From 553102c4eefe89cd08cf2aff6fef68c946e21aca Mon Sep 17 00:00:00 2001
From: Filip Sykala <filip.sykala@prusa3d.cz>
Date: Thu, 16 Dec 2021 15:57:32 +0100
Subject: [PATCH] Fix reselect in flattening

---
 src/slic3r/GUI/Gizmos/GLGizmoFlatten.cpp | 35 +++++++++++++++---------
 src/slic3r/GUI/Gizmos/GLGizmoFlatten.hpp |  2 +-
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/src/slic3r/GUI/Gizmos/GLGizmoFlatten.cpp b/src/slic3r/GUI/Gizmos/GLGizmoFlatten.cpp
index 53eb1bb8b..08c2e2912 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoFlatten.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoFlatten.cpp
@@ -23,23 +23,32 @@ bool GLGizmoFlatten::on_mouse(const wxMouseEvent &mouse_event)
     if (mouse_event.Moving()) {
         // only for sure 
         m_mouse_left_down = false;
-
-        if (m_hover_id != -1) m_parent.set_as_dirty();
         return false;
     }
-    if (mouse_event.LeftDown() && m_hover_id != -1) {
-        Selection &selection = m_parent.get_selection();
-        if (selection.is_single_full_instance()) {
-            // Rotate the object so the normal points downward:
-            selection.flattening_rotate(m_planes[m_hover_id].normal);
-            m_parent.do_rotate(L("Gizmo-Place on Face"));
+    if (mouse_event.LeftDown()) {
+        if (m_hover_id != -1) {
+            m_mouse_left_down = true;
+            Selection &selection = m_parent.get_selection();
+            if (selection.is_single_full_instance()) {
+                // Rotate the object so the normal points downward:
+                selection.flattening_rotate(m_planes[m_hover_id].normal);
+                m_parent.do_rotate(L("Gizmo-Place on Face"));
+            }
+            return true;
         }
-        m_mouse_left_down = true;
-        return true;
-    } else if (m_mouse_left_down && mouse_event.LeftUp()) {
-        // responsible for mouse left up
+
+        // fix: prevent restart gizmo when reselect object
+        // take responsibility for left up
+        if (m_parent.get_first_hover_volume_idx() >= 0) m_mouse_left_down = true;
+        
+    } else if (mouse_event.LeftUp()) {
+        if (m_mouse_left_down) {
+            // responsible for mouse left up after selecting plane
+            m_mouse_left_down = false;
+            return true;
+        }
+    } else if (mouse_event.Leaving()) {
         m_mouse_left_down = false;
-        return true;
     }
     return false;
 }
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoFlatten.hpp b/src/slic3r/GUI/Gizmos/GLGizmoFlatten.hpp
index bddf829c4..dcb9e48ba 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoFlatten.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoFlatten.hpp
@@ -33,7 +33,7 @@ private:
     Vec3d m_first_instance_mirror;
 
     std::vector<PlaneData> m_planes;
-    bool m_mouse_left_down = false;
+    bool m_mouse_left_down = false; // for detection left_up of this gizmo
     bool m_planes_valid = false;
     const ModelObject* m_old_model_object = nullptr;
     std::vector<const Transform3d*> instances_matrices;