Selection: track selection order

common/tool/selection.cpp

@@ -38,7 +38,10 @@ void SELECTION::Add( EDA_ITEM* aItem )
 
     if( i == m_items.end() || *i > aItem )
     {
+        m_itemsOrders.insert( m_itemsOrders.begin() + std::distance( m_items.begin(), i ),
+                              m_orderCounter );
         m_items.insert( i, aItem );
+        m_orderCounter++;
         m_lastAddedItem = aItem;
     }
 }
@@ -50,6 +53,7 @@ void SELECTION::Remove( EDA_ITEM* aItem )
 
     if( !( i == m_items.end() || *i > aItem ) )
     {
+        m_itemsOrders.erase( m_itemsOrders.begin() + std::distance( m_items.begin(), i ) );
         m_items.erase( i );
 
         if( aItem == m_lastAddedItem )
@@ -193,3 +197,33 @@ bool SELECTION::OnlyContains( std::vector<KICAD_T> aList ) const
                 return ok;
             } ) );
 }
+
+
+const std::vector<EDA_ITEM*> SELECTION::GetItemsSortedBySelectionOrder() const
+{
+    using pairedIterators =
+            std::pair<decltype( m_items.begin() ), decltype( m_itemsOrders.begin() )>;
+
+    // Create a vector of all {selection item, selection order} iterator pairs
+    std::vector<pairedIterators> pairs;
+    auto                         item = m_items.begin();
+    auto                         order = m_itemsOrders.begin();
+
+    for( ; item != m_items.end(); ++item, ++order )
+        pairs.emplace_back( make_pair( item, order ) );
+
+    // Sort the pairs by the selection order
+    std::sort( pairs.begin(), pairs.end(),
+               []( pairedIterators const& a, pairedIterators const& b )
+               {
+                   return *a.second < *b.second;
+               } );
+
+    // Make a vector of just the sortedItems
+    std::vector<EDA_ITEM*> sortedItems;
+
+    for( pairedIterators sortedItem : pairs )
+        sortedItems.emplace_back( *sortedItem.first );
+
+    return sortedItems;
+}

include/tool/selection.h

@@ -42,21 +42,26 @@ public:
     {
         m_isHover = false;
         m_lastAddedItem = nullptr;
+        m_orderCounter = 0;
     }
 
     SELECTION( const SELECTION& aOther ) :
             KIGFX::VIEW_GROUP::VIEW_GROUP()
     {
         m_items = aOther.m_items;
+        m_itemsOrders = aOther.m_itemsOrders;
         m_isHover = aOther.m_isHover;
         m_lastAddedItem = aOther.m_lastAddedItem;
+        m_orderCounter = aOther.m_orderCounter;
     }
 
     SELECTION& operator= ( const SELECTION& aOther )
     {
         m_items = aOther.m_items;
+        m_itemsOrders = aOther.m_itemsOrders;
         m_isHover = aOther.m_isHover;
         m_lastAddedItem = aOther.m_lastAddedItem;
+        m_orderCounter = aOther.m_orderCounter;
         return *this;
     }
 
@@ -85,6 +90,8 @@ public:
     virtual void Clear() override
     {
         m_items.clear();
+        m_itemsOrders.clear();
+        m_orderCounter = 0;
     }
 
     virtual unsigned int GetSize() const override
@@ -157,6 +164,8 @@ public:
         return sorted_items;
     }
 
+    const std::vector<EDA_ITEM*> GetItemsSortedBySelectionOrder() const;
+
     /// Returns the center point of the selection area bounding box.
     virtual VECTOR2I GetCenter() const;
 
@@ -266,6 +275,8 @@ public:
 protected:
     std::optional<VECTOR2I>         m_referencePoint;
     std::deque<EDA_ITEM*> m_items;
+    std::deque<int>       m_itemsOrders;
+    int                   m_orderCounter;
     EDA_ITEM*             m_lastAddedItem;
     bool                  m_isHover;