Wrote behavior of Backspace key during line input in text grid windows.

[rodin/chimara.git] / src / gestalt.c

diff --git a/src/gestalt.c b/src/gestalt.c
index 1709e12488994ba3d851439bd43c5327f503fbd5..4a586ce1d192cce9b2a470e0b20c2b7b753dfaa1 100644 (file)
--- a/src/gestalt.c
+++ b/src/gestalt.c
@@ -27,11 +27,38 @@ glk_gestalt(glui32 sel, glui32 val)
  * @sel: A selector, representing which capability to request information
  * about.
  * @val: Extra information, depending on the value of @sel.
- * @arr: Location of an array to store extra information in, or #NULL.
- * @arrlen: Length of @arr, or 0 if @arr is #NULL.
+ * @arr: Location of an array to store extra information in, or %NULL.
+ * @arrlen: Length of @arr, or 0 if @arr is %NULL.
  *
- * Calls the gestalt system to request information about selector @sel,
- * possibly returning information in @arr.
+ * Calls the gestalt system to request information about the capabilities of the
+ * API. The selector @sel tells which capability you are requesting information
+ * about; the other three arguments are additional information, which may or may
+ * not be meaningful. The @arr and @arrlen arguments are always optional; you
+ * may always pass %NULL and 0, if you do not want whatever information they
+ * represent. glk_gestalt() is simply a shortcut for this; glk_gestalt(x, y) is
+ * exactly the same as glk_gestalt_ext(x, y, NULL, 0).
+ *
+ * The critical point is that if the Glk library has never heard of the selector
+ * sel, it will return 0. It is always safe to call glk_gestalt(x, y) (or
+ * glk_gestalt_ext(x, y, NULL, 0)). Even if you are using an old library, which
+ * was compiled before the given capability was imagined, you can test for the
+ * capability by calling glk_gestalt(); the library will correctly indicate that
+ * it does not support it, by returning 0.
+ *
+ * <note><para>
+ *  It is also safe to call glk_gestalt_ext(x, y, z, zlen) for an unknown 
+ *  selector x, where z is not %NULL, as long as z points at an array of at 
+ *  least zlen elements. The selector will be careful not to write beyond that  
+ *  point in the array, if it writes to the array at all.
+ * </para></note>
+ *
+ * <note><para>
+ *  If a selector does not use the second argument, you should always pass 0; do
+ *  not assume that the second argument is simply ignored. This is because the
+ *  selector may be extended in the future. You will continue to get the current
+ *  behavior if you pass 0 as the second argument, but other values may produce
+ *  other behavior.
+ * </para></note>
  *
  * Returns: an integer, depending on what selector was called.
  */
@@ -42,7 +69,7 @@ glk_gestalt_ext(glui32 sel, glui32 val, glui32 *arr, glui32 arrlen)
        {
                /* Version number */
                case gestalt_Version:
-                       return MAJOR_VERSION << 16 + MINOR_VERSION << 8 + SUB_VERSION;
+                       return (MAJOR_VERSION << 16) + (MINOR_VERSION << 8) + SUB_VERSION;
                
                /* Which characters can we print? */    
                case gestalt_CharOutput:
@@ -54,6 +81,20 @@ glk_gestalt_ext(glui32 sel, glui32 val, glui32 *arr, glui32 arrlen)
                                return gestalt_CharOutput_CannotPrint;
                        /* Can print all other Latin-1 characters */
                        return gestalt_CharOutput_ExactPrint;
+               
+               /* Which characters can the player type in line input? */
+               case gestalt_LineInput:
+                       /* Does not accept control chars */
+                       if( val < 32 || (val >= 127 && val <= 159) )
+                               return 0;
+                       return 1;
+                       
+               /* Which characters can the player type in char input? */
+               case gestalt_CharInput:
+                       /* Does not accept control chars or unknown */
+                       if( val < 32 || (val >= 127 && val <= 159) || val == keycode_Unknown )
+                               return 0;
+                       return 1;
                        
                /* Selector not supported */    
                default: