New backend functions: get_prefs and set_prefs.

These are similar to the existing pair configure() and custom_params()
in that get_prefs() returns an array of config_item describing a set
of dialog-box controls to present to the user, and set_prefs()
receives the same array with answers filled in and implements the
answers. But where configure() and custom_params() operate on a
game_params structure, the new pair operate on a game_ui, and are
intended to permit GUI configuration of all the settings I just moved
into that structure.

However, nothing actually _calls_ these routines yet. All I've done in
this commit is to add them to 'struct game' and implement them for the
functions that need them.

Also, config_item has new fields, permitting each config option to
define a machine-readable identifying keyword as well as the
user-facing description. For options of type C_CHOICES, each choice
also has a keyword. These keyword fields are only defined at all by
the new get_prefs() function - they're left uninitialised in existing
uses of the dialog system. The idea is to use them when writing out
the user's preferences into a configuration file on disk, although I
haven't actually done any of that work in this commit.

1 files changed, 15 insertions, 1 deletions

diff --git a/puzzles.h b/puzzles.h
index b7c34f7..7e192c0 100644
--- a/puzzles.h
+++ b/puzzles.h
@@ -127,8 +127,13 @@ typedef struct psdata psdata;
  */
 enum { C_STRING, C_CHOICES, C_BOOLEAN, C_END };
 struct config_item {
-    /* Not dynamically allocated */
+    /* Not dynamically allocated: the GUI display name for the option */
     const char *name;
+    /* Not dynamically allocated: the keyword identifier for the
+     * option. Only examined in the case where this structure is being
+     * used for options that appear in config files, i.e. the
+     * get_prefs method fills this in but configure does not. */
+    const char *kw;
     /* Value from the above C_* enum */
     int type;
     union {
@@ -146,6 +151,13 @@ struct config_item {
              */
             const char *choicenames;
             /*
+             * choicekws is non-NULL, not dynamically allocated, and
+             * contains a parallel list of keyword strings used to
+             * represent the enumeration in config files. As with 'kw'
+             * above, this is only expected to be set by get_prefs.
+             */
+            const char *choicekws;
+            /*
              * Indicates the chosen index from the options in
              * choicenames. In the above example, 0==Foo, 1==Bar and
              * 2==Baz.
@@ -676,6 +688,8 @@ struct game {
     bool can_format_as_text_ever;
     bool (*can_format_as_text_now)(const game_params *params);
     char *(*text_format)(const game_state *state);
+    config_item *(*get_prefs)(game_ui *ui);
+    void (*set_prefs)(game_ui *ui, const config_item *cfg);
     game_ui *(*new_ui)(const game_state *state);
     void (*free_ui)(game_ui *ui);
     char *(*encode_ui)(const game_ui *ui);