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 "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 struct xsettings
 142 {
 143   FcBool aa, hinting;
 144   int rgba, lcdfilter, hintstyle;
 145   double dpi;
 146 };
 147
 148 #define SWAP32(nr) (((nr) << 24) | (((nr) << 8) & 0xff0000)     \
 149                     | (((nr) >> 8) & 0xff00) | ((nr) >> 24))
 150 #define SWAP16(nr) (((nr) << 8) | ((nr) >> 8))
 151 #define PAD(nr)    (((nr) + 3) & ~3)
 152
 153 /* Parse xsettings and extract those that deal with Xft.
 154    See http://freedesktop.org/wiki/Specifications/XSettingsRegistry
 155    and http://standards.freedesktop.org/xsettings-spec/xsettings-spec-0.5.html.
 156
 157    Layout of prop.  First is a header:
 158
 159    bytes   type     what
 160    ------------------------------------
 161    1      CARD8    byte-order
 162    3               unused
 163    4      CARD32   SERIAL
 164    4      CARD32   N_SETTINGS
 165
 166    Then N_SETTINGS records, with header:
 167
 168    bytes   type          what
 169    ------------------------------------
 170    1      SETTING_TYPE  type (0 = integer, 1 = string, 2 RGB color).
 171    1                    unused
 172    2      CARD16        n == name-length
 173    n      STRING8       name
 174    p                    unused, p=pad_to_even_4(n)
 175    4      CARD32        last-change-serial
 176
 177    and then the value, For string:
 178
 179    bytes   type          what
 180    ------------------------------------
 181    4      CARD32        n = value-length
 182    n      STRING8       value
 183    p                    unused, p=pad_to_even_4(n)
 184
 185    For integer:
 186
 187    bytes   type          what
 188    ------------------------------------
 189    4      INT32         value
 190
 191    For RGB color:
 192
 193    bytes   type          what
 194    ------------------------------------
 195    2      CARD16        red
 196    2      CARD16        blue
 197    2      CARD16        green
 198    2      CARD16        alpha
 199
 200 */
 201
 202 static int
 203 parse_xft_settings (prop, bytes, settings)
 204      unsigned char *prop;
 205      unsigned long bytes;
 206      struct xsettings *settings;
 207 {
 208   Lisp_Object byteorder = Fbyteorder ();
 209   int my_bo = XFASTINT (byteorder) == 'B' ? MSBFirst : LSBFirst;
 210   int that_bo = prop[0];
 211   CARD32 n_settings;
 212   int bytes_parsed = 0;
 213   int settings_seen = 0;
 214   int i = 0;
 215
 216   /* First 4 bytes is a serial number, skip that.  */
 217
 218   if (bytes < 12) return BadLength;
 219   memcpy (&n_settings, prop+8, 4);
 220   if (my_bo != that_bo) n_settings = SWAP32 (n_settings);
 221   bytes_parsed = 12;
 222
 223   memset (settings, 0, sizeof (*settings));
 224
 225   while (bytes_parsed+4 < bytes && settings_seen < 6
 226          && i < n_settings)
 227     {
 228       int type = prop[bytes_parsed++];
 229       CARD16 nlen;
 230       CARD32 vlen, ival = 0;
 231       char name[128]; /* The names we are looking for are not this long.  */
 232       char sval[128]; /* The values we are looking for are not this long.  */
 233       int is_xft;
 234       int to_cpy;
 235
 236       sval[0] = '\0';
 237       ++i;
 238       ++bytes_parsed; /* Padding */
 239
 240       memcpy (&nlen, prop+bytes_parsed, 2);
 241       bytes_parsed += 2;
 242       if (my_bo != that_bo) nlen = SWAP16 (nlen);
 243       if (bytes_parsed+nlen > bytes) return BadLength;
 244       to_cpy = nlen > 127 ? 127 : nlen;
 245       memcpy (name, prop+bytes_parsed, to_cpy);
 246       name[to_cpy] = '\0';
 247
 248       bytes_parsed += nlen;
 249       bytes_parsed = PAD (bytes_parsed);
 250
 251       bytes_parsed += 4; /* Skip serial for this value */
 252       if (bytes_parsed > bytes) return BadLength;
 253
 254       is_xft = nlen > 6 && strncmp (name, "Xft/", 4) == 0;
 255
 256       switch (type)
 257         {
 258         case 0: /* Integer */
 259           if (bytes_parsed+4 > bytes) return BadLength;
 260           if (is_xft)
 261             {
 262               memcpy (&ival, prop+bytes_parsed, 4);
 263               if (my_bo != that_bo) ival = SWAP32 (ival);
 264             }
 265           bytes_parsed += 4;
 266           break;
 267
 268         case 1: /* String */
 269           if (bytes_parsed+4 > bytes) return BadLength;
 270           memcpy (&vlen, prop+bytes_parsed, 4);
 271           bytes_parsed += 4;
 272           if (my_bo != that_bo) vlen = SWAP32 (vlen);
 273           if (is_xft)
 274             {
 275               to_cpy = vlen > 127 ? 127 : vlen;
 276               memcpy (sval, prop+bytes_parsed, to_cpy);
 277               sval[to_cpy] = '\0';
 278             }
 279           bytes_parsed += vlen;
 280           bytes_parsed = PAD (bytes_parsed);
 281           break;
 282
 283         case 2: /* RGB value */
 284           /* No need to parse this */
 285           if (bytes_parsed+8 > bytes) return BadLength;
 286           bytes_parsed += 8; /* 4 values (r, b, g, alpha), 2 bytes each.  */
 287           break;
 288
 289         default: /* Parse Error */
 290           return BadValue;
 291         }
 292
 293       if (is_xft)
 294         {
 295           ++settings_seen;
 296           if (strcmp (name, "Xft/Antialias") == 0)
 297             settings->aa = ival != 0;
 298           else if (strcmp (name, "Xft/Hinting") == 0)
 299             settings->hinting = ival != 0;
 300           else if (strcmp (name, "Xft/HintStyle") == 0)
 301             {
 302               if (strcmp (sval, "hintnone") == 0)
 303                 settings->hintstyle = FC_HINT_NONE;
 304               else if (strcmp (sval, "hintslight") == 0)
 305                 settings->hintstyle = FC_HINT_SLIGHT;
 306               else if (strcmp (sval, "hintmedium") == 0)
 307                 settings->hintstyle = FC_HINT_MEDIUM;
 308               else if (strcmp (sval, "hintfull") == 0)
 309                 settings->hintstyle = FC_HINT_FULL;
 310             }
 311           else if (strcmp (name, "Xft/RGBA") == 0)
 312             {
 313               if (strcmp (sval, "none") == 0)
 314                 settings->rgba = FC_RGBA_NONE;
 315               else if (strcmp (sval, "rgb") == 0)
 316                 settings->rgba = FC_RGBA_RGB;
 317               else if (strcmp (sval, "bgr") == 0)
 318                 settings->rgba = FC_RGBA_BGR;
 319               else if (strcmp (sval, "vrgb") == 0)
 320                 settings->rgba = FC_RGBA_VRGB;
 321               else if (strcmp (sval, "vbgr") == 0)
 322                 settings->rgba = FC_RGBA_VBGR;
 323             }
 324           else if (strcmp (name, "Xft/DPI") == 0)
 325             settings->dpi = (double)ival/1024.0;
 326           else if (strcmp (name, "Xft/lcdfilter") == 0)
 327             {
 328               if (strcmp (sval, "none") == 0)
 329                 settings->lcdfilter = FC_LCD_NONE;
 330               else if (strcmp (sval, "lcddefault") == 0)
 331                 settings->lcdfilter = FC_LCD_DEFAULT;
 332             }
 333         }
 334     }
 335
 336   return Success;
 337 }
 338
 339 static int
 340 read_xft_settings (dpyinfo, settings)
 341      struct x_display_info *dpyinfo;
 342      struct xsettings *settings;
 343 {
 344   long long_len;
 345   Atom act_type;
 346   int act_form;
 347   unsigned long nitems, bytes_after;
 348   unsigned char *prop = NULL;
 349   Display *dpy = dpyinfo->display;
 350   int rc;
 351
 352   x_catch_errors (dpy);
 353   rc = XGetWindowProperty (dpy,
 354                            dpyinfo->xsettings_window,
 355                            dpyinfo->Xatom_xsettings_prop,
 356                            0, LONG_MAX, False, AnyPropertyType,
 357                            &act_type, &act_form, &nitems, &bytes_after,
 358                            &prop);
 359
 360   if (rc == Success && prop != NULL && act_form == 8 && nitems > 0
 361       && act_type == dpyinfo->Xatom_xsettings_prop)
 362     rc = parse_xft_settings (prop, nitems, settings);
