Handle system default font and changing font parameters.

* xterm.h (struct x_display_info): Add atoms and Window for xsettings.

* xterm.c (handle_one_xevent): Call xft_settings_event for
ClientMessage, PropertyNotify and DestroyNotify.
(x_term_init): If we have XFT, get DPI from Xft.dpi.
Call xsettings_initialize.

* xftfont.c (xftfont_fix_match): New function.
(xftfont_open): Call XftDefaultSubstitute before XftFontMatch.
Call xftfont_fix_match after XftFontMatch.

* xfont.c (xfont_driver): Initialize all members.

* xfns.c (x_default_font_parameter): Try font from Ffont_get_system_font.
Do not get font from x_default_parameter if we got one from
Ffont_get_system_font.
(Fx_select_font): Get the defaut font name from :name of FRAME_FONT (f).

* w32font.c (w32font_driver): Initialize all members.

* termhooks.h (enum event_kind): CONFIG_CHANGED_EVENT is new.

* lisp.h: Declare syms_of_xsettings.

* keyboard.c (kbd_buffer_get_event, make_lispy_event): Handle
CONFIG_CHANGED_EVENT.

* ftfont.c (ftfont_filter_properties): New function.

* frame.c (x_set_font): Remove unused variable lval.

* font.h (struct font_driver): filter_properties is new.

* font.c (font_put_extra): Don't return if val is nil, it means
boolean option is off.
(font_parse_fcname): Collect all extra properties in extra_props
and call filter_properties for all drivers with extra_props and
font as parameter.
(font_open_entity): Do not use cache, it does not pick up new fontconfig
settings like hinting.
(font_load_for_lface): If spec had a name in it, store it in entity.

* emacs.c (main): Call syms_of_xsettings

* config.in: HAVE_GCONF is new.

* Makefile.in (GCONF_CFLAGS, GCONF_LIBS): New variables for HAVE_GCONF.
xsettings.o is new.

* menu-bar.el: Put "Use system font" in Option-menu.

* loadup.el: If feature system-font-setting or font-render-setting is
there, load font-setting.

* Makefile.in (ELCFILES): font-settings.el is new.
* font-setting.el: New file.

* NEWS: Mention dynamic font changes (font-use-system-font).

* configure.in: New option: --with(out)-gconf.
Set HAVE_GCONF if we find gconf.

