Nodes: Moved group interface panel code to python.

The node group interface panels were still implemented in C.
Now they ported over to python for easier maintenance.

Differential Revision: https://developer.blender.org/D11834

release/scripts/startup/bl_ui/space_node.py

@@ -694,6 +694,97 @@ class NODE_UL_interface_sockets(bpy.types.UIList):
             layout.template_node_socket(color=color)
 
 
+class NodeTreeInterfacePanel:
+    def draw_socket_list(self, context, in_out, sockets_propname, active_socket_propname):
+        layout = self.layout
+
+        snode = context.space_data
+        tree = snode.edit_tree
+        sockets = getattr(tree, sockets_propname)
+        active_socket_index = getattr(tree, active_socket_propname)
+        active_socket = sockets[active_socket_index] if active_socket_index >= 0 else None
+
+        split = layout.row()
+
+        split.template_list("NODE_UL_interface_sockets", in_out, tree, sockets_propname, tree, active_socket_propname)
+
+        ops_col = split.column()
+
+        add_remove_col = ops_col.column(align=True)
+        props = add_remove_col.operator("node.tree_socket_add", icon='ADD', text="")
+        props.in_out = in_out
+        props = add_remove_col.operator("node.tree_socket_remove", icon='REMOVE', text="")
+        props.in_out = in_out
+
+        ops_col.separator()
+
+        up_down_col = ops_col.column(align=True)
+        props = up_down_col.operator("node.tree_socket_move", icon='TRIA_UP', text="")
+        props.in_out = in_out
+        props.direction = 'UP'
+        props = up_down_col.operator("node.tree_socket_move", icon='TRIA_DOWN', text="")
+        props.in_out = in_out
+        props.direction = 'DOWN'
+
+        if active_socket is not None:
+            # Mimicking property split.
+            layout.use_property_split = False
+            layout.use_property_decorate = False
+            layout_row = layout.row(align=True)
+            layout_split = layout_row.split(factor=0.4, align=True)
+
+            label_column = layout_split.column(align=True)
+            label_column.alignment = 'RIGHT'
+            # Menu to change the socket type.
+            label_column.label(text="Type")
+
+            property_row = layout_split.row(align=True)
+            props = property_row.operator_menu_enum(
+                "node.tree_socket_change_type",
+                "socket_type",
+                text=active_socket.bl_label if active_socket.bl_label else active_socket.bl_idname
+                )
+            props.in_out = in_out
+
+            layout.use_property_split = True
+            layout.use_property_decorate = False
+
+            layout.prop(active_socket, "name")
+            # Display descriptions only for Geometry Nodes, since it's only used in the modifier panel.
+            if tree.type == 'GEOMETRY':
+                layout.prop(active_socket, "description")
+            active_socket.draw(context, layout)
+
+
+class NODE_PT_node_tree_interface_inputs(NodeTreeInterfacePanel, Panel):
+    bl_space_type = 'NODE_EDITOR'
+    bl_region_type = 'UI'
+    bl_category = "Group"
+    bl_label = "Inputs"
+
+    @classmethod
+    def poll(cls, context):
+        snode = context.space_data
+        return snode.edit_tree is not None
+
+    def draw(self, context):
+        self.draw_socket_list(context, "IN", "inputs", "active_input")
+
+class NODE_PT_node_tree_interface_outputs(NodeTreeInterfacePanel, Panel):
+    bl_space_type = 'NODE_EDITOR'
+    bl_region_type = 'UI'
+    bl_category = "Group"
+    bl_label = "Outputs"
+
+    @classmethod
+    def poll(cls, context):
+        snode = context.space_data
+        return snode.edit_tree is not None
+
+    def draw(self, context):
+        self.draw_socket_list(context, "OUT", "outputs", "active_output")
+
+
 # Grease Pencil properties
 class NODE_PT_annotation(AnnotationDataPanel, Panel):
     bl_space_type = 'NODE_EDITOR'
@@ -752,6 +843,8 @@ classes = (
     NODE_PT_quality,
     NODE_PT_annotation,
     NODE_UL_interface_sockets,
+    NODE_PT_node_tree_interface_inputs,
+    NODE_PT_node_tree_interface_outputs,
 
     node_panel(EEVEE_MATERIAL_PT_settings),
     node_panel(MATERIAL_PT_viewport),