src/xsettings.c

   1 /* Functions for handle font changes dynamically.
   2    Copyright (C) 2009
   3                  Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software: you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation, either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include <setjmp.h>
  22 #include <fcntl.h>
  23 #include "lisp.h"
  24 #include "xterm.h"
  25 #include "xsettings.h"
  26 #include "frame.h"
  27 #include "blockinput.h"
  28 #include "termhooks.h"
  29 #include "termopts.h"
  30
  31 #include <X11/Xproto.h>
  32
  33 #ifdef HAVE_GCONF
  34 #include <gconf/gconf-client.h>
  35 #endif
  36 #ifdef HAVE_XFT
  37 #include <X11/Xft/Xft.h>
  38 #endif
  39
  40 static char *current_mono_font;
  41 static struct x_display_info *first_dpyinfo;
  42 static Lisp_Object Qfont_name, Qfont_render;
  43 static int use_system_font;
  44
  45 #ifdef HAVE_GCONF
  46 static GConfClient *gconf_client;
  47 #endif
  48
  49
  50 static void
  51 store_font_changed_event (arg, display_name)
  52      Lisp_Object arg;
  53      Lisp_Object display_name;
  54 {
  55   struct input_event event;
  56   EVENT_INIT (event);
  57   event.kind = CONFIG_CHANGED_EVENT;
  58   event.frame_or_window = display_name;
  59   event.arg = arg;
  60   kbd_buffer_store_event (&event);
  61 }
  62
  63 #ifdef HAVE_GCONF
  64
  65 #define SYSTEM_MONO_FONT       "/desktop/gnome/interface/monospace_font_name"
  66
  67 /* Callback called when something changed in GConf that we care about,
  68    that is SYSTEM_MONO_FONT.  */
  69
  70 static void
  71 something_changedCB (client, cnxn_id, entry, user_data)
  72      GConfClient *client;
  73      guint cnxn_id;
  74      GConfEntry *entry;
  75      gpointer user_data;
  76 {
  77   GConfValue *v = gconf_entry_get_value (entry);
  78
  79   if (!v) return;
  80   if (v->type == GCONF_VALUE_STRING)
  81     {
  82       const char *value = gconf_value_get_string (v);
  83       int i;
  84       if (current_mono_font != NULL && strcmp (value, current_mono_font) == 0)
  85         return; /* No change. */
  86
  87       xfree (current_mono_font);
  88       current_mono_font = xstrdup (value);
  89     }
  90
  91
  92   if (first_dpyinfo != NULL)
  93     {
  94       /* Check if display still open */
  95       struct x_display_info *dpyinfo;
  96       int found = 0;
  97       for (dpyinfo = x_display_list; !found && dpyinfo; dpyinfo = dpyinfo->next)
  98         found = dpyinfo == first_dpyinfo;
  99
 100       if (found && use_system_font)
 101         store_font_changed_event (Qfont_name,
 102                                   XCAR (first_dpyinfo->name_list_element));
 103     }
 104 }
 105 #endif /* HAVE_GCONF */
 106
 107 #ifdef HAVE_XFT
 108
 109 /* Older fontconfig versions don't have FC_LCD_*.  */
 110 #ifndef FC_LCD_NONE
 111 #define FC_LCD_NONE 0
 112 #endif
 113 #ifndef FC_LCD_DEFAULT
 114 #define FC_LCD_DEFAULT 1
 115 #endif
 116 #ifndef FC_LCD_FILTER
 117 #define FC_LCD_FILTER "lcdfilter"
 118 #endif
 119
 120 /* Find the window that contains the XSETTINGS property values.  */
 121
 122 static void
 123 get_prop_window (dpyinfo)
 124      struct x_display_info *dpyinfo;
 125 {
 126   Display *dpy = dpyinfo->display;
 127
 128   XGrabServer (dpy);
 129   dpyinfo->xsettings_window = XGetSelectionOwner (dpy,
 130                                                   dpyinfo->Xatom_xsettings_sel);
 131   if (dpyinfo->xsettings_window != None)
 132     /* Select events so we can detect if window is deleted or if settings
 133        are changed.  */
 134     XSelectInput (dpy, dpyinfo->xsettings_window,
 135                   PropertyChangeMask|StructureNotifyMask);
 136
 137   XUngrabServer (dpy);
 138 }
 139
 140 struct xsettings
 141 {
 142   FcBool aa, hinting;
 143   int rgba, lcdfilter, hintstyle;
 144   double dpi;
 145 };
 146
 147 #define SWAP32(nr) (((nr) << 24) | (((nr) << 8) & 0xff0000)     \
 148                     | (((nr) >> 8) & 0xff00) | ((nr) >> 24))
 149 #define SWAP16(nr) (((nr) << 8) | ((nr) >> 8))
 150 #define PAD(nr)    (((nr) + 3) & ~3)
 151
 152 /* Parse xsettings and extract those that deal with Xft.
