xmradio/xmradio-1.2/remote.c

/*-
 * Copyright (c) 1999 Thomas Runge (coto@core.de)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/param.h>
#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Intrinsic.h>
#include <X11/Xatom.h>
#include <X11/Xmu/WinUtil.h>

#include "radio.h"
#include "remote.h"

static char lock_data[MAXHOSTNAMELEN+16];

Atom XA_XMRADIO_VERSION   = 0;
Atom XA_XMRADIO_LOCK      = 0;
Atom XA_XMRADIO_COMMAND   = 0;
Atom XA_XMRADIO_RESPONSE  = 0;
Atom XA_XMRADIO_FREQUENCY = 0;
Atom XA_XMRADIO_STATION   = 0;

void initAtoms()
{
 if(!XA_XMRADIO_VERSION)
   XA_XMRADIO_VERSION = XInternAtom(dpy, XMRADIO_VERSION_PROP, False);
 if(!XA_XMRADIO_LOCK)
   XA_XMRADIO_LOCK = XInternAtom(dpy, XMRADIO_LOCK_PROP, False);
 if(!XA_XMRADIO_COMMAND)
   XA_XMRADIO_COMMAND = XInternAtom(dpy, XMRADIO_COMMAND_PROP, False);
 if(!XA_XMRADIO_RESPONSE)
   XA_XMRADIO_RESPONSE = XInternAtom(dpy, XMRADIO_RESPONSE_PROP, False);
 if(!XA_XMRADIO_FREQUENCY)
   XA_XMRADIO_FREQUENCY = XInternAtom(dpy, XMRADIO_FREQUENCY_PROP, False);
 if(!XA_XMRADIO_STATION)
   XA_XMRADIO_STATION = XInternAtom(dpy, XMRADIO_STATION_PROP, False);
}

static Window findWindow()
{
 int i;
 Window root = RootWindowOfScreen (DefaultScreenOfDisplay (dpy));
 Window root2, parent, *kids;
 unsigned int nkids;
 unsigned char *version = NULL;

 if(!XQueryTree(dpy, root, &root2, &parent, &kids, &nkids))
 {
  fprintf(stderr, "XQueryTree failed on display %s\n", DisplayString(dpy));
  exit(EXIT_FAILURE);
 }

 if(!(kids && nkids))
 {
  fprintf(stderr, "root window has no children on display %s\n",
                                               DisplayString(dpy));
  exit(EXIT_FAILURE);
 }

 for(i = nkids-1; i >= 0; i--)
 {
  Atom type;
  int format, status;
  unsigned long nitems, bytesafter;
  Window w;

  w = XmuClientWindow(dpy, kids[i]);
  status = XGetWindowProperty(dpy, w, XA_XMRADIO_VERSION, 0, 8192, False,
                              XA_STRING, &type, &format, &nitems, &bytesafter,
                              &version);
  if(!version)
   continue;

  if(debug)
   printf("Found xmradio window(0x%x). Version %s (win %d of %d)\n",
                (unsigned int)kids[i], version, i, nkids);

  XFree(version);

  //return(kids[i]);
  return(w);
 }

 fprintf(stderr, "xmradio not running on display %s\n", DisplayString(dpy));
 exit(EXIT_FAILURE);
}

static void obtainLock(Window win)
{
 int locked = 0;

 sprintf(lock_data, "pid%d@", getpid ());
 if(gethostname(lock_data + strlen(lock_data), MAXHOSTNAMELEN))
 {
  perror("gethostname");
  exit(EXIT_FAILURE);
 }

 do
 {
  int result;
  Atom actual_type;
  int actual_format;
  unsigned long nitems, bytes_after;
  unsigned char *prop = NULL;

  XGrabServer(dpy);

  result = XGetWindowProperty(dpy, win, XA_XMRADIO_LOCK, 0, 8192, False,
                              XA_STRING, &actual_type, &actual_format,
                              &nitems, &bytes_after, &prop);
  if(result != Success || actual_type == None)
  {
   if(debug)
    printf("remote xmradio not locked. lock it now.\n");

   XChangeProperty(dpy, win, XA_XMRADIO_LOCK, XA_STRING, 8, PropModeReplace,
                   lock_data, strlen(lock_data));
   locked = 1;
  }

  XUngrabServer(dpy);
  XSync(dpy, False);

  if(!locked)
  {
   if(debug)
    printf("window 0x%x is locked by %s; waiting...\n", (unsigned int) win,
                                                        prop);

   while(1)
   {
    XEvent event;

