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diff --git a/xbattext.ms b/xbattext.ms new file mode 100644 index 0000000..34b5f62 --- /dev/null +++ b/xbattext.ms @@ -0,0 +1,88 @@ +.so /home/john/prj/re/re.tmac +.nr St 6n +.TL +.BI xbattext , +an X11 battery monitor for NetBSD +.AU +John Ankarström +.AB +.LP +.I xbattext +is a simple X11 program that displays, in text, +the current battery level. +Its source code serves as a good introduction to X11 programnming. +It is short, simple and easy to follow, +as it accounts only for a single system \(en NetBSD. +It makes use of both Xt (X toolkit intrinsics) and Xm (Motif), +two of the most popular X libraries. +It demonstrates how to access resources from +.I ~/.Xdefaults , +how to display text in various colors and fonts and +how to set timers outside of the main event loop +to perform asynchronous tasks that are not triggered by user interaction. +.PP +This document is a commented version of the +.I xbattext +source code. +It is generated with +.I re , +a reference-based literate programming system available at the address +http://git.\:ankarstrom.se/re/. +.AE +.Re xbattext.c:/^#include/ +.LP +.I Xm/Label.h +contains the definitions for Motif's label widget, +which is used to display the text. +That headerf file, in turn, includes +.I X11/Xlib.h +for us. +.PP +.I machine/apmvar.h +is needed in order to inspect the battery status on NetBSD. +.Re xbattext.c:/^struct _res/ +.LP +Two structures are created to access the application's resources: +.I res , +which will hold the values of the resources, and +.I res_opts , +which defines how those resources should be accessed. +.PP +The +.I res +structure is going to be filled by the function +.I XtGetApplicationResources +using the information defined in +.I res_opts .\** +.FS +For more information about resource management and the structure of the +.I XtResource +type, see +.nh +http://lesstif.sourceforge.net/doc/super-ux/g1ae03e/part1/chap9.html. +.hy +.FE +.Re xbattext.c:/"alertFontList"/ +\& +.Re xbattext.c:/"chargeForeground"/ +.LP +.I wargs +is used by +.I XtSetArg , +which stores arguments in it, and +.I XtSetValues , +which sets new values for a widget +according to the arguments stored in it. +.PP +.I alert +and +.I charge +are boolean variables that are set to true +whenever +.I xbattext +detects that the battery is low or +that the AC adapter is plugged in. +.PP +.I timer +contains the identifier for the current timer. +.Re xbattext.c:/^main/ |