1/*
2 * Copyright (C) 2006 Rob Buis <buis@kde.org>
3 *           (C) 2008 Nikolas Zimmermann <zimmermann@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
40namespace blink {
41
42static 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
48CSSCursorImageValue::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
57CSSCursorImageValue::~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
77String 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
90bool 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
124StyleImage* 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
156StyleImage* 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
168bool 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
178String CSSCursorImageValue::cachedImageURL()
179{
180    if (!m_image || !m_image->isImageResource())
181        return String();
182    return toStyleFetchedImage(m_image)->cachedImage()->url().string();
183}
184
185void CSSCursorImageValue::clearImageResource()
186{
187    m_image = nullptr;
188    m_accessedImage = false;
189}
190
191#if !ENABLE(OILPAN)
192void CSSCursorImageValue::removeReferencedElement(SVGElement* element)
193{
194    m_referencedElements.remove(element);
195}
196#endif
197
198bool 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
204void CSSCursorImageValue::traceAfterDispatch(Visitor* visitor)
205{
206    visitor->trace(m_imageValue);
207    CSSValue::traceAfterDispatch(visitor);
208}
209
210} // namespace blink
211