 
    191 #if !ENABLE(OILPAN)
    192 void CSSCursorImageValue::removeReferencedElement(SVGElement* element)
    193 {
    194     m_referencedElements.remove(element);
    195 }
    196 #endif
    197 
    198 bool CSSCursorImageValue::equals(const CSSCursorImageValue& other) const
    199 {
    200     return m_hasHotSpot ? other.m_hasHotSpot && m_hotSpot == other.m_hotSpot : !other.m_hasHotSpot
    201         && compareCSSValuePtr(m_imageValue, other.m_imageValue);
    202 }
    203 
    204 void CSSCursorImageValue::traceAfterDispatch(Visitor* visitor)
    205 {
    206     visitor->trace(m_imageValue);
    207     CSSValue::traceAfterDispatch(visitor);
    208 }
    209 
    210 } // namespace blink
    211