[gnu-emacs] / src / xrdb.c

/* Deal with the X Resource Manager.
   Copyright (C) 1990, 1993, 1994, 2000, 2001, 2002, 2003, 2004,
                 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.

Author: Joseph Arceneaux
Created: 4/90

This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

#include <unistd.h>
#include <errno.h>
#include <epaths.h>

#include <stdio.h>
#include <setjmp.h>

#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <X11/X.h>
#include <X11/Xutil.h>
#include <X11/Xresource.h>
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#include <sys/stat.h>

#if !defined(S_ISDIR) && defined(S_IFDIR)
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif

#include "lisp.h"

#ifdef USE_MOTIF
/* For Vdouble_click_time.  */
#include "keyboard.h"
#endif

extern char *getenv (const char *);

extern struct passwd *getpwuid (uid_t);
extern struct passwd *getpwnam (const char *);

extern const char *get_system_name (void);

char *x_get_string_resource (XrmDatabase rdb, const char *name,
                             const char *class);
static int file_p (const char *filename);

\f
/* X file search path processing.  */


/* The string which gets substituted for the %C escape in XFILESEARCHPATH
   and friends, or zero if none was specified.  */
char *x_customization_string;


/* Return the value of the emacs.customization (Emacs.Customization)
   resource, for later use in search path decoding.  If we find no
   such resource, return zero.  */
static char *
x_get_customization_string (XrmDatabase db, const char *name,
                            const char *class)
{
  char *full_name
    = (char *) alloca (strlen (name) + sizeof ("customization") + 3);
  char *full_class
    = (char *) alloca (strlen (class) + sizeof ("Customization") + 3);
  char *result;

  sprintf (full_name,  "%s.%s", name,  "customization");
  sprintf (full_class, "%s.%s", class, "Customization");

  result = x_get_string_resource (db, full_name, full_class);

  if (result)
    {
      char *copy = (char *) xmalloc (strlen (result) + 1);
      strcpy (copy, result);
      return copy;
    }
  else
    return 0;
}


/* Expand all the Xt-style %-escapes in STRING, whose length is given
   by STRING_LEN.  Here are the escapes we're supposed to recognize:

        %N      The value of the application's class name
        %T      The value of the type parameter ("app-defaults" in this
                context)
        %S      The value of the suffix parameter ("" in this context)
        %L      The language string associated with the specified display
                (We use the "LANG" environment variable here, if it's set.)
        %l      The language part of the display's language string
                (We treat this just like %L.  If someone can tell us what
                 we're really supposed to do, dandy.)
        %t      The territory part of the display's language string
                (This never gets used.)
        %c      The codeset part of the display's language string
                (This never gets used either.)
        %C      The customization string retrieved from the resource
                database associated with display.
                (This is x_customization_string.)

   Return the expanded file name if it exists and is readable, and
   refers to %L only when the LANG environment variable is set, or
   otherwise provided by X.

   ESCAPED_SUFFIX and SUFFIX are postpended to STRING if they are
   non-zero.  %-escapes in ESCAPED_SUFFIX are expanded; STRING is left
   alone.

   Return NULL otherwise.  */

static char *
magic_file_p (const char *string, EMACS_INT string_len, const char *class, const char *escaped_suffix, const char *suffix)
{
  char *lang = getenv ("LANG");

  int path_size = 100;
  char *path = (char *) xmalloc (path_size);
  int path_len = 0;

  const char *p = string;

  while (p < string + string_len)
    {
      /* The chunk we're about to stick on the end of result.  */
      const char *next = NULL;
      int next_len;

      if (*p == '%')
        {
          p++;

          if (p >= string + string_len)
            next_len = 0;
          else
            switch (*p)
              {
              case '%':
                next = "%";
                next_len = 1;
                break;

              case 'C':
                next = (x_customization_string
                        ? x_customization_string
                        : "");
                next_len = strlen (next);
                break;

              case 'N':
                next = class;
                next_len = strlen (class);
                break;

              case 'T':
                next = "app-defaults";
                next_len = strlen (next);
                break;

              default:
              case 'S':
                next_len = 0;
                break;

              case 'L':
              case 'l':
                if (! lang)
                  {
                    xfree (path);
                    return NULL;
                  }

                next = lang;
                next_len = strlen (next);
                break;

              case 't':
              case 'c':
                xfree (path);
                return NULL;
              }
        }
      else
        next = p, next_len = 1;

      /* Do we have room for this component followed by a '\0' ?  */
      if (path_len + next_len + 1 > path_size)
        {
          path_size = (path_len + next_len + 1) * 2;
          path = (char *) xrealloc (path, path_size);
        }

      memcpy (path + path_len, next, next_len);
      path_len += next_len;

      p++;

