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Creating a new Component (Win32)

This guide is intended to walk the reader through setting up a skeleton XPCOM project in Microsoft Visual Studio 6.0. Familiarity with XPIDL and C++ is assumed.

Download the following packages:

• Gecko SDK (Win32, Linux) - Provides headers, libs, and IDL files for FROZEN XPCOM interfaces.
• Mozilla Windows Tools - Provides libIDL-X.dll required to process IDL files.

Configure Environment:

• Set MOZ_TOOLS environment variable to path where you'd like WinTools to install (we'll call it $TOOLDIR).
• Unpack wintools.zip, and run buildtools\windows\install.bat
• Add $TOOLDIR\bin to PATH environment variable.
• Unpack Gecko SDK wherever you like (we'll call the path $SDK).
• Add $SDK\bin to PATH environment variable.

Setup new Visual Studio project for XPCOM component:

• Create new VS project "Win32 Dynamic-Link Library"
• Under "C/C++" tab, goto "Preprocessor" Category
• Add following preprocessor defines: "XPCOM_GLUE"
• Add sdk include dir to "Additional Include Directories" box
• Goto "C++ Language" Category
• Disable exception handling
• Under "Link" tab, goto "Input" category
• Add sdk "bin" dir to "Additional Library Path" box
• Add following libraries to the "Object/library Modules" box: "xpcomglue.lib nspr4.lib plds4.lib plc4.lib"
• Under "C/C++" tab, goto "Code Generation" Category
• Select "Multithreaded DLL" for "Use runtime library" box

Create Interface Definition: $IDL.idl

• generate GUID (genguid.exe)
• write interface definition
• generate header and typelib from interface file (assuming gecko-sdk lives at $SDK)
• xpidl -m header -I $SDK/idl $IDL.idl
• xpidl -m typelib -I $SDK/idl $IDL.idl
• this creates $IDL.h and $IDL.xpt
• For more information, see mtIMachine.idl.

Create Component Header File: $COMPONENT.h

• add double inclusion protection
• #include "$IDL.h"
• generate GUID
• Create component constants:

  #define ${COMPONENT}_CONTRACTID "@cs.pdx.edu/MozTorch/WebLock;1"
  #define ${COMPONENT}_CLASSNAME "MozTorch WebLock Example"
  // {4D598E8A-B69C-4826-B40B-90FE8F80286C}
  #define ${COMPONENT}_CID { 0x4d598e8a, 0xb69c, 0x4826, { 0xb4, 0xb, 0x90, 0xfe, 0x8f, 0x80, 0x28, 0x6c } } 
  

• copy header file template from $IDL.h (replacing component name)
• For more information, see mtMachineKnn.h.

Create Component Source File: $COMPONENT.cpp

• #include $COMPONENT.h
• copy source file template from $IDL.h (replacing component name)
• For more information, see mtMachineKnn.cpp.

Create Module Source File: ${COMPONENT}Module.cpp

• #include "nsIGenericFactory.h"
• #include "COMPONENT.h"
• NS_GENERIC_FACTORY_CONSTRUCTOR($COMPONENT)

• static nsModuleComponentInfo components[] = {{
  ${COMPONENT}_CLASSNAME,
  ${COMPONENT}_CID,
  ${COMPONENT}_CONTRACTID,
  ${COMPONENT}Constructor,
  }};
  

• NS_IMPL_NSGETMODULE("${COMPONENT}Module", components)
• For more information, see mtModule.cpp.

Build the component: $COMPONENT.dll

Register Component with Firefox

• copy $COMPONENT.dll and $IDL.xpt to Firefox components dir
• run regxpcom (might need "-x $COMPONENTS_DIR")
• touch ".autoreg" in main firefox dir