src/xsettings.c

   1 /* Functions for handle font changes dynamically.
   2    Copyright (C) 2009, 2010
   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 "keyboard.h"
  28 #include "blockinput.h"
  29 #include "termhooks.h"
  30 #include "termopts.h"
  31
  32 #include <X11/Xproto.h>
  33
  34 #ifdef HAVE_GCONF
  35 #include <gconf/gconf-client.h>
  36 #endif
  37 #ifdef HAVE_XFT
  38 #include <X11/Xft/Xft.h>
  39 #endif
  40
  41 static char *current_mono_font;
  42 static struct x_display_info *first_dpyinfo;
  43 static Lisp_Object Qfont_name, Qfont_render;
  44 static int use_system_font;
  45
  46 #ifdef HAVE_GCONF
  47 static GConfClient *gconf_client;
  48 #endif
  49
  50
  51 static void
  52 store_font_changed_event (arg, display_name)
  53      Lisp_Object arg;
  54      Lisp_Object display_name;
  55 {
  56   struct input_event event;
  57   EVENT_INIT (event);
  58   event.kind = CONFIG_CHANGED_EVENT;
  59   event.frame_or_window = display_name;
  60   event.arg = arg;
  61   kbd_buffer_store_event (&event);
  62 }
  63
  64 #ifdef HAVE_GCONF
  65
  66 #define SYSTEM_MONO_FONT       "/desktop/gnome/interface/monospace_font_name"
  67
  68 /* Callback called when something changed in GConf that we care about,
  69    that is SYSTEM_MONO_FONT.  */
  70
  71 static void
  72 something_changedCB (client, cnxn_id, entry, user_data)
  73      GConfClient *client;
  74      guint cnxn_id;
  75      GConfEntry *entry;
  76      gpointer user_data;
  77 {
  78   GConfValue *v = gconf_entry_get_value (entry);
  79
  80   if (!v) return;
  81   if (v->type == GCONF_VALUE_STRING)
  82     {
  83       const char *value = gconf_value_get_string (v);
  84       int i;
  85       if (current_mono_font != NULL && strcmp (value, current_mono_font) == 0)
  86         return; /* No change. */
  87
  88       xfree (current_mono_font);
  89       current_mono_font = xstrdup (value);
  90     }
  91
  92
  93   if (first_dpyinfo != NULL)
  94     {
  95       /* Check if display still open */
  96       struct x_display_info *dpyinfo;
  97       int found = 0;
  98       for (dpyinfo = x_display_list; !found && dpyinfo; dpyinfo = dpyinfo->next)
  99         found = dpyinfo == first_dpyinfo;
 100
 101       if (found && use_system_font)
 102         store_font_changed_event (Qfont_name,
 103                                   XCAR (first_dpyinfo->name_list_element));
 104     }
 105 }
 106 #endif /* HAVE_GCONF */
 107
 108 #ifdef HAVE_XFT
 109
 110 /* Older fontconfig versions don't have FC_LCD_*.  */
 111 #ifndef FC_LCD_NONE
 112 #define FC_LCD_NONE 0
 113 #endif
 114 #ifndef FC_LCD_DEFAULT
 115 #define FC_LCD_DEFAULT 1
 116 #endif
 117 #ifndef FC_LCD_FILTER
 118 #define FC_LCD_FILTER "lcdfilter"
 119 #endif
 120
 121 /* Find the window that contains the XSETTINGS property values.  */
 122
 123 static void
 124 get_prop_window (dpyinfo)
 125      struct x_display_info *dpyinfo;
 126 {
 127   Display *dpy = dpyinfo->display;
 128
 129   XGrabServer (dpy);
 130   dpyinfo->xsettings_window = XGetSelectionOwner (dpy,
 131                                                   dpyinfo->Xatom_xsettings_sel);
 132   if (dpyinfo->xsettings_window != None)
 133     /* Select events so we can detect if window is deleted or if settings
 134        are changed.  */
 135     XSelectInput (dpy, dpyinfo->xsettings_window,
 136                   PropertyChangeMask|StructureNotifyMask);
 137
 138   XUngrabServer (dpy);
 139 }
 140
 141 enum {
 142   SEEN_AA         = 0x01,
 143   SEEN_HINTING    = 0x02,
 144   SEEN_RGBA       = 0x04,
 145   SEEN_LCDFILTER  = 0x08,
 146   SEEN_HINTSTYLE  = 0x10,
 147   SEEN_DPI        = 0x20,
 148 };
 149 struct xsettings
 150 {
 151   FcBool aa, hinting;
 152   int rgba, lcdfilter, hintstyle;
 153   double dpi;
 154
 155   unsigned seen;
 156 };
 157
 158 #define SWAP32(nr) (((nr) << 24) | (((nr) << 8) & 0xff0000)     \
 159                     | (((nr) >> 8) & 0xff00) | ((nr) >> 24))
 160 #define SWAP16(nr) (((nr) << 8) | ((nr) >> 8))
 161 #define PAD(nr)    (((nr) + 3) & ~3)
 162
 163 /* Parse xsettings and extract those that deal with Xft.
