WIP: expose a new method of PCellDeclaration called 'wants_lazy_evaluation'

src/db/db/dbPCellDeclaration.h

@@ -429,6 +429,17 @@ public:
     return db::Trans ();
   }
 
+  /**
+   *  @brief Returns a value indicating that the PCell wants lazy evaluation
+   *
+   *  In lazy evaluation mode, the PCell is not immediately updated when a parameter is changed in the UI, but only when it is requested
+   *  to be updated.
+   */
+  virtual bool wants_lazy_evaluation () const
+  {
+    return false;
+  }
+
   /**
    *  @brief Gets the Layout object the PCell is registered inside or NULL if it is not registered
    */

src/db/db/gsiDeclDbLibrary.cc

@@ -276,6 +276,7 @@ Class<db::PCellDeclaration> decl_PCellDeclaration_Native ("db", "PCellDeclaratio
   gsi::method ("can_create_from_shape", &db::PCellDeclaration::can_create_from_shape) +
   gsi::method ("parameters_from_shape", &db::PCellDeclaration::parameters_from_shape) +
   gsi::method ("transformation_from_shape", &db::PCellDeclaration::transformation_from_shape) +
+  gsi::method ("wants_lazy_evaluation", &db::PCellDeclaration::wants_lazy_evaluation) +
   gsi::method ("display_text", &db::PCellDeclaration::get_display_name) +
   gsi::method ("layout", &db::PCellDeclaration::layout,
     "@brief Gets the Layout object the PCell is registered in or nil if it is not registered yet.\n"
@@ -407,6 +408,20 @@ public:
     }
   }
 
+  bool wants_lazy_evaluation_fb () const
+  {
+    return db::PCellDeclaration::wants_lazy_evaluation ();
+  }
+
+  virtual bool wants_lazy_evaluation () const
+  {
+    if (cb_wants_lazy_evaluation.can_issue ()) {
+      return cb_wants_lazy_evaluation.issue<db::PCellDeclaration, bool> (&db::PCellDeclaration::wants_lazy_evaluation);
+    } else {
+      return db::PCellDeclaration::wants_lazy_evaluation ();
+    }
+  }
+
   std::string get_display_name_fb (const db::pcell_parameters_type &parameters) const
   {
     return db::PCellDeclaration::get_display_name (parameters);
@@ -427,6 +442,7 @@ public:
   gsi::Callback cb_can_create_from_shape;
   gsi::Callback cb_parameters_from_shape;
   gsi::Callback cb_transformation_from_shape;
+  gsi::Callback cb_wants_lazy_evaluation;
   gsi::Callback cb_coerce_parameters;
   gsi::Callback cb_get_display_name;
 };
@@ -507,6 +523,16 @@ Class<PCellDeclarationImpl> decl_PCellDeclaration (decl_PCellDeclaration_Native,
     "it will use this method to derive the transformation for the PCell instance that will replace the shape. "
     "See also \\parameters_from_shape and \\can_create_from_shape."
   ) +
+  gsi::callback ("wants_lazy_evaluation", &PCellDeclarationImpl::wants_lazy_evaluation, &PCellDeclarationImpl::cb_wants_lazy_evaluation,
+    "@brief Gets a value indicating whether the PCell wants lazy evaluation\n"
+    "In lazy evaluation mode, the PCell UI will not immediately update the layout when a parameter is changed. "
+    "Instead, the user has to commit the changes in order to have the parameters updated. This is "
+    "useful for PCells that take a long time to compute.\n"
+    "\n"
+    "The default implementation will return 'false' indicating immediate updates.\n"
+    "\n"
+    "This method has been added in version 0.27.6.\n"
+  ) +
   gsi::callback ("display_text", &PCellDeclarationImpl::get_display_name, &PCellDeclarationImpl::cb_get_display_name, gsi::arg ("parameters"),
     "@brief Returns the display text for this PCell given a certain parameter set\n"
     "Reimplement this method to create a distinct display text for a PCell variant with \n"

src/edt/edt/edtPCellParametersPage.cc

@@ -227,7 +227,7 @@ PCellParametersPage::init ()
 bool
 PCellParametersPage::lazy_evaluation ()
 {
-  return false; // @@@
+  return mp_pcell_decl.get () && mp_pcell_decl->wants_lazy_evaluation ();
 }
 
 void

src/lay/lay/macro_templates/pcell.lym

@@ -71,6 +71,13 @@ module PCellLibModule
     #   TODO: return a RBA::Trans object for the initial transformation of
     #   the instance
     # end
+    #
+    # optional:
+    # def wants_lazy_evaluation
+    #   TODO: return "true" here if the PCell takes a long time to compute.
+    #   In lazy mode, the user has to acknowledge parameter changes before 
+    #   they are executed.
+    # end
     
   end
   

src/lay/lay/macro_templates/pcell_python.lym

@@ -54,6 +54,12 @@ class PCell(pya.PCellDeclarationHelper):
   # def transformation_from_shape_impl(self):
   #   TODO: return a RBA::Trans object for the initial transformation of
   #   the instance
+  # 
+  # optional:
+  # def wants_lazy_evaluation(self):
+  #   TODO: return "True" here if the PCell takes a long time to compute.
+  #   In lazy mode, the user has to acknowledge parameter changes before 
+  #   they are executed.
   
 # TODO: add more PCell classes ..