Merge pull request #5 from erikarn/ahc_20220425_menu_widgets

This is the beginning of adding some battery display support into the menu and figuring out how to add arbitrary widgets into the menu bar. It's going to take a bunch more commits / time to clean this up to be more flexible, but at least now we have an MVP of adding a new "thing", buggy as it is.
2026-03-24 01:24:15 +00:00 · 2022-05-21 16:05:17 -07:00
parent 9ac42a9f4a 2a9bd912a1
commit f116f9c335
15 changed files with 512 additions and 30 deletions
--- a/MODULES.md
+++ b/MODULES.md
@@ -121,3 +121,13 @@ Module "Launcher" "(<label>) (<icon>) (<command and args>)"

 The icon is one of the .info icons in the amiwm IconDir.

+## Battery module
+
+This is a simple battery state polling module that is being used
+during battery monitoring / menu toolbar development.
+
+It's currently FreeBSD specific and based on what xbatt does
+to pull info from APM/ACPI.  Adding Linux and other OS support
+shouldn't be too difficult.
+
+Module "Battery"
--- a/Makefile.in
+++ b/Makefile.in
@@ -171,6 +171,9 @@ Filesystem : filesystem.o $(LIBAMI)
 Keyboard : kbdmodule.o kbdlexer.o $(LIBAMI)
 	$(CC) -o Keyboard kbdmodule.o kbdlexer.o $(LIBS)

+Battery : battery_module.o $(LIBAMI)
+	$(CC) -o Battery battery_module.o $(LIBS)
+
 Launcher : launchermodule.o $(LIBAMI)
 	$(CC) -o Launcher launchermodule.o $(LIBS)

@@ -181,7 +184,7 @@ localetest : localetest.o $(LIBAMI)
 	$(CC) -o localetest localetest.o $(LIBS)

 clean : lib_clean
-	$(RM) core $(PROGS) $(LIBAMI) Keyboard Launcher *.o
+	$(RM) core $(PROGS) $(LIBAMI) Keyboard Battery Launcher *.o
 	$(RM) lex.yy.c lex.c y.tab.c y.tab.h gram.h gram.c
 	$(RM) kbdlexer.c kbdmodule.h kbdmodule.c
 	$(RM) config.log
--- a/amiwm.1
+++ b/amiwm.1
@@ -94,6 +94,12 @@ The time string is formatted with the standard strftime() parameters.
 The default is "%c".  It has been found that "%a %b %e %Y   %l:%M %p" works
 well too.  Number is the update interval in seconds.  

+.SH BatteryInfo {yes|no}
+
+This lets you display battery information on the menu bar.
+It reqiures a module (such as Battery) to gather current battery status
+and push it into amiwm to display.
+
 .SH ToolItem \f1\*(lq\f3name" \f1\*(lq\f3command" \f1\*(lq\f3hotkey"