 164    See http://freedesktop.org/wiki/Specifications/XSettingsRegistry
 165    and http://standards.freedesktop.org/xsettings-spec/xsettings-spec-0.5.html.
 166
 167    Layout of prop.  First is a header:
 168
 169    bytes   type     what
 170    ------------------------------------
 171    1      CARD8    byte-order
 172    3               unused
 173    4      CARD32   SERIAL
 174    4      CARD32   N_SETTINGS
 175
 176    Then N_SETTINGS records, with header:
 177
 178    bytes   type          what
 179    ------------------------------------
 180    1      SETTING_TYPE  type (0 = integer, 1 = string, 2 RGB color).
 181    1                    unused
 182    2      CARD16        n == name-length
 183    n      STRING8       name
 184    p                    unused, p=pad_to_even_4(n)
 185    4      CARD32        last-change-serial
 186
 187    and then the value, For string:
 188
 189    bytes   type          what
 190    ------------------------------------
 191    4      CARD32        n = value-length
 192    n      STRING8       value
 193    p                    unused, p=pad_to_even_4(n)
 194
 195    For integer:
 196
 197    bytes   type          what
 198    ------------------------------------
 199    4      INT32         value
 200
 201    For RGB color:
 202
 203    bytes   type          what
 204    ------------------------------------
 205    2      CARD16        red
 206    2      CARD16        blue
 207    2      CARD16        green
 208    2      CARD16        alpha
 209
 210    Returns non-zero if some Xft settings was seen, zero otherwise.
 211 */
 212
 213 static int
 214 parse_xft_settings (prop, bytes, settings)
 215      unsigned char *prop;
 216      unsigned long bytes;
 217      struct xsettings *settings;
 218 {
 219   Lisp_Object byteorder = Fbyteorder ();
 220   int my_bo = XFASTINT (byteorder) == 'B' ? MSBFirst : LSBFirst;
 221   int that_bo = prop[0];
 222   CARD32 n_settings;
 223   int bytes_parsed = 0;
 224   int settings_seen = 0;
 225   int i = 0;
 226
 227   /* First 4 bytes is a serial number, skip that.  */
 228
 229   if (bytes < 12) return BadLength;
 230   memcpy (&n_settings, prop+8, 4);
 231   if (my_bo != that_bo) n_settings = SWAP32 (n_settings);
 232   bytes_parsed = 12;
 233
 234   memset (settings, 0, sizeof (*settings));
 235
 236   while (bytes_parsed+4 < bytes && settings_seen < 6
 237          && i < n_settings)
 238     {
 239       int type = prop[bytes_parsed++];
 240       CARD16 nlen;
 241       CARD32 vlen, ival = 0;
 242       char name[128]; /* The names we are looking for are not this long.  */
 243       char sval[128]; /* The values we are looking for are not this long.  */
 244       int is_xft;
 245       int to_cpy;
 246
 247       sval[0] = '\0';
 248       ++i;
 249       ++bytes_parsed; /* Padding */
 250
 251       memcpy (&nlen, prop+bytes_parsed, 2);
 252       bytes_parsed += 2;
 253       if (my_bo != that_bo) nlen = SWAP16 (nlen);
 254       if (bytes_parsed+nlen > bytes) return BadLength;
 255       to_cpy = nlen > 127 ? 127 : nlen;
 256       memcpy (name, prop+bytes_parsed, to_cpy);
 257       name[to_cpy] = '\0';
 258
 259       bytes_parsed += nlen;
 260       bytes_parsed = PAD (bytes_parsed);
 261
 262       bytes_parsed += 4; /* Skip serial for this value */
