1 /*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 * (C) 1999 Antti Koivisto (koivisto@kde.org)
4 * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010 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 "ImageLoader.h"
24
25 #include "CachedImage.h"
26 #include "CachedResourceLoader.h"
27 #include "Document.h"
28 #include "Element.h"
29 #include "HTMLNames.h"
30 #include "HTMLObjectElement.h"
31 #include "RenderImage.h"
32
33 #if ENABLE(SVG)
34 #include "RenderSVGImage.h"
35 #endif
36 #if ENABLE(VIDEO)
37 #include "RenderVideo.h"
38 #endif
39
40 #if !ASSERT_DISABLED
41 // ImageLoader objects are allocated as members of other objects, so generic pointer check would always fail.
42 namespace WTF {
43
44 template<> struct ValueCheck<WebCore::ImageLoader*> {
45 typedef WebCore::ImageLoader* TraitType;
checkConsistencyWTF::ValueCheck46 static void checkConsistency(const WebCore::ImageLoader* p)
47 {
48 if (!p)
49 return;
50 ASSERT(p->element());
51 ValueCheck<WebCore::Element*>::checkConsistency(p->element());
52 }
53 };
54
55 }
56 #endif
57
58 namespace WebCore {
59
60 class ImageEventSender {
61 WTF_MAKE_NONCOPYABLE(ImageEventSender); WTF_MAKE_FAST_ALLOCATED;
62 public:
63 ImageEventSender(const AtomicString& eventType);
64
65 void dispatchEventSoon(ImageLoader*);
66 void cancelEvent(ImageLoader*);
67
68 void dispatchPendingEvents();
69
70 #if !ASSERT_DISABLED
hasPendingEvents(ImageLoader * loader)71 bool hasPendingEvents(ImageLoader* loader) { return m_dispatchSoonList.find(loader) != notFound; }
72 #endif
73
74 private:
75 void timerFired(Timer<ImageEventSender>*);
76
77 AtomicString m_eventType;
78 Timer<ImageEventSender> m_timer;
79 Vector<ImageLoader*> m_dispatchSoonList;
80 Vector<ImageLoader*> m_dispatchingList;
81 };
82
beforeLoadEventSender()83 static ImageEventSender& beforeLoadEventSender()
84 {
85 DEFINE_STATIC_LOCAL(ImageEventSender, sender, (eventNames().beforeloadEvent));
86 return sender;
87 }
88
loadEventSender()89 static ImageEventSender& loadEventSender()
90 {
91 DEFINE_STATIC_LOCAL(ImageEventSender, sender, (eventNames().loadEvent));
92 return sender;
93 }
94
ImageLoader(Element * element)95 ImageLoader::ImageLoader(Element* element)
96 : m_element(element)
97 , m_image(0)
98 , m_firedBeforeLoad(true)
99 , m_firedLoad(true)
100 , m_imageComplete(true)
101 , m_loadManually(false)
102 {
103 }
104
~ImageLoader()105 ImageLoader::~ImageLoader()
106 {
107 if (m_image)
108 m_image->removeClient(this);
109
110 ASSERT(!m_firedBeforeLoad || !beforeLoadEventSender().hasPendingEvents(this));
111 if (!m_firedBeforeLoad)
112 beforeLoadEventSender().cancelEvent(this);
113
114 ASSERT(!m_firedLoad || !loadEventSender().hasPendingEvents(this));
115 if (!m_firedLoad)
116 loadEventSender().cancelEvent(this);
117 }
118
setImage(CachedImage * newImage)119 void ImageLoader::setImage(CachedImage* newImage)
120 {
121 ASSERT(m_failedLoadURL.isEmpty());
122 CachedImage* oldImage = m_image.get();
123 if (newImage != oldImage) {
124 m_image = newImage;
125 if (!m_firedBeforeLoad) {
126 beforeLoadEventSender().cancelEvent(this);
127 m_firedBeforeLoad = true;
128 }
129 if (!m_firedLoad) {
130 loadEventSender().cancelEvent(this);
131 m_firedLoad = true;
132 }
133 m_imageComplete = true;
134 if (newImage)
135 newImage->addClient(this);
136 if (oldImage)
137 oldImage->removeClient(this);
138 }
139
140 if (RenderImageResource* imageResource = renderImageResource())
141 imageResource->resetAnimation();
142 }
143
updateFromElement()144 void ImageLoader::updateFromElement()
145 {
146 // If we're not making renderers for the page, then don't load images. We don't want to slow
147 // down the raw HTML parsing case by loading images we don't intend to display.
