Tutorial: How to Create a Helix Plug-in

The Qt Extended media server is able to use the Helix DNA Client multi-media engine. Information on writing plug-ins for Helix DNA Client can be found in the Helix DNA Client SDK Documentation.

To include your plug-in into the Helix build systems requires the following steps:

1. Modify src/3rdparty/libraries/helix/src/build/build/BIF/helix.bif within the Helix source directory as follows:

       <!-- FILESYSTEM/QTOPIA -->
       <module id="filesystem_qtopia" name="filesystem/qtopia" group="core">
           <cvs root="helix"/>
           <includeplatforms>
               unix
           </includeplatforms>
   
           <source_dependlist>
               common_include
           </source_dependlist>
   
           <dependlist>
               common_container
               common_util
               common_system
               common_fileio
               common_dbgtool
               common_runtime
           </dependlist>
       </module>

   where

   • id="filesystem_qtopia" : identifies the module within the bif file.
   • name="filesystem/qtopia" : points to the module source within the Helix source tree.
2. Add the plug-in to the target as follows:

       <!-- SPLAY_NODIST -->
       <module id="splay_nodist_qtopia" name="clientapps/simpleplayer" group="core">
           <includeplatforms>
               unix mac win32 symbian openwave wince
           </includeplatforms>
   
           <dependlist>
               filesystem_qtopia
       ...
           </dependlist>
       </module>

   where the target is the top-level module definition that defines modules included in the build.

3. Create a Umakefile, for example, the following Umakefile is used for the Qt Extended filesystem plug-in:

       UmakefileVersion(2,1)
   
       project.AddModuleIncludes("common/include",
                                 "common/system/pub")
   
       project.AddIncludes(os.path.join(GetSDKPath("qt"),"include"))
       project.AddIncludes(os.path.join(GetSDKPath("qt"),"include","Qt"))
       project.AddIncludes(os.path.join(GetSDKPath("qt"),"include","QtGui"))
       project.AddIncludes(os.path.join(GetSDKPath("qt"),"include","QtCore"))
   
       project.AddIncludes(os.path.join(GetSDKPath("qtopia"),"include"))
   
       project.AddSystemPaths("-L" + os.path.join(GetSDKPath("qt"),"lib"))
   
       if project.BuildOption("debug"):
           project.AddSystemLibraries("QtCore_debug")
       else:
           project.AddSystemLibraries("QtCore")
   
       project.AddSystemPaths("-L" + os.path.join(GetSDKPath("qtopia"),"lib"))
       project.AddSystemLibraries("qtopia");
   
       project.AddSources('qtopiafileobject.cpp', 'qtopiafilesystem.cpp')
   
       project.ExportFunction("RMACreateInstance",
                              "IUnknown** ppObj",
                              "common/include",
                              "hxcom.h")
   
       DLLTarget('qtopiafsys')

   Note: If your plug-in does not use the Qt or Qt Extended libraries you can exclude:

   • the Qt and Qt Extended project .AddIncludes
   • project .AddSystemPaths.
4. At configure time after copying the Helix sources and Qt Extended additions to src/3rdparty/libraries/helixbuild the Qt Extended build system applies patches to the Helix source tree.

   To have your changes applied at configure time you may perform one or both of the following:

   • create a patch file in src/3rdparty/libraries/helix/trolltech/patches/.
   • place your plug-in sources in src/3rdparty/libraries/helix/trolltech/src. This directory is copied to the helixbuild directory at configure time.

Note: Reference documentation for Helix build system including Umakefiles is available in build/doc within the Helix source directory.