 263       if (bytes_parsed > bytes) return BadLength;
 264
 265       is_xft = nlen > 6 && strncmp (name, "Xft/", 4) == 0;
 266
 267       switch (type)
 268         {
 269         case 0: /* Integer */
 270           if (bytes_parsed+4 > bytes) return BadLength;
 271           if (is_xft)
 272             {
 273               memcpy (&ival, prop+bytes_parsed, 4);
 274               if (my_bo != that_bo) ival = SWAP32 (ival);
 275             }
 276           bytes_parsed += 4;
 277           break;
 278
 279         case 1: /* String */
 280           if (bytes_parsed+4 > bytes) return BadLength;
 281           memcpy (&vlen, prop+bytes_parsed, 4);
 282           bytes_parsed += 4;
 283           if (my_bo != that_bo) vlen = SWAP32 (vlen);
 284           if (is_xft)
 285             {
 286               to_cpy = vlen > 127 ? 127 : vlen;
 287               memcpy (sval, prop+bytes_parsed, to_cpy);
 288               sval[to_cpy] = '\0';
 289             }
 290           bytes_parsed += vlen;
 291           bytes_parsed = PAD (bytes_parsed);
 292           break;
 293
 294         case 2: /* RGB value */
 295           /* No need to parse this */
 296           if (bytes_parsed+8 > bytes) return BadLength;
 297           bytes_parsed += 8; /* 4 values (r, b, g, alpha), 2 bytes each.  */
 298           break;
 299
 300         default: /* Parse Error */
 301           return BadValue;
 302         }
 303
 304       if (is_xft)
 305         {
 306           ++settings_seen;
 307           if (strcmp (name, "Xft/Antialias") == 0)
 308             {
 309               settings->seen |= SEEN_AA;
 310               settings->aa = ival != 0;
 311             }
 312           else if (strcmp (name, "Xft/Hinting") == 0)
 313             {
 314               settings->seen |= SEEN_HINTING;
 315               settings->hinting = ival != 0;
 316             }
 317           else if (strcmp (name, "Xft/HintStyle") == 0)
 318             {
 319               settings->seen |= SEEN_HINTSTYLE;
 320               if (strcmp (sval, "hintnone") == 0)
 321                 settings->hintstyle = FC_HINT_NONE;
 322               else if (strcmp (sval, "hintslight") == 0)
 323                 settings->hintstyle = FC_HINT_SLIGHT;
 324               else if (strcmp (sval, "hintmedium") == 0)
 325                 settings->hintstyle = FC_HINT_MEDIUM;
 326               else if (strcmp (sval, "hintfull") == 0)
 327                 settings->hintstyle = FC_HINT_FULL;
 328               else
 329                 settings->seen &= ~SEEN_HINTSTYLE;
 330             }
 331           else if (strcmp (name, "Xft/RGBA") == 0)
 332             {
 333               settings->seen |= SEEN_RGBA;
 334               if (strcmp (sval, "none") == 0)
 335                 settings->rgba = FC_RGBA_NONE;
 336               else if (strcmp (sval, "rgb") == 0)
 337                 settings->rgba = FC_RGBA_RGB;
 338               else if (strcmp (sval, "bgr") == 0)
 339                 settings->rgba = FC_RGBA_BGR;
 340               else if (strcmp (sval, "vrgb") == 0)
 341                 settings->rgba = FC_RGBA_VRGB;
 342               else if (strcmp (sval, "vbgr") == 0)
 343                 settings->rgba = FC_RGBA_VBGR;
 344               else
 345                 settings->seen &= ~SEEN_RGBA;
 346             }
