This commit frees list ui items from their dependencies to Panel, and hence from all the limitations this implied (mostly, the "only one list per panel" one).

It introduces a new (py-extendable and registrable) RNA type, UIList (roughly similar to Panel one), which currently contains only "standard" list's scroll pos and size (but may be expended to include e.g. some filtering data, etc.). This now makes lists completely independent from Panels!

This UIList has a draw_item callback which allows to customize items' drawing from python, that all addons can now use. Incidentally, this also greatly simplifies the C code of this widget, as we do not code any "special case" here anymore!

To make all this work, other changes were also necessary:

* Now all buttons (uiBut struct) have a 'custom_data' void pointer, used currently to store the uiList struct associated with a given uiLayoutListBox.

* DynamicPaintSurface now exposes a new bool, use_color_preview (readonly), saying whether that surface has some 3D view preview data or not.

* UILayout class has now four new (static) functions, to get the actual icon of any RNA object (important e.g. with materials or textures), and to get an enum item's UI name, description and icon.

* UILayout's label() func now takes an optional 'icon_value' integer parameter, which if not zero will override the 'icon' one (mandatory to use "custom" icons as generated for material/texture/... previews).
  Note: not sure whether we should add that one to all UILayout's prop funcs?

Note: will update addons using template list asap.

3 files changed, 66 insertions, 1 deletions

diff --git a/source/blender/windowmanager/WM_api.h b/source/blender/windowmanager/WM_api.h
index c418b07401d..eee4b5a3a57 100644
--- a/source/blender/windowmanager/WM_api.h
+++ b/source/blender/windowmanager/WM_api.h
@@ -265,6 +265,13 @@ char		*WM_prop_pystring_assign(struct bContext *C, struct PointerRNA *ptr, struc
 void		WM_operator_bl_idname(char *to, const char *from);
 void		WM_operator_py_idname(char *to, const char *from);
 
+/* *************** uilist types ******************** */
+void                WM_uilisttype_init(void);
+struct uiListType  *WM_uilisttype_find(const char *idname, int quiet);
+int                 WM_uilisttype_add(struct uiListType *ult);
+void                WM_uilisttype_freelink(struct uiListType *ult);
+void                WM_uilisttype_free(void);
+
 /* *************** menu types ******************** */
 void                WM_menutype_init(void);
 struct MenuType    *WM_menutype_find(const char *idname, int quiet);
diff --git a/source/blender/windowmanager/intern/wm.c b/source/blender/windowmanager/intern/wm.c
index 8fe387765ce..53e67e91bd2 100644
--- a/source/blender/windowmanager/intern/wm.c
+++ b/source/blender/windowmanager/intern/wm.c
@@ -149,7 +149,63 @@ void WM_operator_stack_clear(wmWindowManager *wm)
 	WM_main_add_notifier(NC_WM | ND_HISTORY, NULL);
 }
 
-/* ****************************************** */
+
+/* ************ uiListType handling ************** */
+
+static GHash *uilisttypes_hash = NULL;
+
+uiListType *WM_uilisttype_find(const char *idname, int quiet)
+{
+	uiListType *ult;
+
+	if (idname[0]) {
+		ult = BLI_ghash_lookup(uilisttypes_hash, idname);
+		if (ult) {
+			return ult;
+		}
+	}
+
+	if (!quiet) {
+		printf("search for unknown uilisttype %s\n", idname);
+	}
+
+	return NULL;
+}
+
+int WM_uilisttype_add(uiListType *ult)
+{
+	BLI_ghash_insert(uilisttypes_hash, (void *)ult->idname, ult);
+	return 1;
+}
+
+void WM_uilisttype_freelink(uiListType *ult)
+{
+	BLI_ghash_remove(uilisttypes_hash, ult->idname, NULL, (GHashValFreeFP)MEM_freeN);
+}
+
+/* called on initialize WM_init() */
+void WM_uilisttype_init(void)
+{
+	uilisttypes_hash = BLI_ghash_str_new("uilisttypes_hash gh");
+}
+
+void WM_uilisttype_free(void)
+{
+	GHashIterator *iter = BLI_ghashIterator_new(uilisttypes_hash);
+
+	for (; !BLI_ghashIterator_isDone(iter); BLI_ghashIterator_step(iter)) {
+		uiListType *ult = BLI_ghashIterator_getValue(iter);
+		if (ult->ext.free) {
+			ult->ext.free(ult->ext.data);
+		}
+	}
+	BLI_ghashIterator_free(iter);
+
+	BLI_ghash_free(uilisttypes_hash, NULL, (GHashValFreeFP)MEM_freeN);
+	uilisttypes_hash = NULL;
+}
+
+/* ************ MenuType handling ************** */
 
 static GHash *menutypes_hash = NULL;
 
diff --git a/source/blender/windowmanager/intern/wm_init_exit.c b/source/blender/windowmanager/intern/wm_init_exit.c
index 3cffa143ebc..aae44f51f18 100644
--- a/source/blender/windowmanager/intern/wm_init_exit.c
+++ b/source/blender/windowmanager/intern/wm_init_exit.c
@@ -137,6 +137,7 @@ void WM_init(bContext *C, int argc, const char **argv)
 	GHOST_CreateSystemPaths();
 	wm_operatortype_init();
 	WM_menutype_init();
+	WM_uilisttype_init();
 
 	set_free_windowmanager_cb(wm_close_and_free);   /* library.c */
 	set_blender_test_break_cb(wm_window_testbreak); /* blender.c */
@@ -403,6 +404,7 @@ void WM_exit_ext(bContext *C, const short do_python)
 	wm_operatortype_free();
 	wm_dropbox_free();
 	WM_menutype_free();
+	WM_uilisttype_free();
 	
 	/* all non-screen and non-space stuff editors did, like editmode */
 	if (C)