148 Document* document = m_element->document();
149 if (!document->renderer())
150 return;
151
152 AtomicString attr = m_element->getAttribute(m_element->imageSourceAttributeName());
153
154 if (attr == m_failedLoadURL)
155 return;
156
157 // Do not load any image if the 'src' attribute is missing or if it is
158 // an empty string referring to a local file. The latter condition is
159 // a quirk that preserves old behavior that Dashboard widgets
160 // need (<rdar://problem/5994621>).
161 CachedImage* newImage = 0;
162 if (!(attr.isNull() || (attr.isEmpty() && document->baseURI().isLocalFile()))) {
163 if (m_loadManually) {
164 bool autoLoadOtherImages = document->cachedResourceLoader()->autoLoadImages();
165 document->cachedResourceLoader()->setAutoLoadImages(false);
166 newImage = new CachedImage(sourceURI(attr));
167 newImage->setLoading(true);
168 newImage->setOwningCachedResourceLoader(document->cachedResourceLoader());
169 document->cachedResourceLoader()->m_documentResources.set(newImage->url(), newImage);
170 document->cachedResourceLoader()->setAutoLoadImages(autoLoadOtherImages);
171 } else
172 newImage = document->cachedResourceLoader()->requestImage(sourceURI(attr));
173
174 // If we do not have an image here, it means that a cross-site
175 // violation occurred.
176 m_failedLoadURL = !newImage ? attr : AtomicString();
177 }
178
179 CachedImage* oldImage = m_image.get();
180 if (newImage != oldImage) {
181 if (!m_firedBeforeLoad)
182 beforeLoadEventSender().cancelEvent(this);
183 if (!m_firedLoad)
184 loadEventSender().cancelEvent(this);
185
186 m_image = newImage;
187 m_firedBeforeLoad = !newImage;
188 m_firedLoad = !newImage;
189 m_imageComplete = !newImage;
190
191 if (newImage) {
192 newImage->addClient(this);
193 if (!m_element->document()->hasListenerType(Document::BEFORELOAD_LISTENER))
194 dispatchPendingBeforeLoadEvent();
195 else
196 beforeLoadEventSender().dispatchEventSoon(this);
197 }
198 if (oldImage)
199 oldImage->removeClient(this);
200 }
201
202 if (RenderImageResource* imageResource = renderImageResource())
203 imageResource->resetAnimation();
204 }
205
updateFromElementIgnoringPreviousError()206 void ImageLoader::updateFromElementIgnoringPreviousError()
207 {
208 // Clear previous error.
209 m_failedLoadURL = AtomicString();
210 updateFromElement();
211 }
212
notifyFinished(CachedResource *)213 void ImageLoader::notifyFinished(CachedResource*)
214 {
215 ASSERT(m_failedLoadURL.isEmpty());
216
217 m_imageComplete = true;
218 if (haveFiredBeforeLoadEvent())
219 updateRenderer();
220
221 if (m_firedLoad)
222 return;
223
224 loadEventSender().dispatchEventSoon(this);
225 }
226
renderImageResource()227 RenderImageResource* ImageLoader::renderImageResource()
228 {
229 RenderObject* renderer = m_element->renderer();
230
231 if (!renderer)
232 return 0;
233
234 if (renderer->isImage())
235 return toRenderImage(renderer)->imageResource();
236
237 #if ENABLE(SVG)
238 if (renderer->isSVGImage())
239 return toRenderSVGImage(renderer)->imageResource();
240 #endif
241
242 #if ENABLE(VIDEO)
243 if (renderer->isVideo())
244 return toRenderVideo(renderer)->imageResource();
245 #endif
246
247 return 0;
248 }
249
updateRenderer()250 void ImageLoader::updateRenderer()
251 {
252 RenderImageResource* imageResource = renderImageResource();
253
254 if (!imageResource)
255 return;
256
257 // Only update the renderer if it doesn't have an image or if what we have
258 // is a complete image. This prevents flickering in the case where a dynamic
259 // change is happening between two images.