 Adds an item in the Tools menu with the specified name, which executes
--- a/battery_module.c
+++ b/battery_module.c
@@ -0,0 +1,84 @@
+#include <stdio.h>
+#include <string.h>
+#include <err.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <unistd.h>
+
+#include <machine/apm_bios.h>
+
+#define APM_DEV "/dev/apm"
+
+#include "libami.h"
+
+/* XXX should be an md method */
+extern void (*md_periodic_func)(void);
+
+/*
+ * Test battery module for FreeBSD, using APM.
+ */
+
+void docmd(XEvent *e, void *callback)
+{
+  ((void (*)(Window))callback)(e->xany.window);
+}
+
+static char *progname;
+static int apm_fd = -1;
+
+static bool
+get_apm_info(void)
+{
+	int ret;
+	struct apm_info info;
+
+	ret = ioctl(apm_fd, APMIO_GETINFO, &info);
+	if (ret < 0) {
+		warn("ioctl (APMIO_GETINFO)");
+		return false;
+	}
+
+#if 0
+	printf("Battery life: %d\n", info.ai_batt_life);
+	printf("Battery time: %d\n", info.ai_batt_time);
+	printf("Battery AC: %d\n", info.ai_acline);
+#endif
+
+	md_update_battery(info.ai_batt_life, info.ai_batt_time,
+	    info.ai_acline);
+
+	return true;
+}
+
+static void
+periodic_func(void)
+{
+	get_apm_info();
+}
+
+int
+main(int argc, char *argv[])
+{
+  char *arg;
+
+  arg = md_init(argc, argv);
+  (void) arg;
+
+  progname=argv[0];
+
+  md_periodic_func = periodic_func;
+
+  apm_fd = open(APM_DEV, O_RDONLY);
+  if (apm_fd < 0) {
+    err(127, "open");
+  }
+
+  /* initial battery info */
+  get_apm_info();
+
+  /* Run main loop */
+  md_main_loop();
+
+  close(apm_fd);
+  return 0;
+}
--- a/gram.y
+++ b/gram.y
@@ -66,6 +66,7 @@ static int ti_level=0;
 %token <num> INTERSCREENGAP AUTORAISE FOCUS FOLLOWMOUSE CLICKTOTYPE SLOPPY
 %token <num> CUSTOMICONSONLY
 %token <num> TITLEBARCLOCK TITLECLOCKFORMAT
+%token <num> BATTERYINFO
 %token <num> OPAQUEMOVE OPAQUERESIZE SCREENMENU STYLE CLASS TITLE ICONTITLE ICON
 %token <num> SHORTLABELICONS
 %token <ptr> STRING
@@ -118,6 +119,7 @@ stmt		: error
 					prefs.titleclockinterval=$2; 
 					prefs.titleclockformat=$3; }
 		| SCREENMENU truth { prefs.screenmenu=$2; }
+		| BATTERYINFO truth { prefs.battery_info = $2; }
 		| stylespec styleitems RIGHTBRACE
 		;

--- a/libami/Makefile.in
+++ b/libami/Makefile.in
@@ -19,12 +19,12 @@ LN_S = @LN_S@
 RM = -rm -f

 OBJS  = drawinfo.o module.o broker.o eventdispatcher.o mdscreen.o \
-	mdicon.o mdwindow.o kbdsupport.o hotkey.o \
+	mdicon.o mdwindow.o kbdsupport.o hotkey.o mdbattery.o \
 	lists.o readargs.o iconlib.o iconutil.o error.o strutil.o \
 	iffparse.o gadget_button.o gadget_textbox.o gadget_textinput.o

 SRCS = drawinfo.c module.c broker.c eventdispatcher.c mdscreen.c \
-	mdicon.c mdwindow.c kbdsupport.c hotkey.c \
+	mdicon.c mdwindow.c kbdsupport.c hotkey.c mdbattery.c \
 	lists.c readargs.c iconlib.c iconutil.c error.c strutil.c \
 	iffparse.c gadget_button.c gadget_textbox.c gadget_textinput.c

--- a/libami/libami.h
+++ b/libami/libami.h
@@ -389,6 +389,9 @@ extern Pixmap md_image_to_pixmap(Window, unsigned long, struct Image *,
 				 int, int, struct ColorStore *);
 extern char *get_current_icondir(void);

+/* mdbattery.c */
+extern void md_update_battery(int pct, int time, int ac);
+
 /* mdwindow.c */
 extern int md_set_appwindow(Window);

