Initial revision

1 files changed, 512 insertions, 0 deletions

diff --git a/xsettings/xsettings-client.c b/xsettings/xsettings-client.c
new file mode 100644
index 0000000..7e1e356
--- /dev/null
+++ b/xsettings/xsettings-client.c
@@ -0,0 +1,512 @@
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <X11/Xlib.h>
+#include <X11/Xmd.h>		/* For CARD16 */
+
+#include "xsettings-client.h"
+
+struct _XSettingsClient
+{
+  Display *display;
+  int screen;
+  XSettingsNotifyFunc notify;
+  XSettingsWatchFunc watch;
+  void *cb_data;
+
+  Window manager_window;
+  Atom manager_atom;
+  Atom selection_atom;
+  Atom xsettings_atom;
+
+  XSettingsList *settings;
+};
+
+static void
+notify_changes (XSettingsClient *client,
+		XSettingsList   *old_list)
+{
+  XSettingsList *old_iter = old_list;
+  XSettingsList *new_iter = client->settings;
+
+  if (!client->notify)
+    return;
+
+  while (old_iter || new_iter)
+    {
+      int cmp;
+      
+      if (old_iter && new_iter)
+	cmp = strcmp (old_iter->setting->name, new_iter->setting->name);
+      else if (old_iter)
+	cmp = -1;
+      else
+	cmp = 1;
+
+      if (cmp < 0)
+	{
+	  client->notify (old_iter->setting->name,
+			  XSETTINGS_ACTION_DELETED,
+			  NULL,
+			  client->cb_data);
+	}
+      else if (cmp == 0)
+	{
+	  if (!xsettings_setting_equal (old_iter->setting,
+					new_iter->setting))
+	    client->notify (old_iter->setting->name,
+			    XSETTINGS_ACTION_CHANGED,
+			    new_iter->setting,
+			    client->cb_data);
+	}
+      else
+	{
+	  client->notify (new_iter->setting->name,
+			  XSETTINGS_ACTION_NEW,
+			  new_iter->setting,
+			  client->cb_data);
+	}
+
+      if (old_iter)
+	old_iter = old_iter->next;
+      if (new_iter)
+	new_iter = new_iter->next;
+    }
+}
+
+static int
+ignore_errors (Display *display, XErrorEvent *event)
+{
+  return True;
+}
+
+static char local_byte_order = '\0';
+
+#define BYTES_LEFT(buffer) ((buffer)->data + (buffer)->len - (buffer)->pos)
+
+static XSettingsResult
+fetch_card16 (XSettingsBuffer *buffer,
+	      CARD16          *result)
+{
+  CARD16 x;
+
+  if (BYTES_LEFT (buffer) < 2)
+    return XSETTINGS_ACCESS;
+
+  x = *(CARD16 *)buffer->pos;
+  buffer->pos += 2;
+  
+  if (buffer->byte_order == local_byte_order)
+    *result = x;
+  else
+    *result = (x << 8) | (x >> 8);
+
+  return XSETTINGS_SUCCESS;
+}
+
+static XSettingsResult
+fetch_ushort (XSettingsBuffer *buffer,
+	      unsigned short  *result) 
+{
+  CARD16 x;
+  XSettingsResult r;  
+
+  r = fetch_card16 (buffer, &x);
+  if (r == XSETTINGS_SUCCESS)
+    *result = x;
+
+  return r;
+}
+
+static XSettingsResult
+fetch_card32 (XSettingsBuffer *buffer,
+	      CARD32          *result)
+{
+  CARD32 x;
+
+  if (BYTES_LEFT (buffer) < 4)
+    return XSETTINGS_ACCESS;
+
+  x = *(CARD32 *)buffer->pos;
+  buffer->pos += 4;
+  
+  if (buffer->byte_order == local_byte_order)
+    *result = x;
+  else
+    *result = (x << 24) | ((x & 0xff00) << 8) | ((x & 0xff0000) >> 8) | (x >> 24);
+  
+  return XSETTINGS_SUCCESS;
+}
+
+static XSettingsResult
+fetch_card8 (XSettingsBuffer *buffer,
+	     CARD8           *result)
+{
+  if (BYTES_LEFT (buffer) < 1)
+    return XSETTINGS_ACCESS;
+
+  *result = *(CARD32 *)buffer->pos;
+  buffer->pos += 1;
+
+  return XSETTINGS_SUCCESS;
+}
+
+#define XSETTINGS_PAD(n,m) ((n + m - 1) & (~(m-1)))
+
+static XSettingsList *
+parse_settings (unsigned char *data,
+		size_t         len)
+{
+  XSettingsBuffer buffer;
+  XSettingsResult result = XSETTINGS_SUCCESS;
+  XSettingsList *settings = NULL;
+  CARD32 serial;
+  CARD32 n_entries;
+  CARD32 i;
+  XSettingsSetting *setting;
+  
+  local_byte_order = xsettings_byte_order ();
+
+  buffer.pos = buffer.data = data;
+  buffer.len = len;
+  
+  result = fetch_card8 (&buffer, &buffer.byte_order);
+  if (buffer.byte_order != MSBFirst &&
+      buffer.byte_order != LSBFirst)
+    {
+      fprintf (stderr, "Invalid byte order in XSETTINGS property\n");
+      result = XSETTINGS_FAILED;
+      goto out;
+    }
+
+  buffer.pos += 3;
+
+  result = fetch_card32 (&buffer, &serial);
+  if (result != XSETTINGS_SUCCESS)
+    goto out;
