1NSDEJAVU(1)                        DjView-4                        NSDEJAVU(1)
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NAME

6       nsdejavu - DjVu browser plugin
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SYNOPSIS

10       /usr/lib64/mozilla/plugins/nsdejavu.so
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DESCRIPTION

14       The  shared library nsdejavu.so uses the Netscape browser plugin API to
15       display DjVu images in in a number of popular web browsers.   Different
16       web  browsers  provide  various  level of support for Netscape plugins.
17       Please check section "Browser Compatibility" for instructions on how to
18       enable the DjVu browser plugin.
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20       The DjVuLibre browser plugin works by invoking a standalone viewer with
21       the special command line option -netscape.  The plugin first searches a
22       program named djview.  If this program cannot be found, it searches for
23       djview4 and finally djview3.  It is always possible  to  override  this
24       search  strategy  by setting the environment variable NPX_DJVIEW to the
25       full path of the desired executable.
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MIME TYPES AND EXTENSIONS

30       Typing the URL of a recognized DjVu document in your web browser should
31       automatically  invoke  the DjVu browser plugin.  Each browser uses dif‐
32       ferent methods to determine that a particular URL is  in  fact  a  DjVu
33       document.   Web  server  normally  provide a MIME type to web browsers.
34       The official MIME type for DjVu documents is image/vnd.djvu.  For  com‐
35       patibility  with  ancient  versions of the DjVu viewer, it is common to
36       use instead the experimental MIME type  image/x-djvu  or  image/x.djvu.
37       Web  servers should be configured to send the proper MIME type for DjVu
38       documents.  Most web browsers also recognize files ending with .djvu or
39       .djv as DjVu files.
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41       An  easy  way  to check if an http server is giving an appropriate con‐
42       tent-type is to invoke the following command with a  URL  corresponding
43       to an actual DjVu file on the server.
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45         curl -u URL | grep Content-Type
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47       The result should be one of the following, preferably the first.
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49         Content-Type: image/vnd.djvu
50         Content-Type: image/x.djvu
51         Content-Type: image/x-djvu
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53       Any other MIME type indicates a server misconfiguration.
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CGI-STYLE FLAGS

58       The  behavior of the DjVu browser plugin can be specified by augmenting
59       the URL using a syntax similar to that used by the CGI programs.   This
60       syntax is described by the following template:
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62          http://.../file.djvu?djvuopts&keyword=value&keyword=value&...
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64       The  DjVu browser plugin only recognizes keywords that appear after the
65       word djvuopts.  The keywords recognized by each viewer  are  listed  in
66       the  corresponding  man  page.  Unrecognized keywords are ignored.  The
67       most common keywords are:
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69       page=pagename
70              Specify which page is displayed by name or by ordinal number.
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72       zoom=zoomfactor
73              Set the zoom factor.  Legal values for zoomfactor are:
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75                  ┌───────────────────────────────────────────────────────┐
76number    Magnification factor in range 10% to 999%.   │
77one2one   Select the "one-to-one" mode.                │
78width     Select the "fit width" mode.                 │
79page      Select the "fit page" mode.                  │
80stretch   Stretch the image to the plugin window size. │
81                  └───────────────────────────────────────────────────────┘
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BROWSER COMPATIBILITY

85       The DjVu browser plugin  has  been  tested  with  several  popular  web
86       browsers:  Netscape  4  and  6;  Gecko  based browsers such as Mozilla,
87       Galeon and Firefox; KHTML based browsers such as Konqueror; and  Opera.
88       Please  read  the  browser  documentation  to find out where the plugin
89       library should be installed.
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EMBEDDING DJVU IMAGES IN HTML PAGES

94       You can integrate DjVu content on an HTML  web  page  with  either  the
95       <embed>  or  the  <object> tag.  This method will work even if your web
96       server does not support the DjVu MIME type.  The CGI style flags can be
97       directly  used as attributes of the embedding tag.  The following exam‐
98       ple shows the W3C standard syntax with the OBJECT tag:
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100          <object data="myfile.djvu" type="image/vnd.djvu"
101                    width="100%" height="100%" >
102              <param name="page" value="iii">
103              <param name="zoom" value="stretch">
104              This browser cannot render djvu data.
105          </object>
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107       And this is the customary syntax with the EMBED tag:
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109          <embed src="myfile.djvu" type="image/vnd.djvu"
110                    width="100%" height="100%"
111                    page="iii" zoom="stretch"></embed>
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INTERFACING THE DJVIEW PLUGIN WITH JAVASCRIPT

114       Recent versions of the  djview4  plugin  can  be  controlled  from  the
115       JavaScript  intepreter  of  browsers implementing the Mozilla NPRuntime
116       API.  To access the plugin object, include  the  attribute  id="plugin‐
117       name"  into the <object> or <embed> tag and use the JavaScript function
118       getElementById("pluginname").
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120       The plugin object implements two methods to retrieve and set the  value
121       of  the  options  usually  recognized  as CGI-style flags.  It also can
122       evaluate a specified JavaScript expression whenever  something  changes
123       in the status of the djview interface.
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125       pluginobject.setdjvuopt("key",value)
126              Set  the  value  of  the djvu option key to the character string
127              value.  This achieves  the  same  effect  as  specifying  option
128              key=value  among  the  CGI-style flags.  For instance, values of
129              the key page can be page IDs, page titles, page numbers, or page
130              names.
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132       pluginobject.getdjvuopt("key")
133              Return  the  value  of  the  djvu  option  key as a string.  The
134              returned value is always  a  character  string,  even  when  the
135              return  is  logically  a number.  Boolean values are returned as
136              strings yes or no.  Besides  the  usual  CGI-style  flags,  this
137              function  recognizes  the  additional  key pages and returns the
138              total number of pages in the DjVu document.  An empty string  is
139              returned when the key is not recognized.
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141       pluginobject.onchange="code";
142              Ensure that string code is evaluated in the context of the plug‐
143              in object whenever something changes  in  the  djview  graphical
144              user interface.  For instance, this evaluation happens when pro‐
145              gressive refinements are painted, and when the user  manipulates
146              the image interactively.
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148       pluginobject.version
149              Return  a  string  describing the plugin version.  This property
150              can be used to test whether the djview plugin is  scriptable  in
151              this browser.
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153       Note  that  the  scriptability  feature may not be accessible until the
154       djview plugin is fully loaded.  Therefore  it  is  advisable  to  check
155       pluginobject.version  from  the  JavaScript  onload  before calling any
156       other method.
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CREDITS

160       This program was written by Andrei  Erofeev  <andrew_erofeev@yahoo.com>
161       and  was  then  improved  by Bill Riemers <docbill@sourceforge.net> and
162       Léon Bottou <leonb@users.sourceforge.net>.
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SEE ALSO

166       djvu(1), ddjvu(1), djview4(1)
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170DjView-4                           1/4/2007                        NSDEJAVU(1)
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