WIP: debugging, added const version of parameter getter

src/db/db/gsiDeclDbPCellDeclaration.cc

@@ -168,6 +168,13 @@ Class<db::ParameterStates> decl_PCellParameterStates ("db", "PCellParameterState
     "\n"
     "This will return a \\PCellParameterState object that can be used to manipulate the "
     "parameter state."
+  ) +
+  gsi::method ("parameter", static_cast<const db::ParameterState & (db::ParameterStates::*) (const std::string &name) const> (&db::ParameterStates::parameter), gsi::arg ("name"),
+    "@brief Gets the parameter by name (const version)\n"
+    "\n"
+    "This will return a \\PCellParameterState object which cannot be manipulated, but read.\n"
+    "\n"
+    "The const flavor has been introduced in version 0.30.11."
   ),
   "@brief Provides access to the parameter states inside a 'callback' implementation of a PCell\n"
   "\n"

src/edt/edt/edtPCellParametersPageBase.cc

@@ -392,6 +392,9 @@ PCellParametersPageBase::State
 PCellParametersPageBase::get_state ()
 {
   State s;
+  if (! mp_page_widget) {
+    return s;
+  }
 
   s.valid = true;
   s.v_scroll_position = mp_parameters_area->verticalScrollBar ()->value ();
@@ -409,7 +412,7 @@ PCellParametersPageBase::get_state ()
 void
 PCellParametersPageBase::set_state (const State &s)
 {
-  if (s.valid) {
+  if (s.valid && mp_page_widget) {
 
     mp_parameters_area->verticalScrollBar ()->setValue (s.v_scroll_position);
     mp_parameters_area->horizontalScrollBar ()->setValue (s.h_scroll_position);

testdata/ruby/dbPCells.rb

@@ -1082,6 +1082,34 @@ class DBPCellParameterStates_TestClass < TestBase
 
   end
 
+  def test_2
+
+    pss = RBA::PCellParameterStates::new
+    assert_equal(pss.has_parameter?("a"), false)
+    pa = pss.parameter("a")
+    assert_equal(pss.has_parameter?("a"), true)
+
+    # manipulating the value is reflected in the states collection
+    pa.value = 17
+    assert_equal(pss.parameter("a").value, 17)
+
+    pss_const = pss._to_const_object
+    assert_equal(pss_const._is_const_object?, true)
+
+    assert_equal(pss_const.has_parameter?("a"), true)
+    pa = pss_const.parameter("a")
+    assert_equal(pa.value, 17)
+
+    begin
+      # can't manipulate the const value
+      pa.value = 18
+      assert_equal(true, false)
+    rescue => ex
+      # goes here
+    end
+
+  end
+
 end
 
 load("test_epilogue.rb")