1 files changed, 627 insertions, 0 deletions

diff --git a/src/xsettings.c b/src/xsettings.c
new file mode 100644
index 00000000000..84e05a1898a
--- /dev/null
+++ b/src/xsettings.c
@@ -0,0 +1,627 @@
+/* Functions for handle font changes dynamically.
+   Copyright (C) 2009
+                 Free Software Foundation, Inc.
+
+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 <setjmp.h>
+#include <fcntl.h>
+#include "lisp.h"
+#include "xterm.h"
+#include "xsettings.h"
+#include "frame.h"
+#include "blockinput.h"
+#include "termhooks.h"
+#include "termopts.h"
+
+#include <X11/Xproto.h>
+
+#ifdef HAVE_GCONF
+#include <gconf/gconf-client.h>
+#endif
+#ifdef HAVE_XFT
+#include <X11/Xft/Xft.h>
+#endif
+
+static char *current_mono_font;
+static struct x_display_info *first_dpyinfo;
+static Lisp_Object Qfont_name, Qfont_render;
+
+#ifdef HAVE_GCONF
+static GConfClient *gconf_client;
+#endif
+
+
+static void
+store_font_changed_event (arg, display_name)
+     Lisp_Object arg;
+     Lisp_Object display_name;
+{
+  struct input_event event;
+  EVENT_INIT (event);
+  event.kind = CONFIG_CHANGED_EVENT;
+  event.frame_or_window = display_name;
+  event.arg = arg;
+  kbd_buffer_store_event (&event);
+}
+
+#ifdef HAVE_GCONF
+
+#define SYSTEM_MONO_FONT       "/desktop/gnome/interface/monospace_font_name"
+
+/* Callback called when something changed in GConf that we care about,
+   that is SYSTEM_MONO_FONT.  */
+
+static void
+something_changedCB (client, cnxn_id, entry, user_data)
+     GConfClient *client;
+     guint cnxn_id;
+     GConfEntry *entry;
+     gpointer user_data;
+{
+  GConfValue *v = gconf_entry_get_value (entry);
+  
+  if (!v) return;
+  if (v->type == GCONF_VALUE_STRING)
+    {
+      const char *value = gconf_value_get_string (v);
+      int i;
+      if (current_mono_font != NULL && strcmp (value, current_mono_font) == 0)
+        return; // No change.
+
+      xfree (current_mono_font);
+      current_mono_font = xstrdup (value);
+    }
+
+
+  if (first_dpyinfo != NULL)
+    {
+      /* Check if display still open */
+      struct x_display_info *dpyinfo;
+      int found = 0;
+      for (dpyinfo = x_display_list; !found && dpyinfo; dpyinfo = dpyinfo->next)
+        found = dpyinfo == first_dpyinfo;
+
+      if (found)
+        store_font_changed_event (Qfont_name,
+                                  XCAR (first_dpyinfo->name_list_element));
+    }
+}
+#endif /* HAVE_GCONF */
+
+#ifdef HAVE_XFT
+
+/* Find the window that contains the XSETTINGS property values.  */
+
+static void
+get_prop_window (dpyinfo)
+     struct x_display_info *dpyinfo;
+{
+  Display *dpy = dpyinfo->display;
+
+  XGrabServer (dpy);
+  dpyinfo->xsettings_window = XGetSelectionOwner (dpy,
+                                                  dpyinfo->Xatom_xsettings_sel);
+  if (dpyinfo->xsettings_window != None)
+    /* Select events so we can detect if window is deleted or if settings
+       are changed.  */
+    XSelectInput (dpy, dpyinfo->xsettings_window,
+                  PropertyChangeMask|StructureNotifyMask);
+
+  XUngrabServer (dpy);
+}
+
+struct xsettings 
+{
+  FcBool aa, hinting;
+  int rgba, lcdfilter, hintstyle;
+  double dpi;
+};
+
+#define SWAP32(nr) (((nr) << 24) | (((nr) << 8) & 0xff0000)     \
+                    | (((nr) >> 8) & 0xff00) | ((nr) >> 24))
+#define SWAP16(nr) (((nr) << 8) | ((nr) >> 8))
+#define PAD(nr)    (((nr) + 3) & ~3)
+
+/* Parse xsettings and extract those that deal with Xft.
+   See http://freedesktop.org/wiki/Specifications/XSettingsRegistry
+   and http://standards.freedesktop.org/xsettings-spec/xsettings-spec-0.5.html.
+
+   Layout of prop.  First is a header:
