Replacing the node Add menu and making the toolbar useful

As some people have already noticed, the "Add" menu for nodes is a bit messy since pynodes merge. The reason for this is that the order of nodes in submenus (categories) was previously defined by the order in which all nodes are registered (at the bottom of blenkernel/intern/node.c). For the dynamic registration of node types now possible this system of defining node order along with registration is no longer viable: while it would still sort of work for C nodes, it is completely meaningless for dynamic (python) nodes, which are basically registered automatically in whatever order modules and addons are loaded, with the added complexity of unloading and reloading.

To fix this problem and add a bunch of desirable features this commit replaces the C menu with a python implementation. The new menu does not rely on any particular order of types in the node registry, but instead uses a simple explicit list of all the available nodes, grouped by categories (in scripts/nodeitems_builtins.py).

There are a number of additional features that become possible with this implementation:

1) Node Toolbar can be populated!
The list of nodes is used to create 2 UI items for each node: 1 entry in a submenu of "Add" menu and 1 item in a node toolbar panel with basically the same functionality. Clicking a button in the toolbar will add a new node of this type, just like selecting an item in the menu. The toolbar has the advantage of having collapsible panels for each category, so users can decide if they don't need certain nodes categories and have the rest more easily accessible.

2) Each node item is a true operator call.
The old Add menu is a pretty old piece of C code which doesn't even use proper operator buttons. Now there is a generic node_add operator which can be used very flexibly for adding any of the available nodes.

3) Node Items support additional settings.
Each "NodeItem" consists of the basic node type plus an optional list of initial settings that shall be applied to a new instance. This gives additional flexibility for creating variants of the same node or for defining preferred initial settings. E.g. it has been requested to disable previews for all nodes except inputs, this would be simple change in the py code and much less intrusive than in C.

4) Node items can be generated with a function.
A callback can be used in any category instead of the fixed list, which generates a set of items based on the context (much like dynamic enum items in bpy.props). Originally this was implemented for group nodes, because these nodes only make sense when linked to a node tree from the library data. This principle could come in handy for a number of other nodes, e.g. Image nodes could provide a similar list of node variants based on images in the library - no need to first add node, then select an image.

WARNING: pynodes scripters will have to rework their "draw_add_menu" callback in node tree types, this has been removed now! It was already pretty redundant, since one can add draw functions to the Add menu just like for any other menu. In the future i'd like to improve the categories system further so scripters can use it for custom node systems too, for now just make a draw callback and attach it to the Add menu.

7 files changed, 2 insertions, 234 deletions

diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index 3c4c3fc6f5c..aca5d49824c 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -305,8 +305,6 @@ typedef struct bNodeTreeType {
 	void (*free_cache)(struct bNodeTree *ntree);
 	void (*free_node_cache)(struct bNodeTree *ntree, struct bNode *node);
 	void (*foreach_nodeclass)(struct Scene *scene, void *calldata, bNodeClassCallback func);	/* iteration over all node classes */
-	/* Add menu for this node tree. */
-	void (*draw_add_menu)(const struct bContext *C, struct uiLayout *layout, struct bNodeTree *ntree);
 	/* Check visibility in the node editor */
 	int (*poll)(const struct bContext *C, struct bNodeTreeType *ntreetype);
 	/* Select a node tree from the context */
diff --git a/source/blender/editors/space_node/CMakeLists.txt b/source/blender/editors/space_node/CMakeLists.txt
index 3803f899ccc..ed37a4c97c7 100644
--- a/source/blender/editors/space_node/CMakeLists.txt
+++ b/source/blender/editors/space_node/CMakeLists.txt
@@ -47,7 +47,6 @@ set(SRC
 	node_draw.c
 	node_edit.c
 	node_group.c
-	node_header.c
 	node_ops.c
 	node_relationships.c
 	node_select.c
diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index cd3de834e78..b78ddc1d946 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -77,108 +77,6 @@
 #include "NOD_shader.h"
 #include "NOD_texture.h"
 
