layer.active_collection

This one is straight from the "layers" branch. I nailed it quite nicely there, so it was simply a matter of bringing it over :)

1 files changed, 76 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/layer.c b/source/blender/blenkernel/intern/layer.c
index 5022f4e9737..924a6b28dcb 100644
--- a/source/blender/blenkernel/intern/layer.c
+++ b/source/blender/blenkernel/intern/layer.c
@@ -157,6 +157,81 @@ void BKE_layer_collection_free(SceneLayer *sl, LayerCollection *lc)
 	}
 }
 
+/* Recursively get the collection for a given index */
+static LayerCollection *collection_from_index(ListBase *lb, const int number, int *i)
+{
+	for (LayerCollection *lc = lb->first; lc; lc = lc->next) {
+		if (*i == number) {
+			return lc;
+		}
+
+		(*i)++;
+
+		LayerCollection *lc_nested = collection_from_index(&lc->collections, number, i);
+		if (lc_nested) {
+			return lc_nested;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * Get the active collection
+*/
+LayerCollection *BKE_layer_collection_active(SceneLayer *sl)
+{
+	int i = 0;
+	return collection_from_index(&sl->collections, sl->active_collection, &i);
+}
+
+/*
+ * Recursively get the count of collections
+*/
+static int collection_count(ListBase *lb)
+{
+	int i = 0;
+	for (LayerCollection *lc = lb->first; lc; lc = lc->next) {
+		i += collection_count(&lc->collections) + 1;
+	}
+	return i;
+}
+
+/*
+ * Get the total number of collections
+ * (including all the nested collections)
+ */
+int BKE_layer_collection_count(SceneLayer *sl)
+{
+	return collection_count(&sl->collections);
+}
+
+/* Recursively get the index for a given collection */
+static int index_from_collection(ListBase *lb, LayerCollection *lc, int *i)
+{
+	for (LayerCollection *lcol = lb->first; lcol; lcol = lcol->next) {
+		if (lcol == lc) {
+			return *i;
+		}
+
+		(*i)++;
+
+		int i_nested = index_from_collection(&lcol->collections, lc, i);
+		if (i_nested != -1) {
+			return i_nested;
+		}
+	}
+	return -1;
+}
+
+/*
+ * Return -1 if not found
+ */
+int BKE_layer_collection_findindex(SceneLayer *sl, LayerCollection *lc)
+{
+	int i = 0;
+	return index_from_collection(&sl->collections, lc, &i);
+}
+
 /*
  * Link a collection to a renderlayer
  * The collection needs to be created separately
@@ -177,6 +252,7 @@ void BKE_collection_unlink(SceneLayer *sl, LayerCollection *lc)
 
 	BLI_remlink(&sl->collections, lc);
 	MEM_freeN(lc);
+	sl->active_collection = 0;
 }
 
 static void object_base_populate(SceneLayer *sl, LayerCollection *lc, ListBase *objects)