From 829b97a0d820d49a8c0092d3739e795699086917 Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Sun, 9 Aug 2020 11:33:47 +1000
Subject: [PATCH] New feature to calculate area of selected faces

---
 src/ifcblenderexport/blenderbim/bim/__init__.py |  1 +
 src/ifcblenderexport/blenderbim/bim/operator.py | 16 ++++++++++++++++
 src/ifcblenderexport/blenderbim/bim/ui.py       |  2 ++
 3 files changed, 19 insertions(+)

diff --git a/src/ifcblenderexport/blenderbim/bim/__init__.py b/src/ifcblenderexport/blenderbim/bim/__init__.py
index ff988a16cb..664e884b7d 100644
--- a/src/ifcblenderexport/blenderbim/bim/__init__.py
+++ b/src/ifcblenderexport/blenderbim/bim/__init__.py
@@ -170,6 +170,7 @@ if bpy is not None:
         operator.SelectIfcPatchOutput,
         operator.ExecuteIfcPatch,
         operator.CalculateEdgeLengths,
+        operator.CalculateFaceAreas,
         prop.StrProperty,
         prop.Variable,
         prop.Role,
diff --git a/src/ifcblenderexport/blenderbim/bim/operator.py b/src/ifcblenderexport/blenderbim/bim/operator.py
index baba4cb489..8b008e6768 100644
--- a/src/ifcblenderexport/blenderbim/bim/operator.py
+++ b/src/ifcblenderexport/blenderbim/bim/operator.py
@@ -3363,3 +3363,19 @@ class CalculateEdgeLengths(bpy.types.Operator):
                         obj.data.vertices[edge.vertices[0]].co).length
         bpy.context.scene.BIMProperties.qto_result = str(result)
         return {'FINISHED'}
+
+
+class CalculateFaceAreas(bpy.types.Operator):
+    bl_idname = 'bim.calculate_face_areas'
+    bl_label = 'Calculate Face Areas'
+
+    def execute(self, context):
+        result = 0
+        for obj in bpy.context.selected_objects:
+            if not obj.data or not obj.data.polygons:
+                continue
+            for polygon in obj.data.polygons:
+                if polygon.select:
+                    result += polygon.area
+        bpy.context.scene.BIMProperties.qto_result = str(result)
+        return {'FINISHED'}
diff --git a/src/ifcblenderexport/blenderbim/bim/ui.py b/src/ifcblenderexport/blenderbim/bim/ui.py
index 6da710ddeb..6ce2fe0931 100644
--- a/src/ifcblenderexport/blenderbim/bim/ui.py
+++ b/src/ifcblenderexport/blenderbim/bim/ui.py
@@ -525,6 +525,8 @@ class BIM_PT_qto(Panel):
 
         row = layout.row(align=True)
         row.operator("bim.calculate_edge_lengths")
+        row = layout.row(align=True)
+        row.operator("bim.calculate_face_areas")
 
 
 class BIM_PT_classifications(Panel):