-/* ****************** MENU FUNCTIONS ***************** */
-
-static void node_add_menu_class(bContext *C, uiLayout *layout, void *arg_nodeclass)
-{
-	Scene *scene = CTX_data_scene(C);
-	SpaceNode *snode = CTX_wm_space_node(C);
-	bNodeTree *ntree;
-	int nodeclass = GET_INT_FROM_POINTER(arg_nodeclass);
-	int event, compatibility = 0;
-	
-	ntree = snode->nodetree;
-	
-	if (!ntree) {
-		uiItemS(layout);
-		return;
-	}
-
-	if (ntree->type == NTREE_SHADER) {
-		if (BKE_scene_use_new_shading_nodes(scene))
-			compatibility = NODE_NEW_SHADING;
-		else
-			compatibility = NODE_OLD_SHADING;
-	}
-	
-	if (nodeclass == NODE_CLASS_GROUP) {
-		Main *bmain = CTX_data_main(C);
-		bNodeTree *ngroup;
-		const char *ngroup_type, *node_type;
-		PointerRNA ptr;
-		
-		NODE_TYPES_BEGIN(ntype)
-			if (ntype->nclass != nodeclass || !ntype->ui_name)
-				continue;
-			if (!ntype->poll(ntype, ntree))
-				continue;
-			
-			switch (ntree->type) {
-				case NTREE_COMPOSIT:
-					ngroup_type = "CompositorNodeTree";
-					node_type = "CompositorNodeGroup";
-					break;
-				case NTREE_SHADER:
-					ngroup_type = "ShaderNodeTree";
-					node_type = "ShaderNodeGroup";
-					break;
-				case NTREE_TEXTURE:
-					ngroup_type = "TextureNodeTree";
-					node_type = "TextureNodeGroup";
-					break;
-			}
-			
-			ptr = uiItemFullO(layout, "NODE_OT_group_make", "New Group", ntype->ui_icon, NULL, WM_OP_INVOKE_DEFAULT, UI_ITEM_O_RETURN_PROPS);
-			RNA_string_set(&ptr, "node_type", node_type);
-			
-			uiItemS(layout);
-
-			for (ngroup = bmain->nodetree.first, event = 0; ngroup; ngroup = ngroup->id.next, ++event) {
-				/* only use group trees of the right type */
-				if (STRNEQ(ngroup->idname, ngroup_type))
-					continue;
-				if (!nodeGroupPoll(ntree, ngroup))
-					continue;
-				
-				ptr = uiItemFullO(layout, "NODE_OT_add_group_node", ngroup->id.name + 2, ntype->ui_icon, NULL, WM_OP_INVOKE_DEFAULT, UI_ITEM_O_RETURN_PROPS);
-				RNA_string_set(&ptr, "type", ntype->idname);
-				RNA_string_set(&ptr, "grouptree", ngroup->id.name + 2);
-			}
-		NODE_TYPES_END
-	}
-	else if (nodeclass == NODE_DYNAMIC) {
-		/* disabled */
-	}
-	else {
-		PointerRNA ptr;
-		
-		NODE_TYPES_BEGIN(ntype)
-			if (ntype->nclass != nodeclass || !ntype->ui_name)
-				continue;
-			if (!ntype->poll(ntype, ntree))
-				continue;
-			if (compatibility && (ntype->compatibility & compatibility) == 0)
-				continue;
-			
-			ptr = uiItemFullO(layout, "NODE_OT_add_node", IFACE_(ntype->ui_name), ntype->ui_icon, NULL, WM_OP_INVOKE_DEFAULT, UI_ITEM_O_RETURN_PROPS);
-			RNA_string_set(&ptr, "type", ntype->idname);
-		NODE_TYPES_END
-	}
-}
-
-static void node_add_menu_foreach_class_cb(void *calldata, int nclass, const char *name)
-{
-	uiLayout *layout = calldata;
-	uiItemMenuF(layout, IFACE_(name), 0, node_add_menu_class, SET_INT_IN_POINTER(nclass));
-}
-
-static void node_add_menu_default(const bContext *C, uiLayout *layout, bNodeTree *ntree)
-{
-	Scene *scene = CTX_data_scene(C);
-	
-	if (ntree->typeinfo->foreach_nodeclass)
-		ntree->typeinfo->foreach_nodeclass(scene, layout, node_add_menu_foreach_class_cb);
-}
 
