How to add a new wxUSE_XXX preprocessor constant ================================================ 0. Purpose ---------- Detailed description of what needs to be done when you want to add a new wxUSE_XXX compilation flag. The text below assumes you need new wxUSE_FOO. 1. Overview ----------- wxWidgets uses wxUSE_XXX macros for conditionally compiling in (or not) optional components. In general, whenever a new non critical (i.e. not absolutely required by important parts of the library) class Foo is added it should use its own wxUSE_FOO compilation flag. wxUSE_FOO must be always defined and have value of 0 or 1. Be careful with testing for it in wx/foo.h: don't do it at the very beginning of the file because then wxUSE_FOO would be not defined at all if the user directly includes wx/foo.h, include "wx/defs.h" before testing for wxUSE_FOO. 2. Required files update ------------------------ Assuming wxUSE_FOO is used on all platforms, the following must be done: a) update include/wx/setup_inc.h This file contains all common wxUSE_XXXs, and is used to update wxMSW, wxMac setup.h and Unix setup.h.in using build/update-setup-h. Please try to add the new define in a logical place (i.e. near any related ones) and write a detailed comment explaining what does it do and why would you want to turn it on/off. Choose the appropriate default value: this should be usually 1 but can be 0 if there are some problems preventing the use of Foo by default (e.g. it requires installation of some non standard 3rd party libraries). After changing this file, run the update-setup-h script (this is probably better done on a Unix machine although it should work under Cygwin too). b) update other setup.h files Currently include/wx/univ/setup.h and setup.h_vms are not automatically updated so please update them manually (or modify the update-setup-h script to take care of them...). c) update configure.in Here you need to add DEFAULT_wxUSE_FOO define. It should be added in the block beginning after WX_ARG_CACHE_INIT line and should default to "no" for "if DEBUG_CONFIGURE = 1" branch (this is used for absolutely minimal builds) and the same as default valye in setup_inc.h in the "else" branch. You also need to add a WX_ARG_ENABLE (or, if new functionality can be reasonably described as support for a 3rd party library, WX_ARG_WITH) line togetherw with all the existing WX_ARG_ENABLEs. If you have a sample/foo which should be only built when wxUSE_FOO==1, then only add it to the SAMPLES_SUBDIRS if wxUSE_FOO=yes in configure. 3. Documentation ---------------- Currently wxUSE_XXXs are not documented, except for a few important global ones which are in docs/latex/wx/cppconst.tex. So normally there is nothing to do (but this could change in the future). === EOF === Author: VZ Version: $Id$