 153    See http://freedesktop.org/wiki/Specifications/XSettingsRegistry
 154    and http://standards.freedesktop.org/xsettings-spec/xsettings-spec-0.5.html.
 155
 156    Layout of prop.  First is a header:
 157
 158    bytes   type     what
 159    ------------------------------------
 160    1      CARD8    byte-order
 161    3               unused
 162    4      CARD32   SERIAL
 163    4      CARD32   N_SETTINGS
 164
 165    Then N_SETTINGS records, with header:
 166
 167    bytes   type          what
 168    ------------------------------------
 169    1      SETTING_TYPE  type (0 = integer, 1 = string, 2 RGB color).
 170    1                    unused
 171    2      CARD16        n == name-length
 172    n      STRING8       name
 173    p                    unused, p=pad_to_even_4(n)
 174    4      CARD32        last-change-serial
 175
 176    and then the value, For string:
 177
 178    bytes   type          what
 179    ------------------------------------
 180    4      CARD32        n = value-length
 181    n      STRING8       value
 182    p                    unused, p=pad_to_even_4(n)
 183
 184    For integer:
 185
 186    bytes   type          what
 187    ------------------------------------
 188    4      INT32         value
 189
 190    For RGB color:
 191
 192    bytes   type          what
 193    ------------------------------------
 194    2      CARD16        red
 195    2      CARD16        blue
 196    2      CARD16        green
 197    2      CARD16        alpha
 198
 199 */
 200
 201 static int
 202 parse_xft_settings (prop, bytes, settings)
 203      unsigned char *prop;
 204      unsigned long bytes;
 205      struct xsettings *settings;
 206 {
 207   Lisp_Object byteorder = Fbyteorder ();
 208   int my_bo = XFASTINT (byteorder) == 'B' ? MSBFirst : LSBFirst;
 209   int that_bo = prop[0];
 210   CARD32 n_settings;
 211   int bytes_parsed = 0;
 212   int settings_seen = 0;
 213   int i = 0;
 214
 215   /* First 4 bytes is a serial number, skip that.  */
 216
 217   if (bytes < 12) return BadLength;
 218   memcpy (&n_settings, prop+8, 4);
 219   if (my_bo != that_bo) n_settings = SWAP32 (n_settings);
 220   bytes_parsed = 12;
 221
 222   memset (settings, 0, sizeof (*settings));
 223
 224   while (bytes_parsed+4 < bytes && settings_seen < 6
 225          && i < n_settings)
 226     {
 227       int type = prop[bytes_parsed++];
 228       CARD16 nlen;
 229       CARD32 vlen, ival = 0;
 230       char name[128]; /* The names we are looking for are not this long.  */
 231       char sval[128]; /* The values we are looking for are not this long.  */
 232       int is_xft;
 233       int to_cpy;
 234
 235       sval[0] = '\0';
 236       ++i;
 237       ++bytes_parsed; /* Padding */
 238
 239       memcpy (&nlen, prop+bytes_parsed, 2);
 240       bytes_parsed += 2;
 241       if (my_bo != that_bo) nlen = SWAP16 (nlen);
 242       if (bytes_parsed+nlen > bytes) return BadLength;
 243       to_cpy = nlen > 127 ? 127 : nlen;
 244       memcpy (name, prop+bytes_parsed, to_cpy);
 245       name[to_cpy] = '\0';
 246
 247       bytes_parsed += nlen;
 248       bytes_parsed = PAD (bytes_parsed);
 249
 250       bytes_parsed += 4; /* Skip serial for this value */
 251       if (bytes_parsed > bytes) return BadLength;
 252
 253       is_xft = nlen > 6 && strncmp (name, "Xft/", 4) == 0;
 254
 255       switch (type)
 256         {
 257         case 0: /* Integer */
 258           if (bytes_parsed+4 > bytes) return BadLength;
 259           if (is_xft)
 260             {
 261               memcpy (&ival, prop+bytes_parsed, 4);
 262               if (my_bo != that_bo) ival = SWAP32 (ival);
 263             }
 264           bytes_parsed += 4;
 265           break;
 266
 267         case 1: /* String */
 268           if (bytes_parsed+4 > bytes) return BadLength;
 269           memcpy (&vlen, prop+bytes_parsed, 4);
