Fix bug: SketchUp model can't be saved...

source/pbr/load.rb

@@ -22,6 +22,7 @@
 
 require 'sketchup'
 require 'pbr/app_observer'
+require 'pbr/model_observer'
 require 'pbr/menu'
 require 'pbr/toolbar'
 require 'pbr/viewport'
@@ -31,6 +32,8 @@ module PBR
 
   Sketchup.add_observer(AppObserver.new)
 
+  Sketchup.active_model.add_observer(ModelObserver.new)
+
   # Material Editor is not open yet.
   SESSION[:mat_editor_open?] = false
 

source/pbr/model_observer.rb

@@ -0,0 +1,52 @@
+# Physically-Based Rendering extension for SketchUp 2017 or newer.
+# Copyright: © 2019 Samuel Tallet <samuel.tallet arobase gmail.com>
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3.0 of the License, or
+# (at your option) any later version.
+# 
+# If you release a modified version of this program TO THE PUBLIC,
+# the GPL requires you to MAKE THE MODIFIED SOURCE CODE AVAILABLE
+# to the program's users, UNDER THE GPL.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+# 
+# Get a copy of the GPL here: https://www.gnu.org/licenses/gpl.html
+
+raise 'The PBR plugin requires at least Ruby 2.2.0 or SketchUp 2017.'\
+  unless RUBY_VERSION.to_f >= 2.2 # SketchUp 2017 includes Ruby 2.2.4.
+
+require 'sketchup'
+require 'pbr/viewport'
+
+# PBR plugin namespace.
+module PBR
+
+  # Observes SketchUp model events and reacts.
+  class ModelObserver < Sketchup::ModelObserver
+
+    # rubocop: disable MethodName
+
+    # Before a SketchUp model is saved to disk.
+    def onPreSaveModel(_model)
+
+      Viewport.close
+
+    end
+
+    # After a SketchUp model has been saved to disk.
+    def onPostSaveModel(_model)
+
+      Viewport.open
+
+    end
+
+    # rubocop: enable MethodName
+
+  end
+
+end