 347           else if (strcmp (name, "Xft/DPI") == 0)
 348             {
 349               settings->seen |= SEEN_DPI;
 350               settings->dpi = (double)ival/1024.0;
 351             }
 352           else if (strcmp (name, "Xft/lcdfilter") == 0)
 353             {
 354               settings->seen |= SEEN_LCDFILTER;
 355               if (strcmp (sval, "none") == 0)
 356                 settings->lcdfilter = FC_LCD_NONE;
 357               else if (strcmp (sval, "lcddefault") == 0)
 358                 settings->lcdfilter = FC_LCD_DEFAULT;
 359               else
 360                 settings->seen &= ~SEEN_LCDFILTER;
 361             }
 362         }
 363     }
 364
 365   return settings_seen;
 366 }
 367
 368 static int
 369 read_xft_settings (dpyinfo, settings)
 370      struct x_display_info *dpyinfo;
 371      struct xsettings *settings;
 372 {
 373   long long_len;
 374   Atom act_type;
 375   int act_form;
 376   unsigned long nitems, bytes_after;
 377   unsigned char *prop = NULL;
 378   Display *dpy = dpyinfo->display;
 379   int rc;
 380
 381   x_catch_errors (dpy);
 382   rc = XGetWindowProperty (dpy,
 383                            dpyinfo->xsettings_window,
 384                            dpyinfo->Xatom_xsettings_prop,
 385                            0, LONG_MAX, False, AnyPropertyType,
 386                            &act_type, &act_form, &nitems, &bytes_after,
 387                            &prop);
 388
 389   if (rc == Success && prop != NULL && act_form == 8 && nitems > 0
 390       && act_type == dpyinfo->Xatom_xsettings_prop)
 391     rc = parse_xft_settings (prop, nitems, settings);
 392
 393   XFree (prop);
 394
 395   x_uncatch_errors ();
 396
 397   return rc != 0;
 398 }
 399
 400
 401 static void
 402 apply_xft_settings (dpyinfo, send_event_p)
 403      struct x_display_info *dpyinfo;
 404      int send_event_p;
 405 {
 406   FcPattern *pat;
 407   struct xsettings settings, oldsettings;
 408   int changed = 0;
 409
 410   if (!read_xft_settings (dpyinfo, &settings))
 411     return;
 412
 413   memset (&oldsettings, 0, sizeof (oldsettings));
 414
 415   pat = FcPatternCreate ();
 416   XftDefaultSubstitute (dpyinfo->display,
 417                         XScreenNumberOfScreen (dpyinfo->screen),
 418                         pat);
 419   FcPatternGetBool (pat, FC_ANTIALIAS, 0, &oldsettings.aa);
 420   FcPatternGetBool (pat, FC_HINTING, 0, &oldsettings.hinting);
 421   FcPatternGetInteger (pat, FC_HINT_STYLE, 0, &oldsettings.hintstyle);
 422   FcPatternGetInteger (pat, FC_LCD_FILTER, 0, &oldsettings.lcdfilter);
 423   FcPatternGetInteger (pat, FC_RGBA, 0, &oldsettings.rgba);
 424   FcPatternGetDouble (pat, FC_DPI, 0, &oldsettings.dpi);
 425
 426   if ((settings.seen & SEEN_AA) != 0 && oldsettings.aa != settings.aa)
 427     {
 428       FcPatternDel (pat, FC_ANTIALIAS);
 429       FcPatternAddBool (pat, FC_ANTIALIAS, settings.aa);
 430       ++changed;
 431     }
 432   if ((settings.seen & SEEN_HINTING) != 0
 433       && oldsettings.hinting != settings.hinting)
 434     {
 435       FcPatternDel (pat, FC_HINTING);
 436       FcPatternAddBool (pat, FC_HINTING, settings.hinting);
 437       ++changed;
 438     }
 439   if ((settings.seen & SEEN_RGBA) != 0 && oldsettings.rgba != settings.rgba)
 440     {
 441       FcPatternDel (pat, FC_RGBA);