--- a/libami/mdbattery.c
+++ b/libami/mdbattery.c
@@ -0,0 +1,85 @@
+#include <stdlib.h>
+#include <string.h>
+
+#include "libami.h"
+#include "module.h"
+#include "alloc.h"
+
+void
+md_update_battery(int pct, int time, int ac)
+{
+	struct mcmd_update_battery batt = { 0 };
+	int res;
+
+	batt.battery_time = time;
+	batt.battery_pct = pct;
+	batt.battery_ac = ac;
+
+	res = md_command0(None, MCMD_UPDATE_BATTERY, &batt, sizeof(batt));
+	(void) res;
+}
+
+Window md_create_appicon(Window p, int x, int y, char *name,
+			 Pixmap pm1, Pixmap pm2, Pixmap pmm)
+{
+  char *data;
+  Window w;
+  int res, l=strlen(name);
+#ifdef HAVE_ALLOCA
+  struct NewAppIcon *nai=alloca(sizeof(struct NewAppIcon)+l);
+#else
+  struct NewAppIcon *nai=malloc(sizeof(struct NewAppIcon)+l);
+  if(nai==NULL) return None;
+#endif
+  nai->x=x; nai->y=y;
+  nai->pm1=pm1; nai->pm2=pm2; nai->pmm=pmm;
+  strcpy(nai->name, name);
+  res=md_command(p, MCMD_CREATEAPPICON, nai, sizeof(struct NewAppIcon)+l,
+		 &data);
+  if(res<sizeof(w)) {
+    if(data) free(data);
+#ifndef HAVE_ALLOCA
+    free(nai);
+#endif
+    return None;
+  }
+  memcpy(&w, data, sizeof(w));
+  free(data);
+#ifndef HAVE_ALLOCA
+  free(nai);
+#endif
+  return w;
+}
+
+Pixmap md_image_to_pixmap(Window w, unsigned long bgcolor, struct Image *i,
+			  int width, int height, struct ColorStore *cs)
+{
+  Display *dpy = md_display();
+  static GC gc = None;
+  Pixmap pm;
+  static int iconcolormask;
+  static unsigned long *iconcolor = NULL;
+  if(gc == None && w != None)
+    gc = XCreateGC(dpy, w, 0, NULL);
+  if(iconcolor == NULL) {
+    char *p;
+    int res = md_command(w, MCMD_GETICONPALETTE, NULL, 0, &p);
+    if(res<0)
+      return None;
+    iconcolor = (unsigned long *)(void *)p;
+    iconcolormask = (res/sizeof(unsigned long))-1;
+  }
+  pm = image_to_pixmap(md_display(), w, gc, bgcolor, iconcolor, iconcolormask,
+		       i, width, height, cs);
+  return pm;
+}
+
+char *get_current_icondir()
+{
+  char *p;
+  if(md_command(None, MCMD_GETICONDIR, NULL, 0, &p)>=0 && p)
+    return p;
+  if(p) free(p);
+  return NULL;
+}
+
--- a/libami/module.c
+++ b/libami/module.c
@@ -8,6 +8,7 @@
 #ifdef HAVE_UNISTD_H
 #include <unistd.h>
 #endif
+#include <sys/select.h>

 #include "libami.h"
 #include "module.h"
@@ -24,6 +25,7 @@ Window md_root = None;
 static int md_int_len=0;
 static char *md_int_buf=NULL;
 void (*md_broker_func)(XEvent *, unsigned long);
+void (*md_periodic_func)(void);

 void md_exit(int signal)
 {
@@ -54,30 +56,120 @@ static int md_write(void *ptr, int len)
  return tot;
 }

-static int md_read(void *ptr, int len)
+/*
+ * Wait until the read FD is ready, or timeout (5 seconds.)
+ *
+ * Returns:
+ * + 1 if OK
+ * + 0 if timeout
+ * < 0 if error
+ */
+static int
+md_wait_read_fd(void)
+{
+  fd_set readfds;
+  struct timeval tv;
+  int ret;
+
+  FD_ZERO(&readfds);
+  FD_SET(md_in_fd, &readfds);
+  tv.tv_sec = 5;
+  tv.tv_usec = 0;
+
+  ret = select(md_in_fd + 1, &readfds, NULL, NULL, &tv);
+  if (ret == 0) {
+    return (0);
+  }
+  if (ret < 0) {
+    return (-1);
+  }
+  if (FD_ISSET(md_in_fd, &readfds)) {
+    return (1);
+  }
+
+  /* FD wasn't set; just return 0 */
+  return (0);
+}
+
+/*
+ * Read from the input file descriptor until len; ,populate
+ * our buffer.
+ *
+ * Return total read, 0 on timeout, else -1 on error.
+ */
+static int md_read(void *ptr, int len, int block)
 {
  char *p=ptr;
  int r, tot=0;
-  while(len>0) {
-    if((r=read(md_in_fd, p, len))<0) {
-      if(errno==EINTR)
+
+  while (len > 0) {
+
+    /* Wait until the socket is ready, or timeout */
+    r = md_wait_read_fd();
+    if (r < 0) {
+      return (-1);
+    }
+
+    /*
+     * Note: If we've read /anything/, then we just keep
+     * going until we're done.  Otherwise we'll exit
+     * out here with a partial read and things will
+     * go sideways.
+     *
+     * If we're not blocking and select timed out,
+     * return timeout.
+     */
+    if ((tot == 0) && (block == 0) && (r == 0)) {
+      return (0);
+    }
+
+    /*
+     * Try to read some data.  Go back around again
+     * if we hit EINTR/EWOULDBLOCK.
+     *
+     * If we hit EOF then that's an error.
+     */
+    r = read(md_in_fd, p, len);
+
+    /* Error */
+    if (r < 0) {
+      if ((errno == EINTR) || (errno == EWOULDBLOCK)) {
        continue;
-      else
-        return r;
+      } else {
+       return (-1);
+      }
    }
-    if(!r) {
-      if(tot)
-        return tot;
-      else
-        md_exit(0);
+
+    /*
+     * EOF and didn't read anything? md_exit() like
+     * the old code did.
+     */
+    if ((r == 0) && (tot == 0)) {
+      md_exit(0);
    }
+
+    /*
+     * EOF, but we read data, so at least return what
+     * we did read.
+     */
+    if (r == 0) {
+      return (tot);
+    }
+
+    /* r > 0 here */
+
    tot+=r;
    p+=r;
    len-=r;
  }
-  return tot;
+
+  return (tot);
 }