    XNextEvent(dpy, &event);
    if(event.xany.type == DestroyNotify && event.xdestroywindow.window == win)
    {
     fprintf(stderr, "window 0x%x unexpectedly destroyed.\n",
                                             (unsigned int) win);
     exit(EXIT_FAILURE);
    }
    if(event.xany.type == PropertyNotify &&
       event.xproperty.state == PropertyDelete &&
       event.xproperty.window == win &&
       event.xproperty.atom == XA_XMRADIO_LOCK)
    {
     if(debug)
      printf("(0x%x unlocked, trying again...)\n", (unsigned int) win);
     break;
    }
   }
  }
  XFree(prop);
 } while(!locked);
}

static void freeLock(Window win)
{
 int result;
 Atom actual_type;
 int actual_format;
 unsigned long nitems, bytes_after;
 unsigned char *prop = NULL;

 result = XGetWindowProperty(dpy, win, XA_XMRADIO_LOCK, 0, 8192, True,
                             XA_STRING,  &actual_type, &actual_format,
                              &nitems, &bytes_after, &prop);

 if(result != Success)
 {
  fprintf(stderr, " unable to read and delete " XMRADIO_LOCK_PROP
                  " property\n");
  return;
 }
 if(!prop || !*prop)
 {
  fprintf(stderr, " invalid data on " XMRADIO_LOCK_PROP
                  " of window 0x%x.\n", (unsigned int) win);
 }
 if(strcmp((char*)prop, lock_data))
 {
  fprintf(stderr, XMRADIO_LOCK_PROP " was stolen!"
                 "  Expected \"%s\", saw \"%s\"!\n", lock_data, prop);
 }

 if(prop)
  XFree(prop);
}

/*
 * return values:
 *  0 - error
 *  1 - can't happen
 *  2 - okay
 *  3 - win destroyed
 *  4 - unknown command
 *  5 - out of range
 */
static int sendCommand(Window win, char *command)
{
 if(debug)
  printf("writing prop: %s\n", command);

 XChangeProperty(dpy, win, XA_XMRADIO_COMMAND, XA_STRING, 8,
                 PropModeReplace, command, strlen(command));

 while(1)
 {
  XEvent event;

  XNextEvent(dpy, &event);
  if(event.xany.type == DestroyNotify && event.xdestroywindow.window == win)
  {
   fprintf(stderr, "Failed to send remote command."
                   " window 0x%x was destroyed.\n", (unsigned int) win);
   return 3;
  }
  if(event.xany.type == PropertyNotify &&
     event.xproperty.state == PropertyNewValue &&
     event.xproperty.window == win &&
     event.xproperty.atom == XA_XMRADIO_RESPONSE)
  {
   Atom actual_type;
   int actual_format, result;
   unsigned long nitems, bytes_after;
   unsigned char *prop = NULL;

   result = XGetWindowProperty(dpy, win, XA_XMRADIO_RESPONSE, 0, 8192, True,
                               XA_STRING, &actual_type, &actual_format,
                               &nitems, &bytes_after, &prop);
   if(result != Success)
   {
    fprintf(stderr, "Failed to read " XMRADIO_RESPONSE_PROP
                    " from window 0x%0x.\n", (unsigned int) win);
    return 3;
   }
   if(!prop)
   {
    fprintf(stderr, "Invalid data on " XMRADIO_RESPONSE_PROP
                    " property of window 0x%0x.\n", (unsigned int) win);
    return 0;
   }
   if(*prop == '1')
   {
    printf("message arrived. working on it...\n");
    XFree(prop);
   }
   else if(*prop == '2')
   {
    if(debug)
     printf("message arrived. done!\n");
    XFree(prop);
    return 2;
   }
   else if(*prop == '4')
   {
    fprintf(stderr, "unknown command!\n");
    XFree(prop);
    return 4;
   }
   else if(*prop == '5')
   {
    fprintf(stderr, "value out of range!\n");
    XFree(prop);
    return 5;
   }
   else
   {
    fprintf(stderr, "unrecognised " XMRADIO_RESPONSE_PROP
                    " from window 0x%x: %s\n", (unsigned int) win, prop);
    XFree(prop);
   }
  }
 }
}

int sendCommands(char **commands)
{
 int status = 0;
 Window win;

 win = findWindow();

 XSelectInput(dpy, win, (PropertyChangeMask|StructureNotifyMask));

 obtainLock(win);

 while(*commands)
 {
  if(debug)
   printf("sending command: %s\n", *commands);

  status = sendCommand(win, *commands);

  if(status != 2)
  {
   printf("failed!\n");
   break;
  }
  else
  {
   printf("succeded.\n");
  }

  commands++;
 }

 if(status != 3)
  freeLock(win);

 return status;
}