UI: Internal support for custom UI list item drag & activate operators

For pose libraries, we need to be able to apply a pose whenever
activating (clicking) an item in the Pose Library asset view and blend
it by dragging (press & move). And since we want to allow Python scripts
to define what happens at least when activating an asset (so they can
define for example a custom "Apply" operator for preset assets), it
makes sense to just let them pass an operator name to the asset view
template. The template will be introduced in a following commit.

1 files changed, 9 insertions, 0 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 55d0c5c4342..58eaba480e1 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -588,6 +588,8 @@ bool UI_block_is_empty_ex(const uiBlock *block, const bool skip_title);
 bool UI_block_is_empty(const uiBlock *block);
 bool UI_block_can_add_separator(const uiBlock *block);
 
+struct uiList *UI_list_find_mouse_over(const struct ARegion *region, const struct wmEvent *event);
+
 /* interface_region_menu_popup.c */
 /**
  * Popup Menus
@@ -2282,6 +2284,13 @@ void uiTemplateFileSelectPath(uiLayout *layout,
                               struct bContext *C,
                               struct FileSelectParams *params);
 
+struct PointerRNA *UI_list_custom_activate_operator_set(struct uiList *ui_list,
+                                                        const char *opname,
+                                                        bool create_properties);
+struct PointerRNA *UI_list_custom_drag_operator_set(struct uiList *ui_list,
+                                                    const char *opname,
+                                                    bool create_properties);
+
 /* items */
 void uiItemO(uiLayout *layout, const char *name, int icon, const char *opname);
 void uiItemEnumO_ptr(uiLayout *layout,