 270           bytes_parsed += 4;
 271           if (my_bo != that_bo) vlen = SWAP32 (vlen);
 272           if (is_xft)
 273             {
 274               to_cpy = vlen > 127 ? 127 : vlen;
 275               memcpy (sval, prop+bytes_parsed, to_cpy);
 276               sval[to_cpy] = '\0';
 277             }
 278           bytes_parsed += vlen;
 279           bytes_parsed = PAD (bytes_parsed);
 280           break;
 281
 282         case 2: /* RGB value */
 283           /* No need to parse this */
 284           if (bytes_parsed+8 > bytes) return BadLength;
 285           bytes_parsed += 8; /* 4 values (r, b, g, alpha), 2 bytes each.  */
 286           break;
 287
 288         default: /* Parse Error */
 289           return BadValue;
 290         }
 291
 292       if (is_xft)
 293         {
 294           ++settings_seen;
 295           if (strcmp (name, "Xft/Antialias") == 0)
 296             settings->aa = ival != 0;
 297           else if (strcmp (name, "Xft/Hinting") == 0)
 298             settings->hinting = ival != 0;
 299           else if (strcmp (name, "Xft/HintStyle") == 0)
 300             {
 301               if (strcmp (sval, "hintnone") == 0)
 302                 settings->hintstyle = FC_HINT_NONE;
 303               else if (strcmp (sval, "hintslight") == 0)
 304                 settings->hintstyle = FC_HINT_SLIGHT;
 305               else if (strcmp (sval, "hintmedium") == 0)
 306                 settings->hintstyle = FC_HINT_MEDIUM;
 307               else if (strcmp (sval, "hintfull") == 0)
 308                 settings->hintstyle = FC_HINT_FULL;
 309             }
 310           else if (strcmp (name, "Xft/RGBA") == 0)
 311             {
 312               if (strcmp (sval, "none") == 0)
 313                 settings->rgba = FC_RGBA_NONE;
 314               else if (strcmp (sval, "rgb") == 0)
 315                 settings->rgba = FC_RGBA_RGB;
 316               else if (strcmp (sval, "bgr") == 0)
 317                 settings->rgba = FC_RGBA_BGR;
 318               else if (strcmp (sval, "vrgb") == 0)
 319                 settings->rgba = FC_RGBA_VRGB;
 320               else if (strcmp (sval, "vbgr") == 0)
 321                 settings->rgba = FC_RGBA_VBGR;
 322             }
 323           else if (strcmp (name, "Xft/DPI") == 0)
 324             settings->dpi = (double)ival/1024.0;
 325           else if (strcmp (name, "Xft/lcdfilter") == 0)
 326             {
 327               if (strcmp (sval, "none") == 0)
 328                 settings->lcdfilter = FC_LCD_NONE;
 329               else if (strcmp (sval, "lcddefault") == 0)
 330                 settings->lcdfilter = FC_LCD_DEFAULT;
 331             }
 332         }
 333     }
 334
 335   return Success;
 336 }
 337
 338 static int
 339 read_xft_settings (dpyinfo, settings)
 340      struct x_display_info *dpyinfo;
 341      struct xsettings *settings;
 342 {
 343   long long_len;
 344   Atom act_type;
 345   int act_form;
 346   unsigned long nitems, bytes_after;
 347   unsigned char *prop = NULL;
 348   Display *dpy = dpyinfo->display;
 349   int rc;
 350
 351   x_catch_errors (dpy);
 352   rc = XGetWindowProperty (dpy,
 353                            dpyinfo->xsettings_window,
 354                            dpyinfo->Xatom_xsettings_prop,
 355                            0, LONG_MAX, False, AnyPropertyType,
 356                            &act_type, &act_form, &nitems, &bytes_after,
 357                            &prop);
 358
 359   if (rc == Success && prop != NULL && act_form == 8 && nitems > 0
 360       && act_type == dpyinfo->Xatom_xsettings_prop)
 361     rc = parse_xft_settings (prop, nitems, settings);
 362
 363   XFree (prop);
 364
 365   x_uncatch_errors ();
 366
 367   return rc == Success;
 368 }
 369
 370
 371 static void
 372 apply_xft_settings (dpyinfo, send_event_p)
 373      struct x_display_info *dpyinfo;