+
+   bytes   type     what
+   ------------------------------------
+   1      CARD8    byte-order
+   3               unused
+   4      CARD32   SERIAL
+   4      CARD32   N_SETTINGS
+
+   Then N_SETTINGS records, with header:
+
+   bytes   type          what
+   ------------------------------------
+   1      SETTING_TYPE  type (0 = integer, 1 = string, 2 RGB color).
+   1                    unused
+   2      CARD16        n == name-length
+   n      STRING8       name
+   p                    unused, p=pad_to_even_4(n)
+   4      CARD32        last-change-serial
+
+   and then the value, For string:
+   
+   bytes   type          what
+   ------------------------------------
+   4      CARD32        n = value-length
+   n      STRING8       value
+   p                    unused, p=pad_to_even_4(n)
+
+   For integer:
+
+   bytes   type          what
+   ------------------------------------
+   4      INT32         value
+
+   For RGB color:
+
+   bytes   type          what
+   ------------------------------------
+   2      CARD16        red
+   2      CARD16        blue
+   2      CARD16        green
+   2      CARD16        alpha
+
+*/
+
+static int
+parse_xft_settings (prop, bytes, settings)
+     unsigned char *prop;
+     unsigned long bytes;
+     struct xsettings *settings;
+{
+  Lisp_Object byteorder = Fbyteorder ();
+  int my_bo = XFASTINT (byteorder) == 'B' ? MSBFirst : LSBFirst;
+  int that_bo = prop[0];
+  CARD32 n_settings;
+  int bytes_parsed = 0;
+  int settings_seen = 0;
+  int i = 0;
+
+  /* First 4 bytes is a serial number, skip that.  */
+
+  if (bytes < 12) return BadLength;
+  memcpy (&n_settings, prop+8, 4);
+  if (my_bo != that_bo) n_settings = SWAP32 (n_settings);
+  bytes_parsed = 12;
+
+  memset (settings, 0, sizeof (*settings));
+
+  while (bytes_parsed+4 < bytes && settings_seen < 6
+         && i < n_settings)
+    {
+      int type = prop[bytes_parsed++];
+      CARD16 nlen;
+      CARD32 vlen, ival = 0;
+      char name[128]; /* The names we are looking for are not this long.  */
+      char sval[128]; /* The values we are looking for are not this long.  */
+      int is_xft;
+      int to_cpy;
+
+      sval[0] = '\0';
+      ++i;
+      ++bytes_parsed; /* Padding */
+
+      memcpy (&nlen, prop+bytes_parsed, 2);
+      bytes_parsed += 2;
+      if (my_bo != that_bo) nlen = SWAP16 (nlen);
+      if (bytes_parsed+nlen > bytes) return BadLength;
+      to_cpy = nlen > 127 ? 127 : nlen;
+      memcpy (name, prop+bytes_parsed, to_cpy);
+      name[to_cpy] = '\0';
+
+      bytes_parsed += nlen;
+      bytes_parsed = PAD (bytes_parsed);
+
+      bytes_parsed += 4; /* Skip serial for this value */
+      if (bytes_parsed > bytes) return BadLength;
+
+      is_xft = nlen > 6 && strncmp (name, "Xft/", 4) == 0;
+
+      switch (type) 
+        {
+        case 0: /* Integer */
+          if (bytes_parsed+4 > bytes) return BadLength;
+          if (is_xft)
+            {
+              memcpy (&ival, prop+bytes_parsed, 4);
+              if (my_bo != that_bo) ival = SWAP32 (ival);
+            }
+          bytes_parsed += 4;
+          break;
+
+        case 1: /* String */
+          if (bytes_parsed+4 > bytes) return BadLength;
+          memcpy (&vlen, prop+bytes_parsed, 4);
+          bytes_parsed += 4;
+          if (my_bo != that_bo) vlen = SWAP32 (vlen);
+          if (is_xft)
+            {
+              to_cpy = vlen > 127 ? 127 : vlen;
+              memcpy (sval, prop+bytes_parsed, to_cpy);
+              sval[to_cpy] = '\0';
+            }
+          bytes_parsed += vlen;
+          bytes_parsed = PAD (bytes_parsed);
