Fix T102520: Positioning of nodes added via search

Always position the nodes added with the node search at the point where
the search operator was invoked by ensuring the operator context is the
main node editor region.

This was an unintended change of rBbdb57541475f, caused by the operator
now getting the cursor position in region space. So when the operator
was called from the menu, it would get the cursor position in the
region space of the menu, which lead to an offset when adding the node
since it expected the coordinates to be in the space of the node editor.

Setting the correct operator context also fixes inconsistent transform
sensitivity depending on zoom when adding nodes via the search in the
menu which has been an issue since as far back as Blender 2.79.

Also includes a small fix for the vertical offset of nodes added by the
search which varied depending on the UI scale. Same fix as in
rB998ffcbf096e.

Reviewed By: Hans Goudey

Differential Revision: http://developer.blender.org/D16555

release/scripts/startup/bl_ui/space_node.py

@@ -219,7 +219,7 @@ class NODE_MT_add(bpy.types.Menu):
         import nodeitems_utils
 
         layout = self.layout
-        layout.operator_context = 'INVOKE_DEFAULT'
+        layout.operator_context = 'INVOKE_REGION_WIN'
 
         snode = context.space_data
         if snode.tree_type == 'GeometryNodeTree':

source/blender/editors/space_node/add_node_search.cc

@@ -256,7 +256,7 @@ static void add_node_search_exec_fn(bContext *C, void *arg1, void *arg2)
   }
 
   new_node->locx = storage.cursor.x / UI_DPI_FAC;
-  new_node->locy = storage.cursor.y / UI_DPI_FAC + 20 * UI_DPI_FAC;
+  new_node->locy = storage.cursor.y / UI_DPI_FAC + 20;
 
   nodeSetSelected(new_node, true);
   nodeSetActive(&node_tree, new_node);