 363
 364   XFree (prop);
 365
 366   x_uncatch_errors ();
 367
 368   return rc == Success;
 369 }
 370
 371
 372 static void
 373 apply_xft_settings (dpyinfo, send_event_p)
 374      struct x_display_info *dpyinfo;
 375      int send_event_p;
 376 {
 377   FcPattern *pat;
 378   struct xsettings settings, oldsettings;
 379   int changed = 0;
 380
 381   if (!read_xft_settings (dpyinfo, &settings))
 382     return;
 383
 384   memset (&oldsettings, 0, sizeof (oldsettings));
 385
 386   pat = FcPatternCreate ();
 387   XftDefaultSubstitute (dpyinfo->display,
 388                         XScreenNumberOfScreen (dpyinfo->screen),
 389                         pat);
 390   FcPatternGetBool (pat, FC_ANTIALIAS, 0, &oldsettings.aa);
 391   FcPatternGetBool (pat, FC_HINTING, 0, &oldsettings.hinting);
 392   FcPatternGetInteger (pat, FC_HINT_STYLE, 0, &oldsettings.hintstyle);
 393   FcPatternGetInteger (pat, FC_LCD_FILTER, 0, &oldsettings.lcdfilter);
 394   FcPatternGetInteger (pat, FC_RGBA, 0, &oldsettings.rgba);
 395   FcPatternGetDouble (pat, FC_DPI, 0, &oldsettings.dpi);
 396
 397   if (oldsettings.aa != settings.aa)
 398     {
 399       FcPatternDel (pat, FC_ANTIALIAS);
 400       FcPatternAddBool (pat, FC_ANTIALIAS, settings.aa);
 401       ++changed;
 402     }
 403   if (oldsettings.hinting != settings.hinting)
 404     {
 405       FcPatternDel (pat, FC_HINTING);
 406       FcPatternAddBool (pat, FC_HINTING, settings.hinting);
 407       ++changed;
 408     }
 409   if (oldsettings.rgba != settings.rgba)
 410     {
 411       FcPatternDel (pat, FC_RGBA);
 412       FcPatternAddInteger (pat, FC_RGBA, settings.rgba);
 413       ++changed;
 414     }
 415   /* Older fontconfig versions don't have FC_LCD_FILTER. */
 416   if (oldsettings.lcdfilter != settings.lcdfilter)
 417     {
 418       FcPatternDel (pat, FC_LCD_FILTER);
 419       FcPatternAddInteger (pat, FC_LCD_FILTER, settings.lcdfilter);
 420       ++changed;
 421     }
 422   if (oldsettings.hintstyle != settings.hintstyle)
 423     {
 424       FcPatternDel (pat, FC_HINT_STYLE);
 425       FcPatternAddInteger (pat, FC_HINT_STYLE, settings.hintstyle);
 426       ++changed;
 427     }
 428   if (oldsettings.dpi != settings.dpi)
 429     {
 430       Lisp_Object frame, tail;
 431
 432       FcPatternDel (pat, FC_DPI);
 433       FcPatternAddDouble (pat, FC_DPI, settings.dpi);
 434       ++changed;
 435
 436       /* Change the DPI on this display and all frames on the display.  */
 437       dpyinfo->resy = dpyinfo->resx = settings.dpi;
 438       FOR_EACH_FRAME (tail, frame)
 439         if (FRAME_X_P (XFRAME (frame))
 440             && FRAME_X_DISPLAY_INFO (XFRAME (frame)) == dpyinfo)
 441           XFRAME (frame)->resy = XFRAME (frame)->resx = settings.dpi;
 442     }
 443
 444   if (changed)
 445     {
 446       XftDefaultSet (dpyinfo->display, pat);
 447       if (send_event_p)
 448         store_font_changed_event (Qfont_render,
 449                                   XCAR (dpyinfo->name_list_element));
 450     }
 451   else
 452     FcPatternDestroy (pat);
 453 }
 454
 455 #endif /* HAVE_XFT */
 456
 457 void
 458 xft_settings_event (dpyinfo, event)
 459      struct x_display_info *dpyinfo;
 460      XEvent *event;
 461 {
 462 #ifdef HAVE_XFT
 463   int check_window_p = 0;
 464
 465   switch (event->type)
 466     {
 467     case DestroyNotify:
 468       if (dpyinfo->xsettings_window == event->xany.window)
 469         check_window_p = 1;
 470       break;
 471
 472     case ClientMessage:
 473       if (event->xclient.message_type == dpyinfo->Xatom_xsettings_mgr
 474           && event->xclient.data.l[1] == dpyinfo->Xatom_xsettings_sel
 475           && event->xclient.window == dpyinfo->root_window)
 476         check_window_p = 1;
 477       break;
 478
 479     case PropertyNotify:
 480       if (event->xproperty.window == dpyinfo->xsettings_window
 481           && event->xproperty.state == PropertyNewValue
 482           && event->xproperty.atom == dpyinfo->Xatom_xsettings_prop)
