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.

1 files changed, 26 insertions, 4 deletions

diff --git a/source/blender/makesdna/DNA_screen_types.h b/source/blender/makesdna/DNA_screen_types.h
index de6ddb4b896..5d8176c8021 100644
--- a/source/blender/makesdna/DNA_screen_types.h
+++ b/source/blender/makesdna/DNA_screen_types.h
@@ -110,12 +110,26 @@ typedef struct Panel {		/* the part from uiBlock that needs saved in file */
 	int sortorder;			/* panels are aligned according to increasing sortorder */
 	struct Panel *paneltab;		/* this panel is tabbed in *paneltab */
 	void *activedata;			/* runtime for panel manipulation */
-
-	int list_scroll, list_size;
-	int list_last_len, list_grip_size;
-	char list_search[64];
 } Panel;
 
+typedef struct uiList {				/* some list UI data need to be saved in file */
+	struct uiList *next, *prev;
+
+	struct uiListType *type;		/* runtime */
+	void *padp;
+
+	char list_id[64];				/* defined as UI_MAX_NAME_STR */
+
+	int layout_type;				/* How items are layedout in the list */
+	int padi;
+
+	int list_scroll;
+	int list_size;
+	int list_last_len;
+	int list_grip_size;
+/*	char list_search[64]; */
+} uiList;
+
 typedef struct ScrArea {
 	struct ScrArea *next, *prev;
 	
@@ -167,6 +181,7 @@ typedef struct ARegion {
 	
 	ListBase uiblocks;			/* uiBlock */
 	ListBase panels;			/* Panel */
+	ListBase uiLists;			/* uiList */
 	ListBase handlers;			/* wmEventHandler */
 	
 	struct wmTimer *regiontimer; /* blend in/out */
@@ -216,6 +231,13 @@ typedef struct ARegion {
 #define PNL_DEFAULT_CLOSED		1
 #define PNL_NO_HEADER			2
 
+/* uilist layout_type */
+enum {
+	UILST_LAYOUT_DEFAULT          = 0,
+	UILST_LAYOUT_COMPACT          = 1,
+	UILST_LAYOUT_GRID             = 2,
+};
+
 /* regiontype, first two are the default set */
 /* Do NOT change order, append on end. Types are hardcoded needed */
 enum {