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Diffstat (limited to 'xbattext.ms')
| -rw-r--r-- | xbattext.ms | 100 |
1 files changed, 92 insertions, 8 deletions
diff --git a/xbattext.ms b/xbattext.ms index 34b5f62..06c1269 100644 --- a/xbattext.ms +++ b/xbattext.ms @@ -1,5 +1,4 @@ .so /home/john/prj/re/re.tmac -.nr St 6n .TL .BI xbattext , an X11 battery monitor for NetBSD @@ -26,7 +25,7 @@ This document is a commented version of the source code. It is generated with .I re , -a reference-based literate programming system available at the address +a reference-based literate programming system available at the WWW address http://git.\:ankarstrom.se/re/. .AE .Re xbattext.c:/^#include/ @@ -40,13 +39,16 @@ for us. .PP .I machine/apmvar.h is needed in order to inspect the battery status on NetBSD. -.Re xbattext.c:/^struct _res/ +.Re xbattext.c:/^\/\* interval in seconds/ +.LP +By default, the battery status is checked every ten seconds. +.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. +which defines how those resources should be retrieved. .PP The .I res @@ -64,8 +66,14 @@ http://lesstif.sourceforge.net/doc/super-ux/g1ae03e/part1/chap9.html. .FE .Re xbattext.c:/"alertFontList"/ \& -.Re xbattext.c:/"chargeForeground"/ +.Re xbattext.c:/^\/\* application state/ .LP +There is not space to explain the function of all variables +used by the program, +but some of them deserve a special mention: +.PP +.ps -1p +.vs -1p .I wargs is used by .I XtSetArg , @@ -74,6 +82,8 @@ which stores arguments in it, and which sets new values for a widget according to the arguments stored in it. .PP +.ps -1p +.vs -1p .I alert and .I charge @@ -82,7 +92,81 @@ whenever .I xbattext detects that the battery is low or that the AC adapter is plugged in. +.Re xbattext.c:/XtVaAppInitialize(/ +.LP +Many Xt functions have two variants: +a non-variadic variant, which uses +.I XtSetArg +to collect arguments, +and a variadic variant, marked by the +.I Va +component of its name. .PP -.I timer -contains the identifier for the current timer. -.Re xbattext.c:/^main/ +.I toplevel +contains the +.Q main +widget that contains all actual widgets. +.Re xbattext.c:/open("\/dev\/apm"/ +.LP +The battery level is queried through +.I ioctl +requests to +.I /dev/apm . +The file descriptor is closed by the kernel when the program exits. +.Re xbattext.c:/^ \/\* load application resources/ +.LP +As mentioned earlier, +.I XtGetApplicationResources +uses the +.I XtResource +list defined above to fill the +.I res +structure with the corresponding resources. +.bp +.Re xbattext.c:/^ \/\* create motif label/ +.LP +The battery level is displayed in a Motif label widget. +It starts out containing an empty string. +.Re xbattext.c:/^ update(/ +.LP +Before starting the main event loop, the +.I update +function is called, which registers a timeout that will run +independently of the event loop.\** +.FS +For more information about timeouts, see +http://motifdeveloper.com/tips/tip16.html. +.FE +.Re xbattext.c:/^\/\* update battery status and (re-)add timer/ +.LP +The +.I update +function, which is called at the end of each timeout, +is responsible for checking the battery status and +updating the label. +.PP +The first argument is a pointer to a value set by the user +when the timeout is registered. +The second argument contains a pointer to the timeout ID. +Neither argument is used in this program. +.Re xbattext.c:/^ \/\* get battery info/ +.LP +As mentioned earlier, +the battery status is retrieved through an +.I ioctl +request, +.CW APM_IOC_GETPOWER . +It returns an +.I apm_power_info +structure (which must be zeroed first). +.Re xbattext.c:/^ \/\* put battery status into label/ +.LP +The battery percentage, contained in the +.I battery_life +member, is written to an +.I XmString , +which is a special type of string used by Motif. +It is associated with tag, +which contains information about the visual characteristics of the text. +To begin with, the string is set to use the default tag. +.Re xbattext.c:/^ i = 0;/ |