+/*
+ * Read in "len" bytes from the window manager command path
+ * into md_int_buf.
+ */
 static int md_int_load(int len)
 {
  if(len>=md_int_len) {
@@ -88,7 +180,7 @@ static int md_int_load(int len)
  }

  md_int_buf[len]='\0';
-  return md_read(md_int_buf, len);
+  return md_read(md_int_buf, len, 1);
 }

 static struct md_queued_event {
@@ -96,6 +188,13 @@ static struct md_queued_event {
  struct mcmd_event e;
 } *event_head=NULL, *event_tail=NULL;

+/*
+ * Process queued XEvents from the window manager.
+ *
+ * The window manager pushes subscribed XEvents down to
+ * modules and this pulls them out of the queue and
+ * calls md_broker_func() on each of them.
+ */
 void md_process_queued_events()
 {
  struct md_queued_event *e;
@@ -107,6 +206,12 @@ void md_process_queued_events()
  }
 }

+/*
+ * Enqueue an mcmd event into the event queue.
+ *
+ * This is called when there's an XEvent being queued
+ * from the window manager to the module.
+ */
 static void md_enqueue(struct mcmd_event *e)
 {
  struct md_queued_event *qe=malloc(sizeof(struct md_queued_event));
@@ -122,6 +227,13 @@ static void md_enqueue(struct mcmd_event *e)
  }
 }

+/*
+ * Read an async XEvent from the window manager.
+ *
+ * This is called by md_handle_input() to read an XEvent.
+ * The "I'm an Xevent" marker is ~len, so it's de-inverted
+ * and then a subsequent len field match must match it.
+ */
 static int md_get_async(int len)
 {
  if(md_int_load(len)!=len)
@@ -131,18 +243,47 @@ static int md_get_async(int len)
  return 1;
 }

-int md_handle_input()
+/*
+ * Read input from the window manager.
+ *
+ * This reads two chunks - the size of the request,
+ * and then the request itself.
+ *
+ * Negative request lengths are treated special - they're
+ * treated as XEvents thrown into the input stream.
+ *
+ * Returns >1 if got input, 0 if timed out, < 0 if error.
+ */
+int md_handle_input(void)
 {
-  int res;
+  int res, ret;
+
+  /* Read the length of the request, don't block. */
+  ret = md_read(&res, sizeof(res), 0);
+
+  /* Timeout? */
+  if (ret == 0) {
+    return (0);
+  }
+
+  /* Error? */
+  if (ret < 0) {
+    return (-1);
+  }
+
+  /* Read size doesn't match request size? */
+  if (ret != sizeof(res)) {
+    return (-1);
+  }

