Refactoring of UnsavedChangesDialog:

Use std containers instead of wxWidgets containers.
Use unique_ptr for memory management.

src/slic3r/GUI/UnsavedChangesDialog.cpp

@@ -234,8 +234,8 @@ wxDataViewItem UnsavedChangesModel::AddPreset(Preset::Type type, wxString preset
 
 ModelNode* UnsavedChangesModel::AddOption(ModelNode* group_node, wxString option_name, wxString old_value, wxString new_value)
 {
-    ModelNode* option = new ModelNode(group_node, option_name, old_value, new_value);
+    group_node->Append(std::make_unique<ModelNode>(group_node, option_name, old_value, new_value));
-    group_node->Append(option);
+    ModelNode* option = group_node->GetChildren().back().get();
     wxDataViewItem group_item = wxDataViewItem((void*)group_node);
     ItemAdded(group_item, wxDataViewItem((void*)option));
 
@@ -245,8 +245,8 @@ ModelNode* UnsavedChangesModel::AddOption(ModelNode* group_node, wxString option
 
 ModelNode* UnsavedChangesModel::AddOptionWithGroup(ModelNode* category_node, wxString group_name, wxString option_name, wxString old_value, wxString new_value)
 {
-    ModelNode* group_node = new ModelNode(category_node, group_name);
+    category_node->Append(std::make_unique<ModelNode>(category_node, group_name));
-    category_node->Append(group_node);
+    ModelNode* group_node = category_node->GetChildren().back().get();
     ItemAdded(wxDataViewItem((void*)category_node), wxDataViewItem((void*)group_node));
 
     return AddOption(group_node, option_name, old_value, new_value);
@@ -255,8 +255,8 @@ ModelNode* UnsavedChangesModel::AddOptionWithGroup(ModelNode* category_node, wxS
 ModelNode* UnsavedChangesModel::AddOptionWithGroupAndCategory(ModelNode* preset_node, wxString category_name, wxString group_name, 
                                             wxString option_name, wxString old_value, wxString new_value, const std::string category_icon_name)
 {
-    ModelNode* category_node = new ModelNode(preset_node, category_name, category_icon_name);
+    preset_node->Append(std::make_unique<ModelNode>(preset_node, category_name, category_icon_name));
-    preset_node->Append(category_node);
+    ModelNode* category_node = preset_node->GetChildren().back().get();
     ItemAdded(wxDataViewItem((void*)preset_node), wxDataViewItem((void*)category_node));
 
     return AddOptionWithGroup(category_node, group_name, option_name, old_value, new_value);
@@ -278,14 +278,14 @@ wxDataViewItem UnsavedChangesModel::AddOption(Preset::Type type, wxString catego
     for (ModelNode* preset : m_preset_nodes)
         if (preset->type() == type)
         {
-            for (ModelNode* category : preset->GetChildren())
+            for (std::unique_ptr<ModelNode> &category : preset->GetChildren())
                 if (category->text() == category_name)
                 {
-                    for (ModelNode* group : category->GetChildren())
+                    for (std::unique_ptr<ModelNode> &group : category->GetChildren())
                         if (group->text() == group_name)
-                            return wxDataViewItem((void*)AddOption(group, option_name, old_value, new_value));
+                            return wxDataViewItem((void*)AddOption(group.get(), option_name, old_value, new_value));
                     
-                    return wxDataViewItem((void*)AddOptionWithGroup(category, group_name, option_name, old_value, new_value));
+                    return wxDataViewItem((void*)AddOptionWithGroup(category.get(), group_name, option_name, old_value, new_value));
                 }
 
