Dynamic enumerators

Dynamic enums require to hold proper reference to enum array. (may lead to access violation and strange ui behaviour)
Cleanup bpy.props.xxx and bpy.types.xxx
Fix in path for files with hardcoded "/"
BIM_PT_ prefixes for Panel classes
Use poll method for panels

src/ifcblenderexport/io_export_ifc/ui.py

@@ -3,247 +3,317 @@ import json
 import os
 import csv
 from pathlib import Path
+from bpy.types import PropertyGroup, Panel
+from bpy.props import (
+    StringProperty,
+    EnumProperty,
+    BoolProperty,
+    IntProperty,
+    FloatProperty,
+    CollectionProperty
+)
+
 
 cwd = os.path.dirname(os.path.realpath(__file__)) + os.path.sep
 
 class IfcSchema():
     def __init__(self):
-        with open('{}ifc_elements_IFC4.json'.format(cwd + 'schema/')) as f:
+        with open('{}schema{}ifc_elements_IFC4.json'.format(cwd, os.path.sep)) as f:
             self.elements = json.load(f)
 
 ifc_schema = IfcSchema()
 
-class BIMProperties(bpy.types.PropertyGroup):
+# hold reference to dynamic enum
-    def getIfcClasses(self, context):
+classes_enum = []
-        return [(e, e, '') for e in ifc_schema.elements]
+types_enum = []
+psetnames_enum = []
+psetfiles_enum = []
+classification_enum = []
+attributes_enum = []
+documents_enum = []
 
-    def getIfcPredefinedTypes(self, context):
+# Note: unless we need dynamic behaviour
-        results = []
+# enums should be cached especially when file io is involved
-        for name, data in ifc_schema.elements.items():
+# we may clear on need to regen
-            if name != bpy.context.scene.BIMProperties.ifc_class:
+
+def getIfcPredefinedTypes(self):
+    global types_enum
+    types_enum.clear()
+    for name, data in ifc_schema.elements.items():
+        if name != bpy.context.scene.BIMProperties.ifc_class:
+            continue
+        for attribute in data['attributes']:
+            if attribute['name'] != 'PredefinedType':
                 continue
-            for attribute in data['attributes']:
+            types_enum.extend([(e, e, '') for e in attribute['enum_values']])
-                if attribute['name'] != 'PredefinedType':
+    return types_enum
-                    continue
-                return [(e, e, '') for e in attribute['enum_values']]
 
-    def getPsetNames(self, context):
+def getIfcClasses(self):
-        files = os.listdir(bpy.context.scene.BIMProperties.data_dir + 'pset/')
+    global classes_enum
-        return [(f, f, '') for f in files]
+    classes_enum.clear()
+    classes_enum.extend([(e, e, '') for e in ifc_schema.elements])
+    return classes_enum
 
-    def getPsetFiles(self, context):
+def getPsetNames(self):
-        if not bpy.context.scene.BIMProperties.pset_name:
+    global psetnames_enum
-            return []
+    psetnames_enum.clear()
-        files = os.listdir(bpy.context.scene.BIMProperties.data_dir + 'pset/{}/'.format(bpy.context.scene.BIMProperties.pset_name))
+    files = os.listdir(bpy.context.scene.BIMProperties.data_dir + 'pset' + os.path.sep)
-        return [(f.replace('.csv', ''), f.replace('.csv', ''), '') for f in files]
+    psetnames_enum.extend([(f, f, '') for f in files])
+    return psetnames_enum
 
-    def getClassifications(self, context):
+def getPsetFiles(self):
-        with open(bpy.context.scene.BIMProperties.data_dir + 'class/classifications.csv', 'r') as f:
+    global psetfiles_enum
-            data = list(csv.reader(f))
+    psetfiles_enum.clear()
-            keys = data.pop(0)
+    if not bpy.context.scene.BIMProperties.pset_name:
-            index = keys.index('Name')
+        return psetfiles_enum
-            return [(str(i), d[index], '') for i, d in enumerate(data)]
+    files = os.listdir(
+        bpy.context.scene.BIMProperties.data_dir + 'pset{}{}{}'.format(
+            os.path.sep,
+            bpy.context.scene.BIMProperties.pset_name,
+            os.path.sep))
+    psetfiles_enum.extend([(f.replace('.csv', ''), f.replace('.csv', ''), '') for f in files])
+    return psetfiles_enum
 
