pcbnew: Snap items to grouped layers

When moving a group of items, the allowed snapping layers should be each
layer in the group, not just the first item's LSET.

Fixes: lp:1830164
* https://bugs.launchpad.net/kicad/+bug/1830164

pcbnew/tools/edit_tool.cpp

@@ -268,7 +268,7 @@ int EDIT_TOOL::Move( const TOOL_EVENT& aEvent )
     if( m_dragging || selection.Empty() )
         return 0;
 
-    LSET item_layers = static_cast<BOARD_ITEM*>( selection.Front() )->GetLayerSet();
+    LSET item_layers = selection.GetSelectionLayers();
     bool unselect = selection.IsHover(); //N.B. This must be saved before the re-selection below
 
     // Now filter out locked pads.  We cannot do this in the first RequestSelection() as we need
@@ -408,18 +408,18 @@ int EDIT_TOOL::Move( const TOOL_EVENT& aEvent )
 
                     selection.SetReferencePoint( m_cursor );
                 }
-                else if( selection.Size() == 1 )
-                {
-                    // Set the current cursor position to the first dragged item origin, so the
-                    // movement vector could be computed later
-                    updateModificationPoint( selection );
-                    m_cursor = grid.BestDragOrigin( originalCursorPos, curr_item );
-                    grid.SetAuxAxes( true, m_cursor );
-                }
                 else
                 {
-                    updateModificationPoint( selection );
-                    m_cursor = grid.Align( m_cursor );
+                    std::vector<BOARD_ITEM*> items;
+
+                    for( auto item : selection.Items() )
+                        items.push_back( static_cast<BOARD_ITEM*>( item ) );
+
+                    // Set the current cursor position to the first dragged item origin, so the
+                    // movement vector could be computed later
+                    m_cursor = grid.BestDragOrigin( originalCursorPos, items );
+                    selection.SetReferencePoint( m_cursor );
+                    grid.SetAuxAxes( true, m_cursor );
                 }
 
                 controls->SetCursorPosition( m_cursor, false );

pcbnew/tools/grid_helper.cpp

@@ -167,10 +167,12 @@ VECTOR2I GRID_HELPER::AlignToSegment( const VECTOR2I& aPoint, const SEG& aSeg )
 }
 
 
-VECTOR2I GRID_HELPER::BestDragOrigin( const VECTOR2I &aMousePos, BOARD_ITEM* aItem )
+VECTOR2I GRID_HELPER::BestDragOrigin( const VECTOR2I &aMousePos, std::vector<BOARD_ITEM*>& aItems )
 {
     clearAnchors();
-    computeAnchors( aItem, aMousePos, true );
+
+    for( auto item : aItems )
+        computeAnchors( item, aMousePos, true );
 
     double worldScale = m_frame->GetCanvas()->GetGAL()->GetWorldScale();
     double lineSnapMinCornerDistance = 50.0 / worldScale;
@@ -211,7 +213,7 @@ VECTOR2I GRID_HELPER::BestDragOrigin( const VECTOR2I &aMousePos, BOARD_ITEM* aIt
 
 
 std::set<BOARD_ITEM*> GRID_HELPER::queryVisible( const BOX2I& aArea,
-        const std::vector<BOARD_ITEM*> aSkip ) const
+        const std::vector<BOARD_ITEM*>& aSkip ) const
 {
     std::set<BOARD_ITEM*> items;
     std::vector<KIGFX::VIEW::LAYER_ITEM_PAIR> selectedItems;
@@ -256,7 +258,7 @@ VECTOR2I GRID_HELPER::BestSnapAnchor( const VECTOR2I& aOrigin, BOARD_ITEM* aDrag
 
 
 VECTOR2I GRID_HELPER::BestSnapAnchor( const VECTOR2I& aOrigin, const LSET& aLayers,
-        const std::vector<BOARD_ITEM*> aSkip )
+        const std::vector<BOARD_ITEM*>& aSkip )
 {
     double worldScale = m_frame->GetCanvas()->GetGAL()->GetWorldScale();
     int snapRange = (int) ( m_snapSize / worldScale );

pcbnew/tools/grid_helper.h

@@ -58,10 +58,10 @@ public:
 
     VECTOR2I AlignToSegment ( const VECTOR2I& aPoint, const SEG& aSeg );
 
-    VECTOR2I BestDragOrigin( const VECTOR2I& aMousePos, BOARD_ITEM* aItem );
+    VECTOR2I BestDragOrigin( const VECTOR2I& aMousePos, std::vector<BOARD_ITEM*>& aItem );
     VECTOR2I BestSnapAnchor( const VECTOR2I& aOrigin, BOARD_ITEM* aDraggedItem );
     VECTOR2I BestSnapAnchor( const VECTOR2I& aOrigin, const LSET& aLayers,
-                             const std::vector<BOARD_ITEM*> aSkip = {} );
+                             const std::vector<BOARD_ITEM*>& aSkip = {} );
 
     void SetSnap( bool aSnap )
     {
@@ -102,7 +102,7 @@ private:
     std::vector<ANCHOR> m_anchors;
 
     std::set<BOARD_ITEM*> queryVisible( const BOX2I& aArea,
-                                        const std::vector<BOARD_ITEM*> aSkip ) const;
+                                        const std::vector<BOARD_ITEM*>& aSkip ) const;
 
     void addAnchor( const VECTOR2I& aPos, int aFlags, BOARD_ITEM* aItem )
     {

pcbnew/tools/pcbnew_selection.cpp

@@ -108,3 +108,19 @@ const KIGFX::VIEW_GROUP::ITEMS PCBNEW_SELECTION::updateDrawList() const
 
     return items;
 }
+
+
+const LSET PCBNEW_SELECTION::GetSelectionLayers()
+{
+    LSET retval;
+
+    for( auto item : m_items )
+    {
+        auto board_item = dynamic_cast<BOARD_ITEM*>( item );
+
+        if( board_item )
+            retval |= board_item->GetLayerSet();
+    }
+
+    return retval;
+}

pcbnew/tools/pcbnew_selection.h

@@ -24,6 +24,7 @@
 #ifndef PCBNEW_SELECTION_H
 #define PCBNEW_SELECTION_H
 
+#include <layers_id_colors_and_visibility.h>
 #include <tool/selection.h>
 
 
@@ -33,6 +34,8 @@ public:
     EDA_ITEM* GetTopLeftItem( bool onlyModules = false ) const override;
     
     const KIGFX::VIEW_GROUP::ITEMS updateDrawList() const override;
+
+    const LSET GetSelectionLayers();
 };
 
 #endif  //  PCBNEW_SELECTION_H