Add the possibility to disable invisible wxDataViewCtrl items.

Add new wxDataViewModel::IsEnabled() and wxDataViewListStore::IsEnabledByRow()
methods and implement support for actually disabling the items in wxOSX/Cocoa
native implementation of wxDataViewCtrl and limited support for it in the
generic version.

We need to implement this in wxGTK using GtkCellRenderer "sensitive" propriety
later.

Closes #12686.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66403 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/dataview/mymodels.h

@@ -163,6 +163,9 @@ public:
     virtual bool SetValue( const wxVariant &variant,
                            const wxDataViewItem &item, unsigned int col );
 
+    virtual bool IsEnabled( const wxDataViewItem &item,
+                            unsigned int col ) const;
+
     virtual wxDataViewItem GetParent( const wxDataViewItem &item ) const;
     virtual bool IsContainer( const wxDataViewItem &item ) const;
     virtual unsigned int GetChildren( const wxDataViewItem &parent,
@@ -235,3 +238,12 @@ private:
     wxIcon           m_icon[2];
 };
 
+// ----------------------------------------------------------------------------
+// MyListStoreDerivedModel
+// ----------------------------------------------------------------------------
+
+class MyListStoreDerivedModel : public wxDataViewListStore
+{
+public:
+    virtual bool IsEnabledByRow(unsigned int row, unsigned int col) const;
+};