      /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
      if (p >= string + string_len && escaped_suffix)
        {
          string = escaped_suffix;
          string_len = strlen (string);
          p = string;
          escaped_suffix = NULL;
        }
    }

  /* Perhaps we should add the SUFFIX now.  */
  if (suffix)
    {
      int suffix_len = strlen (suffix);

      if (path_len + suffix_len + 1 > path_size)
        {
          path_size = (path_len + suffix_len + 1);
          path = (char *) xrealloc (path, path_size);
        }

      memcpy (path + path_len, suffix, suffix_len);
      path_len += suffix_len;
    }

  path[path_len] = '\0';

  if (! file_p (path))
    {
      xfree (path);
      return NULL;
    }

  return path;
}


static char *
gethomedir (void)
{
  struct passwd *pw;
  char *ptr;
  char *copy;

  if ((ptr = getenv ("HOME")) == NULL)
    {
      if ((ptr = getenv ("LOGNAME")) != NULL
          || (ptr = getenv ("USER")) != NULL)
        pw = getpwnam (ptr);
      else
        pw = getpwuid (getuid ());

      if (pw)
        ptr = pw->pw_dir;
    }

  if (ptr == NULL)
    return xstrdup ("/");

  copy = (char *) xmalloc (strlen (ptr) + 2);
  strcpy (copy, ptr);
  strcat (copy, "/");

  return copy;
}


static int
file_p (const char *filename)
{
  struct stat status;

  return (access (filename, 4) == 0             /* exists and is readable */
          && stat (filename, &status) == 0      /* get the status */
          && (S_ISDIR (status.st_mode)) == 0);  /* not a directory */
}


/* Find the first element of SEARCH_PATH which exists and is readable,
   after expanding the %-escapes.  Return 0 if we didn't find any, and
   the path name of the one we found otherwise.  */

static char *
search_magic_path (const char *search_path, const char *class, const char *escaped_suffix, const char *suffix)
{
  const char *s, *p;

  for (s = search_path; *s; s = p)
    {
      for (p = s; *p && *p != ':'; p++)
        ;

      if (p > s)
        {
          char *path = magic_file_p (s, p - s, class, escaped_suffix,
                                           suffix);
          if (path)
            return path;
        }
      else if (*p == ':')
        {
          char *path;

          s = "%N%S";
          path = magic_file_p (s, strlen (s), class, escaped_suffix, suffix);
          if (path)
            return path;
        }

      if (*p == ':')
        p++;
    }

  return 0;
}
\f
/* Producing databases for individual sources.  */

static XrmDatabase
get_system_app (const char *class)
{
  XrmDatabase db = NULL;
  const char *path;
  char *p;

  path = getenv ("XFILESEARCHPATH");
  if (! path) path = PATH_X_DEFAULTS;

  p = search_magic_path (path, class, 0, 0);
  if (p)
    {
      db = XrmGetFileDatabase (p);
      xfree (p);
    }

  return db;
}


static XrmDatabase
get_fallback (Display *display)
{
  return NULL;
}


static XrmDatabase
get_user_app (const char *class)
{
  const char *path;
  char *file = 0;
  char *free_it = 0;

  /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
     names, not directories.  */
  if (((path = getenv ("XUSERFILESEARCHPATH"))
       && (file = search_magic_path (path, class, 0, 0)))

      /* Check for APPLRESDIR; it is a path of directories.  In each,
         we have to search for LANG/CLASS and then CLASS.  */
      || ((path = getenv ("XAPPLRESDIR"))
          && ((file = search_magic_path (path, class, "/%L/%N", 0))
              || (file = search_magic_path (path, class, "/%N", 0))))

      /* Check in the home directory.  This is a bit of a hack; let's
         hope one's home directory doesn't contain any %-escapes.  */
      || (free_it = gethomedir (),
          ((file = search_magic_path (free_it, class, "%L/%N", 0))
           || (file = search_magic_path (free_it, class, "%N", 0)))))
    {
      XrmDatabase db = XrmGetFileDatabase (file);
      xfree (file);
      xfree (free_it);
      return db;
    }

  xfree (free_it);
  return NULL;
}


static XrmDatabase
get_user_db (Display *display)
{
  XrmDatabase db;
  char *xdefs;

