From 78b62e13d1f99124f503e5920ed792fdf74e06c1 Mon Sep 17 00:00:00 2001
From: Matthias Koefferlein <matthias@klayout.de>
Date: Mon, 1 Dec 2025 18:26:22 +0100
Subject: [PATCH] Handling of guiding shape layers - prevent the properties
 dialogs from changing it

---
 src/edt/edt/edtPropertiesPageUtils.cc |  7 ++++++-
 src/edt/edt/edtPropertiesPageUtils.h  |  2 ++
 src/edt/edt/edtPropertiesPages.cc     | 14 ++++++++++++--
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/src/edt/edt/edtPropertiesPageUtils.cc b/src/edt/edt/edtPropertiesPageUtils.cc
index b79b56b78..89cc47dcf 100644
--- a/src/edt/edt/edtPropertiesPageUtils.cc
+++ b/src/edt/edt/edtPropertiesPageUtils.cc
@@ -129,12 +129,17 @@ ChangeLayerApplicator::ChangeLayerApplicator (unsigned int cv_index, unsigned in
 db::Shape ChangeLayerApplicator::do_apply (db::Shapes & /*shapes*/, const db::Shape &shape, double /*dbu*/, unsigned int cv_index, unsigned int layer, bool /*relative*/) const
 {
   db::Shape s = shape;
-  if (m_cv_index == cv_index && layer != m_new_layer) {
+  if (m_cv_index == cv_index && layer != m_new_layer && m_skipped_layers.find (layer) == m_skipped_layers.end ()) {
     s.set_layer (m_new_layer);
   }
   return s;
 }
 
+void ChangeLayerApplicator::skip_layer (unsigned int l)
+{
+  m_skipped_layers.insert (l);
+}
+
 // -------------------------------------------------------------------------
 //  BoxDimensionsChangeApplicator implementation
 
diff --git a/src/edt/edt/edtPropertiesPageUtils.h b/src/edt/edt/edtPropertiesPageUtils.h
index 723e05f7d..ea724e763 100644
--- a/src/edt/edt/edtPropertiesPageUtils.h
+++ b/src/edt/edt/edtPropertiesPageUtils.h
@@ -125,9 +125,11 @@ public:
 
   bool supports_relative_mode () const { return false; }
   db::Shape do_apply (db::Shapes &shapes, const db::Shape &shape, double dbu, unsigned int cv_index, unsigned int layer, bool relative) const;
+  void skip_layer (unsigned int l);
 
 private:
   unsigned int m_cv_index, m_new_layer;
+  std::set<unsigned int> m_skipped_layers;
 };
 
 /**
diff --git a/src/edt/edt/edtPropertiesPages.cc b/src/edt/edt/edtPropertiesPages.cc
index b538775f6..cb43c96e5 100644
--- a/src/edt/edt/edtPropertiesPages.cc
+++ b/src/edt/edt/edtPropertiesPages.cc
@@ -281,7 +281,10 @@ ShapePropertiesPage::do_apply (bool current_only, bool relative, bool commit)
 
     int new_layer = layer_selector ()->current_layer ();
     if (new_layer >= 0 && int (pos->layer ()) != new_layer) {
-      applicator.reset (new CombinedChangeApplicator (applicator.release (), new ChangeLayerApplicator (cv_index, (unsigned int) new_layer)));
+      unsigned int gs_layer = cv->layout ().guiding_shape_layer ();
+      ChangeLayerApplicator *cla = new ChangeLayerApplicator (cv_index, (unsigned int) new_layer);
+      cla->skip_layer (gs_layer);
+      applicator.reset (new CombinedChangeApplicator (applicator.release (), cla));
     }
   }
 
@@ -425,10 +428,17 @@ ShapePropertiesPage::update_shape ()
 
   const lay::CellView &cv = view ()->cellview (pos->cv_index ());
   double dbu = cv->layout ().dbu ();
+  unsigned int gs_layer = cv->layout ().guiding_shape_layer ();
 
   m_enable_cb_callback = false;
   layer_selector ()->set_view (view (), pos->cv_index (), true);
-  layer_selector ()->set_current_layer (pos->layer ());
+  if (pos->layer () == gs_layer) {
+    layer_selector ()->setEnabled (false);
+    layer_selector ()->set_current_layer (-1);
+  } else {
+    layer_selector ()->setEnabled (true);
+    layer_selector ()->set_current_layer (pos->layer ());
+  }
   m_enable_cb_callback = true;
 
   std::string cell_str;