Make wxValidator::SetWindow() virtual

Allow overriding the method called when the validator is associated with
the window, this can be convenient to perform some initialization on the
validator instance actually used as it can't be done on the initially
created object itself because it will be cloned by SetValidator(),
creating a new instance.

Also change SetWindow() to take wxWindow instead of wxWindowBase, this
still requires the cast in wxWindow::SetValidator(), but it's better to
have it there rather than in wxValidator and use the simpler type in the
public function signature.

include/wx/validate.h

@@ -62,9 +62,12 @@ public:
     // Called to transfer data from the window
     virtual bool TransferFromWindow() { return false; }
 
+    // Called when the validator is associated with a window, may be useful to
+    // override if it needs to somehow initialize the window.
+    virtual void SetWindow(wxWindow *win) { m_validatorWindow = win; }
+
     // accessors
-    wxWindow *GetWindow() const { return (wxWindow *)m_validatorWindow; }
-    void SetWindow(wxWindowBase *win) { m_validatorWindow = win; }
+    wxWindow *GetWindow() const { return m_validatorWindow; }
 
     // validators beep by default if invalid key is pressed, this function
     // allows to change this
@@ -85,7 +88,7 @@ public:
 #endif
 
 protected:
-    wxWindowBase *m_validatorWindow;
+    wxWindow *m_validatorWindow;
 
 private:
     static bool ms_isSilent;

interface/wx/validate.h

@@ -85,8 +85,11 @@ public:
     /**
         Associates a window with the validator.
 
-        This function is automatically called by wxWidgets when creating a wxWindow-derived
-        class instance which takes a wxValidator reference.
+        This function is automatically called by wxWidgets when creating a
+        wxWindow-derived class instance which takes a wxValidator reference.
+        Since wxWidgets 3.1.1, it can be overridden in custom validators in
+        order to perform any one-time initialization or checks of the window
+        when the validator is associated with it.
 
         E.g.
         @code
@@ -94,9 +97,9 @@ public:
                        wxTextValidator(wxFILTER_ALPHA, &g_data.m_string));
         @endcode
         will automatically link the wxTextValidator instance with the wxTextCtrl
-        instance.
+        instance and call SetWindow() method on the wxTextValidator object.
     */
-    void SetWindow(wxWindow* window);
+    virtual void SetWindow(wxWindow* window);
 
     /**
         This overridable function is called when the value in the window must

src/common/wincmn.cpp

@@ -1782,10 +1782,10 @@ void wxWindowBase::SetValidator(const wxValidator& validator)
     if ( m_windowValidator )
         delete m_windowValidator;
 
-    m_windowValidator = (wxValidator *)validator.Clone();
+    m_windowValidator = static_cast<wxValidator *>(validator.Clone());
 
     if ( m_windowValidator )
-        m_windowValidator->SetWindow(this);
+        m_windowValidator->SetWindow(static_cast<wxWindow*>(this));
 }
 #endif // wxUSE_VALIDATORS