emacs/emacs-23.1-fontdpi.patch

diff -up emacs-23.1/src/xterm.c.fontdpi emacs-23.1/src/xterm.c
--- emacs-23.1/src/xterm.c.fontdpi	2010-01-04 15:12:48.367249218 +0100
+++ emacs-23.1/src/xterm.c	2010-01-04 15:14:47.029248464 +0100
@@ -101,6 +101,9 @@ along with GNU Emacs.  If not, see <http
 #include "gtkutil.h"
 #endif
 
+#include <X11/Xft/Xft.h>
+#include <X11/Xproto.h>
+
 #ifdef USE_LUCID
 extern int xlwmenu_window_p P_ ((Widget w, Window window));
 extern void xlwmenu_redisplay P_ ((Widget));
@@ -5829,6 +5832,237 @@ event_handler_gdk (gxev, ev, data)
 }
 #endif /* USE_GTK */
 
+#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)
+
+static int
+parse_xft_dpi (prop, bytes, dpi)
+     unsigned char *prop;
+     unsigned long bytes;
+     double *dpi;
+{
+  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;
+
+  *dpi = 0;
+
+  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. */
+      int is_xft;
+      int to_cpy;
+
+      ++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 */
+	  /* No need to parse this */
+	  if (bytes_parsed+4 > bytes) return BadLength;
+	  memcpy (&vlen, prop+bytes_parsed, 4);
+	  bytes_parsed += 4;
+	  if (my_bo != that_bo) vlen = SWAP32 (vlen);
+	  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/DPI") == 0)
+	    *dpi = (double)ival/1024.0;
+	}
+    }
+
+  return Success;
+}
+
+static int
+read_xft_dpi (dpyinfo, dpi)
+     struct x_display_info *dpyinfo;
+     double *dpi;
+{
+  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_dpi (prop, nitems, dpi);
+    }
+  
+  XFree (prop);
+  x_uncatch_errors ();
+  return rc == Success;
+}
+
+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);
+}
+
+static void
+apply_xft_settings (dpyinfo, send_event_p)
+ struct x_display_info *dpyinfo;
+ int send_event_p;
+{
+ double dpi;
+ if (!read_xft_dpi (dpyinfo, &dpi))
+   return;
+
+ /* Change the DPI on this display and all frames on the display. */
+ Lisp_Object frame, tail;
+ dpyinfo->resy = dpyinfo->resx = 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 = dpi;
+}
+
+static void
+xft_settings_event (dpyinfo, event)
+     struct x_display_info *dpyinfo;
+     XEvent *event;
+{
+  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);
+    }
+}
+
+static void
+init_xfd_settings (dpyinfo)
+     struct x_display_info *dpyinfo;
+{
+  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;
+}
 
 /* Handles the XEvent EVENT on display DPYINFO.
 
@@ -6043,6 +6277,8 @@ handle_one_xevent (dpyinfo, eventp, fini
             goto done;
           }
 
+	xft_settings_event (dpyinfo, &event);
+
 	f = x_any_window_to_frame (dpyinfo, event.xclient.window);
 	if (!f)
 	  goto OTHER;
@@ -6113,6 +6349,7 @@ handle_one_xevent (dpyinfo, eventp, fini
         x_handle_net_wm_state (f, &event.xproperty);
 
       x_handle_property_notify (&event.xproperty);
+      xft_settings_event (dpyinfo, &event);
       goto OTHER;
 
     case ReparentNotify:
@@ -7069,6 +7306,10 @@ handle_one_xevent (dpyinfo, eventp, fini
         }
       goto OTHER;
 
+    case DestroyNotify:
+      xft_settings_event (dpyinfo, &event);
+      break;
+
     default:
     OTHER:
 #ifdef USE_X_TOOLKIT
@@ -10380,17 +10621,31 @@ x_term_init (display_name, xrm_option, r
 				     dpyinfo->visual, AllocNone);
 
   {
-    int screen_number = XScreenNumberOfScreen (dpyinfo->screen);
-    double pixels = DisplayHeight (dpyinfo->display, screen_number);
-    double mm = DisplayHeightMM (dpyinfo->display, screen_number);
-    /* Mac OS X 10.3's Xserver sometimes reports 0.0mm.  */
-    dpyinfo->resy = (mm < 1) ? 100 : pixels * 25.4 / mm;
-    pixels = DisplayWidth (dpyinfo->display, screen_number);
-    mm = DisplayWidthMM (dpyinfo->display, screen_number);
-    /* Mac OS X 10.3's Xserver sometimes reports 0.0mm.  */
-    dpyinfo->resx = (mm < 1) ? 100 : pixels * 25.4 / mm;
+    /* If we are using Xft, check dpi value in X resources.
+       It is better we use it as well, since Xft will use it, as will all
+       Gnome applications. If our real DPI is smaller or larger than the
+       one Xft uses, our font will look smaller or larger than other
+       for other applications, even if it is the same font name (monospace-10
+       for example). */
+    char *v = XGetDefault (dpyinfo->display, "Xft", "dpi");
+    double d;
+    if (v != NULL && sscanf (v, "%lf", &d) == 1)
+      dpyinfo->resy = dpyinfo->resx = d;
   }
 
+  if (dpyinfo->resy < 1)
+    {
+      int screen_number = XScreenNumberOfScreen (dpyinfo->screen);
+      double pixels = DisplayHeight (dpyinfo->display, screen_number);
+      double mm = DisplayHeightMM (dpyinfo->display, screen_number);
+      /* Mac OS X 10.3's Xserver sometimes reports 0.0mm. */
+      dpyinfo->resy = (mm < 1) ? 100 : pixels * 25.4 / mm;
+      pixels = DisplayWidth (dpyinfo->display, screen_number);
+      mm = DisplayWidthMM (dpyinfo->display, screen_number);
+      /* Mac OS X 10.3's Xserver sometimes reports 0.0mm. */
+      dpyinfo->resx = (mm < 1) ? 100 : pixels * 25.4 / mm;
+    }
+
   dpyinfo->Xatom_wm_protocols
     = XInternAtom (dpyinfo->display, "WM_PROTOCOLS", False);
   dpyinfo->Xatom_wm_take_focus
@@ -10492,6 +10747,8 @@ x_term_init (display_name, xrm_option, r
   xim_initialize (dpyinfo, resource_name);
 #endif
 
+  init_xfd_settings (dpyinfo);
+  
 #ifdef subprocesses
   /* This is only needed for distinguishing keyboard and process input.  */
   if (connection != 0)
diff -up emacs-23.1/src/xterm.h.fontdpi emacs-23.1/src/xterm.h
--- emacs-23.1/src/xterm.h.fontdpi	2009-06-21 06:38:20.000000000 +0200
+++ emacs-23.1/src/xterm.h	2010-01-04 15:12:48.393248813 +0100
@@ -360,6 +360,10 @@ struct x_display_info
   /* Atoms dealing with maximization and fullscreen */
   Atom Xatom_net_wm_state, Xatom_net_wm_state_fullscreen_atom,
     Xatom_net_wm_state_maximized_horz, Xatom_net_wm_state_maximized_vert;
+
+  /* XSettings atoms and windows. */
+  Atom Xatom_xsettings_sel, Xatom_xsettings_prop, Xatom_xsettings_mgr;
+  Window xsettings_window;
 };
 
 #ifdef HAVE_X_I18N