+          break;
+
+        case 2: /* RGB value */
+          /* No need to parse this */
+          if (bytes_parsed+8 > bytes) return BadLength;
+          bytes_parsed += 8; /* 4 values (r, b, g, alpha), 2 bytes each.  */ 
+          break;
+
+        default: /* Parse Error */
+          return BadValue;
+        }
+
+      if (is_xft) 
+        {
+          ++settings_seen;
+          if (strcmp (name, "Xft/Antialias") == 0)
+            settings->aa = ival != 0;
+          else if (strcmp (name, "Xft/Hinting") == 0)
+            settings->hinting = ival != 0;
+          else if (strcmp (name, "Xft/HintStyle") == 0)
+            {
+              if (strcmp (sval, "hintnone") == 0)
+                settings->hintstyle = FC_HINT_NONE;
+              else if (strcmp (sval, "hintslight") == 0)
+                settings->hintstyle = FC_HINT_SLIGHT;
+              else if (strcmp (sval, "hintmedium") == 0)
+                settings->hintstyle = FC_HINT_MEDIUM;
+              else if (strcmp (sval, "hintfull") == 0)
+                settings->hintstyle = FC_HINT_FULL;
+            }
+          else if (strcmp (name, "Xft/RGBA") == 0)
+            {
+              if (strcmp (sval, "none") == 0)
+                settings->rgba = FC_RGBA_NONE;
+              else if (strcmp (sval, "rgb") == 0)
+                settings->rgba = FC_RGBA_RGB;
+              else if (strcmp (sval, "bgr") == 0)
+                settings->rgba = FC_RGBA_BGR;
+              else if (strcmp (sval, "vrgb") == 0)
+                settings->rgba = FC_RGBA_VRGB;
+              else if (strcmp (sval, "vbgr") == 0)
+                settings->rgba = FC_RGBA_VBGR;
+            }
+          else if (strcmp (name, "Xft/DPI") == 0)
+            settings->dpi = (double)ival/1024.0;
+          else if (strcmp (name, "Xft/lcdfilter") == 0)
+            {
+              if (strcmp (sval, "none") == 0)
+                settings->lcdfilter = FC_LCD_NONE;
+              else if (strcmp (sval, "lcddefault") == 0)
+                settings->lcdfilter = FC_LCD_DEFAULT;
+            }
+        }
+    }
+
+  return Success;
+}
+
+static int
+read_xft_settings (dpyinfo, settings)
+     struct x_display_info *dpyinfo;
+     struct xsettings *settings;
+{
+  long long_len;
+  Atom act_type;
+  int act_form;
+  unsigned long nitems, bytes_after;
+  unsigned char *prop = NULL;
+  Display *dpy = dpyinfo->display;
+  int rc;
+
+  x_catch_errors (dpy);
+  rc = XGetWindowProperty (dpy,
+                           dpyinfo->xsettings_window,
+                           dpyinfo->Xatom_xsettings_prop,
+                           0, LONG_MAX, False, AnyPropertyType,
+                           &act_type, &act_form, &nitems, &bytes_after,
+                           &prop);
+
+  if (rc == Success && prop != NULL && act_form == 8 && nitems > 0
+      && act_type == dpyinfo->Xatom_xsettings_prop)
+    rc = parse_xft_settings (prop, nitems, settings);
+
+  XFree (prop);
+
+  x_uncatch_errors ();
+
+  return rc == Success;
+}
+
+static void
+apply_xft_settings (dpyinfo, send_event_p)
+     struct x_display_info *dpyinfo;
+     int send_event_p;
+{
+  FcPattern *pat;
+  struct xsettings settings, oldsettings;
+  int changed = 0;
+
+  if (!read_xft_settings (dpyinfo, &settings))
+    return;
+
+  memset (&oldsettings, 0, sizeof (oldsettings));
+
+  pat = FcPatternCreate ();
+  XftDefaultSubstitute (dpyinfo->display,
+                        XScreenNumberOfScreen (dpyinfo->screen),
+                        pat);
+  FcPatternGetBool (pat, FC_ANTIALIAS, 0, &oldsettings.aa);
+  FcPatternGetBool (pat, FC_HINTING, 0, &oldsettings.hinting);