#ifdef PBaseSize                /* Cheap way to test for X11R4 or later.  */
  xdefs = XResourceManagerString (display);
#else
  xdefs = display->xdefaults;
#endif

  if (xdefs != NULL)
    db = XrmGetStringDatabase (xdefs);
  else
    {
      char *home;
      char *xdefault;

      home = gethomedir ();
      xdefault = (char *) xmalloc (strlen (home) + sizeof (".Xdefaults"));
      strcpy (xdefault, home);
      strcat (xdefault, ".Xdefaults");
      db = XrmGetFileDatabase (xdefault);
      xfree (home);
      xfree (xdefault);
    }

#ifdef HAVE_XSCREENRESOURCESTRING
  /* Get the screen-specific resources too.  */
  xdefs = XScreenResourceString (DefaultScreenOfDisplay (display));
  if (xdefs != NULL)
    {
      XrmMergeDatabases (XrmGetStringDatabase (xdefs), &db);
      XFree (xdefs);
    }
#endif

  return db;
}

static XrmDatabase
get_environ_db (void)
{
  XrmDatabase db;
  char *p;
  char *path = 0, *home = 0;
  const char *host;

  if ((p = getenv ("XENVIRONMENT")) == NULL)
    {
      home = gethomedir ();
      host = get_system_name ();
      path = (char *) xmalloc (strlen (home)
                              + sizeof (".Xdefaults-")
                              + strlen (host));
      sprintf (path, "%s%s%s", home, ".Xdefaults-", host);
      p = path;
    }

  db = XrmGetFileDatabase (p);

  xfree (path);
  xfree (home);

  return db;
}
\f
/* External interface.  */

/* Types of values that we can find in a database */

#define XrmStringType "String"  /* String representation */
XrmRepresentation x_rm_string;  /* Quark representation */

/* Load X resources based on the display and a possible -xrm option. */

XrmDatabase
x_load_resources (Display *display, const char *xrm_string,
                  const char *myname, const char *myclass)
{
  XrmDatabase user_database;
  XrmDatabase rdb;
  XrmDatabase db;
  char line[256];

  const char *helv = "-*-helvetica-medium-r-*--*-120-*-*-*-*-iso8859-1";

#ifdef USE_MOTIF
  const char *courier = "-*-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-1";
#endif

  x_rm_string = XrmStringToQuark (XrmStringType);
#ifndef USE_X_TOOLKIT
  /* pmr@osf.org says this shouldn't be done if USE_X_TOOLKIT.
     I suspect it's because the toolkit version does this elsewhere.  */
  XrmInitialize ();
#endif
  rdb = XrmGetStringDatabase ("");

  /* Add some font defaults.  If the font `helv' doesn't exist, widgets
     will use some other default font.  */
#ifdef USE_MOTIF

  sprintf (line, "%s.pane.background: grey75", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fontList: %s", myclass, helv);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*menu*background: grey75", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*menubar*background: grey75", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*verticalScrollBar.background: grey75", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*verticalScrollBar.troughColor: grey75", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s.dialog*.background: grey75", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb.Text.background: white", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb.FilterText.background: white", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb*DirList.background: white", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb*ItemsList.background: white", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb*background: grey75", myclass);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb.Text.fontList: %s", myclass, courier);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb.FilterText.fontList: %s", myclass, courier);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb*ItemsList.fontList: %s", myclass, courier);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "%s*fsb*DirList.fontList: %s", myclass, courier);
  XrmPutLineResource (&rdb, line);

  /* Set double click time of list boxes in the file selection
     dialog from `double-click-time'.  */
  if (INTEGERP (Vdouble_click_time) && XINT (Vdouble_click_time) > 0)
    {
      sprintf (line, "%s*fsb*DirList.doubleClickInterval: %d",
               myclass, XFASTINT (Vdouble_click_time));
      XrmPutLineResource (&rdb, line);
      sprintf (line, "%s*fsb*ItemsList.doubleClickInterval: %d",
               myclass, XFASTINT (Vdouble_click_time));
      XrmPutLineResource (&rdb, line);
    }

#else /* not USE_MOTIF */

  sprintf (line, "Emacs.dialog*.font: %s", helv);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "Emacs.dialog*.background: grey75");
  XrmPutLineResource (&rdb, line);
  sprintf (line, "*XlwMenu*font: %s", helv);
  XrmPutLineResource (&rdb, line);
  sprintf (line, "*XlwMenu*background: grey75");
  XrmPutLineResource (&rdb, line);
  sprintf (line, "Emacs*verticalScrollBar.background: grey75");
  XrmPutLineResource (&rdb, line);

#endif /* not USE_MOTIF */

  user_database = get_user_db (display);

  /* Figure out what the "customization string" is, so we can use it
     to decode paths.  */
  xfree (x_customization_string);
  x_customization_string
    = x_get_customization_string (user_database, myname, myclass);

