From 9ad3180f6cdf897fe49826319291669d409dd337 Mon Sep 17 00:00:00 2001
From: Maciej Suminski <maciej.suminski@cern.ch>
Date: Wed, 2 Apr 2014 15:57:21 +0200
Subject: [PATCH] Added EC_SNAPLINE to make possible snapping EDIT_LINES by
 their ends rather than by its center.

---
 pcbnew/tools/edit_constraints.cpp | 18 ++++++++++++++++--
 pcbnew/tools/edit_constraints.h   | 28 ++++++++++++++++++++++++++++
 pcbnew/tools/edit_points.h        | 16 +++++++++++++---
 pcbnew/tools/point_editor.cpp     | 18 +++++++++++-------
 4 files changed, 68 insertions(+), 12 deletions(-)

diff --git a/pcbnew/tools/edit_constraints.cpp b/pcbnew/tools/edit_constraints.cpp
index 84d417c2ab..f0edf9bc8b 100644
--- a/pcbnew/tools/edit_constraints.cpp
+++ b/pcbnew/tools/edit_constraints.cpp
@@ -131,8 +131,8 @@ EC_CONVERGING::~EC_CONVERGING()
 void EC_CONVERGING::Apply( EDIT_LINE& aHandle )
 {
     // The dragged segment endpoints
-    EDIT_POINT& origin = m_constrained.GetOrigin();
-    EDIT_POINT& end = m_constrained.GetEnd();
+    EDIT_POINT& origin = aHandle.GetOrigin();
+    EDIT_POINT& end = aHandle.GetEnd();
 
     if( m_colinearConstraint )
     {
@@ -173,3 +173,17 @@ void EC_CONVERGING::Apply( EDIT_LINE& aHandle )
         end.SetPosition( *originEndIntersect );
     }
 }
+
+
+EC_SNAPLINE::EC_SNAPLINE( EDIT_LINE& aLine, V2D_TRANSFORM_FUN aSnapFun ) :
+    EDIT_CONSTRAINT<EDIT_LINE>( aLine ), m_snapFun( aSnapFun )
+{}
+
+
+void EC_SNAPLINE::Apply( EDIT_LINE& aHandle )
+{
+    VECTOR2D delta = aHandle.GetEnd().GetPosition() - aHandle.GetOrigin().GetPosition();
+
+    aHandle.GetOrigin().SetPosition( m_snapFun( aHandle.GetOrigin().GetPosition() ) );
+    aHandle.GetEnd().SetPosition( aHandle.GetOrigin().GetPosition() + delta );
+}
diff --git a/pcbnew/tools/edit_constraints.h b/pcbnew/tools/edit_constraints.h
index c86afb5a75..6df17e438d 100644
--- a/pcbnew/tools/edit_constraints.h
+++ b/pcbnew/tools/edit_constraints.h
@@ -26,6 +26,7 @@
 #define EDIT_CONSTRAINTS_H_
 
 #include <math/vector2d.h>
+#include <boost/function.hpp>
 
 class EDIT_POINT;
 class EDIT_LINE;
@@ -236,4 +237,31 @@ private:
     VECTOR2I m_draggedVector;
 };
 
+
+/**
+ * Class EC_SNAPLINE
+ *
+ * EDIT_CONSTRAINT for a EDIT_LINE, one of the ends is snapped to a spot determined by a
+ * transform function passed as parameter (e.g. it can be snapped to a grid), instead of having
+ * the line center snapped to a point.
+ */
+class EC_SNAPLINE : public EDIT_CONSTRAINT<EDIT_LINE>
+{
+public:
+    ///> Typedef for a function that determines snapping point.
+    typedef boost::function<VECTOR2D (const VECTOR2D&)> V2D_TRANSFORM_FUN;
+
+    EC_SNAPLINE( EDIT_LINE& aLine, V2D_TRANSFORM_FUN aSnapFun );
+
+    virtual ~EC_SNAPLINE()
+    {}
+
+    ///> @copydoc EDIT_CONSTRAINT::Apply()
+    virtual void Apply( EDIT_LINE& aHandle );
+
+private:
+    ///> Function that determines snapping point.
+    V2D_TRANSFORM_FUN m_snapFun;
+};
+
 #endif /* EDIT_CONSTRAINTS_H_ */
diff --git a/pcbnew/tools/edit_points.h b/pcbnew/tools/edit_points.h
index 52f54960ff..b06ec30975 100644
--- a/pcbnew/tools/edit_points.h
+++ b/pcbnew/tools/edit_points.h
@@ -418,15 +418,25 @@ public:
     }
 