+  FcPatternGetInteger (pat, FC_HINT_STYLE, 0, &oldsettings.hintstyle);
+  FcPatternGetInteger (pat, FC_LCD_FILTER, 0, &oldsettings.lcdfilter);
+  FcPatternGetInteger (pat, FC_RGBA, 0, &oldsettings.rgba);
+  FcPatternGetDouble (pat, FC_DPI, 0, &oldsettings.dpi);
+
+  if (oldsettings.aa != settings.aa)
+    {
+      FcPatternDel (pat, FC_ANTIALIAS);
+      FcPatternAddBool (pat, FC_ANTIALIAS, settings.aa);
+      ++changed;
+    }
+  if (oldsettings.hinting != settings.hinting)
+    {
+      FcPatternDel (pat, FC_HINTING);
+      FcPatternAddBool (pat, FC_HINTING, settings.hinting);
+      ++changed;
+    }
+  if (oldsettings.rgba != settings.rgba)
+    {
+      FcPatternDel (pat, FC_RGBA);
+      FcPatternAddInteger (pat, FC_RGBA, settings.rgba);
+      ++changed;
+    }
+  if (oldsettings.lcdfilter != settings.lcdfilter)
+    {
+      FcPatternDel (pat, FC_LCD_FILTER);
+      FcPatternAddInteger (pat, FC_LCD_FILTER, settings.lcdfilter);
+      ++changed;
+    }
+  if (oldsettings.hintstyle != settings.hintstyle)
+    {
+      FcPatternDel (pat, FC_HINT_STYLE);
+      FcPatternAddInteger (pat, FC_HINT_STYLE, settings.hintstyle);
+      ++changed;
+    }
+  if (oldsettings.dpi != settings.dpi)
+    {
+      Lisp_Object frame, tail;
+
+      FcPatternDel (pat, FC_DPI);
+      FcPatternAddDouble (pat, FC_DPI, settings.dpi);
+      ++changed;
+
+      /* Change the DPI on this display and all frames on the display.  */
+      dpyinfo->resy = dpyinfo->resx = settings.dpi;
+      FOR_EACH_FRAME (tail, frame)
+        if (FRAME_X_P (XFRAME (frame))
+            && FRAME_X_DISPLAY_INFO (XFRAME (frame)) == dpyinfo)
+          XFRAME (frame)->resy = XFRAME (frame)->resx = settings.dpi;
+    }
+
+  if (changed)
+    {
+      XftDefaultSet (dpyinfo->display, pat);
+      if (send_event_p)
+        store_font_changed_event (Qfont_render,
+                                  XCAR (dpyinfo->name_list_element));
+    }
+  else
+    FcPatternDestroy (pat);
+}
+
+#endif /* HAVE_XFT */
+
+void
+xft_settings_event (dpyinfo, event)
+     struct x_display_info *dpyinfo;
+     XEvent *event;
+{
+#ifdef HAVE_XFT
+  int check_window_p = 0;
+
+  switch (event->type)
+    {
+    case DestroyNotify:
+      if (dpyinfo->xsettings_window == event->xany.window)
+        check_window_p = 1;
+      break;
+
+    case ClientMessage:
+      if (event->xclient.message_type == dpyinfo->Xatom_xsettings_mgr
+          && event->xclient.data.l[1] == dpyinfo->Xatom_xsettings_sel
+          && event->xclient.window == dpyinfo->root_window)
+        check_window_p = 1;
+      break;
+
+    case PropertyNotify:
+      if (event->xproperty.window == dpyinfo->xsettings_window
+          && event->xproperty.state == PropertyNewValue
+          && event->xproperty.atom == dpyinfo->Xatom_xsettings_prop)
+        {
+          apply_xft_settings (dpyinfo, True);
+        }
+      break;
+    }
+
+  if (check_window_p)
+    {
+      dpyinfo->xsettings_window = None;
+      get_prop_window (dpyinfo);
+      if (dpyinfo->xsettings_window != None)
+        apply_xft_settings (dpyinfo, True);
+    }
+#endif /* HAVE_XFT */
+}
+
+
+static void
+init_gconf ()
+{
+#ifdef HAVE_GCONF
+  int i;
+  char *s;
+  /* Should be enough, this is called at startup */
+#define N_FDS 1024
+  int fd_before[N_FDS], fd_before1[N_FDS];
+  int dummy, n_fds;
+  GPollFD gfds[N_FDS];
+
+  /* To find out which filedecriptors GConf uses, check before and after.
+     If we do not do this, GConf changes will only happen when Emacs gets
+     an X event.  */
+  memset (fd_before, 0, sizeof (fd_before));
+  n_fds = g_main_context_query (g_main_context_default (),
