Implemented disabling of Add buttons if next layer range couldn't be added

+ Fixed "Layer ranges" expand.

src/slic3r/GUI/GUI_ObjectLayers.cpp

@@ -156,8 +156,11 @@ void ObjectLayers::create_layers_list()
         const t_layer_height_range& range = layer.first;
         auto del_btn = new PlusMinusButton(m_parent, m_bmp_delete, range);
         del_btn->SetToolTip(_(L("Remove layer range")));
+
         auto add_btn = new PlusMinusButton(m_parent, m_bmp_add, range);
-        add_btn->SetToolTip(_(L("Add layer range")));
+        wxString tooltip = wxGetApp().obj_list()->can_add_new_range_after_current(range);
+        add_btn->SetToolTip(tooltip.IsEmpty() ? _(L("Add layer range")) : tooltip);
+        add_btn->Enable(tooltip.IsEmpty());
 
         auto sizer = create_layer(range, del_btn, add_btn);
         sizer->Add(del_btn, 0, wxRIGHT | wxLEFT, em_unit(m_parent));

src/slic3r/GUI/GUI_ObjectList.cpp

@@ -2978,6 +2978,40 @@ void ObjectList::add_layer_range_after_current(const t_layer_height_range curren
     select_item(layers_item);
 }
 
+wxString ObjectList::can_add_new_range_after_current(const t_layer_height_range current_range)
+{
+    wxString ret;
+    const int obj_idx = get_selected_obj_idx();
+    if (obj_idx < 0)
+        // This should not happen.
+        return ret;
+
+    t_layer_config_ranges& ranges = object(obj_idx)->layer_config_ranges;
+    auto it_range = ranges.find(current_range);
+    assert(it_range != ranges.end());
+    if (it_range == ranges.end())
+        // This shoudl not happen.
+        return ret;
+
+    auto it_next_range = it_range;
+    if (++it_next_range == ranges.end())
+        return ret;
+    
+    if (const std::pair<coordf_t, coordf_t>& next_range = it_next_range->first; current_range.second <= next_range.first)
+    {
+        if (current_range.second == next_range.first &&
+            next_range.second - next_range.first < get_min_layer_height(ranges.at(next_range).opt_int("extruder")))
+                ret = _(L("A difference between ranges is a less than minimum layer height."));
+    }
+    else
+        ret = _(L("End of current range is bigger then next one."));
+    
+    if (!ret.IsEmpty())
+        ret += "\n" + _(L("New range between them couldn't be added."));
+
+    return ret;
+}
+
 void ObjectList::add_layer_item(const t_layer_height_range& range, 
                                 const wxDataViewItem layers_item, 
                                 const int layer_idx /* = -1*/)
@@ -3048,12 +3082,10 @@ bool ObjectList::edit_layer_range(const t_layer_height_range& range, const t_lay
             add_layer_item(r.first, root_item);
     }
 
-    if (dont_update_ui)
-        return true;
+    if (!dont_update_ui)
+        select_item(sel_type&itLayer ? m_objects_model->GetItemByLayerRange(obj_idx, new_range) : root_item);
 
-    select_item(sel_type&itLayer ? m_objects_model->GetItemByLayerRange(obj_idx, new_range) : root_item);
     Expand(root_item);
-
     return true;
 }
 

src/slic3r/GUI/GUI_ObjectList.hpp

@@ -327,6 +327,7 @@ public:
     // may have been postponed from the "kill focus" event of a text field, if the focus was lost for the "add layer" button.
     // Rather providing the range by a value than by a reference, so that the memory referenced cannot be invalidated.
     void add_layer_range_after_current(const t_layer_height_range current_range);
+    wxString can_add_new_range_after_current( t_layer_height_range current_range);
     void add_layer_item (const t_layer_height_range& range, 
                          const wxDataViewItem layers_item, 
                          const int layer_idx = -1);