made wxHeaderCtrl::GetColumn() const to get rid of the const_cast<>s

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@57380 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/headerctrl.h

@@ -154,7 +154,7 @@ public:
 protected:
     // this method must be implemented by the derived classes to return the
     // information for the given column
-    virtual wxHeaderColumn& GetColumn(unsigned int idx) = 0;
+    virtual const wxHeaderColumn& GetColumn(unsigned int idx) const = 0;
 
     // this method is called from the default EVT_HEADER_SEPARATOR_DCLICK
     // handler to update the fitting column width of the given column, it
@@ -311,7 +311,7 @@ public:
 
 protected:
     // implement/override base class methods
-    virtual wxHeaderColumn& GetColumn(unsigned int idx);
+    virtual const wxHeaderColumn& GetColumn(unsigned int idx) const;
     virtual bool UpdateColumnWidthToFit(unsigned int idx, int widthTitle);
 
     // and define another one to be overridden in the derived classes: it

interface/wx/headerctrl.h

@@ -354,7 +354,7 @@ protected:
             The column index, between 0 and the value last passed to
             SetColumnCount().
      */
-    virtual wxHeaderColumnBase& GetColumn(unsigned int idx) = 0;
+    virtual const wxHeaderColumnBase& GetColumn(unsigned int idx) const = 0;
 
     /**
         Method called when the column visibility is changed by the user.
@@ -426,7 +426,7 @@ protected:
             {
             public:
             protected:
-                virtual wxHeaderColumnBase& GetColumn(unsigned int idx)
+                virtual wxHeaderColumnBase& GetColumn(unsigned int idx) const
                 {
                     return m_cols[idx];
                 }

src/common/headerctrlcmn.cpp

@@ -366,7 +366,7 @@ void wxHeaderCtrlSimple::Init()
     m_sortKey = wxNO_COLUMN;
 }
 
-wxHeaderColumn& wxHeaderCtrlSimple::GetColumn(unsigned int idx)
+const wxHeaderColumn& wxHeaderCtrlSimple::GetColumn(unsigned int idx) const
 {
     return m_cols[idx];
 }

src/generic/datavgen.cpp

@@ -91,7 +91,7 @@ public:
 protected:
     // implement/override wxHeaderCtrl functions by forwarding them to the main
     // control
-    virtual wxHeaderColumn& GetColumn(unsigned int idx)
+    virtual const wxHeaderColumn& GetColumn(unsigned int idx) const
     {
         return *(GetOwner()->GetColumn(idx));
     }

src/generic/grid.cpp

@@ -230,7 +230,7 @@ public:
     }
 
 protected:
-    virtual wxHeaderColumn& GetColumn(unsigned int idx)
+    virtual const wxHeaderColumn& GetColumn(unsigned int idx) const
     {
         return m_columns[idx];
     }

src/generic/headerctrlg.cpp

@@ -145,8 +145,6 @@ wxSize wxHeaderCtrl::DoGetBestSize() const
 
 int wxHeaderCtrl::GetColStart(unsigned int idx) const
 {
-    wxHeaderCtrl * const self = const_cast<wxHeaderCtrl *>(this);
-
     int pos = m_scrollOffset;
     for ( unsigned n = 0; ; n++ )
     {
@@ -154,7 +152,7 @@ int wxHeaderCtrl::GetColStart(unsigned int idx) const
         if ( i == idx )
             break;
 
-        const wxHeaderColumn& col = self->GetColumn(i);
+        const wxHeaderColumn& col = GetColumn(i);
         if ( col.IsShown() )
             pos += col.GetWidth();
     }
@@ -166,19 +164,17 @@ int wxHeaderCtrl::GetColEnd(unsigned int idx) const
 {
     int x = GetColStart(idx);
 
-    return x + const_cast<wxHeaderCtrl *>(this)->GetColumn(idx).GetWidth();
+    return x + GetColumn(idx).GetWidth();
 }
 
 unsigned int wxHeaderCtrl::FindColumnAtPoint(int x, bool *onSeparator) const
 {
-    wxHeaderCtrl * const self = const_cast<wxHeaderCtrl *>(this);
-
     int pos = 0;
     const unsigned count = GetColumnCount();
     for ( unsigned n = 0; n < count; n++ )
     {
         const unsigned idx = m_colIndices[n];
-        const wxHeaderColumn& col = self->GetColumn(idx);
+        const wxHeaderColumn& col = GetColumn(idx);
         if ( col.IsHidden() )
             continue;