1 How to add a new wxUSE_XXX preprocessor constant 2 ================================================ 3 40. Purpose 5---------- 6 7Detailed description of what needs to be done when you want to add a new 8wxUSE_XXX compilation flag. The text below assumes you need new wxUSE_FOO. 9 10 111. Overview 12----------- 13 14wxWidgets uses wxUSE_XXX macros for conditionally compiling in (or not) 15optional components. In general, whenever a new non critical (i.e. not 16absolutely required by important parts of the library) class Foo is added it 17should use its own wxUSE_FOO compilation flag. 18 19wxUSE_FOO must be always defined and have value of 0 or 1. Be careful with 20testing for it in wx/foo.h: don't do it at the very beginning of the file 21because then wxUSE_FOO would be not defined at all if the user directly 22includes wx/foo.h, include "wx/defs.h" before testing for wxUSE_FOO. 23 24 252. Required files update 26------------------------ 27 28Assuming wxUSE_FOO is used on all platforms, the following must be done: 29 30a) update include/wx/setup_inc.h 31 32 This file contains all common wxUSE_XXXs, and is used to update wxMSW, wxMac 33 setup.h and Unix setup.h.in using build/update-setup-h. Please try to add 34 the new define in a logical place (i.e. near any related ones) and write a 35 detailed comment explaining what does it do and why would you want to turn 36 it on/off. Choose the appropriate default value: this should be usually 1 37 but can be 0 if there are some problems preventing the use of Foo by default 38 (e.g. it requires installation of some non standard 3rd party libraries). 39 After changing this file, run the update-setup-h script (this is probably 40 better done on a Unix machine although it should work under Cygwin too). 41 42b) update other setup.h files 43 44 Currently include/wx/univ/setup.h and setup.h_vms are not automatically 45 updated so please update them manually (or modify the update-setup-h script 46 to take care of them...). 47 48c) update configure.in 49 50 Here you need to add DEFAULT_wxUSE_FOO define. It should be added in the 51 block beginning after WX_ARG_CACHE_INIT line and should default to "no" for 52 "if DEBUG_CONFIGURE = 1" branch (this is used for absolutely minimal builds) 53 and the same as default value in setup_inc.h in the "else" branch. 54 55 You also need to add a WX_ARG_ENABLE (or, if new functionality can be 56 reasonably described as support for a 3rd party library, WX_ARG_WITH) 57 line togetherw with all the existing WX_ARG_ENABLEs. 58 59 If you have a sample/foo which should be only built when wxUSE_FOO==1, 60 then only add it to the SAMPLES_SUBDIRS if wxUSE_FOO=yes in configure. 61 62 633. Documentation 64---------------- 65 66Currently wxUSE_XXXs are not documented, except for a few important global ones 67which are in docs/latex/wx/cppconst.tex. So normally there is nothing to do 68(but this could change in the future). 69 70 71=== EOF === 72 73Author: VZ 74Version: $Id: tn0021.txt 35738 2005-09-27 15:46:24Z VZ $ 75 76