-    def getReferences(self, context):
+def getClassifications(self):
-        if not bpy.context.scene.BIMProperties.classification:
+    global classification_enum
-            return []
+    classification_enum.clear()
-        with open(bpy.context.scene.BIMProperties.data_dir + 'class/references.csv', 'r') as f:
+    with open(bpy.context.scene.BIMProperties.data_dir + 'class/classifications.csv', 'r') as f:
-            data = list(csv.reader(f))
+        data = list(csv.reader(f))
-            keys = data.pop(0)
+        keys = data.pop(0)
-            return [(d[0], '{} - {}'.format(d[0], d[1]), '') for d in data if
+        index = keys.index('Name')
-                d[2] == bpy.context.scene.BIMProperties.classification]
+        classification_enum.extend([(str(i), d[index], '') for i, d in enumerate(data)])
+    return classification_enum
 
-    schema_dir: bpy.props.StringProperty(default=cwd + 'schema/', name="Schema Directory")
+def getReferences(self):
-    data_dir: bpy.props.StringProperty(default=cwd + 'data/', name="Data Directory")
+    global reference_enum
-    ifc_class: bpy.props.EnumProperty(items = getIfcClasses, name="Class")
+    reference_enum.clear()
-    ifc_predefined_type: bpy.props.EnumProperty(
+    if not bpy.context.scene.BIMProperties.classification:
+        return reference_enum
+    with open(bpy.context.scene.BIMProperties.data_dir + 'class' + os.path.sep + 'references.csv', 'r') as f:
+        data = list(csv.reader(f))
+        keys = data.pop(0)
+        reference_enum.extend([(d[0], '{} - {}'.format(d[0], d[1]), '') for d in data if
+                d[2] == bpy.context.scene.BIMProperties.classification])
+    return reference_enum
+
+def getApplicableAttributes(self):
+    global attributes_enum
+    attributes_enum.clear()
+    if '/' in bpy.context.active_object.name \
+        and bpy.context.active_object.name.split('/')[0] in ifc_schema.elements:
+        attributes_enum.extend([(a['name'], a['name'], '') for a in
+            ifc_schema.elements[bpy.context.active_object.name.split('/')[0]]['attributes']
+            if bpy.context.active_object.BIMObjectProperties.attributes.find(a['name']) == -1])
+    return attributes_enum
+
+def getApplicableDocuments(self):
+    global documents_enum
+    documents_enum.clear()
+    doc_path = bpy.context.scene.BIMProperties.data_dir + 'doc' + os.path.sep
+    for filename in Path(doc_path).glob('**/*'):
+        uri = str(filename.relative_to(doc_path).as_posix())
+        documents_enum.append((uri, uri, ''))
+    return documents_enum
+
+
+class BIMProperties(PropertyGroup):
+
+    schema_dir: StringProperty(default=cwd + 'schema' + os.path.sep, name="Schema Directory")
+    data_dir: StringProperty(default=cwd + 'data'  + os.path.sep, name="Data Directory")
+    ifc_class: EnumProperty(items = getIfcClasses, name="Class")
+    ifc_predefined_type: EnumProperty(
         items = getIfcPredefinedTypes,
         name="Predefined Type", default=None)
-    ifc_userdefined_type: bpy.props.StringProperty(name="Userdefined Type")
+    ifc_userdefined_type: StringProperty(name="Userdefined Type")
-    export_has_representations: bpy.props.BoolProperty(name="Export Representations", default=True)
+    export_has_representations: BoolProperty(name="Export Representations", default=True)
-    export_should_export_all_materials_as_styled_items: bpy.props.BoolProperty(name="Export All Materials as Styled Items", default=False)
+    export_should_export_all_materials_as_styled_items: BoolProperty(name="Export All Materials as Styled Items", default=False)
-    export_should_use_presentation_style_assignment: bpy.props.BoolProperty(name="Export with Presentation Style Assignment", default=False)
+    export_should_use_presentation_style_assignment: BoolProperty(name="Export with Presentation Style Assignment", default=False)
-    import_should_ignore_site_coordinates: bpy.props.BoolProperty(name="Import Ignoring Site Coordinates", default=False)
+    import_should_ignore_site_coordinates: BoolProperty(name="Import Ignoring Site Coordinates", default=False)
-    import_should_import_curves: bpy.props.BoolProperty(name="Import Curves", default=False)
+    import_should_import_curves: BoolProperty(name="Import Curves", default=False)
-    qa_reject_element_reason: bpy.props.StringProperty(name="Element Rejection Reason")
+    qa_reject_element_reason: StringProperty(name="Element Rejection Reason")
-    pset_name: bpy.props.EnumProperty(items=getPsetNames, name="Pset Name")
+    pset_name: EnumProperty(items=getPsetNames, name="Pset Name")
-    pset_file: bpy.props.EnumProperty(items=getPsetFiles, name="Pset File")
+    pset_file: EnumProperty(items=getPsetFiles, name="Pset File")
-    has_georeferencing: bpy.props.BoolProperty(name="Has Georeferencing", default=False)
+    has_georeferencing: BoolProperty(name="Has Georeferencing", default=False)
-    global_id: bpy.props.StringProperty(name="GlobalId")
+    global_id: StringProperty(name="GlobalId")
-    features_dir: bpy.props.StringProperty(default='', name="Features Directory")
+    features_dir: StringProperty(default='', name="Features Directory")
-    diff_json_file: bpy.props.StringProperty(default='', name="Diff JSON File")
+    diff_json_file: StringProperty(default='', name="Diff JSON File")
-    aggregate_class: bpy.props.EnumProperty(items = getIfcClasses, name="Aggregate Class")
+    aggregate_class: EnumProperty(items = getIfcClasses, name="Aggregate Class")
-    aggregate_name: bpy.props.StringProperty(name="Aggregate Name")
+    aggregate_name: StringProperty(name="Aggregate Name")
-    classification: bpy.props.EnumProperty(items = getClassifications, name="Classification")
+    classification: EnumProperty(items = getClassifications, name="Classification")
-    reference: bpy.props.EnumProperty(items = getReferences, name="Reference")
+    reference: EnumProperty(items = getReferences, name="Reference")
 
