UI: add subpanel support.

In the Python API, any panel becomes a subpanel by setting bl_parent_id
to the name of the parent panel. These subpanels can contain advanced or
less commonly used settings.

2 files changed, 20 insertions, 10 deletions

diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index d2542e977e3..b0a1789eb7e 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -6396,19 +6396,24 @@ static void direct_link_gpencil(FileData *fd, bGPdata *gpd)
 
 /* *********** READ AREA **************** */
 
-static void direct_link_region(FileData *fd, ARegion *ar, int spacetype)
+static void direct_link_panel_list(FileData *fd, ListBase *lb)
 {
-	Panel *pa;
-	uiList *ui_list;
-
-	link_list(fd, &ar->panels);
+	link_list(fd, lb);
 
-	for (pa = ar->panels.first; pa; pa = pa->next) {
+	for (Panel *pa = lb->first; pa; pa = pa->next) {
 		pa->paneltab = newdataadr(fd, pa->paneltab);
 		pa->runtime_flag = 0;
 		pa->activedata = NULL;
 		pa->type = NULL;
+		direct_link_panel_list(fd, &pa->children);
 	}
+}
+
+static void direct_link_region(FileData *fd, ARegion *ar, int spacetype)
+{
+	uiList *ui_list;
+
+	direct_link_panel_list(fd, &ar->panels);
 
 	link_list(fd, &ar->panels_category_active);
 
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index de1699e24b7..fb7b3e47153 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -2762,14 +2762,19 @@ static void write_soops(WriteData *wd, SpaceOops *so)
 	}
 }
 
+static void write_panel_list(WriteData *wd, ListBase *lb)
+{
+	for (Panel *pa = lb->first; pa; pa = pa->next) {
+		writestruct(wd, DATA, Panel, 1, pa);
+		write_panel_list(wd, &pa->children);
+	}
+}
+
 static void write_area_regions(WriteData *wd, ScrArea *area)
 {
 	for (ARegion *region = area->regionbase.first; region; region = region->next) {
 		write_region(wd, region, area->spacetype);
-
-		for (Panel *pa = region->panels.first; pa; pa = pa->next) {
-			writestruct(wd, DATA, Panel, 1, pa);
-		}
+		write_panel_list(wd, &region->panels);
 
 		for (PanelCategoryStack *pc_act = region->panels_category_active.first; pc_act; pc_act = pc_act->next) {
 			writestruct(wd, DATA, PanelCategoryStack, 1, pc_act);