+
+  result = fetch_card32 (&buffer, &n_entries);
+  if (result != XSETTINGS_SUCCESS)
+    goto out;
+
+  for (i = 0; i < n_entries; i++)
+    {
+      CARD8 type;
+      CARD16 name_len;
+      CARD32 v_int;
+      size_t pad_len;
+      
+      result = fetch_card8 (&buffer, &type);
+      if (result != XSETTINGS_SUCCESS)
+	goto out;
+
+      buffer.pos += 1;
+
+      result = fetch_card16 (&buffer, &name_len);
+      if (result != XSETTINGS_SUCCESS)
+	goto out;
+
+      pad_len = XSETTINGS_PAD(name_len, 4);
+      if (BYTES_LEFT (&buffer) < pad_len)
+	{
+	  result = XSETTINGS_ACCESS;
+	  goto out;
+	}
+
+      setting = malloc (sizeof *setting);
+      if (!setting)
+	{
+	  result = XSETTINGS_NO_MEM;
+	  goto out;
+	}
+      setting->type = XSETTINGS_TYPE_INT; /* No allocated memory */
+
+      setting->name = malloc (name_len + 1);
+      if (!setting->name)
+	{
+	  result = XSETTINGS_NO_MEM;
+	  goto out;
+	}
+
+      memcpy (setting->name, buffer.pos, name_len);
+      setting->name[name_len] = '\0';
+      buffer.pos += pad_len;
+
+      result = fetch_card32 (&buffer, &v_int);
+      if (result != XSETTINGS_SUCCESS)
+	goto out;
+      setting->last_change_serial = v_int;
+
+      switch (type)
+	{
+	case XSETTINGS_TYPE_INT:
+	  result = fetch_card32 (&buffer, &v_int);
+	  if (result != XSETTINGS_SUCCESS)
+	    goto out;
+
+	  setting->data.v_int = (INT32)v_int;
+	  break;
+	case XSETTINGS_TYPE_STRING:
+	  result = fetch_card32 (&buffer, &v_int);
+	  if (result != XSETTINGS_SUCCESS)
+	    goto out;
+
+	  pad_len = XSETTINGS_PAD (v_int, 4);
+	  if (v_int + 1 == 0 || /* Guard against wrap-around */
+	      BYTES_LEFT (&buffer) < pad_len)
+	    {
+	      result = XSETTINGS_ACCESS;
+	      goto out;
+	    }
+
+	  setting->data.v_string = malloc (v_int + 1);
+	  if (!setting->data.v_string)
+	    {
+	      result = XSETTINGS_NO_MEM;
+	      goto out;
+	    }
+	  
+	  memcpy (setting->data.v_string, buffer.pos, v_int);
+	  setting->data.v_string[v_int] = '\0';
+	  buffer.pos += pad_len;
+
+	  break;
+	case XSETTINGS_TYPE_COLOR:
+	  result = fetch_ushort (&buffer, &setting->data.v_color.red);
+	  if (result != XSETTINGS_SUCCESS)
+	    goto out;
+	  result = fetch_ushort (&buffer, &setting->data.v_color.green);
+	  if (result != XSETTINGS_SUCCESS)
+	    goto out;
+	  result = fetch_ushort (&buffer, &setting->data.v_color.blue);
+	  if (result != XSETTINGS_SUCCESS)
+	    goto out;
+	  result = fetch_ushort (&buffer, &setting->data.v_color.alpha);
+	  if (result != XSETTINGS_SUCCESS)
+	    goto out;
+
+	  break;
+	default:
+	  /* Quietly ignore unknown types */
+	  break;
+	}
+
+      setting->type = type;
+
+      result = xsettings_list_insert (&settings, setting);
+      if (result != XSETTINGS_SUCCESS)
+	goto out;
+
+      setting = NULL;
+    }
+
+ out:
+
+  if (result != XSETTINGS_SUCCESS)
+    {
+      switch (result)
+	{
+	case XSETTINGS_NO_MEM:
+	  fprintf(stderr, "Out of memory reading XSETTINGS property\n");
+	  break;
+	case XSETTINGS_ACCESS:
+	  fprintf(stderr, "Invalid XSETTINGS property (read off end)\n");
+	  break;
+	case XSETTINGS_DUPLICATE_ENTRY:
+	  fprintf (stderr, "Duplicate XSETTINGS entry for '%s'\n", setting->name);
+	case XSETTINGS_FAILED:
+	case XSETTINGS_SUCCESS:
+	case XSETTINGS_NO_ENTRY:
+	  break;
+	}
+
+      if (setting)
+	xsettings_setting_free (setting);
+
+      xsettings_list_free (settings);
+      settings = NULL;
+
+    }
+
+  return settings;
+}
+
+static void
+read_settings (XSettingsClient *client)
+{
+  Atom type;
+  int format;
+  unsigned long n_items;
+  unsigned long bytes_after;
+  unsigned char *data;
+  int result;
+
+  int (*old_handler) (Display *, XErrorEvent *);
+  
+  XSettingsList *old_list = client->settings;
+
+  client->settings = NULL;
+  
+  old_handler = XSetErrorHandler (ignore_errors);
+  result = XGetWindowProperty (client->display, client->manager_window,
+			       client->xsettings_atom, 0, LONG_MAX,
+			       False, client->xsettings_atom,
+			       &type, &format, &n_items, &bytes_after, &data);
+  XSetErrorHandler (old_handler);
+
+  if (result == Success && type == client->xsettings_atom)