             return wxDataViewItem((void*)AddOptionWithGroupAndCategory(preset, category_name, group_name, option_name, old_value, new_value, category_icon_name));
@@ -298,10 +298,10 @@ static void update_children(ModelNode* parent)
 {
     if (parent->IsContainer()) {
         bool toggle = parent->IsToggled();
-        for (ModelNode* child : parent->GetChildren()) {
+        for (std::unique_ptr<ModelNode> &child : parent->GetChildren()) {
             child->Toggle(toggle);
             child->UpdateEnabling();
-            update_children(child);
+            update_children(child.get());
         }
     }
 }
@@ -311,7 +311,7 @@ static void update_parents(ModelNode* node)
     ModelNode* parent = node->GetParent();
     if (parent) {
         bool toggle = false;
-        for (ModelNode* child : parent->GetChildren()) {
+        for (std::unique_ptr<ModelNode> &child : parent->GetChildren()) {
             if (child->IsToggled()) {
                 toggle = true;
                 break;
@@ -476,16 +476,10 @@ unsigned int UnsavedChangesModel::GetChildren(const wxDataViewItem& parent, wxDa
         return m_preset_nodes.size();
     }
 
-    if (node->GetChildCount() == 0)
+    for (std::unique_ptr<ModelNode> &child : node->GetChildren())
-        return 0;
+        array.Add(wxDataViewItem((void*)child.get()));
 
-    unsigned int count = node->GetChildren().GetCount();
+    return node->GetChildCount();
-    for (unsigned int pos = 0; pos < count; pos++) {
-        ModelNode* child = node->GetChildren().Item(pos);
-        array.Add(wxDataViewItem((void*)child));
-    }
-
-    return count;
 }
 
 
@@ -506,9 +500,9 @@ wxString UnsavedChangesModel::GetColumnType(unsigned int col) const
 static void rescale_children(ModelNode* parent)
 {
     if (parent->IsContainer()) {
-        for (ModelNode* child : parent->GetChildren()) {
+        for (std::unique_ptr<ModelNode> &child : parent->GetChildren()) {
             child->UpdateIcons();
-            rescale_children(child);
+            rescale_children(child.get());
         }
     }
 }

src/slic3r/GUI/UnsavedChangesDialog.hpp

@@ -20,7 +20,7 @@ namespace GUI{
 // ----------------------------------------------------------------------------
 
 class ModelNode;
-WX_DEFINE_ARRAY_PTR(ModelNode*, ModelNodePtrArray);
+using ModelNodePtrArray = std::vector<std::unique_ptr<ModelNode>>;
 
 // On all of 3 different platforms Bitmap+Text icon column looks different 
 // because of Markup text is missed or not implemented.
@@ -47,7 +47,7 @@ class ModelNode
     // needs to know in advance if a node is or _will be_ a container.
     // Thus implementing:
     //   bool IsContainer() const
-    //    { return m_children.GetCount()>0; }
+    //    { return m_children.size()>0; }
     // doesn't work with wxGTK when UnsavedChangesModel::AddToClassical is called
     // AND the classical node was removed (a new node temporary without children
     // would be added to the control)
@@ -87,15 +87,6 @@ public:
     // option node
     ModelNode(ModelNode* parent, const wxString& text, const wxString& old_value, const wxString& new_value);
 
-    ~ModelNode() {
-        // free all our children nodes
-        size_t count = m_children.GetCount();
-        for (size_t i = 0; i < count; i++) {
-            ModelNode* child = m_children[i];
-            delete child;
-        }
-    }
-
     bool                IsContainer() const         { return m_container; }
     bool                IsToggled() const           { return m_toggle; }
     void                Toggle(bool toggle = true)  { m_toggle = toggle; }
@@ -105,11 +96,10 @@ public:
 
     ModelNode*          GetParent()                 { return m_parent; }
     ModelNodePtrArray&  GetChildren()               { return m_children; }
-    ModelNode*          GetNthChild(unsigned int n) { return m_children.Item(n); }
+    ModelNode*          GetNthChild(unsigned int n) { return m_children[n].get(); }
-    unsigned int        GetChildCount() const       { return m_children.GetCount(); }
+    unsigned int        GetChildCount() const       { return m_children.size(); }
 
-    void Insert(ModelNode* child, unsigned int n)   { m_children.Insert(child, n); }
+    void Append(std::unique_ptr<ModelNode> child)   { m_children.emplace_back(std::move(child)); }
-    void Append(ModelNode* child)                   { m_children.Add(child); }
 
     void UpdateEnabling();
     void UpdateIcons();