-class MapConversion(bpy.types.PropertyGroup):
+class MapConversion(PropertyGroup):
-    eastings: bpy.props.StringProperty(name="Eastings")
+    eastings: StringProperty(name="Eastings")
-    northings: bpy.props.StringProperty(name="Northings")
+    northings: StringProperty(name="Northings")
-    orthogonal_height: bpy.props.StringProperty(name="Orthogonal Height")
+    orthogonal_height: StringProperty(name="Orthogonal Height")
-    x_axis_abscissa: bpy.props.StringProperty(name="X Axis Abscissa")
+    x_axis_abscissa: StringProperty(name="X Axis Abscissa")
-    x_axis_ordinate: bpy.props.StringProperty(name="X Axis Ordinate")
+    x_axis_ordinate: StringProperty(name="X Axis Ordinate")
-    scale: bpy.props.StringProperty(name="Scale")
+    scale: StringProperty(name="Scale")
 
-class TargetCRS(bpy.types.PropertyGroup):
+class TargetCRS(PropertyGroup):
-    name: bpy.props.StringProperty(name="Name")
+    name: StringProperty(name="Name")
-    description: bpy.props.StringProperty(name="Description")
+    description: StringProperty(name="Description")
-    geodetic_datum: bpy.props.StringProperty(name="Geodetic Datum")
+    geodetic_datum: StringProperty(name="Geodetic Datum")
-    vertical_datum: bpy.props.StringProperty(name="Vertical Datum")
+    vertical_datum: StringProperty(name="Vertical Datum")
-    map_projection: bpy.props.StringProperty(name="Map Projection")
+    map_projection: StringProperty(name="Map Projection")
-    map_zone: bpy.props.StringProperty(name="Map Zone")
+    map_zone: StringProperty(name="Map Zone")
-    map_unit: bpy.props.StringProperty(name="Map Unit")
+    map_unit: StringProperty(name="Map Unit")
 