 483         {
 484           apply_xft_settings (dpyinfo, True);
 485         }
 486       break;
 487     }
 488
 489   if (check_window_p)
 490     {
 491       dpyinfo->xsettings_window = None;
 492       get_prop_window (dpyinfo);
 493       if (dpyinfo->xsettings_window != None)
 494         apply_xft_settings (dpyinfo, True);
 495     }
 496 #endif /* HAVE_XFT */
 497 }
 498
 499
 500 static void
 501 init_gconf ()
 502 {
 503 #if defined (HAVE_GCONF) && defined (HAVE_XFT)
 504   int i;
 505   char *s;
 506
 507   g_type_init ();
 508   gconf_client = gconf_client_get_default ();
 509   s = gconf_client_get_string (gconf_client, SYSTEM_MONO_FONT, NULL);
 510   if (s)
 511     {
 512       current_mono_font = xstrdup (s);
 513       g_free (s);
 514     }
 515   gconf_client_set_error_handling (gconf_client, GCONF_CLIENT_HANDLE_NONE);
 516   gconf_client_add_dir (gconf_client,
 517                         SYSTEM_MONO_FONT,
 518                         GCONF_CLIENT_PRELOAD_ONELEVEL,
 519                         NULL);
 520   gconf_client_notify_add (gconf_client,
 521                            SYSTEM_MONO_FONT,
 522                            something_changedCB,
 523                            NULL, NULL, NULL);
 524 #endif /* HAVE_GCONF && HAVE_XFT */
 525 }
 526
 527 static void
 528 init_xfd_settings (dpyinfo)
 529      struct x_display_info *dpyinfo;
 530 {
 531 #ifdef HAVE_XFT
 532   char sel[64];
 533   Display *dpy = dpyinfo->display;
 534
 535   BLOCK_INPUT;
 536
 537   sprintf (sel, "_XSETTINGS_S%d", XScreenNumberOfScreen (dpyinfo->screen));
 538   dpyinfo->Xatom_xsettings_sel = XInternAtom (dpy, sel, False);
 539   dpyinfo->Xatom_xsettings_prop = XInternAtom (dpy,
 540                                                "_XSETTINGS_SETTINGS",
 541                                                False);
 542   dpyinfo->Xatom_xsettings_mgr = XInternAtom (dpy, "MANAGER", False);
 543
 544   /* Select events so we can detect client messages sent when selection
 545      owner changes.  */
 546   XSelectInput (dpy, dpyinfo->root_window, StructureNotifyMask);
 547
 548   get_prop_window (dpyinfo);
 549   if (dpyinfo->xsettings_window != None)
 550     apply_xft_settings (dpyinfo, False);
 551
 552   UNBLOCK_INPUT;
 553
 554 #else /* ! HAVE_XFT */
 555
 556   dpyinfo->Xatom_xsettings_sel = None;
 557   dpyinfo->Xatom_xsettings_prop = None;
 558   dpyinfo->Xatom_xsettings_mgr = None;
 559   dpyinfo->xsettings_window = None;
 560
 561 #endif /* ! HAVE_XFT */
 562 }
 563
 564 void
 565 xsettings_initialize (dpyinfo)
 566      struct x_display_info *dpyinfo;
 567 {
 568   if (first_dpyinfo == NULL) first_dpyinfo = dpyinfo;
 569   init_gconf ();
 570   init_xfd_settings (dpyinfo);
 571 }
 572
 573 const char *
 574 xsettings_get_system_font ()
 575 {
 576   return current_mono_font;
 577 }
 578
 579 DEFUN ("font-get-system-font", Ffont_get_system_font, Sfont_get_system_font,
 580        0, 0, 0,
 581        doc: /* Get the system default monospaced font. */)
 582   ()
 583 {
 584   return current_mono_font && use_system_font
 585     ? make_string (current_mono_font, strlen (current_mono_font))
 586     : Qnil;
 587 }
 588
 589 void
 590 syms_of_xsettings ()
 591 {
 592   current_mono_font = NULL;
 593   first_dpyinfo = NULL;
 594 #ifdef HAVE_GCONF
 595   gconf_client = NULL;
 596 #endif
 597
 598   Qfont_name = intern_c_string ("font-name");
 599   staticpro (&Qfont_name);
 600   Qfont_render = intern_c_string ("font-render");
 601   staticpro (&Qfont_render);
 602   defsubr (&Sfont_get_system_font);
 603
 604   DEFVAR_BOOL ("font-use-system-font", &use_system_font,
 605     doc: /* *Non-nil means to use the system defined font.  */);
 606   use_system_font = 0;
 607
 608 #ifdef HAVE_XFT
 609   Fprovide (intern_c_string ("font-render-setting"), Qnil);
 610 #ifdef HAVE_GCONF
 611   Fprovide (intern_c_string ("system-font-setting"), Qnil);
 612 #endif
 613 #endif
 614 }
 615
 616 /* arch-tag: 541716ed-2e6b-42e1-8212-3197e01ea61d
 617    (do not change this comment) */