Have Print::apply_config() return true if any step was invalidated

lib/Slic3r/Print.pm

@@ -43,13 +43,17 @@ sub apply_config {
     # apply variables to placeholder parser
     $self->placeholder_parser->apply_config($config);
     
+    my $invalidated = 0;
+    
     # handle changes to print config
     my $print_diff = $self->config->diff($config);
     if (@$print_diff) {
         $self->config->apply_dynamic($config);
         
-        $self->invalidate_all_steps
+        my $res;
+        $res = $self->invalidate_all_steps
             if !$self->invalidate_state_by_config_options($print_diff);
+        $invalidated = 1 if $res;
     }
     
     # handle changes to object config defaults
@@ -69,8 +73,11 @@ sub apply_config {
         my $diff = $object->config->diff($new);
         if (@$diff) {
             $object->config->apply($new);
-            $object->invalidate_all_steps
+            
+            my $res;
+            $res = $object->invalidate_all_steps
                 if !$object->invalidate_state_by_config_options($diff);
+            $invalidated = 1 if $res;
         }
     }
     
@@ -124,8 +131,10 @@ sub apply_config {
                 if (@$region_config_diff) {
                     $region->config->apply($new);
                     foreach my $o (@{$self->objects}) {
-                        $o->invalidate_all_steps
+                        my $res;
+                        $res = $o->invalidate_all_steps
                             if !$o->invalidate_state_by_config_options($region_config_diff);
+                        $invalidated = 1 if $res;
                     }
                 }
             }
@@ -139,7 +148,10 @@ sub apply_config {
         my @model_objects = map $_->model_object, @{$self->objects};
         $self->clear_objects;
         $self->add_model_object($_) for @model_objects;
+        $invalidated = 1;
     }
+    
+    return $invalidated;
 }
 
 sub has_support_material {

xs/src/Print.cpp

@@ -40,11 +40,13 @@ PrintState<StepClass>::invalidate(StepClass step)
 }
 
 template <class StepClass>
-void
+bool
 PrintState<StepClass>::invalidate_all()
 {
+    bool empty = this->_started.empty();
     this->_started.clear();
     this->_done.clear();
+    return !empty;  // return true if we invalidated something
 }
 
 template class PrintState<PrintStep>;

xs/src/Print.hpp

@@ -36,7 +36,7 @@ class PrintState
     void set_started(StepType step);
     void set_done(StepType step);
     void invalidate(StepType step);
-    void invalidate_all();
+    bool invalidate_all();
 };
 
 // A PrintRegion object represents a group of volumes to print

xs/xsp/Print.xsp

@@ -87,8 +87,8 @@ _constant()
     
     bool invalidate_state_by_config_options(std::vector<std::string> opt_keys);
     void invalidate_step(PrintObjectStep step);
-    void invalidate_all_steps()
-        %code%{ THIS->state.invalidate_all(); %};
+    bool invalidate_all_steps()
+        %code%{ RETVAL = THIS->state.invalidate_all(); %};
     bool step_done(PrintObjectStep step)
         %code%{ RETVAL = THIS->state.done(step); %};
     void set_step_done(PrintObjectStep step)
@@ -142,8 +142,8 @@ _constant()
     
     bool invalidate_state_by_config_options(std::vector<std::string> opt_keys);
     void invalidate_step(PrintStep step);
-    void invalidate_all_steps()
-        %code%{ THIS->state.invalidate_all(); %};
+    bool invalidate_all_steps()
+        %code%{ RETVAL = THIS->state.invalidate_all(); %};
     bool step_done(PrintStep step)
         %code%{ RETVAL = THIS->state.done(step); %};
     void set_step_done(PrintStep step)