-class Attribute(bpy.types.PropertyGroup):
+class Attribute(PropertyGroup):
-    name: bpy.props.StringProperty(name="Name")
+    name: StringProperty(name="Name")
-    data_type: bpy.props.StringProperty(name="Data Type")
+    data_type: StringProperty(name="Data Type")
-    string_value: bpy.props.StringProperty(name="Value")
+    string_value: StringProperty(name="Value")
-    bool_value: bpy.props.BoolProperty(name="Value")
+    bool_value: BoolProperty(name="Value")
-    int_value: bpy.props.IntProperty(name="Value")
+    int_value: IntProperty(name="Value")
-    float_value: bpy.props.FloatProperty(name="Value")
+    float_value: FloatProperty(name="Value")
 
-class Pset(bpy.types.PropertyGroup):
+class Pset(PropertyGroup):
-    name: bpy.props.StringProperty(name="Name")
+    name: StringProperty(name="Name")
-    file: bpy.props.StringProperty(name="File")
+    file: StringProperty(name="File")
 
-class Document(bpy.types.PropertyGroup):
+class Document(PropertyGroup):
-    file: bpy.props.StringProperty(name="File")
+    file: StringProperty(name="File")
 
-class Classification(bpy.types.PropertyGroup):
+class Classification(PropertyGroup):
-    name: bpy.props.StringProperty(name="Name")
+    name: StringProperty(name="Name")
-    identification: bpy.props.StringProperty(name="Identification")
+    identification: StringProperty(name="Identification")
 
-class GlobalId(bpy.types.PropertyGroup):
-    name: bpy.props.StringProperty(name="Name")
 
-class BIMObjectProperties(bpy.types.PropertyGroup):
+class GlobalId(PropertyGroup):
-    def getApplicableAttributes(self, context):
+    name: StringProperty(name="Name")
-        if '/' in bpy.context.active_object.name \
-            and bpy.context.active_object.name.split('/')[0] in ifc_schema.elements:
-            return [(a['name'], a['name'], '') for a in
-                ifc_schema.elements[bpy.context.active_object.name.split('/')[0]]['attributes']
-                if bpy.context.active_object.BIMObjectProperties.attributes.find(a['name']) == -1]
-        return []
 
-    def getApplicableDocuments(self, context):
-        results = []
-        doc_path = bpy.context.scene.BIMProperties.data_dir + 'doc/'
-        for filename in Path(doc_path).glob('**/*'):
-            uri = str(filename.relative_to(doc_path).as_posix())
-            results.append((uri, uri, ''))
-        return results
 
-    global_ids: bpy.props.CollectionProperty(name="GlobalIds", type=GlobalId)
+class BIMObjectProperties(PropertyGroup):
-    attributes: bpy.props.CollectionProperty(name="Attributes", type=Attribute)
-    psets: bpy.props.CollectionProperty(name="Psets", type=Pset)
-    applicable_attributes: bpy.props.EnumProperty(items=getApplicableAttributes, name="Attribute Names")
-    documents: bpy.props.CollectionProperty(name="Documents", type=Document)
-    applicable_documents: bpy.props.EnumProperty(items=getApplicableDocuments, name="Available Documents")
-    classifications: bpy.props.CollectionProperty(name="Classifications", type=Classification)
 
-class BIMMaterialProperties(bpy.types.PropertyGroup):
-    is_external: bpy.props.BoolProperty(name="Has External Definition")
-    location: bpy.props.StringProperty(name="Location")
-    identification: bpy.props.StringProperty(name="Identification")
-    name: bpy.props.StringProperty(name="Name")
 
-class SweptSolid(bpy.types.PropertyGroup):
+    global_ids: CollectionProperty(name="GlobalIds", type=GlobalId)
-    name: bpy.props.StringProperty(name="Name")
+    attributes: CollectionProperty(name="Attributes", type=Attribute)
-    outer_curve: bpy.props.StringProperty(name="Outer Curve")
+    psets: CollectionProperty(name="Psets", type=Pset)
-    inner_curves: bpy.props.StringProperty(name="Inner Curves")
+    applicable_attributes: EnumProperty(items=getApplicableAttributes, name="Attribute Names")
-    extrusion: bpy.props.StringProperty(name="Extrusion")
+    documents: CollectionProperty(name="Documents", type=Document)
+    applicable_documents: EnumProperty(items=getApplicableDocuments, name="Available Documents")
+    classifications: CollectionProperty(name="Classifications", type=Classification)
 
