Use paths relative to .ifc instead of .blend choosing texture paths

Texture path file dialog is also filtering image files now.

Removed subtype from `FILE_PATH` from all related props since `layout.prop()` for those props starts file dialog that cannot return path relative to .ifc. It can return path relative to .blend - though it can be processed in props update to convert to relative to .ifc, this doesn't allow setting relative paths if .blend is not saved. Therefore, I've created a separate operator.

add

src/blenderbim/blenderbim/bim/module/style/__init__.py

@@ -25,6 +25,7 @@ classes = (
     operator.AddStyle,
     operator.BrowseExternalStyle,
     operator.ClearTextureMapPath,
+    operator.ChooseTextureMapPath,
     operator.DisableAddingPresentationStyle,
     operator.DisableEditingExternalStyle,
     operator.DisableEditingStyle,

src/blenderbim/blenderbim/bim/module/style/operator.py

@@ -410,6 +410,46 @@ class SelectByStyle(bpy.types.Operator, tool.Ifc.Operator):
         core.select_by_style(tool.Style, tool.Spatial, style=tool.Ifc.get().by_id(self.style))
 
 
+class ChooseTextureMapPath(bpy.types.Operator):
+    bl_idname = "bim.choose_texture_map_path"
+    bl_label = "Choose Texture Map Path"
+    bl_options = {"REGISTER", "UNDO"}
+    texture_map_prop: bpy.props.StringProperty(default="")
+
+    use_relative_path: bpy.props.BoolProperty(name="Use Relative Path", default=True)
+    filepath: bpy.props.StringProperty(
+        name="File Path", description="Filepath used to import from", maxlen=1024, default="", subtype="FILE_PATH"
+    )
+    filter_image: bpy.props.BoolProperty(default=True, options={"HIDDEN", "SKIP_SAVE"})
+    filter_folder: bpy.props.BoolProperty(default=True, options={"HIDDEN", "SKIP_SAVE"})
+
+    def invoke(self, context, event):
+        context.window_manager.fileselect_add(self)
+        return {"RUNNING_MODAL"}
+
+    @classmethod
+    def poll(cls, context):
+        poll = getattr(context, "material", None)
+        if not poll:
+            cls.poll_message_set("Select a material")
+        return poll
+
+    def execute(self, context):
+        if not self.texture_map_prop:
+            self.report({"ERROR"}, "Provide a texture map")
+            return {"CANCELLED"}
+
+        abs_path = Path(self.filepath)
+        if self.use_relative_path:
+            image_filepath = abs_path.relative_to(Path(tool.Ifc.get_path()).parent)
+        else:
+            image_filepath = abs_path
+
+        props = context.material.BIMStyleProperties
+        setattr(props, self.texture_map_prop, image_filepath.as_posix())
+        return {"FINISHED"}
+
+
 class ClearTextureMapPath(bpy.types.Operator):
     bl_idname = "bim.clear_texture_map_path"
     bl_label = "Clear Texture Map Path"

src/blenderbim/blenderbim/bim/module/style/prop.py

@@ -269,21 +269,18 @@ class BIMStyleProperties(PropertyGroup):
         name="NormalMap",
         maxlen=1024,
         default="",
-        subtype="FILE_PATH",
         update=update_shader_graph,
     )
     emissive_path: bpy.props.StringProperty(
         name="Emissive",
         maxlen=1024,
         default="",
-        subtype="FILE_PATH",
         update=update_shader_graph,
     )
     metallic_roughness_path: bpy.props.StringProperty(
         name="Metallic/Roughness",
         maxlen=1024,
         default="",
-        subtype="FILE_PATH",
         update=update_shader_graph,
         description="Green Channel = Roughness,\nBlue Channel = Metallic",
     )
@@ -291,7 +288,6 @@ class BIMStyleProperties(PropertyGroup):
         name="Diffuse",
         maxlen=1024,
         default="",
-        subtype="FILE_PATH",
         update=update_shader_graph,
     )
     occlusion_path: bpy.props.StringProperty(
@@ -299,6 +295,5 @@ class BIMStyleProperties(PropertyGroup):
         description="Note that occlusion isn't actually used in Blender shader, we're just storing the data",
         maxlen=1024,
         default="",
-        subtype="FILE_PATH",
         update=update_shader_graph,
     )

src/blenderbim/blenderbim/bim/module/style/ui.py

@@ -417,15 +417,14 @@ class BIM_PT_STYLE_GRAPH(Panel):
         def add_texture_path(path_name):
             row = layout.row(align=True)
             row.prop(props, path_name)
-            op = row.operator("bim.clear_texture_map_path", text="", icon="X")
+            op_path = row.operator("bim.choose_texture_map_path", text="", icon="FILEBROWSER")
-            op.texture_map_prop = path_name
+            op_clear = row.operator("bim.clear_texture_map_path", text="", icon="X")
+            op_path.texture_map_prop = op_clear.texture_map_prop = path_name
 
         layout.separator()
         texture_maps = TEXTURE_MAPS_BY_METHODS.get(props.reflectance_method, [])
         if not texture_maps:
             return
-        if not bpy.data.filepath:
-            layout.label(text="Save .blend file to keep relative paths", icon="ERROR")
 
         layout.prop(props, "uv_mode")
         layout.label(text="Texture Maps:")