Add new parameter to reverse UIList items

Now, it was possible to invert the order of the UIlist using the filter, but it was impossible to know if the list was inverted or not.

The problem with this is that any other element depending of this value could not be adjusted.

See https://devtalk.blender.org/t/how-to-access-uilist-properties/2268

The new parameter allows to set the reverse order by default. When the list is set as reverse, it cannot be inverted again, so the invert button is removed of the filter.

This change is needed to fix a requested feature for Grease Pencil (T56985) and because a lot of 2D softwares use the drawing layers in the inverse order used in Blender.

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/makesrna/intern/rna_ui.c b/source/blender/makesrna/intern/rna_ui.c
index 333181b3593..0756d5e39ee 100644
--- a/source/blender/makesrna/intern/rna_ui.c
+++ b/source/blender/makesrna/intern/rna_ui.c
@@ -378,7 +378,7 @@ static void uilist_draw_item(uiList *ui_list, bContext *C, uiLayout *layout, Poi
 	RNA_parameter_list_free(&list);
 }
 
-static void uilist_draw_filter(uiList *ui_list, bContext *C, uiLayout *layout)
+static void uilist_draw_filter(uiList *ui_list, bContext *C, uiLayout *layout, bool reverse)
 {
 	extern FunctionRNA rna_UIList_draw_filter_func;
 
@@ -392,6 +392,7 @@ static void uilist_draw_filter(uiList *ui_list, bContext *C, uiLayout *layout)
 	RNA_parameter_list_create(&list, &ul_ptr, func);
 	RNA_parameter_set_lookup(&list, "context", &C);
 	RNA_parameter_set_lookup(&list, "layout", &layout);
+	RNA_parameter_set_lookup(&list, "reverse", &reverse);
 	ui_list->type->ext.call((bContext *)C, &ul_ptr, func, &list);
 
 	RNA_parameter_list_free(&list);
@@ -1307,6 +1308,7 @@ static void rna_def_uilist(BlenderRNA *brna)
 	RNA_def_parameter_flags(parm, 0, PARM_REQUIRED);
 	parm = RNA_def_pointer(func, "layout", "UILayout", "", "Layout to draw the item");
 	RNA_def_parameter_flags(parm, PROP_NEVER_NULL, PARM_REQUIRED);
+	RNA_def_boolean(func, "reverse", false, "", "Display items in reverse order");
 
 	/* filter */
 	func = RNA_def_function(srna, "filter_items", NULL);