-  if(md_read(&res, sizeof(res))!=sizeof(res))
-    return -1;
  if(res>=0) {
    if(!res)
      return 0;
+    /* Read the command */
    md_int_load(res);
    return 0;
  } else {
+    /* Negative length; treat as an XEvent */
    res=~res;
    if(!res)
      return 0;
@@ -150,6 +291,16 @@ int md_handle_input()
  }
 }

+/*
+ * Send a command from the module back to the window manager.
+ *
+ * This sends a request up to the window manager and then reads the
+ * response to return.  If asynchronous XEvents occur in the reply
+ * stream then those are enqueued via md_get_async().
+ *
+ * If there is a response, buffer is set to a memory buffer containing it.
+ * It is thus up to the caller to free it.
+ */
 int md_command(XID id, int cmd, void *data, int data_len, char **buffer)
 {
  int res;
@@ -161,21 +312,38 @@ int md_command(XID id, int cmd, void *data, int data_len, char **buffer)
  mcmd.cmd = cmd;
  mcmd.len = data_len;

+  /*
+   * Send header, read response code.
+   */
  if(md_write(&mcmd, sizeof(mcmd))!=sizeof(mcmd) ||
     md_write(data, data_len)!=data_len ||
-     md_read(&res, sizeof(res))!=sizeof(res))
+     md_read(&res, sizeof(res), 1)!=sizeof(res))
    return -1;

+  /*
+   * If the response code is negative (well, less than -1)
+   * then its treated as an async XEvent.  So, queue that
+   * and keep reading for the response code.
+   */
  while(res<-1) {
    md_get_async(~res);
-    if(md_read(&res, sizeof(res))!=sizeof(res))
+    if(md_read(&res, sizeof(res), 1)!=sizeof(res))
      return -1;
  }
+
+  /*
+   * If the response code is >0, then allocate a buffer
+   * of a suitable size and read the response into the buffer.
+   */
  if(res>0) {
    *buffer=malloc(res);
-    if(md_read(*buffer, res)!=res)
+    if(md_read(*buffer, res, 1)!=res)
      return -1;
  }
+
+  /*
+   * Return the response size.
+   */
  return res;
 }

@@ -206,6 +374,23 @@ Display *md_display()
  return dpy;
 }

+/*
+ * make the fd blocking or non-blocking.
+ */
+static int
+md_fd_nonblocking(int fd, int nb)
+{
+  int ret, val;
+
+  val = fcntl(fd, F_GETFD);
+  if (nb) {
+    ret = fcntl(fd, F_SETFD, val | O_NONBLOCK);
+  } else {
+    ret = fcntl(fd, F_SETFD, val & ~O_NONBLOCK);
+  }
+  return (ret == 0);
+}
+
 char *md_init(int argc, char *argv[])
 {
  if(argc>0)
@@ -227,12 +412,24 @@ char *md_init(int argc, char *argv[])
  if(md_command(None, MCMD_GET_VERSION, NULL, 0, &amiwm_version)<=0)
    md_fail();

+  md_fd_nonblocking(md_in_fd, 1);
+
  return (argc>4? argv[4]:NULL);
 }

-void md_main_loop()
+void
+md_main_loop()
 {
-  do md_process_queued_events(); while(md_handle_input()>=0);
+  do {
+    if (md_periodic_func != NULL) {
+      md_periodic_func();
+    }
+
+    /* Process async XEvent events that have been read */
+    md_process_queued_events();
+
+    /* Loop over, reading input events */
+  } while(md_handle_input()>=0);
 }

 int md_connection_number()
--- a/main.c
+++ b/main.c
@@ -820,9 +820,12 @@ void internal_broker(XEvent *e)

 static void update_clock(void *dontcare)
 {
+  Scrn *scr;
+
  if(server_grabs)
    return;
  call_out(prefs.titleclockinterval, 0, update_clock, dontcare);
+
  scr = get_front_scr();
  do {
    redrawmenubar(scr->menubar);
--- a/menu.c
+++ b/menu.c
@@ -37,6 +37,8 @@ extern struct Library *XLibBase;
 #define CHECKED 2
 #define DISABLED 4

