• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4  * Copyright (C) 2004, 2009 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 
23 #ifndef ImageLoader_h
24 #define ImageLoader_h
25 
26 #include "core/fetch/ImageResource.h"
27 #include "core/fetch/ImageResourceClient.h"
28 #include "core/fetch/ResourcePtr.h"
29 #include "wtf/HashSet.h"
30 #include "wtf/text/AtomicString.h"
31 
32 namespace WebCore {
33 
34 class ImageLoaderClient {
35 public:
36     virtual void notifyImageSourceChanged() = 0;
37 
38     // Determines whether the observed ImageResource should have higher priority in the decoded resources cache.
requestsHighLiveResourceCachePriority()39     virtual bool requestsHighLiveResourceCachePriority() { return false; }
40 
41 protected:
ImageLoaderClient()42     ImageLoaderClient() { }
43 };
44 
45 class Element;
46 class ImageLoader;
47 class RenderImageResource;
48 
49 template<typename T> class EventSender;
50 typedef EventSender<ImageLoader> ImageEventSender;
51 
52 class ImageLoader : public ImageResourceClient {
53 public:
54     explicit ImageLoader(Element*);
55     virtual ~ImageLoader();
56 
57     // This function should be called when the element is attached to a document; starts
58     // loading if a load hasn't already been started.
59     void updateFromElement();
60 
61     // This function should be called whenever the 'src' attribute is set, even if its value
62     // doesn't change; starts new load unconditionally (matches Firefox and Opera behavior).
63     void updateFromElementIgnoringPreviousError();
64 
65     void elementDidMoveToNewDocument();
66 
element()67     Element* element() const { return m_element; }
imageComplete()68     bool imageComplete() const { return m_imageComplete; }
69 
image()70     ImageResource* image() const { return m_image.get(); }
71     void setImage(ImageResource*); // Cancels pending beforeload and load events, and doesn't dispatch new ones.
72 
setLoadManually(bool loadManually)73     void setLoadManually(bool loadManually) { m_loadManually = loadManually; }
74 
hasPendingBeforeLoadEvent()75     bool hasPendingBeforeLoadEvent() const { return m_hasPendingBeforeLoadEvent; }
hasPendingActivity()76     bool hasPendingActivity() const { return m_hasPendingLoadEvent || m_hasPendingErrorEvent; }
77 
78     void dispatchPendingEvent(ImageEventSender*);
79 
80     static void dispatchPendingBeforeLoadEvents();
81     static void dispatchPendingLoadEvents();
82     static void dispatchPendingErrorEvents();
83 
84     void addClient(ImageLoaderClient*);
85     void removeClient(ImageLoaderClient*);
86 
87 protected:
88     virtual void notifyFinished(Resource*);
89 
90 private:
91     virtual void dispatchLoadEvent() = 0;
92     virtual String sourceURI(const AtomicString&) const = 0;
93 
94     void updatedHasPendingEvent();
95 
96     void dispatchPendingBeforeLoadEvent();
97     void dispatchPendingLoadEvent();
98     void dispatchPendingErrorEvent();
99 
100     RenderImageResource* renderImageResource();
101     void updateRenderer();
102 
103     void setImageWithoutConsideringPendingLoadEvent(ImageResource*);
104     void sourceImageChanged();
105     void clearFailedLoadURL();
106 
107     void timerFired(Timer<ImageLoader>*);
108 
109     Element* m_element;
110     ResourcePtr<ImageResource> m_image;
111     HashSet<ImageLoaderClient*> m_clients;
112     Timer<ImageLoader> m_derefElementTimer;
113     AtomicString m_failedLoadURL;
114     bool m_hasPendingBeforeLoadEvent : 1;
115     bool m_hasPendingLoadEvent : 1;
116     bool m_hasPendingErrorEvent : 1;
117     bool m_imageComplete : 1;
118     bool m_loadManually : 1;
119     bool m_elementIsProtected : 1;
120     unsigned m_highPriorityClientCount;
121 };
122 
123 }
124 
125 #endif
126