+                                G_PRIORITY_LOW,
+                                &dummy,
+                                gfds,
+                                N_FDS);
+  for (i = 0; i < n_fds; ++i)
+    if (gfds[i].fd < N_FDS && gfds[i].fd > 0 && gfds[i].events > 0)
+      fd_before[gfds[i].fd] = 1;
+
+  g_type_init ();
+  gconf_client = gconf_client_get_default ();
+  s = gconf_client_get_string (gconf_client, SYSTEM_MONO_FONT, NULL);
+  if (s)
+    {
+      current_mono_font = xstrdup (s);
+      g_free (s);
+    }
+  gconf_client_set_error_handling (gconf_client, GCONF_CLIENT_HANDLE_NONE);
+  gconf_client_add_dir (gconf_client,
+                        SYSTEM_MONO_FONT,
+                        GCONF_CLIENT_PRELOAD_ONELEVEL,
+                        NULL);
+  gconf_client_notify_add (gconf_client,
+                           SYSTEM_MONO_FONT,
+                           something_changedCB,
+                           NULL, NULL, NULL);
+  n_fds = g_main_context_query (g_main_context_default (),
+                                G_PRIORITY_LOW,
+                                &dummy,
+                                gfds,
+                                N_FDS);
+
+  for (i = 0; i < n_fds; ++i)
+    if (gfds[i].fd < N_FDS && gfds[i].fd > 0 && gfds[i].events > 0
+        && !fd_before[gfds[i].fd])
+      {
+#ifdef F_SETOWN
+        fcntl (i, F_SETOWN, getpid ());
+#endif /* ! defined (F_SETOWN) */
+
+#ifdef SIGIO
+        if (interrupt_input)
+          init_sigio (i);
+#endif /* ! defined (SIGIO) */
+      }
+#endif /* HAVE_GCONF */
+}
+
+static void
+init_xfd_settings (dpyinfo)
+     struct x_display_info *dpyinfo;
+{
+#ifdef HAVE_XFT
+  char sel[64];
+  Display *dpy = dpyinfo->display;
+
+  BLOCK_INPUT;
+
+  sprintf (sel, "_XSETTINGS_S%d", XScreenNumberOfScreen (dpyinfo->screen));
+  dpyinfo->Xatom_xsettings_sel = XInternAtom (dpy, sel, False);
+  dpyinfo->Xatom_xsettings_prop = XInternAtom (dpy,
+                                               "_XSETTINGS_SETTINGS",
+                                               False);
+  dpyinfo->Xatom_xsettings_mgr = XInternAtom (dpy, "MANAGER", False);
+
+  /* Select events so we can detect client messages sent when selection
+     owner changes.  */
+  XSelectInput (dpy, dpyinfo->root_window, StructureNotifyMask);
+
+  get_prop_window (dpyinfo);
+  if (dpyinfo->xsettings_window != None)
+    apply_xft_settings (dpyinfo, False);
+
+  UNBLOCK_INPUT;
+
+#else /* ! HAVE_XFT */
+
+  dpyinfo->Xatom_xsettings_sel = None;
+  dpyinfo->Xatom_xsettings_prop = None;
+  dpyinfo->Xatom_xsettings_mgr = None;
+  dpyinfo->xsettings_window = None;
+
+#endif /* ! HAVE_XFT */
+}
+
+void
+xsettings_initialize (dpyinfo)
+     struct x_display_info *dpyinfo;
+{
+  if (first_dpyinfo == NULL) first_dpyinfo = dpyinfo;
+  init_gconf ();
+  init_xfd_settings (dpyinfo);
+}
+
+
+DEFUN ("font-get-system-font", Ffont_get_system_font, Sfont_get_system_font,
+       0, 0, 0,
+       doc: /* Get the system default monospaced font. */)
+  ()
+{
+  return current_mono_font
+    ? make_string (current_mono_font, strlen (current_mono_font))
+    : Qnil;
+}
+
+void
+syms_of_xsettings ()
+{
+  current_mono_font = NULL;
+  first_dpyinfo = NULL;
+#ifdef HAVE_GCONF
+  gconf_client = NULL;
+#endif
+
+  Qfont_name = intern_c_string ("font-name");
+  staticpro (&Qfont_name);
+  Qfont_render = intern_c_string ("font-render");
+  staticpro (&Qfont_render);
+  defsubr (&Sfont_get_system_font);
+
+#ifdef HAVE_GCONF
+  Fprovide (intern_c_string ("system-font-setting"), Qnil);
+#endif
+#ifdef HAVE_XFT
+  Fprovide (intern_c_string ("font-render-setting"), Qnil);
+#endif
+}