 374      int send_event_p;
 375 {
 376   FcPattern *pat;
 377   struct xsettings settings, oldsettings;
 378   int changed = 0;
 379
 380   if (!read_xft_settings (dpyinfo, &settings))
 381     return;
 382
 383   memset (&oldsettings, 0, sizeof (oldsettings));
 384
 385   pat = FcPatternCreate ();
 386   XftDefaultSubstitute (dpyinfo->display,
 387                         XScreenNumberOfScreen (dpyinfo->screen),
 388                         pat);
 389   FcPatternGetBool (pat, FC_ANTIALIAS, 0, &oldsettings.aa);
 390   FcPatternGetBool (pat, FC_HINTING, 0, &oldsettings.hinting);
 391   FcPatternGetInteger (pat, FC_HINT_STYLE, 0, &oldsettings.hintstyle);
 392   FcPatternGetInteger (pat, FC_LCD_FILTER, 0, &oldsettings.lcdfilter);
 393   FcPatternGetInteger (pat, FC_RGBA, 0, &oldsettings.rgba);
 394   FcPatternGetDouble (pat, FC_DPI, 0, &oldsettings.dpi);
 395
 396   if (oldsettings.aa != settings.aa)
 397     {
 398       FcPatternDel (pat, FC_ANTIALIAS);
 399       FcPatternAddBool (pat, FC_ANTIALIAS, settings.aa);
 400       ++changed;
 401     }
 402   if (oldsettings.hinting != settings.hinting)
 403     {
 404       FcPatternDel (pat, FC_HINTING);
 405       FcPatternAddBool (pat, FC_HINTING, settings.hinting);
 406       ++changed;
 407     }
 408   if (oldsettings.rgba != settings.rgba)
 409     {
 410       FcPatternDel (pat, FC_RGBA);
 411       FcPatternAddInteger (pat, FC_RGBA, settings.rgba);
 412       ++changed;
 413     }
 414   /* Older fontconfig versions don't have FC_LCD_FILTER. */
 415   if (oldsettings.lcdfilter != settings.lcdfilter)
 416     {
 417       FcPatternDel (pat, FC_LCD_FILTER);
 418       FcPatternAddInteger (pat, FC_LCD_FILTER, settings.lcdfilter);
 419       ++changed;
 420     }
 421   if (oldsettings.hintstyle != settings.hintstyle)
 422     {
 423       FcPatternDel (pat, FC_HINT_STYLE);
 424       FcPatternAddInteger (pat, FC_HINT_STYLE, settings.hintstyle);
 425       ++changed;
 426     }
 427   if (oldsettings.dpi != settings.dpi)
 428     {
 429       Lisp_Object frame, tail;
 430
 431       FcPatternDel (pat, FC_DPI);
 432       FcPatternAddDouble (pat, FC_DPI, settings.dpi);
 433       ++changed;
 434
 435       /* Change the DPI on this display and all frames on the display.  */
 436       dpyinfo->resy = dpyinfo->resx = settings.dpi;
 437       FOR_EACH_FRAME (tail, frame)
 438         if (FRAME_X_P (XFRAME (frame))
 439             && FRAME_X_DISPLAY_INFO (XFRAME (frame)) == dpyinfo)
 440           XFRAME (frame)->resy = XFRAME (frame)->resx = settings.dpi;
 441     }
 442
 443   if (changed)
 444     {
 445       XftDefaultSet (dpyinfo->display, pat);
 446       if (send_event_p)
 447         store_font_changed_event (Qfont_render,
 448                                   XCAR (dpyinfo->name_list_element));
 449     }
 450   else
 451     FcPatternDestroy (pat);
 452 }
 453
 454 #endif /* HAVE_XFT */
 455
 456 void
 457 xft_settings_event (dpyinfo, event)
 458      struct x_display_info *dpyinfo;
 459      XEvent *event;
 460 {
 461 #ifdef HAVE_XFT
 462   int check_window_p = 0;
 463
 464   switch (event->type)
 465     {
 466     case DestroyNotify:
 467       if (dpyinfo->xsettings_window == event->xany.window)
 468         check_window_p = 1;
 469       break;
 470
 471     case ClientMessage:
 472       if (event->xclient.message_type == dpyinfo->Xatom_xsettings_mgr
 473           && event->xclient.data.l[1] == dpyinfo->Xatom_xsettings_sel
 474           && event->xclient.window == dpyinfo->root_window)
 475         check_window_p = 1;
 476       break;
 477
 478     case PropertyNotify:
 479       if (event->xproperty.window == dpyinfo->xsettings_window
 480           && event->xproperty.state == PropertyNewValue
 481           && event->xproperty.atom == dpyinfo->Xatom_xsettings_prop)
 482         {
 483           apply_xft_settings (dpyinfo, True);