260 CachedImage* cachedImage = imageResource->cachedImage();
261 if (m_image != cachedImage && (m_imageComplete || !cachedImage))
262 imageResource->setCachedImage(m_image.get());
263 }
264
dispatchPendingBeforeLoadEvent()265 void ImageLoader::dispatchPendingBeforeLoadEvent()
266 {
267 if (m_firedBeforeLoad)
268 return;
269 if (!m_image)
270 return;
271 if (!m_element->document()->attached())
272 return;
273 m_firedBeforeLoad = true;
274 if (m_element->dispatchBeforeLoadEvent(m_image->url())) {
275 updateRenderer();
276 return;
277 }
278 if (m_image) {
279 m_image->removeClient(this);
280 m_image = 0;
281 }
282 loadEventSender().cancelEvent(this);
283
284 if (m_element->hasTagName(HTMLNames::objectTag))
285 static_cast<HTMLObjectElement*>(m_element)->renderFallbackContent();
286 }
287
dispatchPendingLoadEvent()288 void ImageLoader::dispatchPendingLoadEvent()
289 {
290 if (m_firedLoad)
291 return;
292 if (!m_image)
293 return;
294 if (!m_element->document()->attached())
295 return;
296 m_firedLoad = true;
297 dispatchLoadEvent();
298 }
299
dispatchPendingBeforeLoadEvents()300 void ImageLoader::dispatchPendingBeforeLoadEvents()
301 {
302 beforeLoadEventSender().dispatchPendingEvents();
303 }
304
dispatchPendingLoadEvents()305 void ImageLoader::dispatchPendingLoadEvents()
306 {
307 loadEventSender().dispatchPendingEvents();
308 }
309
elementWillMoveToNewOwnerDocument()310 void ImageLoader::elementWillMoveToNewOwnerDocument()
311 {
312 setImage(0);
313 }
314
ImageEventSender(const AtomicString & eventType)315 ImageEventSender::ImageEventSender(const AtomicString& eventType)
316 : m_eventType(eventType)
317 , m_timer(this, &ImageEventSender::timerFired)
318 {
319 }
320
dispatchEventSoon(ImageLoader * loader)321 void ImageEventSender::dispatchEventSoon(ImageLoader* loader)
322 {
323 m_dispatchSoonList.append(loader);
324 if (!m_timer.isActive())
325 m_timer.startOneShot(0);
326 }
327
cancelEvent(ImageLoader * loader)328 void ImageEventSender::cancelEvent(ImageLoader* loader)
329 {
330 // Remove instances of this loader from both lists.
331 // Use loops because we allow multiple instances to get into the lists.
332 size_t size = m_dispatchSoonList.size();
333 for (size_t i = 0; i < size; ++i) {
334 if (m_dispatchSoonList[i] == loader)
335 m_dispatchSoonList[i] = 0;
336 }
337 size = m_dispatchingList.size();
338 for (size_t i = 0; i < size; ++i) {
339 if (m_dispatchingList[i] == loader)
340 m_dispatchingList[i] = 0;
341 }
342 if (m_dispatchSoonList.isEmpty())
343 m_timer.stop();
344 }
345
dispatchPendingEvents()346 void ImageEventSender::dispatchPendingEvents()
347 {
348 // Need to avoid re-entering this function; if new dispatches are
349 // scheduled before the parent finishes processing the list, they
350 // will set a timer and eventually be processed.
351 if (!m_dispatchingList.isEmpty())
352 return;
353
354 m_timer.stop();
355
356 m_dispatchSoonList.checkConsistency();
357
358 m_dispatchingList.swap(m_dispatchSoonList);
359 size_t size = m_dispatchingList.size();
360 for (size_t i = 0; i < size; ++i) {
361 if (ImageLoader* loader = m_dispatchingList[i]) {
362 if (m_eventType == eventNames().beforeloadEvent)
363 loader->dispatchPendingBeforeLoadEvent();
364 else
365 loader->dispatchPendingLoadEvent();
366 }
367 }
368 m_dispatchingList.clear();
369 }
370
timerFired(Timer<ImageEventSender> *)371 void ImageEventSender::timerFired(Timer<ImageEventSender>*)
372 {
373 dispatchPendingEvents();
374 }
375
376 }
377