RNA path: add util to find the char in an RNA path where the array indexing starts.

Usefull to easily trim away the 'aray index' part of an RNA path, e.g.
when searching for an FCurve (which never contains that index part in
its RNA path).

1 files changed, 46 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_access.c b/source/blender/makesrna/intern/rna_access.c
index 75579107465..312c0753ce7 100644
--- a/source/blender/makesrna/intern/rna_access.c
+++ b/source/blender/makesrna/intern/rna_access.c
@@ -5482,6 +5482,52 @@ static UNUSED_FUNCTION_WITH_RETURN_TYPE(char *, RNA_path_back)(const char *path)
   return result;
 }
 
+const char *RNA_path_array_index_token_find(const char *rna_path, const PropertyRNA *array_prop)
+{
+  if (array_prop != NULL) {
+    if (!ELEM(array_prop->type, PROP_BOOLEAN, PROP_INT, PROP_FLOAT)) {
+      BLI_assert(array_prop->arraydimension == 0);
+      return NULL;
+    }
+    if (array_prop->arraydimension == 0) {
+      return NULL;
+    }
+  }
+
+  /* Valid 'array part' of a rna path can only have '[', ']' and digit characters.
+   * It may have more than one of those (e.g. `[12][1]`) in case of multi-dimensional arrays. */
+  off_t rna_path_len = (off_t)strlen(rna_path);
+  if (rna_path[rna_path_len] != ']') {
+    return NULL;
+  }
+  const char *last_valid_index_token_start = NULL;
+  for (rna_path_len--; rna_path_len >= 0; rna_path_len--) {
+    switch (rna_path[rna_path_len]) {
+      case '[':
+        if (rna_path_len <= 0 || rna_path[rna_path_len - 1] != ']') {
+          return &rna_path[rna_path_len];
+        }
+        last_valid_index_token_start = &rna_path[rna_path_len];
+        rna_path_len--;
+        break;
+      case '0':
+      case '1':
+      case '2':
+      case '3':
+      case '4':
+      case '5':
+      case '6':
+      case '7':
+      case '8':
+      case '9':
+        break;
+      default:
+        return last_valid_index_token_start;
+    }
+  }
+  return last_valid_index_token_start;
+}
+
 /* generic path search func
  * if its needed this could also reference the IDProperty direct */
 typedef struct IDP_Chain {