+    {
+      if (format != 8)
+	{
+	  fprintf (stderr, "Invalid format for XSETTINGS property %d", format);
+	}
+      else
+	client->settings = parse_settings (data, n_items);
+
+      XFree (data);
+    }
+
+  notify_changes (client, old_list);
+  xsettings_list_free (old_list);
+}
+
+static void
+add_events (Display *display,
+	    Window   window,
+	    long     mask)
+{
+  XWindowAttributes attr;
+
+  XGetWindowAttributes (display, window, &attr);
+  XSelectInput (display, window, attr.your_event_mask | mask);
+}
+
+static void
+check_manager_window (XSettingsClient *client)
+{
+  if (client->manager_window && client->watch)
+    client->watch (client->manager_window, False, 0, client->cb_data);
+  
+  XGrabServer (client->display);
+
+  client->manager_window = XGetSelectionOwner (client->display,
+					       client->selection_atom);
+  if (client->manager_window)
+    XSelectInput (client->display, client->manager_window,
+		  PropertyChangeMask | StructureNotifyMask);
+
+  XUngrabServer (client->display);
+  XFlush (client->display);
+
+  if (client->manager_window && client->watch)
+    client->watch (client->manager_window, True, 
+		   PropertyChangeMask | StructureNotifyMask,
+		   client->cb_data);
+  
+  read_settings (client);
+}
+
+XSettingsClient *
+xsettings_client_new (Display             *display,
+		      int                  screen,
+		      XSettingsNotifyFunc  notify,
+		      XSettingsWatchFunc   watch,
+		      void                *cb_data)
+{
+  XSettingsClient *client;
+  char buffer[256];
+
+  client = malloc (sizeof *client);
+  if (!client)
+    return NULL;
+
+  client->display = display;
+  client->screen = screen;
+  client->notify = notify;
+  client->watch = watch;
+  client->cb_data = cb_data;
+  
+  client->manager_window = None;
+  client->settings = NULL;
+
+  sprintf(buffer, "_XSETTINGS_S%d", screen);
+  client->selection_atom = XInternAtom (display, buffer, False);
+  client->xsettings_atom = XInternAtom (display, "_XSETTINGS_SETTINGS", False);
+  client->manager_atom = XInternAtom (display, "MANAGER", False);
+
+  /* Select on StructureNotify so we get MANAGER events
+   */
+  add_events (display, RootWindow (display, screen), StructureNotifyMask);
+
+  if (client->watch)
+    client->watch (RootWindow (display, screen), True, StructureNotifyMask,
+		   client->cb_data);
+
+  check_manager_window (client);
+
+  return client;
+}
+
+void
+xsettings_client_destroy (XSettingsClient *client)
+{
+  if (client->watch)
+    client->watch (RootWindow (client->display, client->screen),
+		   False, 0, client->cb_data);
+  if (client->manager_window && client->watch)
+    client->watch (client->manager_window, False, 0, client->cb_data);
+  
+  xsettings_list_free (client->settings);
+  free (client);
+}
+
+XSettingsResult
+xsettings_client_get_setting (XSettingsClient   *client,
+			      const char        *name,
+			      XSettingsSetting **setting)
+{
+  XSettingsSetting *search = xsettings_list_lookup (client->settings, name);
+  if (search)
+    {
+      *setting = xsettings_setting_copy (search);
+      return *setting ? XSETTINGS_SUCCESS : XSETTINGS_NO_MEM;
+    }
+  else
+    return XSETTINGS_NO_ENTRY;
+}
+
+Bool
+xsettings_client_process_event (XSettingsClient *client,
+				XEvent          *xev)
+{
+  /* The checks here will not unlikely cause us to reread
+   * the properties from the manager window a number of
+   * times when the manager changes from A->B. But manager changes
+   * are going to be pretty rare.
+   */
+  if (xev->xany.window == RootWindow (client->display, client->screen))
+    {
+      if (xev->xany.type == ClientMessage &&
+	  xev->xclient.message_type == client->manager_atom)
+	{
+	  check_manager_window (client);
+	  return True;
+	}
+    }
+  else if (xev->xany.window == client->manager_window)
+    {
+      if (xev->xany.type == DestroyNotify)
+	{
+	  check_manager_window (client);
+	  return True;
+	}
+      else if (xev->xany.type == PropertyNotify)
+	{
+	  read_settings (client);
+	  return True;
+	}
+    }
+  
+  return False;
+}