-class BIMMeshProperties(bpy.types.PropertyGroup):
-    is_wireframe: bpy.props.BoolProperty(name="Is Wireframe")
-    is_swept_solid: bpy.props.BoolProperty(name="Is Swept Solid")
-    swept_solids: bpy.props.CollectionProperty(name="Swept Solids", type=SweptSolid)
 
-class ObjectPanel(bpy.types.Panel):
+class BIMMaterialProperties(PropertyGroup):
+    is_external: BoolProperty(name="Has External Definition")
+    location: StringProperty(name="Location")
+    identification: StringProperty(name="Identification")
+    name: StringProperty(name="Name")
+
+
+class SweptSolid(PropertyGroup):
+    name: StringProperty(name="Name")
+    outer_curve: StringProperty(name="Outer Curve")
+    inner_curves: StringProperty(name="Inner Curves")
+    extrusion: StringProperty(name="Extrusion")
+
+
+class BIMMeshProperties(PropertyGroup):
+    is_wireframe: BoolProperty(name="Is Wireframe")
+    is_swept_solid: BoolProperty(name="Is Swept Solid")
+    swept_solids: CollectionProperty(name="Swept Solids", type=SweptSolid)
+
+
+class BIM_PT_object(Panel):
     bl_label = 'IFC Object'
     bl_idname = 'BIM_PT_object'
     bl_space_type = 'PROPERTIES'
     bl_region_type = 'WINDOW'
     bl_context = 'object'
-
+    
+    @classmethod
+    def poll(cls, context):
+        return context.active_object is not None and hasattr(context.active_object, "BIMObjectProperties")
+    
     def draw(self, context):
-        if not bpy.context.active_object:
+        
+        if context.active_object is None:
             return
         layout = self.layout
+        props = context.active_object.BIMObjectProperties
+
         layout.label(text="Software Identity:")
         row = layout.row()
         row.operator('bim.generate_global_id')
 
         layout.label(text="Attributes:")
         row = layout.row(align=True)
-        row.prop(bpy.context.active_object.BIMObjectProperties, 'applicable_attributes', text='')
+        row.prop(props, 'applicable_attributes', text='')
         row.operator('bim.add_attribute')
 
-        for index, attribute in enumerate(bpy.context.active_object.BIMObjectProperties.attributes):
+        for index, attribute in enumerate(props.attributes):
             row = layout.row(align=True)
             row.prop(attribute, 'name', text='')
             row.prop(attribute, 'string_value', text='')
             row.operator('bim.remove_attribute', icon='X', text='').attribute_index = index
 
         row = layout.row()
-        row.prop(bpy.context.active_object.BIMObjectProperties, 'attributes')
+        row.prop(props, 'attributes')
 
         layout.label(text="Property Sets:")
         row = layout.row()
         row.operator('bim.add_pset')
 
-        for index, pset in enumerate(bpy.context.active_object.BIMObjectProperties.psets):
+        for index, pset in enumerate(props.psets):
             row = layout.row(align=True)
             row.prop(pset, 'name', text='')
             row.prop(pset, 'file', text='')
             row.operator('bim.remove_pset', icon='X', text='').pset_index = index
 
         row = layout.row()
-        row.prop(bpy.context.active_object.BIMObjectProperties, 'psets')
+        row.prop(props, 'psets')
 
         layout.label(text="Documents:")
         row = layout.row(align=True)
-        row.prop(bpy.context.active_object.BIMObjectProperties, 'applicable_documents', text='')
+        row.prop(props, 'applicable_documents', text='')
         row.operator('bim.add_document')
 
-        for index, document in enumerate(bpy.context.active_object.BIMObjectProperties.documents):
+        for index, document in enumerate(props.documents):
             row = layout.row(align=True)
             row.prop(document, 'file', text='')
             row.operator('bim.remove_document', icon='X', text='').document_index = index
 
         row = layout.row()
-        row.prop(bpy.context.active_object.BIMObjectProperties, 'documents')
+        row.prop(props, 'documents')
 
         layout.label(text="Classification:")
 
-        for index, classification in enumerate(bpy.context.active_object.BIMObjectProperties.classifications):
+        for index, classification in enumerate(props.classifications):
             row = layout.row(align=True)
             row.prop(classification, 'identification', text='')
             row.prop(classification, 'name', text='')
             row.operator('bim.remove_classification', icon='X', text='').classification_index = index
 
         row = layout.row()
-        row.prop(bpy.context.active_object.BIMObjectProperties, 'classifications')
+        row.prop(props, 'classifications')
 
