Question

The Qt-based Netscape Plugin software makes it easy to write plugins
that can be used on both Unix/Linux and Windows/95/NT, in Netscape and
Internet Explorer, and any other web browser supporting the same
protocol.

How-to

1. Download the
   Plugin SDK from Netscape, and copy the following files from there to
   $QTDIR/extensions/nsplugin/src
   • common/npwin.cpp
   • common/npunix.c
   • include/npapi.h
   • include/npupp.h
   • include/jri.h
   • include/jri_md.h
   • include/jritypes.h
2. Build the Netscape Plugin extension library, found in the
   extensions/nsplugin/src directory of your Qt distribution.
   This produces a static library to be linked with your plugin code.

3. Read the plugin class documentation, and
   examine the example plugins.

4. Do most of your development as a stand-alone Qt application - debugging
   Netscape Plugins is cumbersome. You may want to use signal(2)
   in your plugin to enable core-dumps if your browser disables them.

5. Note the platform-specific build steps below.
6. Read about the raw plugin interface
   in Netscape's handbook.

7. If files viewed by a plugin are provided by an HTTP server
   (using a http://... URL) then
   the server must be configured to send the correct MIME type
   for the file, e.g. by editing Apache's mime.types file.
   If the files are viewed via a //...
   URL, then the browser will use the filename extension to decide
   the file type (and hence the plugin to load) - the user may need
   to set the filename extension in the Helpers or Applications
   section of their browser preferences.

Building under X11

• The Makefiles in the examples are appropriate for UNIX/X11.
• The user must install the resulting Shared Object in the Plugins
  directory of the browser.

Building under Windows

• Qt needs to be built as a static library when building Netscape
  plugins.

• Plugins must be named npname.dll,
  or the browser will ignore them.

• The link step must include:
  • /def:name.def
  • /dll
  • a compiled resource file defining the
    file/MIME types accepted by the plugin.
• The user must install the resulting DLL in the Plugins directory
  of the browser.

Known Bugs

The Qt-based LiveConnect Plugin binding code has a number of
minor bugs, but is sufficiently stable for many production applications.

• MSIE 4.0 support is poor.
• Crashes on X11 if window is closed via window manager.
• Keyboard problems on Windows.