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, 49 insertions, 0 deletions

diff --git a/source/blender/editors/interface/interface_templates.c b/source/blender/editors/interface/interface_templates.c
index 9fbaa62b77f..548852b407e 100644
--- a/source/blender/editors/interface/interface_templates.c
+++ b/source/blender/editors/interface/interface_templates.c
@@ -5835,6 +5835,15 @@ static void uilist_free_dyn_data(uiList *ui_list)
     return;
   }
 
+  if (dyn_data->custom_activate_opptr) {
+    WM_operator_properties_free(dyn_data->custom_activate_opptr);
+    MEM_freeN(dyn_data->custom_activate_opptr);
+  }
+  if (dyn_data->custom_drag_opptr) {
+    WM_operator_properties_free(dyn_data->custom_drag_opptr);
+    MEM_freeN(dyn_data->custom_drag_opptr);
+  }
+
   MEM_SAFE_FREE(dyn_data->items_filter_flags);
   MEM_SAFE_FREE(dyn_data->items_filter_neworder);
   MEM_SAFE_FREE(dyn_data->customdata);
@@ -6848,6 +6857,46 @@ void uiTemplateList(uiLayout *layout,
                     NULL);
 }
 
+/**
+ * \return: A RNA pointer for the operator properties.
+ */
+PointerRNA *UI_list_custom_activate_operator_set(uiList *ui_list,
+                                                 const char *opname,
+                                                 bool create_properties)
+{
+  uiListDyn *dyn_data = ui_list->dyn_data;
+  dyn_data->custom_activate_optype = WM_operatortype_find(opname, false);
+  if (!dyn_data->custom_activate_optype) {
+    return NULL;
+  }
+
+  if (create_properties) {
+    WM_operator_properties_alloc(&dyn_data->custom_activate_opptr, NULL, opname);
+  }
+
+  return dyn_data->custom_activate_opptr;
+}
+
+/**
+ * \return: A RNA pointer for the operator properties.
+ */
+PointerRNA *UI_list_custom_drag_operator_set(uiList *ui_list,
+                                             const char *opname,
+                                             bool create_properties)
+{
+  uiListDyn *dyn_data = ui_list->dyn_data;
+  dyn_data->custom_drag_optype = WM_operatortype_find(opname, false);
+  if (!dyn_data->custom_drag_optype) {
+    return NULL;
+  }
+
+  if (create_properties) {
+    WM_operator_properties_alloc(&dyn_data->custom_drag_opptr, NULL, opname);
+  }
+
+  return dyn_data->custom_drag_opptr;
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */