diff --git a/interface/wx/sizer.h b/interface/wx/sizer.h
index 055429d596..96c1de9e36 100644
--- a/interface/wx/sizer.h
+++ b/interface/wx/sizer.h
@@ -290,6 +290,8 @@ public:
                      int border = 0,
                      wxObject* userData = NULL);
 
+    wxSizerItem* Add(wxSizerItem* item);
+    
     /**
         This base function adds non-stretchable space to both the horizontal
         and vertical orientation of the sizer.
@@ -406,6 +408,14 @@ public:
     */
     void FitInside(wxWindow* window);
 
+    /**
+       Inform sizer about the first direction that has been decided (by
+       parent item).  Returns true if it made use of the informtion (and
+       recalculated min size).
+    */
+    virtual bool InformFirstDirection(int direction, int size, int availableOtherDir);
+
+    
     //@{
     /**
         Returns the list of the items in this sizer.
@@ -568,6 +578,8 @@ public:
                         int border = 0,
                         wxObject* userData = NULL);
 
+    wxSizerItem* Insert(size_t index, wxSizerItem* item);
+    
     /**
         Inserts non-stretchable space to the sizer.
         More readable way of calling wxSizer::Insert(index, size, size).
@@ -656,6 +668,8 @@ public:
                          int border = 0,
                          wxObject* userData = NULL);
 
+    wxSizerItem* Prepend(wxSizerItem* item);
+    
     /**
         Prepends non-stretchable space to the sizer.
         More readable way of calling wxSizer::Prepend(size, size, 0).
@@ -967,6 +981,9 @@ public:
         outlined above.
     */
     void SetNegativeButton(wxButton* button);
+
+    virtual void RecalcSizes();
+    virtual wxSize CalcMin();
 };
 
 
@@ -1007,7 +1024,7 @@ public:
     /**
         Construct a sizer item for tracking a subsizer.
     */
-    wxSizerItem(wxSizer* window, const wxSizerFlags& flags);
+    wxSizerItem(wxSizer* sizer, const wxSizerFlags& flags);
     wxSizerItem(wxSizer* sizer, int proportion, int flag,
                 int border,
                 wxObject* userData);
@@ -1039,7 +1056,7 @@ public:
         Old spacer, if any, is deleted.
     */
     void AssignSpacer(const wxSize& size);
-    void AssignSpacer(int w, int h) { AssignSpacer(wxSize(w, h)); }
+    void AssignSpacer(int w, int h);
     //@}
 
     /**
@@ -1585,7 +1602,6 @@ public:
     void SetNonFlexibleGrowMode(wxFlexSizerGrowMode mode);
     
     virtual void RecalcSizes();
-    
     virtual wxSize CalcMin();
     
 };
@@ -1710,6 +1726,9 @@ public:
         Sets the vertical gap (in pixels) between the cells in the sizer.
     */
     void SetVGap(int gap);
+
+    virtual wxSize CalcMin();
+    virtual void RecalcSizes();
 };
 
 
@@ -1770,6 +1789,9 @@ public:
         Returns the static box associated with the sizer.
     */
     wxStaticBox* GetStaticBox() const;
+
+    virtual wxSize CalcMin();
+    virtual void RecalcSizes();
 };
 
 
@@ -1834,6 +1856,6 @@ public:
         It is used internally only and must not be called by the user
         (call Layout() if you want to resize). Documented for information.
     */
-    void RecalcSizes();
+    virtual void RecalcSizes();
 };
 
diff --git a/interface/wx/slider.h b/interface/wx/slider.h
index 882c8bcb2b..36554a629d 100644
--- a/interface/wx/slider.h
+++ b/interface/wx/slider.h
@@ -6,6 +6,23 @@
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
+
+#define wxSL_HORIZONTAL      wxHORIZONTAL /* 0x0004 */
+#define wxSL_VERTICAL        wxVERTICAL   /* 0x0008 */
+
+#define wxSL_TICKS           0x0010
+#define wxSL_AUTOTICKS       wxSL_TICKS // we don't support manual ticks
+#define wxSL_LEFT            0x0040
+#define wxSL_TOP             0x0080
+#define wxSL_RIGHT           0x0100
+#define wxSL_BOTTOM          0x0200
+#define wxSL_BOTH            0x0400
+#define wxSL_SELRANGE        0x0800
+#define wxSL_INVERSE         0x1000
+#define wxSL_MIN_MAX_LABELS  0x2000
+#define wxSL_VALUE_LABEL     0x4000
+#define wxSL_LABELS          (wxSL_MIN_MAX_LABELS|wxSL_VALUE_LABEL)
+
 /**
     @class wxSlider
 
diff --git a/interface/wx/spinctrl.h b/interface/wx/spinctrl.h
index b17763bb28..7a735a1d61 100644
--- a/interface/wx/spinctrl.h
+++ b/interface/wx/spinctrl.h
@@ -327,3 +327,6 @@ public:
     */
     void SetValue(double value);
 };
+
+wxEventType wxEVT_COMMAND_SPINCTRL_UPDATED;
+wxEventType wxEVT_COMMAND_SPINCTRLDOUBLE_UPDATED;
diff --git a/interface/wx/splitter.h b/interface/wx/splitter.h
index 3a7dbee2a3..864c2135af 100644
--- a/interface/wx/splitter.h
+++ b/interface/wx/splitter.h
@@ -7,6 +7,18 @@
 /////////////////////////////////////////////////////////////////////////////
 
 
+#define wxSP_NOBORDER         0x0000
+#define wxSP_THIN_SASH        0x0000    // NB: the default is 3D sash
+#define wxSP_NOSASH           0x0010
+#define wxSP_PERMIT_UNSPLIT   0x0040
+#define wxSP_LIVE_UPDATE      0x0080
+#define wxSP_3DSASH           0x0100
+#define wxSP_3DBORDER         0x0200
+#define wxSP_NO_XP_THEME      0x0400
+#define wxSP_BORDER           wxSP_3DBORDER
+#define wxSP_3D               (wxSP_3DBORDER | wxSP_3DSASH)
+
+
 enum wxSplitMode
 {
     wxSPLIT_HORIZONTAL = 1,
@@ -503,3 +515,8 @@ public:
     void SetSashPosition(int pos);
 };
 
+
+wxEventType wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGED;
+wxEventType wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGING;
+wxEventType wxEVT_COMMAND_SPLITTER_DOUBLECLICKED;
+wxEventType wxEVT_COMMAND_SPLITTER_UNSPLIT;
diff --git a/interface/wx/wrapsizer.h b/interface/wx/wrapsizer.h
index 4378b2f45f..f3e09387ca 100644
--- a/interface/wx/wrapsizer.h
+++ b/interface/wx/wrapsizer.h
@@ -51,6 +51,9 @@ public:
     */
     virtual bool InformFirstDirection(int direction, int size,
                                       int availableOtherDir);
+    
+    virtual void RecalcSizes();
+    virtual wxSize CalcMin();
 
 protected:
     /**