 442       FcPatternAddInteger (pat, FC_RGBA, settings.rgba);
 443       ++changed;
 444     }
 445   /* Older fontconfig versions don't have FC_LCD_FILTER. */
 446   if ((settings.seen & SEEN_LCDFILTER) != 0
 447       && oldsettings.lcdfilter != settings.lcdfilter)
 448     {
 449       FcPatternDel (pat, FC_LCD_FILTER);
 450       FcPatternAddInteger (pat, FC_LCD_FILTER, settings.lcdfilter);
 451       ++changed;
 452     }
 453   if ((settings.seen & SEEN_HINTSTYLE) != 0
 454       && oldsettings.hintstyle != settings.hintstyle)
 455     {
 456       FcPatternDel (pat, FC_HINT_STYLE);
 457       FcPatternAddInteger (pat, FC_HINT_STYLE, settings.hintstyle);
 458       ++changed;
 459     }
 460   if ((settings.seen & SEEN_DPI) != 0 && oldsettings.dpi != settings.dpi
 461       && settings.dpi > 0)
 462     {
 463       Lisp_Object frame, tail;
 464
 465       FcPatternDel (pat, FC_DPI);
 466       FcPatternAddDouble (pat, FC_DPI, settings.dpi);
 467       ++changed;
 468
 469       /* Change the DPI on this display and all frames on the display.  */
 470       dpyinfo->resy = dpyinfo->resx = settings.dpi;
 471       FOR_EACH_FRAME (tail, frame)
 472         if (FRAME_X_P (XFRAME (frame))
 473             && FRAME_X_DISPLAY_INFO (XFRAME (frame)) == dpyinfo)
 474           XFRAME (frame)->resy = XFRAME (frame)->resx = settings.dpi;
 475     }
 476
 477   if (changed)
 478     {
 479       XftDefaultSet (dpyinfo->display, pat);
 480       if (send_event_p)
 481         store_font_changed_event (Qfont_render,
 482                                   XCAR (dpyinfo->name_list_element));
 483     }
 484   else
 485     FcPatternDestroy (pat);
 486 }
 487
 488 #endif /* HAVE_XFT */
 489
 490 void
 491 xft_settings_event (dpyinfo, event)
 492      struct x_display_info *dpyinfo;
 493      XEvent *event;
 494 {
 495 #ifdef HAVE_XFT
 496   int check_window_p = 0;
 497
 498   switch (event->type)
 499     {
 500     case DestroyNotify:
 501       if (dpyinfo->xsettings_window == event->xany.window)
 502         check_window_p = 1;
 503       break;
 504
 505     case ClientMessage:
 506       if (event->xclient.message_type == dpyinfo->Xatom_xsettings_mgr
 507           && event->xclient.data.l[1] == dpyinfo->Xatom_xsettings_sel
 508           && event->xclient.window == dpyinfo->root_window)
 509         check_window_p = 1;
 510       break;
 511
 512     case PropertyNotify:
 513       if (event->xproperty.window == dpyinfo->xsettings_window
 514           && event->xproperty.state == PropertyNewValue
 515           && event->xproperty.atom == dpyinfo->Xatom_xsettings_prop)
 516         {
 517           apply_xft_settings (dpyinfo, True);
 518         }
 519       break;
 520     }
 521
 522   if (check_window_p)
 523     {
 524       dpyinfo->xsettings_window = None;
 525       get_prop_window (dpyinfo);
 526       if (dpyinfo->xsettings_window != None)
 527         apply_xft_settings (dpyinfo, True);
 528     }
 529 #endif /* HAVE_XFT */
 530 }
 531
 532
 533 static void
 534 init_gconf ()
 535 {
 536 #if defined (HAVE_GCONF) && defined (HAVE_XFT)
 537   int i;
 538   char *s;
 539
 540   g_type_init ();
 541   gconf_client = gconf_client_get_default ();
 542   s = gconf_client_get_string (gconf_client, SYSTEM_MONO_FONT, NULL);
 543   if (s)
 544     {