 /* ****************** SOCKET BUTTON DRAW FUNCTIONS ***************** */
 
@@ -2784,11 +2682,8 @@ void ED_node_init_butfuncs(void)
 	
 	/* tree type icons */
 	ntreeType_Composite->ui_icon = ICON_RENDERLAYERS;
-	ntreeType_Composite->draw_add_menu = node_add_menu_default;
 	ntreeType_Shader->ui_icon = ICON_MATERIAL;
-	ntreeType_Shader->draw_add_menu = node_add_menu_default;
 	ntreeType_Texture->ui_icon = ICON_TEXTURE;
-	ntreeType_Texture->draw_add_menu = node_add_menu_default;
 }
 
 void ED_init_custom_node_type(bNodeType *ntype)
diff --git a/source/blender/editors/space_node/node_header.c b/source/blender/editors/space_node/node_header.c
deleted file mode 100644
index 8de2daf9e42..00000000000
--- a/source/blender/editors/space_node/node_header.c
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * ***** BEGIN GPL LICENSE BLOCK *****
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version. 
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
- * The Original Code is Copyright (C) 2008 Blender Foundation.
- * All rights reserved.
- *
- * 
- * Contributor(s): Blender Foundation
- *
- * ***** END GPL LICENSE BLOCK *****
- */
-
-/** \file blender/editors/space_node/node_header.c
- *  \ingroup spnode
- */
-
-#include <string.h>
-
-#include "DNA_space_types.h"
-#include "DNA_node_types.h"
-#include "DNA_screen_types.h"
-
-#include "MEM_guardedalloc.h"
-
-#include "BLI_blenlib.h"
-#include "BLI_utildefines.h"
-
-#include "BLF_translation.h"
-
-#include "BKE_blender.h"
-#include "BKE_context.h"
-#include "BKE_global.h"
-#include "BKE_main.h"
-#include "BKE_node.h"
-#include "BKE_scene.h"
-#include "BKE_screen.h"
-
-#include "WM_api.h"
-#include "WM_types.h"
-
-#include "UI_view2d.h"
-
-#include "node_intern.h"  /* own include */
-
-/* ************************ add menu *********************** */
-
-static void node_menu_add(const bContext *C, Menu *menu)
-{
-	SpaceNode *snode = CTX_wm_space_node(C);
-	uiLayout *layout = menu->layout;
-	bNodeTree *ntree = snode->edittree;
-
-	if (!ntree || !ntree->typeinfo || !ntree->typeinfo->draw_add_menu) {
-		uiLayoutSetActive(layout, FALSE);
-		return;
-	}
-
-	uiLayoutSetOperatorContext(layout, WM_OP_INVOKE_DEFAULT);
-	uiItemO(layout, CTX_IFACE_(BLF_I18NCONTEXT_OPERATOR_DEFAULT, "Search ..."), 0, "NODE_OT_add_search");
-	
-	ntree->typeinfo->draw_add_menu(C, layout, ntree);
-}
-
-void node_menus_register(void)
-{
-	MenuType *mt;
-
-	mt = MEM_callocN(sizeof(MenuType), "spacetype node menu add");
-	strcpy(mt->idname, "NODE_MT_add");
-	strcpy(mt->label, N_("Add"));
-	strcpy(mt->translation_context, BLF_I18NCONTEXT_DEFAULT_BPYRNA);
-	mt->draw = node_menu_add;
-	WM_menutype_add(mt);
-}
diff --git a/source/blender/editors/space_node/node_intern.h b/source/blender/editors/space_node/node_intern.h
index b45ca8b228f..4b31f22b172 100644
--- a/source/blender/editors/space_node/node_intern.h
+++ b/source/blender/editors/space_node/node_intern.h
@@ -68,9 +68,6 @@ ARegion *node_has_tools_region(ScrArea *sa);
 
 void snode_group_offset(struct SpaceNode *snode, float *x, float *y);	/* transform between View2Ds in the tree path */
 
-/* node_header.c */
-void node_menus_register(void);
-
 /* node_draw.c */
 int node_get_colorid(struct bNode *node);
 void node_socket_circle_draw(const struct bContext *C, struct bNodeTree *ntree, struct bNode *node,
diff --git a/source/blender/editors/space_node/space_node.c b/source/blender/editors/space_node/space_node.c
index 2075cc055e1..86cf9d98e78 100644
--- a/source/blender/editors/space_node/space_node.c
+++ b/source/blender/editors/space_node/space_node.c
@@ -784,8 +784,6 @@ void ED_spacetype_node(void)
 