  /* Get application system defaults */
  db = get_system_app (myclass);
  if (db != NULL)
    XrmMergeDatabases (db, &rdb);

  /* Get Fallback resources */
  db = get_fallback (display);
  if (db != NULL)
    XrmMergeDatabases (db, &rdb);

  /* Get application user defaults */
  db = get_user_app (myclass);
  if (db != NULL)
    XrmMergeDatabases (db, &rdb);

  /* get User defaults */
  if (user_database != NULL)
    XrmMergeDatabases (user_database, &rdb);

  /* Get Environment defaults. */
  db = get_environ_db ();
  if (db != NULL)
    XrmMergeDatabases (db, &rdb);

  /* Last, merge in any specification from the command line. */
  if (xrm_string != NULL)
    {
      db = XrmGetStringDatabase (xrm_string);
      if (db != NULL)
        XrmMergeDatabases (db, &rdb);
    }

  return rdb;
}


/* Retrieve the value of the resource specified by NAME with class CLASS
   and of type TYPE from database RDB.  The value is returned in RET_VALUE. */

static int
x_get_resource (XrmDatabase rdb, const char *name, const char *class,
                XrmRepresentation expected_type, XrmValue *ret_value)
{
  XrmValue value;
  XrmName namelist[100];
  XrmClass classlist[100];
  XrmRepresentation type;

  XrmStringToNameList(name, namelist);
  XrmStringToClassList(class, classlist);

  if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
      && (type == expected_type))
    {
      if (type == x_rm_string)
        ret_value->addr = (char *) value.addr;
      else
        memcpy (ret_value->addr, value.addr, ret_value->size);

      return value.size;
    }

  return 0;
}

/* Retrieve the string resource specified by NAME with CLASS from
   database RDB. */

char *
x_get_string_resource (XrmDatabase rdb, const char *name, const char *class)
{
  XrmValue value;

  if (inhibit_x_resources)
    /* --quick was passed, so this is a no-op.  */
    return NULL;

  if (x_get_resource (rdb, name, class, x_rm_string, &value))
    return (char *) value.addr;

  return (char *) 0;
}
\f
/* Stand-alone test facilities.  */

#ifdef TESTRM

typedef char **List;
#define arg_listify(len, list) (list)
#define car(list) (*(list))
#define cdr(list) (list + 1)
#define NIL(list) (! *(list))
#define free_arglist(list)

static List
member (elt, list)
     char *elt;
     List list;
{
  List p;

  for (p = list; ! NIL (p); p = cdr (p))
    if (! strcmp (elt, car (p)))
      return p;

  return p;
}

static void
fatal (msg, prog, x1, x2, x3, x4, x5)
    char *msg, *prog;
    int x1, x2, x3, x4, x5;
{
    if (errno)
      perror (prog);

    (void) fprintf (stderr, msg, prog, x1, x2, x3, x4, x5);
    exit (1);
}

main (argc, argv)
    int argc;
    char **argv;
{
  Display *display;
  char *displayname, *resource_string, *class, *name;
  XrmDatabase xdb;
  List arg_list, lp;

  arg_list = arg_listify (argc, argv);

  lp = member ("-d", arg_list);
  if (!NIL (lp))
    displayname = car (cdr (lp));
  else
    displayname = "localhost:0.0";

  lp = member ("-xrm", arg_list);
  if (! NIL (lp))
    resource_string = car (cdr (lp));
  else
    resource_string = (char *) 0;

  lp = member ("-c", arg_list);
  if (! NIL (lp))
    class = car (cdr (lp));
  else
    class = "Emacs";

  lp = member ("-n", arg_list);
  if (! NIL (lp))
    name = car (cdr (lp));
  else
    name = "emacs";

  free_arglist (arg_list);

  if (!(display = XOpenDisplay (displayname)))
    fatal ("Can't open display '%s'\n", XDisplayName (displayname));

  xdb = x_load_resources (display, resource_string, name, class);

  /* In a real program, you'd want to also do this: */
  display->db = xdb;

  while (1)
    {
      char query_name[90];
      char query_class[90];

      printf ("Name: ");
      gets (query_name);

      if (strlen (query_name))
        {
          char *value;

          printf ("Class: ");
          gets (query_class);

          value = x_get_string_resource (xdb, query_name, query_class);

          if (value != NULL)
            printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
          else
            printf ("\tNo Value.\n\n");
        }
      else
        break;
    }
  printf ("\tExit.\n\n");

  XCloseDisplay (display);
}
#endif /* TESTRM */