Fixed issue #2174 - two new events

1.) LayoutView#on_current_layer_changed(iter)
"iter" is the iterator pointing to the new current layer
Is called after the current layer (the highlighted layer)
changed.

2.) LayoutView#on_selected_layers_changed
Is called after the selected layer set changed.

src/laybasic/laybasic/gsiDeclLayLayoutViewBase.cc

@@ -1781,6 +1781,21 @@ LAYBASIC_PUBLIC Class<lay::LayoutViewBase> decl_LayoutViewBase (decl_Dispatcher,
     "\n"
     "This event was introduced in version 0.25.\n"
   ) +
+  gsi::event ("on_current_layer_changed", static_cast<tl::event<const lay::LayerPropertiesConstIterator &> (lay::LayoutViewBase::*)> (&lay::LayoutViewBase::current_layer_changed_event), gsi::arg ("new_layer"),
+    "@brief An event indicating the current layer has changed\n"
+    "@param new_layer The layer iterator of the new current layer\n"
+    "\n"
+    "This event is triggered after the current layer was changed - i.e. a new layer is selected in the layer list.\n"
+    "\n"
+    "This event was introduced in version 0.30.5.\n"
+  ) +
+  gsi::event ("on_selected_layers_changed", static_cast<tl::Event (lay::LayoutViewBase::*)> (&lay::LayoutViewBase::selected_layers_changed_event),
+    "@brief An event indicating the layer selection has changed\n"
+    "\n"
+    "This event is triggered after the layer selection was changed - i.e. layers got selected or unselected.\n"
+    "\n"
+    "This event was introduced in version 0.30.5.\n"
+  ) +
   gsi::event ("on_cell_visibility_changed", static_cast<tl::Event (lay::LayoutViewBase::*)> (&lay::LayoutViewBase::cell_visibility_changed_event),
     "@brief An event indicating that the visibility of one or more cells has changed\n"
     "\n"

src/laybasic/laybasic/layLayoutViewBase.cc

@@ -5643,7 +5643,13 @@ LayoutViewBase::current_layer_changed_slot (const lay::LayerPropertiesConstItera
   current_layer_changed_event (iter);
 }
 
-void 
+void
+LayoutViewBase::selected_layers_changed_slot ()
+{
+  selected_layers_changed_event ();
+}
+
+void
 LayoutViewBase::add_new_layers (const LayerState &state)
 {
   std::vector <lay::ParsedLayerSource> actual;

src/laybasic/laybasic/layLayoutViewBase.h

@@ -786,9 +786,17 @@ public:
 
   /**
    *  @brief An event signalling that the current layer has changed
+   *
+   *  The event is emitted when the user changes the current layer.
    */
   tl::event<const lay::LayerPropertiesConstIterator &> current_layer_changed_event;
 
+  /**
+   *  @brief An event signalling that the selected layers have changed
+   *
+   *  The event is emitted when the user changes the selection.
+   */
+  tl::Event selected_layers_changed_event;
 
   /**
    *  @brief An event signalling that the visibility of some cells has changed
@@ -2794,6 +2802,11 @@ public:
    */
   void current_layer_changed_slot (const lay::LayerPropertiesConstIterator &iter);
 
+  /**
+   *  @brief Called when the layer selection changed
+   */
+  void selected_layers_changed_slot ();
+
   //  zoom slots
   void zoom_fit ();
   void zoom_fit_sel ();