KHtml

imageloader.h
1 /*
2  Progressive image displaying library.
3 
4  Copyright (C) 2004,2005 Maks Orlovich ([email protected])
5 
6  Permission is hereby granted, free of charge, to any person obtaining a copy
7  of this software and associated documentation files (the "Software"), to deal
8  in the Software without restriction, including without limitation the rights
9  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  copies of the Software, and to permit persons to whom the Software is
11  furnished to do so, subject to the following conditions:
12 
13  The above copyright notice and this permission notice shall be included in
14  all copies or substantial portions of the Software.
15 
16  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
20  AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 
23 */
24 
25 #ifndef IMAGE_LOADER_H
26 #define IMAGE_LOADER_H
27 
28 #include "imageformat.h"
29 #include "image.h"
30 
31 namespace khtmlImLoad
32 {
33 
34 class Image;
35 
36 /**
37  A base class for decoders. The decoders should inherit off this, and use the protected functions to
38  feed their images data
39 */
41 {
42 protected:
43  Image *image;
44 
45  ImageLoader()
46  {
47  image = nullptr;
48  }
49 
50  /**
51  Call to declare canvas geometry and format. May only be called once
52  */
53  void notifyImageInfo(int width, int height)
54  {
55  image->notifyImageInfo(width, height);
56  }
57 
58  /**
59  Call to declare frame geometry, should be called for each frame.
60  */
61  void notifyAppendFrame(int fwidth, int fheight, const ImageFormat &format)
62  {
63  image->notifyAppendFrame(fwidth, fheight, format);
64  }
65 
66  /**
67  wrapper for the above method for single-frame images
68  */
69  void notifySingleFrameImage(int width, int height, const ImageFormat &format)
70  {
71  notifyImageInfo(width, height);
72  notifyAppendFrame(width, height, format);
73  }
74 
75  /**
76  Call to provide a scanline, for active frame, and given "version".
77  The decoder must feed multiple versions of the image inside here, top-to-bottom,
78  and incrementing versions. When it's done, it should either feed the last
79  version with FinalVersionID, or call notifyFinished() separately.
80  */
81  void notifyScanline(unsigned char version, unsigned char *line)
82  {
83  image->notifyScanline(version, line);
84  }
85 
86  void notifyQImage(unsigned char version, const QImage *qimage)
87  {
88  image->notifyQImage(version, qimage);
89  }
90 
91  /**
92  Call this to exract the current state of a scanline to the provided bufer
93  */
94  void requestScanline(unsigned int lineNum, unsigned char *lineBuf)
95  {
96  image->requestScanline(lineNum, lineBuf);
97  }
98 
99  /**
100  Call this to get the first frame
101  */
103  {
104  return image->getSize(image->size());
105  }
106 
107 public:
108  //Some constants. Not consts since some compilers are broken
109  enum {
110  DefaultFrame = 0,
111  FinalVersionID = 0xff
112  };
113 
114  void setImage(Image *_image)
115  {
116  image = _image;
117  }
118 
119  virtual ~ImageLoader()
120  {}
121 
122  enum Status {
123  Done = -2,
124  Error = -1
125  };
126 
127  /**
128  Decodes a portion of the image, and returns the appropriate
129  status, or the number of bytes read
130  */
131  virtual int processData(uchar *data, int length) = 0;
132 
133  /**
134  This method is called to notify the decoder that the input is done, if the decoder
135  has not already indicated some sort of completion on the stream; this is intended
136  mostly for non-incremental decoders. It should return Done if all is OK. Note that
137  the "if" above should mean that the non-incremental decoders should just return
138  the bytes read in processData
139  */
140  virtual int processEOF()
141  {
142  return Done; //### Probably should be Error if notifyImageInfo has not been called
143  }
144 };
145 
146 }
147 
148 #endif
void notifyImageInfo(int width, int height)
Call to declare canvas geometry and format.
Definition: imageloader.h:53
An image represents a static picture or an animation, that may be incrementally loaded.
Definition: image.h:51
A pixmap plane is responsible for drawing data of an image plane.
Definition: pixmapplane.h:41
A base class for decoders.
Definition: imageloader.h:40
QSize size() const
Returns the image's size.
Definition: image.cpp:353
PixmapPlane * requestFrame0()
Call this to get the first frame.
Definition: imageloader.h:102
virtual int processData(uchar *data, int length)=0
Decodes a portion of the image, and returns the appropriate status, or the number of bytes read...
void notifyScanline(unsigned char version, unsigned char *line)
Call to provide a scanline, for active frame, and given "version".
Definition: imageloader.h:81
void notifySingleFrameImage(int width, int height, const ImageFormat &format)
wrapper for the above method for single-frame images
Definition: imageloader.h:69
void notifyAppendFrame(int fwidth, int fheight, const ImageFormat &format)
Call to declare frame geometry, should be called for each frame.
Definition: imageloader.h:61
virtual int processEOF()
This method is called to notify the decoder that the input is done, if the decoder has not already in...
Definition: imageloader.h:140
void requestScanline(unsigned int lineNum, unsigned char *lineBuf)
Call this to exract the current state of a scanline to the provided bufer.
Definition: imageloader.h:94
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