 484         }
 485       break;
 486     }
 487
 488   if (check_window_p)
 489     {
 490       dpyinfo->xsettings_window = None;
 491       get_prop_window (dpyinfo);
 492       if (dpyinfo->xsettings_window != None)
 493         apply_xft_settings (dpyinfo, True);
 494     }
 495 #endif /* HAVE_XFT */
 496 }
 497
 498
 499 static void
 500 init_gconf ()
 501 {
 502 #if defined (HAVE_GCONF) && defined (HAVE_XFT)
 503   int i;
 504   char *s;
 505
 506   g_type_init ();
 507   gconf_client = gconf_client_get_default ();
 508   s = gconf_client_get_string (gconf_client, SYSTEM_MONO_FONT, NULL);
 509   if (s)
 510     {
 511       current_mono_font = xstrdup (s);
 512       g_free (s);
 513     }
 514   gconf_client_set_error_handling (gconf_client, GCONF_CLIENT_HANDLE_NONE);
 515   gconf_client_add_dir (gconf_client,
 516                         SYSTEM_MONO_FONT,
 517                         GCONF_CLIENT_PRELOAD_ONELEVEL,
 518                         NULL);
 519   gconf_client_notify_add (gconf_client,
 520                            SYSTEM_MONO_FONT,
 521                            something_changedCB,
 522                            NULL, NULL, NULL);
 523 #endif /* HAVE_GCONF && HAVE_XFT */
 524 }
 525
 526 static void
 527 init_xfd_settings (dpyinfo)
 528      struct x_display_info *dpyinfo;
 529 {
 530 #ifdef HAVE_XFT
 531   char sel[64];
 532   Display *dpy = dpyinfo->display;
 533
 534   BLOCK_INPUT;
 535
 536   sprintf (sel, "_XSETTINGS_S%d", XScreenNumberOfScreen (dpyinfo->screen));
 537   dpyinfo->Xatom_xsettings_sel = XInternAtom (dpy, sel, False);
 538   dpyinfo->Xatom_xsettings_prop = XInternAtom (dpy,
 539                                                "_XSETTINGS_SETTINGS",
 540                                                False);
 541   dpyinfo->Xatom_xsettings_mgr = XInternAtom (dpy, "MANAGER", False);
 542
 543   /* Select events so we can detect client messages sent when selection
 544      owner changes.  */
 545   XSelectInput (dpy, dpyinfo->root_window, StructureNotifyMask);
 546
 547   get_prop_window (dpyinfo);
 548   if (dpyinfo->xsettings_window != None)
 549     apply_xft_settings (dpyinfo, False);
 550
 551   UNBLOCK_INPUT;
 552
 553 #else /* ! HAVE_XFT */
 554
 555   dpyinfo->Xatom_xsettings_sel = None;
 556   dpyinfo->Xatom_xsettings_prop = None;
 557   dpyinfo->Xatom_xsettings_mgr = None;
 558   dpyinfo->xsettings_window = None;
 559
 560 #endif /* ! HAVE_XFT */
 561 }
 562
 563 void
 564 xsettings_initialize (dpyinfo)
 565      struct x_display_info *dpyinfo;
 566 {
 567   if (first_dpyinfo == NULL) first_dpyinfo = dpyinfo;
 568   init_gconf ();
 569   init_xfd_settings (dpyinfo);
 570 }
 571
 572 const char *
 573 xsettings_get_system_font ()
 574 {
 575   return current_mono_font;
 576 }
 577
 578 DEFUN ("font-get-system-font", Ffont_get_system_font, Sfont_get_system_font,
 579        0, 0, 0,
 580        doc: /* Get the system default monospaced font. */)
 581   ()
 582 {
 583   return current_mono_font && use_system_font
 584     ? make_string (current_mono_font, strlen (current_mono_font))
 585     : Qnil;
 586 }
 587
 588 void
 589 syms_of_xsettings ()
 590 {
 591   current_mono_font = NULL;
 592   first_dpyinfo = NULL;
 593 #ifdef HAVE_GCONF
 594   gconf_client = NULL;
 595 #endif
 596
 597   Qfont_name = intern_c_string ("font-name");
 598   staticpro (&Qfont_name);
 599   Qfont_render = intern_c_string ("font-render");
 600   staticpro (&Qfont_render);
 601   defsubr (&Sfont_get_system_font);
 602
 603   DEFVAR_BOOL ("font-use-system-font", &use_system_font,
 604     doc: /* *Non-nil means to use the system defined font.  */);
 605   use_system_font = 0;
 606
 607 #ifdef HAVE_XFT
 608   Fprovide (intern_c_string ("font-render-setting"), Qnil);
 609 #ifdef HAVE_GCONF
 610   Fprovide (intern_c_string ("system-font-setting"), Qnil);
 611 #endif
 612 #endif
 613 }