 
-class MeshPanel(bpy.types.Panel):
+class BIM_PT_mesh(Panel):
     bl_label = 'IFC Representations'
     bl_idname = 'BIM_PT_mesh'
     bl_space_type = 'PROPERTIES'
     bl_region_type = 'WINDOW'
     bl_context = 'data'
 
+    @classmethod
+    def poll(cls, context):
+        return context.active_object is not None and context.active_object.type == "MESH" and \
+               hasattr(context.active_object.data, "BIMMeshProperties")
+    
     def draw(self, context):
-        if not bpy.context.active_object.data:
+        if not context.active_object.data:
             return
         layout = self.layout
+        props = context.active_object.data.BIMMeshProperties
         row = layout.row()
-        row.prop(bpy.context.active_object.data.BIMMeshProperties, 'is_wireframe')
+        row.prop(props, 'is_wireframe')
         row = layout.row()
-        row.prop(bpy.context.active_object.data.BIMMeshProperties, 'is_swept_solid')
+        row.prop(props, 'is_swept_solid')
 
         row = layout.row()
         row.operator('bim.add_swept_solid')
-        for index, swept_solid in enumerate(bpy.context.active_object.data.BIMMeshProperties.swept_solids):
+        for index, swept_solid in enumerate(props.swept_solids):
             row = layout.row(align=True)
             row.prop(swept_solid, 'name', text='')
             row.operator('bim.remove_swept_solid', icon='X', text='').index = index
@@ -258,30 +328,37 @@ class MeshPanel(bpy.types.Panel):
             row.operator('bim.assign_swept_solid_extrusion').index = index
             row.operator('bim.select_swept_solid_extrusion', icon='RESTRICT_SELECT_OFF', text='').index = index
         row = layout.row()
-        row.prop(bpy.context.active_object.data.BIMMeshProperties, 'swept_solids')
+        row.prop(props, 'swept_solids')
 
-class MaterialPanel(bpy.types.Panel):
+
+class BIM_PT_material(Panel):
     bl_label = 'IFC Materials'
     bl_idname = 'BIM_PT_material'
     bl_space_type = 'PROPERTIES'
     bl_region_type = 'WINDOW'
     bl_context = 'material'
-
+    
+    @classmethod
+    def poll(cls, context):
+        return context.active_object is not None and context.active_object.active_material is not None
+    
     def draw(self, context):
         if not bpy.context.active_object.active_material:
             return
+        props = context.active_object.active_material.BIMMaterialProperties
         layout = self.layout
         row = layout.row()
-        row.prop(bpy.context.active_object.active_material.BIMMaterialProperties, 'is_external')
+        row.prop(props, 'is_external')
         row = layout.row(align=True)
-        row.prop(bpy.context.active_object.active_material.BIMMaterialProperties, 'location')
+        row.prop(props, 'location')
         row.operator('bim.select_external_material_dir', icon="FILE_FOLDER", text="")
         row = layout.row()
-        row.prop(bpy.context.active_object.active_material.BIMMaterialProperties, 'identification')
+        row.prop(props, 'identification')
         row = layout.row()
-        row.prop(bpy.context.active_object.active_material.BIMMaterialProperties, 'name')
+        row.prop(props, 'name')
 
-class GISPanel(bpy.types.Panel):
+
+class BIM_PT_gis(Panel):
     bl_label = 'IFC Georeferencing'
     bl_idname = "BIM_PT_gis"
     bl_space_type = 'PROPERTIES'
@@ -291,27 +368,28 @@ class GISPanel(bpy.types.Panel):
     def draw(self, context):
         layout = self.layout
         layout.use_property_split = True
-
+        scene = context.scene
-        layout.row().prop(bpy.context.scene.BIMProperties, 'has_georeferencing')
+        layout.row().prop(scene.BIMProperties, 'has_georeferencing')
 
