From 3e9fff6c198f04d7a90f1b82a89fd2f82d3ef731 Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Tue, 23 Jun 2020 23:42:33 +1000
Subject: [PATCH] New feature to unassign/reassign IFC class easily

---
 .../blenderbim/bim/__init__.py                |  1 +
 .../blenderbim/bim/operator.py                | 21 +++++++++++-
 src/ifcblenderexport/blenderbim/bim/ui.py     | 34 ++++++++++++-------
 3 files changed, 42 insertions(+), 14 deletions(-)

diff --git a/src/ifcblenderexport/blenderbim/bim/__init__.py b/src/ifcblenderexport/blenderbim/bim/__init__.py
index d68222b6e1..50f3fa8f03 100644
--- a/src/ifcblenderexport/blenderbim/bim/__init__.py
+++ b/src/ifcblenderexport/blenderbim/bim/__init__.py
@@ -13,6 +13,7 @@ if bpy is not None:
 
     classes = (
         operator.AssignClass,
+        operator.UnassignClass,
         operator.SelectClass,
         operator.SelectType,
         operator.SelectBcfFile,
diff --git a/src/ifcblenderexport/blenderbim/bim/operator.py b/src/ifcblenderexport/blenderbim/bim/operator.py
index 26b2c80d09..d9ea5532be 100644
--- a/src/ifcblenderexport/blenderbim/bim/operator.py
+++ b/src/ifcblenderexport/blenderbim/bim/operator.py
@@ -174,7 +174,7 @@ class AssignClass(bpy.types.Operator):
         for obj in objects:
             existing_class = None
             if '/' in obj.name \
-                and obj.name[0:3] == 'Ifc':
+                    and obj.name[0:3] == 'Ifc':
                 existing_class = obj.name.split('/')[0]
             if existing_class:
                 obj.name = '{}/{}'.format(
@@ -200,6 +200,25 @@ class AssignClass(bpy.types.Operator):
                 object_type.string_value = bpy.context.scene.BIMProperties.ifc_userdefined_type
         return {'FINISHED'}
 
+
+class UnassignClass(bpy.types.Operator):
+    bl_idname = 'bim.unassign_class'
+    bl_label = 'Unassign IFC Class'
+    object_name: bpy.props.StringProperty()
+
+    def execute(self, context):
+        if self.object_name:
+            objects = [bpy.data.objects.get(self.object_name)]
+        else:
+            objects = bpy.context.selected_objects
+        for obj in objects:
+            existing_class = None
+            if '/' in obj.name \
+                    and obj.name[0:3] == 'Ifc':
+                obj.name = '/'.join(obj.name.split('/')[1:])
+        return {'FINISHED'}
+
+
 class SelectClass(bpy.types.Operator):
     bl_idname = 'bim.select_class'
     bl_label = 'Select IFC Class'
diff --git a/src/ifcblenderexport/blenderbim/bim/ui.py b/src/ifcblenderexport/blenderbim/bim/ui.py
index 2ff8943737..e47abfc68f 100644
--- a/src/ifcblenderexport/blenderbim/bim/ui.py
+++ b/src/ifcblenderexport/blenderbim/bim/ui.py
@@ -20,20 +20,26 @@ class BIM_PT_object(Panel):
         props = context.active_object.BIMObjectProperties
         bim_properties = context.scene.BIMProperties
 
+        row = layout.row()
+        row.prop(bim_properties, "ifc_product")
+        row = layout.row()
+        row.prop(bim_properties, "ifc_class")
+        if bim_properties.ifc_predefined_type:
+            row = layout.row()
+            row.prop(bim_properties, "ifc_predefined_type")
+        if bim_properties.ifc_predefined_type == 'USERDEFINED':
+            row = layout.row()
+            row.prop(bim_properties, "ifc_userdefined_type")
+        row = layout.row(align=True)
         if 'Ifc' not in context.active_object.name:
-            row = layout.row()
-            row.prop(bim_properties, "ifc_product")
-            row = layout.row()
-            row.prop(bim_properties, "ifc_class")
-            if bim_properties.ifc_predefined_type:
-                row = layout.row()
-                row.prop(bim_properties, "ifc_predefined_type")
-            if bim_properties.ifc_predefined_type == 'USERDEFINED':
-                row = layout.row()
-                row.prop(bim_properties, "ifc_userdefined_type")
-            row = layout.row()
             op = row.operator("bim.assign_class")
-            op.object_name = context.active_object.name
+        else:
+            op = row.operator("bim.assign_class", text='Reassign IFC Class')
+        op.object_name = context.active_object.name
+        op = row.operator("bim.unassign_class", icon='X', text='')
+        op.object_name = context.active_object.name
+
+        if 'Ifc' not in context.active_object.name:
             return
 
         layout.label(text="Software Identity:")
@@ -845,9 +851,11 @@ class BIM_PT_bim(Panel):
         if bim_properties.ifc_predefined_type == 'USERDEFINED':
             row = layout.row()
             row.prop(bim_properties, "ifc_userdefined_type")
-        row = layout.row()
+        row = layout.row(align=True)
         op = row.operator("bim.assign_class")
         op.object_name = ''
+        op = row.operator("bim.unassign_class", icon='X', text='')
+        op.object_name = ''
 
         row = layout.row(align=True)
         row.operator("bim.select_class")