handles the creation of unique window numbers.

1 files changed, 114 insertions, 0 deletions

diff --git a/number.c b/number.c
new file mode 100644
index 0000000..d1dfe3a
--- /dev/null
+++ b/number.c
@@ -0,0 +1,114 @@
+/* handles the handing out of and uniqueness of window numbers.
+
+ * Copyright (C) 2000 Shawn Betts
+ * 
+ * This program 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 2, or (at your option)
+ * any later version.
+ * 
+ * This program 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "ratpoison.h"
+
+
+/* A list of the numbers taken. */
+static int *numbers_taken;
+
+/* the number of numbers currently stored in the numbers_taken
+   array. */
+static int num_taken;
+
+/* the size of the numbers_taken array. */
+static int max_taken;
+
+static int
+number_is_taken (int n)
+{
+  int i;
+
+  for (i=0; i<num_taken; i++)
+    {
+      if (numbers_taken[i] == n) return 1;
+    }
+  return 0;
+}
+
+/* returns index into numbers_taken that can be used. */
+static int
+find_empty_cell ()
+{
+  int i;
+
+  for (i=0; i<num_taken; i++)
+    {
+      if (numbers_taken[i] == -1) return i;
+    }
+
+  /* no vacant ones, so grow the array. */
+  if (num_taken >= max_taken)
+    {
+      max_taken *= 2;
+      numbers_taken = realloc (numbers_taken, sizeof (int) * max_taken);
+      if (numbers_taken == NULL)
+	{
+	  fprintf (stderr, "numbers.c: Out of memory\n");
+	  exit (EXIT_FAILURE);
+	}
+    }
+  num_taken++;
+
+  return num_taken-1;
+}
+
+static int
+add_to_list (int n)
+{
+  if (number_is_taken (n)) return 0; /* failed. */
+  
+  numbers_taken[find_empty_cell()] = n;
+  return 1; /* success! */
+}
+
+/* returns a unique number that can be used as the window number in
+   the program bar. */
+int
+get_unique_window_number ()
+{
+  int i;
+  
+  /* look for a unique number, and add it to the list of taken
+     numbers. */
+  i = 0;
+  while (add_to_list (i)) i++;
+
+  return i;
+}
+
+/* When a window is destroyed, it gives back its window number with
+   this function. */
+void
+return_window_number (int n)
+{
+  int i;
+
+  for (i=0; i<num_taken; i++)
+    {
+      if (numbers_taken[i] == n) 
+	{
+	  numbers_taken[i] = -1;
+	  return;
+	}
+    }
+}