         layout.label(text="Map Conversion:")
-        layout.row().prop(bpy.context.scene.MapConversion, 'eastings')
+        layout.row().prop(scene.MapConversion, 'eastings')
-        layout.row().prop(bpy.context.scene.MapConversion, 'northings')
+        layout.row().prop(scene.MapConversion, 'northings')
-        layout.row().prop(bpy.context.scene.MapConversion, 'orthogonal_height')
+        layout.row().prop(scene.MapConversion, 'orthogonal_height')
-        layout.row().prop(bpy.context.scene.MapConversion, 'x_axis_abscissa')
+        layout.row().prop(scene.MapConversion, 'x_axis_abscissa')
-        layout.row().prop(bpy.context.scene.MapConversion, 'x_axis_ordinate')
+        layout.row().prop(scene.MapConversion, 'x_axis_ordinate')
-        layout.row().prop(bpy.context.scene.MapConversion, 'scale')
+        layout.row().prop(scene.MapConversion, 'scale')
 
         layout.label(text="Target CRS:")
-        layout.row().prop(bpy.context.scene.TargetCRS, 'name')
+        layout.row().prop(scene.TargetCRS, 'name')
-        layout.row().prop(bpy.context.scene.TargetCRS, 'description')
+        layout.row().prop(scene.TargetCRS, 'description')
-        layout.row().prop(bpy.context.scene.TargetCRS, 'geodetic_datum')
+        layout.row().prop(scene.TargetCRS, 'geodetic_datum')
-        layout.row().prop(bpy.context.scene.TargetCRS, 'vertical_datum')
+        layout.row().prop(scene.TargetCRS, 'vertical_datum')
-        layout.row().prop(bpy.context.scene.TargetCRS, 'map_projection')
+        layout.row().prop(scene.TargetCRS, 'map_projection')
-        layout.row().prop(bpy.context.scene.TargetCRS, 'map_zone')
+        layout.row().prop(scene.TargetCRS, 'map_zone')
-        layout.row().prop(bpy.context.scene.TargetCRS, 'map_unit')
+        layout.row().prop(scene.TargetCRS, 'map_unit')
 
-class BIMPanel(bpy.types.Panel):
+
+class BIM_PT_bim(Panel):
     bl_label = "Building Information Modeling"
     bl_idname = "BIM_PT_bim"
     bl_space_type = 'PROPERTIES'
@@ -323,7 +401,7 @@ class BIMPanel(bpy.types.Panel):
         layout.use_property_split = True
 
         scene = context.scene
-        bim_properties = bpy.context.scene.BIMProperties
+        bim_properties = scene.BIMProperties
 
         layout.label(text="System Setup:")
 
@@ -394,7 +472,8 @@ class BIMPanel(bpy.types.Panel):
         row.operator("bim.assign_classification")
         row.operator("bim.unassign_classification")
 
-class QAPanel(bpy.types.Panel):
+
+class BIM_PT_qa(Panel):
     bl_label = "BIMTester Quality Auditing"
     bl_idname = "BIM_PT_qa"
     bl_space_type = 'PROPERTIES'
@@ -432,7 +511,8 @@ class QAPanel(bpy.types.Panel):
         row = layout.row()
         row.operator("bim.select_audited")
 
-class DiffPanel(bpy.types.Panel):
+
+class BIM_PT_diff(Panel):
     bl_label = "IFC Diff"
     bl_idname = "BIM_PT_diff"
     bl_space_type = 'PROPERTIES'
@@ -444,7 +524,7 @@ class DiffPanel(bpy.types.Panel):
         layout.use_property_split = True
 
         scene = context.scene
-        bim_properties = bpy.context.scene.BIMProperties
+        bim_properties = scene.BIMProperties
 
         layout.label(text="IFC Diff Setup:")
 
@@ -452,7 +532,8 @@ class DiffPanel(bpy.types.Panel):
         row.prop(bim_properties, "diff_json_file")
         row.operator("bim.select_diff_json_file", icon="FILE_FOLDER", text="")
 
-class MVDPanel(bpy.types.Panel):
+
+class BIM_PT_mvd(Panel):
     bl_label = "Model View Definitions"
     bl_idname = "BIM_PT_mvd"
     bl_space_type = 'PROPERTIES'
@@ -463,7 +544,7 @@ class MVDPanel(bpy.types.Panel):
         layout = self.layout
 
         scene = context.scene
-        bim_properties = bpy.context.scene.BIMProperties
+        bim_properties = scene.BIMProperties
 
         layout.label(text="Custom MVD:")