til_settings: always describe relevant settings

The existing iterative *_setup() interface only described
settings not found, quietly accepting usable settings already
present in the til_settings_t.

This worked fine for the existing interactive text setup thing,
but it's especially problematic for providing a GUI setup
frontend.

This commit makes it so the *_setup() methods always describe
undescribed settings they recognize, leaving the setup frontend
loop calling into the *_setup() methods to both apply the
description validation if wanted and actually tie the description
to respective setting returned by the _setup() methods as being
related to the returned description.

A new helper called til_settings_get_and_describe_value() has
been introduced primarily for use of module setup methods to
simplify this nonsense, replacing the til_settings_get_value()
calls and surrounding logic, but retaining the til_setting_desc_t
definitions largely verbatim.

This also results in discarding of some ad-hoc
til_setting_desc_check() calls, now that there's a centralized
place where settings become "described" (setup_interactively in
the case of rototiller).

Now a GUI frontend (like glimmer) would just provide its own
setup_interactively() equivalent for constructing its widgets for
a given *_setup() method's chain of returned descs.  Whereas in
the past this wasn't really feasible unless there was never going
to be pre-supplied settings.

I suspect the til_setting_desc_check() integration into
setup_interactively() needs more work, but I think this is good
enough for now and I'm out of spare time for the moment.

1 files changed, 11 insertions, 13 deletions

diff --git a/src/modules/stars/stars.c b/src/modules/stars/stars.c
index 9a0d2a9..c762043 100644
--- a/src/modules/stars/stars.c
+++ b/src/modules/stars/stars.c
@@ -201,10 +201,10 @@ static void stars_render_fragment(void *context, unsigned ticks, unsigned cpu, t
 	ctxt->offset_y = tmp_y;
 }
 
-int stars_setup(const til_settings_t *settings, til_setting_desc_t **next_setting)
+int stars_setup(const til_settings_t *settings, const til_setting_t **res_setting, const til_setting_desc_t **res_desc)
 {
 	const char	*rot_adj;
-	const char      *rot_adj_values[] = {
+	const char	*rot_adj_values[] = {
 				".0",
 				".00001",
 				".00003",
@@ -213,24 +213,22 @@ int stars_setup(const til_settings_t *settings, til_setting_desc_t **next_settin
 				".001",
 				NULL
 			};
+	int		r;
 
-	rot_adj = til_settings_get_value(settings, "rot_adj");
-	if(!rot_adj) {
-		int ret_val;
-
-		ret_val = til_setting_desc_clone(&(til_setting_desc_t){
+	r = til_settings_get_and_describe_value(settings,
+						&(til_setting_desc_t){
 							.name = "Rotation Rate",
 							.key = "rot_adj",
 							.regex = "\\.[0-9]+",
 							.preferred = TIL_SETTINGS_STR(DEFAULT_ROT_ADJ),
 							.values = rot_adj_values,
 							.annotations = NULL
-						}, next_setting);
-		if(ret_val<0)
-			return ret_val;
-
-		return 1;
-	}
+						},
+						&rot_adj,
+						res_setting,
+						res_desc);
+	if (r)
+		return r;
 
 	sscanf(rot_adj, "%f", &stars_rot_adj);