From 5da9197bc594baf37480f46f4612867880136972 Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Mon, 27 Jan 2020 11:39:36 +1100
Subject: [PATCH] Import transparent and IFC4 colours

---
 src/Mod/Arch/importIFC.py       |  7 +++++--
 src/Mod/Arch/importIFCHelper.py | 14 ++++++++++++--
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/Mod/Arch/importIFC.py b/src/Mod/Arch/importIFC.py
index 57f530837f..bd6e343660 100644
--- a/src/Mod/Arch/importIFC.py
+++ b/src/Mod/Arch/importIFC.py
@@ -799,9 +799,12 @@ def insert(filename,docname,skip=[],only=[],root=None,preferences=None):
 
             # color
 
-            if FreeCAD.GuiUp and (pid in colors) and hasattr(obj.ViewObject,"ShapeColor"):
+            if FreeCAD.GuiUp and (pid in colors) and colors[pid]:
                 # if preferences['DEBUG']: print("    setting color: ",int(colors[pid][0]*255),"/",int(colors[pid][1]*255),"/",int(colors[pid][2]*255))
-                obj.ViewObject.ShapeColor = colors[pid]
+                if hasattr(obj.ViewObject,"ShapeColor"):
+                    obj.ViewObject.ShapeColor = tuple(colors[pid][0:3])
+                if hasattr(obj.ViewObject,"Transparency"):
+                    obj.ViewObject.Transparency = colors[pid][3]
 
             # if preferences['DEBUG'] is on, recompute after each shape
             if preferences['DEBUG']: FreeCAD.ActiveDocument.recompute()
diff --git a/src/Mod/Arch/importIFCHelper.py b/src/Mod/Arch/importIFCHelper.py
index d825142314..74e346e2ac 100644
--- a/src/Mod/Arch/importIFCHelper.py
+++ b/src/Mod/Arch/importIFCHelper.py
@@ -347,6 +347,7 @@ def getColorFromStyledItem(styled_item):
         return None
 
     rgb_color = None
+    transparency = None
 
     # print(styled_item)
     # The IfcStyledItem holds presentation style information for products,
@@ -370,7 +371,11 @@ def getColorFromStyledItem(styled_item):
             # never seen an ifc with more than one Styles in IfcStyledItem
     else:
         # get the IfcPresentationStyleAssignment, there should only be one, see above
-        assign_style = styled_item.Styles[0]
+        if styled_item.Styles[0].is_a('IfcPresentationStyleAssignment'):
+            assign_style = styled_item.Styles[0]
+        else:
+            # IfcPresentationStyleAssignment is deprecated in IFC4.
+            assign_style = styled_item
         # print(assign_style)  # IfcPresentationStyleAssignment
 
         # IfcPresentationStyleAssignment can hold various kinde and count of styles
@@ -380,6 +385,10 @@ def getColorFromStyledItem(styled_item):
             # print(assign_style.Styles[0].Styles[0])  # IfcSurfaceStyleRendering
             rgb_color = assign_style.Styles[0].Styles[0].SurfaceColour  # IfcColourRgb
             # print(rgb_color)
+            if assign_style.Styles[0].Styles[0].is_a('IfcSurfaceStyleShading') \
+                    and hasattr(assign_style.Styles[0].Styles[0], 'Transparency') \
+                    and assign_style.Styles[0].Styles[0].Transparency:
+                transparency = assign_style.Styles[0].Styles[0].Transparency * 100
         elif assign_style.Styles[0].is_a("IfcCurveStyle"):
             if (
                 len(assign_style.Styles) == 2
@@ -398,7 +407,8 @@ def getColorFromStyledItem(styled_item):
                 rgb_color = assign_style.Styles[0].CurveColour
 
     if rgb_color is not None:
-        col = rgb_color.Red, rgb_color.Green, rgb_color.Blue
+        col = [rgb_color.Red, rgb_color.Green, rgb_color.Blue]
+        col.append(int(transparency) if transparency else 0)
         # print(col)
     else:
         col = None