 	BLI_addhead(&st->regiontypes, art);
 
-	node_menus_register();
-
 	/* regions: listview/buttons */
 	art = MEM_callocN(sizeof(ARegionType), "spacetype node region");
 	art->regionid = RGN_TYPE_UI;
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index dce4bcc2171..11431e355a8 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -553,25 +553,6 @@ static void rna_NodeTree_update_reg(bNodeTree *ntree)
 	RNA_parameter_list_free(&list);
 }
 
-static void rna_NodeTree_draw_add_menu(const bContext *C, struct uiLayout *layout, bNodeTree *ntree)
-{
-	extern FunctionRNA rna_NodeTree_draw_add_menu_func;
-
-	PointerRNA ptr;
-	ParameterList list;
-	FunctionRNA *func;
-
-	RNA_id_pointer_create(&ntree->id, &ptr);
-	func = &rna_NodeTree_draw_add_menu_func; /* RNA_struct_find_function(&ptr, "draw_add_menu"); */
-
-	RNA_parameter_list_create(&list, &ptr, func);
-	RNA_parameter_set_lookup(&list, "context", &C);
-	RNA_parameter_set_lookup(&list, "layout", &layout);
-	ntree->typeinfo->ext.call((bContext *)C, &ptr, func, &list);
-
-	RNA_parameter_list_free(&list);
-}
-
 static void rna_NodeTree_get_from_context(const bContext *C, bNodeTreeType *ntreetype,
                                           bNodeTree **r_ntree, ID **r_id, ID **r_from)
 {
@@ -622,7 +603,7 @@ static StructRNA *rna_NodeTree_register(Main *bmain, ReportList *reports, void *
 	bNodeTreeType *nt, dummynt;
 	bNodeTree dummyntree;
 	PointerRNA dummyptr;
-	int have_function[4];
+	int have_function[3];
 
 	/* setup dummy tree & tree type to store static properties in */
 	memset(&dummynt, 0, sizeof(bNodeTreeType));
@@ -662,8 +643,7 @@ static StructRNA *rna_NodeTree_register(Main *bmain, ReportList *reports, void *
 
 	nt->poll = (have_function[0]) ? rna_NodeTree_poll : NULL;
 	nt->update = (have_function[1]) ? rna_NodeTree_update_reg : NULL;
-	nt->draw_add_menu = (have_function[2]) ? rna_NodeTree_draw_add_menu : NULL;
-	nt->get_from_context = (have_function[3]) ? rna_NodeTree_get_from_context : NULL;
+	nt->get_from_context = (have_function[2]) ? rna_NodeTree_get_from_context : NULL;
 
 	ntreeTypeAdd(nt);
 
@@ -6856,17 +6836,6 @@ static void rna_def_nodetree(BlenderRNA *brna)
 	RNA_def_function_ui_description(func, "Update on editor changes");
 	RNA_def_function_flag(func, FUNC_REGISTER_OPTIONAL | FUNC_ALLOW_WRITE);
 
-	/* draw add menu */
-	func = RNA_def_function(srna, "draw_add_menu", NULL);
-	RNA_def_function_ui_description(func, "Draw the menu for adding nodes");
-	RNA_def_function_flag(func, FUNC_REGISTER_OPTIONAL);
-	parm = RNA_def_pointer(func, "context", "Context", "", "");
-	RNA_def_property_flag(parm, PROP_REQUIRED | PROP_NEVER_NULL);
-	parm = RNA_def_property(func, "layout", PROP_POINTER, PROP_NONE);
-	RNA_def_property_struct_type(parm, "UILayout");
-	RNA_def_property_ui_text(parm, "Layout", "Menu layout in the UI");
-	RNA_def_property_flag(parm, PROP_REQUIRED | PROP_NEVER_NULL);
-
 	/* get a node tree from context */
 	func = RNA_def_function(srna, "get_from_context", NULL);
 	RNA_def_function_ui_description(func, "Get a node tree from the context");