 545       current_mono_font = xstrdup (s);
 546       g_free (s);
 547     }
 548   gconf_client_set_error_handling (gconf_client, GCONF_CLIENT_HANDLE_NONE);
 549   gconf_client_add_dir (gconf_client,
 550                         SYSTEM_MONO_FONT,
 551                         GCONF_CLIENT_PRELOAD_ONELEVEL,
 552                         NULL);
 553   gconf_client_notify_add (gconf_client,
 554                            SYSTEM_MONO_FONT,
 555                            something_changedCB,
 556                            NULL, NULL, NULL);
 557 #endif /* HAVE_GCONF && HAVE_XFT */
 558 }
 559
 560 static void
 561 init_xfd_settings (dpyinfo)
 562      struct x_display_info *dpyinfo;
 563 {
 564 #ifdef HAVE_XFT
 565   char sel[64];
 566   Display *dpy = dpyinfo->display;
 567
 568   BLOCK_INPUT;
 569
 570   sprintf (sel, "_XSETTINGS_S%d", XScreenNumberOfScreen (dpyinfo->screen));
 571   dpyinfo->Xatom_xsettings_sel = XInternAtom (dpy, sel, False);
 572   dpyinfo->Xatom_xsettings_prop = XInternAtom (dpy,
 573                                                "_XSETTINGS_SETTINGS",
 574                                                False);
 575   dpyinfo->Xatom_xsettings_mgr = XInternAtom (dpy, "MANAGER", False);
 576
 577   /* Select events so we can detect client messages sent when selection
 578      owner changes.  */
 579   XSelectInput (dpy, dpyinfo->root_window, StructureNotifyMask);
 580
 581   get_prop_window (dpyinfo);
 582   if (dpyinfo->xsettings_window != None)
 583     apply_xft_settings (dpyinfo, False);
 584
 585   UNBLOCK_INPUT;
 586
 587 #else /* ! HAVE_XFT */
 588
 589   dpyinfo->Xatom_xsettings_sel = None;
 590   dpyinfo->Xatom_xsettings_prop = None;
 591   dpyinfo->Xatom_xsettings_mgr = None;
 592   dpyinfo->xsettings_window = None;
 593
 594 #endif /* ! HAVE_XFT */
 595 }
 596
 597 void
 598 xsettings_initialize (dpyinfo)
 599      struct x_display_info *dpyinfo;
 600 {
 601   if (first_dpyinfo == NULL) first_dpyinfo = dpyinfo;
 602   init_gconf ();
 603   init_xfd_settings (dpyinfo);
 604 }
 605
 606 const char *
 607 xsettings_get_system_font ()
 608 {
 609   return current_mono_font;
 610 }
 611
 612 DEFUN ("font-get-system-font", Ffont_get_system_font, Sfont_get_system_font,
 613        0, 0, 0,
 614        doc: /* Get the system default monospaced font. */)
 615   ()
 616 {
 617   return current_mono_font && use_system_font
 618     ? make_string (current_mono_font, strlen (current_mono_font))
 619     : Qnil;
 620 }
 621
 622 void
 623 syms_of_xsettings ()
 624 {
 625   current_mono_font = NULL;
 626   first_dpyinfo = NULL;
 627 #ifdef HAVE_GCONF
 628   gconf_client = NULL;
 629 #endif
 630
 631   Qfont_name = intern_c_string ("font-name");
 632   staticpro (&Qfont_name);
 633   Qfont_render = intern_c_string ("font-render");
 634   staticpro (&Qfont_render);
 635   defsubr (&Sfont_get_system_font);
 636
 637   DEFVAR_BOOL ("font-use-system-font", &use_system_font,
 638     doc: /* *Non-nil means to use the system defined font.  */);
 639   use_system_font = 0;
 640
 641 #ifdef HAVE_XFT
 642   Fprovide (intern_c_string ("font-render-setting"), Qnil);
 643 #ifdef HAVE_GCONF
 644   Fprovide (intern_c_string ("system-font-setting"), Qnil);
 645 #endif
 646 #endif
 647 }
 648
 649 /* arch-tag: 541716ed-2e6b-42e1-8212-3197e01ea61d
 650    (do not change this comment) */