     /**
-     * Function Size()
+     * Function PointsSize()
      *
-     * Returns number of stored points.
+     * Returns number of stored EDIT_POINTs.
      */
-    unsigned int Size() const
+    unsigned int PointsSize() const
     {
         return m_points.size();
     }
 
+    /**
+     * Function LinesSize()
+     *
+     * Returns number of stored EDIT_LINEs.
+     */
+    unsigned int LinesSize() const
+    {
+        return m_lines.size();
+    }
+
     ///> @copydoc VIEW_ITEM::ViewBBox()
     virtual const BOX2I ViewBBox() const
     {
diff --git a/pcbnew/tools/point_editor.cpp b/pcbnew/tools/point_editor.cpp
index 5fd82edf53..f4aa4baa17 100644
--- a/pcbnew/tools/point_editor.cpp
+++ b/pcbnew/tools/point_editor.cpp
@@ -23,6 +23,7 @@
  */
 
 #include <boost/make_shared.hpp>
+#include <boost/bind.hpp>
 
 #include <tool/tool_manager.h>
 #include <view/view_controls.h>
@@ -64,16 +65,11 @@ enum DIMENSION_POINTS
     DIM_FEATUREDO,
 };
 
-/**
- * Class POINT_EDITOR
- *
- * Tool that displays edit points allowing to modify items by dragging the points.
- */
 
 class EDIT_POINTS_FACTORY
 {
 public:
-    static boost::shared_ptr<EDIT_POINTS> Make( EDA_ITEM* aItem )
+    static boost::shared_ptr<EDIT_POINTS> Make( EDA_ITEM* aItem, KIGFX::GAL* aGal )
     {
         boost::shared_ptr<EDIT_POINTS> points = boost::make_shared<EDIT_POINTS>( aItem );
 
@@ -126,10 +122,18 @@ public:
                 // Lines have to be added after creating edit points,
                 // as they use EDIT_POINT references
                 for( int i = 0; i < cornersCount - 1; ++i )
+                {
                     points->AddLine( points->Point( i ), points->Point( i + 1 ) );
+                    points->Line( i ).SetConstraint(
+                            new EC_SNAPLINE( points->Line( i ),
+                            boost::bind( &KIGFX::GAL::GetGridPoint, aGal, _1 ) ) );
+                }
 
                 // The last missing line, connecting the last and the first polygon point
                 points->AddLine( points->Point( cornersCount - 1 ), points->Point( 0 ) );
+                points->Line( points->LinesSize() - 1 ).SetConstraint(
+                        new EC_SNAPLINE( points->Line( points->LinesSize() - 1 ),
+                        boost::bind( &KIGFX::GAL::GetGridPoint, aGal, _1 ) ) );
                 break;
             }
 
@@ -208,7 +212,7 @@ int POINT_EDITOR::OnSelectionChange( TOOL_EVENT& aEvent )
         PCB_EDIT_FRAME* editFrame = getEditFrame<PCB_EDIT_FRAME>();
         EDA_ITEM* item = selection.items.GetPickedItem( 0 );
 
-        m_editPoints = EDIT_POINTS_FACTORY::Make( item );
+        m_editPoints = EDIT_POINTS_FACTORY::Make( item, m_toolMgr->GetView()->GetGAL() );
         if( !m_editPoints )
         {
             setTransitions();