From fdf5b821f0a337a25d04ab66c25d8b81cab374bc Mon Sep 17 00:00:00 2001
From: Jon Neal <reportingsjr@gmail.com>
Date: Thu, 9 Jul 2015 10:18:27 +0200
Subject: [PATCH] Add centering cursor on zoom to GAL.

---
 common/draw_frame.cpp            |  3 +++
 common/draw_panel.cpp            | 10 ++++++++++
 common/view/wx_view_controls.cpp | 14 ++++++++++++--
 include/class_drawpanel.h        |  2 +-
 include/view/view_controls.h     | 20 ++++++++++++++++++++
 pcbnew/tools/pcbnew_control.cpp  | 10 +++++++++-
 6 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/common/draw_frame.cpp b/common/draw_frame.cpp
index 485a5deff0..32cd93a111 100644
--- a/common/draw_frame.cpp
+++ b/common/draw_frame.cpp
@@ -1062,6 +1062,9 @@ void EDA_DRAW_FRAME::UseGalCanvas( bool aEnable )
         gal->SetGridSize( VECTOR2D( GetScreen()->GetGridSize() ) );
         gal->SetGridOrigin( VECTOR2D( GetGridOrigin() ) );
 
+        // Transfer EDA_DRAW_PANEL settings
+        GetGalCanvas()->GetViewControls()->SetEnableZoomNoCenter( m_canvas->GetEnableZoomNoCenter() );
+
         GetToolManager()->RunAction( "pcbnew.Control.switchCursor" );
     }
     else if( m_galCanvasActive )
diff --git a/common/draw_panel.cpp b/common/draw_panel.cpp
index 437324d1ed..74b4e1bcb7 100644
--- a/common/draw_panel.cpp
+++ b/common/draw_panel.cpp
@@ -38,6 +38,7 @@
 #include <class_draw_panel_gal.h>
 #include <class_base_screen.h>
 #include <draw_frame.h>
+#include <view/view_controls.h>
 
 #include <kicad_device_context.h>
 
@@ -638,6 +639,15 @@ void EDA_DRAW_PANEL::ReDraw( wxDC* DC, bool erasebg )
 }
 
 
+void EDA_DRAW_PANEL::SetEnableZoomNoCenter( bool aEnable )
+{
+    m_enableZoomNoCenter = aEnable;
+
+    if( GetParent()->IsGalCanvasActive() )
+        GetParent()->GetGalCanvas()->GetViewControls()->SetEnableZoomNoCenter( aEnable );
+}
+
+
 void EDA_DRAW_PANEL::DrawBackGround( wxDC* DC )
 {
     EDA_COLOR_T axis_color = BLUE;
diff --git a/common/view/wx_view_controls.cpp b/common/view/wx_view_controls.cpp
index 061f88246d..7bb333004a 100644
--- a/common/view/wx_view_controls.cpp
+++ b/common/view/wx_view_controls.cpp
@@ -151,8 +151,18 @@ void WX_VIEW_CONTROLS::onWheel( wxMouseEvent& aEvent )
             zoomScale = ( rotation > 0 ) ? 1.05 : 0.95;
         }
 
-        VECTOR2D anchor = m_view->ToWorld( VECTOR2D( aEvent.GetX(), aEvent.GetY() ) );
-        m_view->SetScale( m_view->GetScale() * zoomScale, anchor );
+        if( GetEnableZoomNoCenter() )
+        {
+            VECTOR2D anchor = m_view->ToWorld( VECTOR2D( aEvent.GetX(), aEvent.GetY() ) );
+            m_view->SetScale( m_view->GetScale() * zoomScale, anchor );
+        }
+        else
+        {
+            const VECTOR2I& screenSize = m_view->GetGAL()->GetScreenPixelSize();
+            m_view->SetCenter( GetCursorPosition() );
+            m_view->SetScale( m_view->GetScale() * zoomScale );
+            m_parentPanel->WarpPointer( screenSize.x / 2, screenSize.y / 2 );
+        }
     }
 
     aEvent.Skip();
diff --git a/include/class_drawpanel.h b/include/class_drawpanel.h
index 738f19947d..f03e220997 100644
--- a/include/class_drawpanel.h
+++ b/include/class_drawpanel.h
@@ -148,7 +148,7 @@ public:
 
     bool GetEnableZoomNoCenter() const { return m_enableZoomNoCenter; }
 
-    void SetEnableZoomNoCenter( bool aEnable ) { m_enableZoomNoCenter = aEnable; }
+    void SetEnableZoomNoCenter( bool aEnable );
 
     bool GetMiddleButtonPanLimited() const { return m_panScrollbarLimits; }
 
diff --git a/include/view/view_controls.h b/include/view/view_controls.h
index e0d3e31d98..74c3d64a17 100644
--- a/include/view/view_controls.h
+++ b/include/view/view_controls.h
@@ -161,6 +161,23 @@ public:
         return m_forceCursorPosition;
     }
 
+    /**
+     * Function SetEnableZoomNoCenter()
+     * Enables or Disables warping the cursor to the center of the drawing i
+     * panel area when zooming.
+     * @param aEnabled is true if the cursor should not be centered and false if
+     * the cursor should be centered.
+     */
+    virtual void SetEnableZoomNoCenter( bool aEnable )
+    {
+        m_enableZoomNoCenter = aEnable;
+    }
+
+    virtual bool GetEnableZoomNoCenter() const
+    {
+        return m_enableZoomNoCenter;
+    }
+
 protected:
     /// Pointer to controlled VIEW.
     VIEW*       m_view;
@@ -191,6 +208,9 @@ protected:
 
     /// How fast is panning when in auto mode
     float       m_autoPanSpeed;
+
+    /// If the cursor should be warped to the center of the view area when zooming
+    bool        m_enableZoomNoCenter;
 };
 } // namespace KIGFX
 
diff --git a/pcbnew/tools/pcbnew_control.cpp b/pcbnew/tools/pcbnew_control.cpp
index 926a38d004..44f380297c 100644
--- a/pcbnew/tools/pcbnew_control.cpp
+++ b/pcbnew/tools/pcbnew_control.cpp
@@ -84,7 +84,15 @@ int PCBNEW_CONTROL::ZoomInOut( const TOOL_EVENT& aEvent )
     else if( aEvent.IsAction( &COMMON_ACTIONS::zoomOut ) )
         zoomScale = 0.7;
 
-    view->SetScale( view->GetScale() * zoomScale, getViewControls()->GetCursorPosition() );
+    if( getViewControls()->GetEnableZoomNoCenter() )
+        view->SetScale( view->GetScale() * zoomScale, getViewControls()->GetCursorPosition() );
+    else
+    {
+        const VECTOR2I& screenSize = view->GetGAL()->GetScreenPixelSize();
+        view->SetCenter( getViewControls()->GetCursorPosition() );
+        view->SetScale( view->GetScale() * zoomScale );
+        m_frame->GetGalCanvas()->WarpPointer( screenSize.x / 2, screenSize.y / 2 );
+    }
 
     return 0;
 }