///////////////////////////////////////////////////////////////////////////// // Name: strategies.h // Purpose: Strategies page of the Doxygen manual // Author: wxWidgets team // RCS-ID: $Id$ // Licence: wxWindows license ///////////////////////////////////////////////////////////////////////////// /*! @page page_strategies Programming strategies This chapter is intended to list strategies that may be useful when writing and debugging wxWidgets programs. If you have any good tips, please submit them for inclusion here. @li @ref page_strategies_reducingerr @li @ref page_strategies_portability @li @ref page_strategies_debug
@section page_strategies_reducingerr Strategies for reducing programming errors @subsection page_strategies_reducingerr_useassert Use ASSERT It is good practice to use ASSERT statements liberally, that check for conditions that should or should not hold, and print out appropriate error messages. These can be compiled out of a non-debugging version of wxWidgets and your application. Using ASSERT is an example of `defensive programming': it can alert you to problems later on. See wxASSERT for more info. @subsection page_strategies_reducingerr_usewxstring Use wxString in preference to character arrays Using wxString can be much safer and more convenient than using wxChar *. You can reduce the possibility of memory leaks substantially, and it is much more convenient to use the overloaded operators than functions such as @c strcmp. wxString won't add a significant overhead to your program; the overhead is compensated for by easier manipulation (which means less code). The same goes for other data types: use classes wherever possible. @section page_strategies_portability Strategies for portability @subsection page_strategies_portability_usesizers Use sizers Don't use absolute panel item positioning if you can avoid it. Different GUIs have very differently sized panel items. Consider using the @ref overview_sizers instead. @subsection page_strategies_portability_useresources Use wxWidgets resource files Use .xrc (wxWidgets resource files) where possible, because they can be easily changed independently of source code. See the @ref overview_xrc for more info. @section page_strategies_debug Strategies for debugging @subsection page_strategies_debug_positivethinking Positive thinking It is common to blow up the problem in one's imagination, so that it seems to threaten weeks, months or even years of work. The problem you face may seem insurmountable: but almost never is. Once you have been programming for some time, you will be able to remember similar incidents that threw you into the depths of despair. But remember, you always solved the problem, somehow! Perseverance is often the key, even though a seemingly trivial problem can take an apparently inordinate amount of time to solve. In the end, you will probably wonder why you worried so much. That's not to say it isn't painful at the time. Try not to worry -- there are many more important things in life. @subsection page_strategies_debug_simplifyproblem Simplify the problem Reduce the code exhibiting the problem to the smallest program possible that exhibits the problem. If it is not possible to reduce a large and complex program to a very small program, then try to ensure your code doesn't hide the problem (you may have attempted to minimize the problem in some way: but now you want to expose it). With luck, you can add a small amount of code that causes the program to go from functioning to non-functioning state. This should give a clue to the problem. In some cases though, such as memory leaks or wrong deallocation, this can still give totally spurious results! @subsection page_strategies_debug_usedebugger Use a debugger This sounds like facetious advice, but it is surprising how often people don't use a debugger. Often it is an overhead to install or learn how to use a debugger, but it really is essential for anything but the most trivial programs. @subsection page_strategies_debug_uselogging Use logging functions There is a variety of logging functions that you can use in your program: see @ref logfunctions. Using tracing statements may be more convenient than using the debugger in some circumstances (such as when your debugger doesn't support a lot of debugging code, or you wish to print a bunch of variables). @subsection page_strategies_debug_usedebuggingfacilities Use the wxWidgets debugging facilities You can use wxDebugContext to check for memory leaks and corrupt memory: in fact in debugging mode, wxWidgets will automatically check for memory leaks at the end of the program if wxWidgets is suitably configured. Depending on the operating system and compiler, more or less specific information about the problem will be logged. You should also use @ref debugmacros as part of a `defensive programming' strategy, scattering wxASSERTs liberally to test for problems in your code as early as possible. Forward thinking will save a surprising amount of time in the long run. See the @ref overview_debugging for further information. */