Nodes: Add node group assets to search menus

Currently node group assets are supported, but using them by dragging
from the asset browser is cumbersome. This patch adds all node group
assets from user asset libraries and the current file libraries to the
add node search menu and the link drag search menu.

Node groups added through the search will have their "options" hidden,
meaning the data-block selector is displayed. This helps keep the UI
clean, and the selector shouldn't be necessary anyway.

To make that possible, metadata like the node tree type and its inputs
and outputs has to be saved in the file. This requires re-saving the
files that contain the assets with the patch applied.

The node add search operator is moved from Python to C++ to ease
development and allow more flexibility. It supports a tooltip that
gives the description of assets.

Currently the node groups are added with the asset system's existing
"Append & Reuse" behavior. It's likely that linking should be possible
in the future too, but for now the idea is to use the more foolproof
option that doesn't create dependencies between files.

Because loading assets can potentially take a long time, the search
menu refreshes its items as new assets are loaded. However, changing
the search field is necessary to see the update.

Differential Revision: https://developer.blender.org/D15568

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 27e2f89f684..c3376493413 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -532,6 +532,7 @@ typedef struct ARegion *(*uiButSearchTooltipFn)(struct bContext *C,
                                                 const struct rcti *item_rect,
                                                 void *arg,
                                                 void *active);
+typedef void (*uiButSearchListenFn)(const struct wmRegionListenerParams *params, void *arg);
 
 /* Must return allocated string. */
 typedef char *(*uiButToolTipFunc)(struct bContext *C, void *argN, const char *tip);
@@ -1659,6 +1660,7 @@ void UI_but_func_search_set(uiBut *but,
                             void *active);
 void UI_but_func_search_set_context_menu(uiBut *but, uiButSearchContextMenuFn context_menu_fn);
 void UI_but_func_search_set_tooltip(uiBut *but, uiButSearchTooltipFn tooltip_fn);
+void UI_but_func_search_set_listen(uiBut *but, uiButSearchListenFn listen_fn);
 /**
  * \param search_sep_string: when not NULL, this string is used as a separator,
  * showing the icon and highlighted text after the last instance of this string.