+char battery_status[128];
+
 extern Display *dpy;
 extern Cursor wm_curs;
 extern XContext screen_context, client_context;
@@ -303,7 +305,7 @@ void redraw_item(struct Item *i, Window w)
    XSetForeground(dpy, scr->menubargc, scr->dri.dri_Pens[BARDETAILPEN]);
    XSetBackground(dpy, scr->menubargc, scr->dri.dri_Pens[BARBLOCKPEN]);
  }
-  if(i->text)
+  if(i->text) {
 #ifdef USE_FONTSETS
    XmbDrawImageString(dpy, w, scr->dri.dri_FontSet,
 		       scr->menubargc, (i->flags&CHECKIT)?1+scr->checkmarkspace:1,
@@ -312,8 +314,9 @@ void redraw_item(struct Item *i, Window w)
    XDrawImageString(dpy, w, scr->menubargc, (i->flags&CHECKIT)?1+scr->checkmarkspace:1,
 		     scr->dri.dri_Ascent+1, i->text, i->textlen);
 #endif
-  else
+  } else {
    XFillRectangle(dpy, w, scr->menubargc, 2, 2, m->width-10, 2);
+  }
  if(i->sub) {
    int x=m->width-6-scr->hotkeyspace-1+8;
 #ifdef USE_FONTSETS
@@ -485,9 +488,16 @@ void createmenubar()
  }
 }

+/*
+ * Redraw the menu bar and its components.
+ *
+ * This takes in the target window, which may be the basic menubar,
+ * a clicked-on menu, or the depth widget.
+ */
 void redrawmenubar(Window w)
 {
  static const char defaultTimeFormat[] = "%c";
+  int widget_rhs;

