m_property: add `>` for fixed precision floating-point expansion

This enhancement makes it easier to create constant width property
expansions, useful for the `--term-status-msg`. Additionally, it changes
to `%f` printing with manual zero trimming, which is easier to control
than `%g`. With this method, we can directly specify precision, not just
significant numbers. This approach also avoids overly high precision for
values less than 1, which is not necessary for a generic floating-point
print function.

A new print helper function is added, which can be used with adjusted
precision for specific cases where a different default is needed. This
also unifies the code slightly.

1 files changed, 5 insertions, 2 deletions

diff --git a/options/m_property.c b/options/m_property.c
index 1b76f05e7d..eb3f78e847 100644
--- a/options/m_property.c
+++ b/options/m_property.c
@@ -108,13 +108,14 @@ int m_property_do(struct mp_log *log, const struct m_property *prop_list,
     assert(opt.type);
 
     switch (action) {
+    case M_PROPERTY_FIXED_LEN_PRINT:
     case M_PROPERTY_PRINT: {
-        if ((r = do_action(prop_list, name, M_PROPERTY_PRINT, arg, ctx)) >= 0)
+        if ((r = do_action(prop_list, name, action, arg, ctx)) >= 0)
             return r;
         // Fallback to m_option
         if ((r = do_action(prop_list, name, M_PROPERTY_GET, &val, ctx)) <= 0)
             return r;
-        char *str = m_option_pretty_print(&opt, &val);
+        char *str = m_option_pretty_print(&opt, &val, action == M_PROPERTY_FIXED_LEN_PRINT);
         m_option_free(&opt, &val);
         *(char **)arg = str;
         return str != NULL;
@@ -258,11 +259,13 @@ static int expand_property(const struct m_property *prop_list, char **ret,
     bool cond_no = !cond_yes && bstr_eatstart0(&prop, "!");
     bool test = cond_yes || cond_no;
     bool raw = bstr_eatstart0(&prop, "=");
+    bool fixed_len = !raw && bstr_eatstart0(&prop, ">");
     bstr comp_with = {0};
     bool comp = test && bstr_split_tok(prop, "==", &prop, &comp_with);
     if (test && !comp)
         raw = true;
     int method = raw ? M_PROPERTY_GET_STRING : M_PROPERTY_PRINT;
+    method = fixed_len ? M_PROPERTY_FIXED_LEN_PRINT : method;
 
     char *s = NULL;
     int r = m_property_do_bstr(prop_list, prop, method, &s, ctx);