+ System options can be set by the program itself using SetOption() method
+ and they also can be set from the program environment by defining an
+ environment variable @c wx_option to set the given option for all wxWidgets
+ applications or @c wx_appname_option to set it just for the application
+ with the given name (as returned by wxApp::GetAppName()). Notice that any
+ characters not allowed in the environment variables names, such as periods
+ and dashes, should be replaced with underscores. E.g. to define a system
+ option "foo-bar" you need to define the environment variable "wx_foo_bar".
+
+ The program may use system options for its own needs but they are mostly
+ used to control the behaviour of wxWidgets library itself.
+
+ These options are currently recognised by wxWidgets:
+
+ @section sysopt_all All platforms
+
+ @beginFlagTable
+ @flag{exit-on-assert}
+ If set to non-zero value, abort the program if an assertion fails. The
+ default behaviour in case of assertion failure depends on the build mode
+ and can be changed by overriding wxApp::OnAssertFailure() but setting
+ this option allows to change it without modifying the program code and
+ also applies to asserts which may happen before the wxApp object
+ creation or after its destruction.
+ @endFlagTable
+
+ @section sysopt_win Windows
+
+ @beginFlagTable
+ @flag{no-maskblt}
+ 1 to never use WIN32's MaskBlt function, 0 to allow it to be used where possible.
+ Default: 0. In some circumstances the MaskBlt function can be slower than using
+ the fallback code, especially if using DC caching. By default, MaskBlt will be
+ used where it is implemented by the operating system and driver.
+ @flag{msw.remap}
+ If 1 (the default), wxToolBar bitmap colours will be remapped to the current
+ theme's values. Set this to 0 to disable this functionality, for example if
+ you're using more than 16 colours in your tool bitmaps.
+ @flag{msw.window.no-clip-children}
+ If 1, windows will not automatically get the WS_CLIPCHILDREN style.
+ This restores the way windows are refreshed back to the method used in
+ versions of wxWidgets earlier than 2.5.4, and for some complex window
+ hierarchies it can reduce apparent refresh delays.
+ You may still specify wxCLIP_CHILDREN for individual windows.
+ @flag{msw.notebook.themed-background}
+ If set to 0, globally disables themed backgrounds on notebook pages.
+ Note that this won't disable the theme on the actual notebook background
+ (noticeable only if there are no pages).
+ @flag{msw.staticbox.optimized-paint}
+ If set to 0, switches off optimized wxStaticBox painting.
+ Setting this to 0 causes more flicker, but allows applications to paint
+ graphics on the parent of a static box (the optimized refresh causes any
+ such drawing to disappear).
+ @flag{msw.display.directdraw}
+ If set to 1, use DirectDraw-based implementation of wxDisplay.
+ By default the standard Win32 functions are used.
+ @flag{msw.font.no-proof-quality}
+ If set to 1, use default fonts quality instead of proof quality when
+ creating fonts. With proof quality the fonts have slightly better
+ appearance but not all fonts are available in this quality,
+ e.g. the Terminal font in small sizes is not and this option may be
+ used if wider fonts selection is more important than higher quality.
+ @flag{wince.dialog.real-ok-cancel}
+ The PocketPC guidelines recommend for Ok/Cancel dialogs to use an OK button
+ located inside the caption bar and implement Cancel functionality through
+ Undo outside the dialog.
+ wxDialog::CreateButtonSizer will follow the native behaviour on WinCE but
+ it can be overridden with real wxButtons by setting the option below to 1.
+ @endFlagTable
+
+
+ @section sysopt_gtk GTK+
+
+ @beginFlagTable
+ @flag{gtk.tlw.can-set-transparent}
+ wxTopLevelWindow::CanSetTransparent() method normally tries to detect
+ automatically whether transparency for top level windows is currently
+ supported, however this may sometimes fail and this option allows to
+ override the automatic detection. Setting it to 1 makes the transparency
+ be always available (setting it can still fail, of course) and setting it
+ to 0 makes it always unavailable.
+ @flag{gtk.desktop}
+ This option can be set to override the default desktop environment
+ determination. Supported values are GNOME and KDE.
+ @flag{gtk.window.force-background-colour}
+ If 1, the backgrounds of windows with the wxBG_STYLE_COLOUR background
+ style are cleared forcibly instead of relying on the underlying GTK+
+ window colour. This works around a display problem when running
+ applications under KDE with the gtk-qt theme installed (0.6 and below).
+ @endFlagTable
+
+
+ @section sysopt_mac Mac
+
+ @beginFlagTable
+ @flag{mac.window-plain-transition}
+ If 1, uses a plainer transition when showing a window.
+ You can also use the symbol wxMAC_WINDOW_PLAIN_TRANSITION.
+ @flag{window-default-variant}
+ The default variant used by windows (cast to integer from the wxWindowVariant enum).
+ Also known as wxWINDOW_DEFAULT_VARIANT.
+ @flag{mac.listctrl.always_use_generic}
+ Tells wxListCtrl to use the generic control even when it is capable of
+ using the native control instead. Also known as wxMAC_ALWAYS_USE_GENERIC_LISTCTRL.
+ @flag{mac.textcontrol-use-spell-checker}
+ This option only has effect for Mac OS X 10.4 and higher.
+ If 1 activates the spell checking in wxTextCtrl.
+ @flag{osx.openfiledialog.always-show-types}
+ Per default a wxFileDialog with wxFD_OPEN does not show a types-popup on OSX but allows
+ the selection of files from any of the supported types. Setting this to 1 shows a wxChoice
+ for selection (if there is more than one supported filetype).
+ @endFlagTable
+
+
+ @section sysopt_motif Motif
+
+ @beginFlagTable
+ @flag{motif.largebuttons}
+ If 1, uses a bigger default size for wxButtons.
+ @endFlagTable
+
+
+ The compile-time option to include or exclude this functionality is wxUSE_SYSTEM_OPTIONS.