  struct Menu *m;
  struct Item *item;
@@ -495,6 +505,7 @@ void redrawmenubar(Window w)
  if(!w)
    return;
  if(w==scr->menubar) {
+    /* Menubar itself */
    XSetForeground(dpy, scr->menubargc, scr->dri.dri_Pens[BARDETAILPEN]);
    XSetBackground(dpy, scr->menubargc, scr->dri.dri_Pens[BARBLOCKPEN]);
 #ifdef USE_FONTSETS
@@ -507,6 +518,13 @@ void redrawmenubar(Window w)
 #endif
    XSetForeground(dpy, scr->menubargc, scr->dri.dri_Pens[BARTRIMPEN]);  
    XDrawLine(dpy, w, scr->menubargc, 0, scr->bh-1, scr->width-1, scr->bh-1);
+
+    /* Widgets start here and move to the left */
+    widget_rhs = (scr->width - 30);
+    /*
+     * Update the title bar clock if it's enabled.
+     */
+
    if( prefs.titlebarclock )
    {
      char clockbuf[512];
@@ -519,15 +537,38 @@ void redrawmenubar(Window w)
 #ifdef USE_FONTSETS
      l = XmbTextEscapement(scr->dri.dri_FontSet, clockbuf, strlen(clockbuf));
      XmbDrawImageString(dpy, w, scr->dri.dri_FontSet, scr->menubargc,
-			 (scr->width-30-l), 1+scr->dri.dri_Ascent,
+			 widget_rhs - l, 1+scr->dri.dri_Ascent,
 			 clockbuf, strlen(clockbuf));
 #else
      l = XTextWidth(scr->dri.dri_Font, clockbuf, strlen(clockbuf));
-      XDrawImageString( dpy, w, scr->menubargc,(scr->width-30-l),
+      XDrawImageString( dpy, w, scr->menubargc, widget_rhs - l,
 			1+scr->dri.dri_Ascent, clockbuf, strlen(clockbuf));
 #endif
-    }    
+      widget_rhs = widget_rhs - l - 8; // 8 = padding
+    }
+
+    /*
+     * Update the battery indicator if it's enabled.
+     */
+    if (prefs.battery_info) {
+      char battery_buf[512];
+      int l;
+
+      sprintf(battery_buf, "| %s |", battery_status);
+#ifdef USE_FONTSETS
+      l = XmbTextEscapement(scr->dri.dri_FontSet, battery_buf, strlen(battery_buf));
+      XmbDrawImageString(dpy, w, scr->dri.dri_FontSet, scr->menubargc,
+			 widget_rhs - l, 1+scr->dri.dri_Ascent,
+			 battery_buf, strlen(battery_buf));
+#else
+      l = XTextWidth(scr->dri.dri_Font, battery_buf, strlen(battery_buf));
+      XDrawImageString( dpy, w, scr->menubargc, widget_rhs - l,
+			1+scr->dri.dri_Ascent, battery_buf, strlen(battery_buf));
+#endif
+      widget_rhs = widget_rhs - l - 8; // 8 = padding
+    }
  } else if(w==scr->menubardepth) {
+    /* Menubar depth widget */
    if(!mbdclick) {
      XSetForeground(dpy, scr->menubargc, scr->dri.dri_Pens[SHADOWPEN]);
      XDrawRectangle(dpy, w, scr->menubargc, 4, scr->h2, 10, scr->h6-scr->h2);
@@ -545,6 +586,7 @@ void redrawmenubar(Window w)
    XDrawLine(dpy, w, scr->menubargc, 0, scr->bh-1, 22, scr->bh-1);
    XDrawLine(dpy, w, scr->menubargc, 22, 0, 22, scr->bh-1);
  } else {
+    /* One of the menus is being displayed */
    for(m=scr->firstmenu; m; m=m->next)
      if(m->win==w)
 	redraw_menu(m, w);
--- a/module.c
+++ b/module.c
@@ -490,6 +490,42 @@ static void handle_module_cmd(struct module *m, char *data, int data_len)
    } else
      reply_module(m, NULL, -1);
    break;
+  case MCMD_UPDATE_BATTERY:
+    {
+        struct mcmd_update_battery *batt;
+        extern char battery_status[];
+
+        if (data == NULL) {
+          reply_module(m, NULL, -1);
+          break;
+        }
+        if (data_len != sizeof(struct mcmd_update_battery)) {
+          reply_module(m, NULL, -1);
+          break;
+        }
+        batt = (void *) data;
+
+#if 0
+        fprintf(stderr, "%s: called, BATTERY, pct=%d, time=%d, ac=%d\n",
+            __func__,
+            batt->battery_pct,
+            batt->battery_time,
+            batt->battery_ac);
+#endif
+
+        /*
+         * XXX TODO: for now we're just populating a string here.
+         * Later on we should just store the current battery state
+         * somewhere (a key/value table would be nice!) and then
+         * the widget code can pull out its needed state to render.
+         */
+        snprintf(battery_status, 128, "%d pct%s", batt->battery_pct,
+            batt->battery_ac == 1 ? " A" : " -");
+
+        reply_module(m, NULL, 0);
+        break;
+    }
+    break;
  default:
    reply_module(m, NULL, -1);
  }
--- a/module.h
+++ b/module.h
@@ -16,6 +16,7 @@
 #define MCMD_MANAGEMENU 18
 #define MCMD_ROTATE_WINDOW_RAISE 19
 #define MCMD_ROTATE_WINDOW_LOWER 20
+#define MCMD_UPDATE_BATTERY 21

 struct mcmd_header {
  XID id;
@@ -42,6 +43,14 @@ struct NewAppIcon {
  char name[1];
 };

+struct mcmd_update_battery {
+  int battery_time;
+  int battery_pct;
+  int battery_cap;
+  int battery_ac;
+  int battery_charging;
+};
+
 extern struct module {
  struct module *next;
  int in_fd, out_fd;
--- a/prefs.h
+++ b/prefs.h
@@ -17,6 +17,7 @@ extern struct prefs_struct {
  char *titleclockformat;		/* format to use for the clock */
  int titleclockinterval;		/* how often do we update the clock?*/
  int icontray;				// if true then icons will be shown in a tray on top of each screen (besides clock and screen name)
+  int battery_info;			/* display battery info? */
  struct _Style *firststyle, *laststyle;
 } prefs;

--- a/rc.c
+++ b/rc.c
@@ -105,6 +105,7 @@ struct keyword { char *name; int token; } keywords[] = {
  { "barblockpen", T_BARBLOCKPEN },
  { "bardetailpen", T_BARDETAILPEN },
  { "bartrimpen", T_BARTRIMPEN },
+  { "batteryinfo", BATTERYINFO },
  { "blockpen", T_BLOCKPEN },
  { "both", BOTH },
  { "bottom", BOTTOM },