From 427c7c702792439966d8a8d2ffb8f580bae8f6db Mon Sep 17 00:00:00 2001
From: Joseph Lenox <lenox.joseph@gmail.com>
Date: Sat, 12 May 2018 16:58:29 -0500
Subject: [PATCH] Assign on_instances_moved and put a try/catch to not crash if
 it accidentally gets called while uninitialzed.

---
 src/GUI/Plater.cpp         | 2 ++
 src/GUI/Plater/Plate2D.cpp | 6 +++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/GUI/Plater.cpp b/src/GUI/Plater.cpp
index a33fa713e..4e299aaa6 100644
--- a/src/GUI/Plater.cpp
+++ b/src/GUI/Plater.cpp
@@ -60,6 +60,8 @@ Plater::Plater(wxWindow* parent, const wxString& title, std::shared_ptr<Settings
     canvas2D->on_select_object = std::function<void (ObjIdx obj_idx)>(on_select_object);
     canvas2D->on_double_click = std::function<void ()>(on_double_click);
     canvas2D->on_right_click = std::function<void (const wxPoint& pos)>([=](const wxPoint& pos){ on_right_click(canvas2D, pos); });
+    canvas2D->on_instances_moved = std::function<void ()>(on_instances_moved);
+
 
     canvas3D = new Plate3D(preview_notebook, wxDefaultSize, objects, model, config, settings);
     preview_notebook->AddPage(canvas3D, _("3D"));
diff --git a/src/GUI/Plater/Plate2D.cpp b/src/GUI/Plater/Plate2D.cpp
index 3e865086b..10f9122e5 100644
--- a/src/GUI/Plater/Plate2D.cpp
+++ b/src/GUI/Plater/Plate2D.cpp
@@ -212,7 +212,11 @@ void Plate2D::mouse_down(wxMouseEvent& e) {
 
 void Plate2D::mouse_up(wxMouseEvent& e) {
     if (e.LeftUp()) {
-        //if (this->drag_object.obj != -1 && this->drag_object.inst != -1) this->on_instances_moved();
+        try {
+            if (this->drag_object.obj != -1 && this->drag_object.inst != -1) this->on_instances_moved();
+        } catch (std::bad_function_call &ex) {
+            Slic3r::Log::error(LogChannel, L"On_instances_moved was not intialized to a function.");
+        }
         this->drag_start_pos = wxPoint(-1, -1);
         this->drag_object = {-1, -1};
         this->SetCursor(*wxSTANDARD_CURSOR);