Fix recently broken wxPickerBase::SetPickerCtrlGrowable()

Resetting growable flag didn't work correctly after the changes of
0d86c01b8b, fix this and reuse the same code for
both this function and SetTextCtrlGrowable().

See https://github.com/wxWidgets/wxWidgets/pull/296

include/wx/pickerbase.h

@@ -76,29 +76,14 @@ public:     // public API
         { return (GetTextCtrlItem()->GetFlag() & wxGROW) != 0; }
     void SetTextCtrlGrowable(bool grow = true)
     {
-        wxSizerItem* const item = GetTextCtrlItem();
+        DoSetGrowableFlagFor(GetTextCtrlItem(), grow);
-        int f = item->GetFlag();
-        if ( grow )
-            f |= wxGROW;
-        else
-            f &= ~wxGROW;
-
-        item->SetFlag(f);
     }
 
     bool IsPickerCtrlGrowable() const
         { return (GetPickerCtrlItem()->GetFlag() & wxGROW) != 0; }
     void SetPickerCtrlGrowable(bool grow = true)
     {
-        wxSizerItem* const item = GetPickerCtrlItem();
+        DoSetGrowableFlagFor(GetPickerCtrlItem(), grow);
-        int f = item->GetFlag();
-        if ( grow )
-        {
-            f &= ~wxALIGN_MASK;
-            f |= wxGROW;
-        }
-
-        item->SetFlag(f);
     }
 
     bool HasTextCtrl() const
@@ -174,6 +159,9 @@ protected:
     wxBoxSizer *m_sizer;
 
 private:
+    // Common implementation of Set{Text,Picker}CtrlGrowable().
+    void DoSetGrowableFlagFor(wxSizerItem* item, bool grow);
+
     wxDECLARE_ABSTRACT_CLASS(wxPickerBase);
 };
 

src/common/pickerbase.cpp

@@ -153,6 +153,26 @@ void wxPickerBase::DoSetToolTip(wxToolTip *tip)
 
 #endif // wxUSE_TOOLTIPS
 
+void wxPickerBase::DoSetGrowableFlagFor(wxSizerItem* item, bool grow)
+{
+    // We assume that our controls use either wxALIGN_CENTER_VERTICAL or wxGROW
+    // style, this code would need to be changed in the unlikely event any
+    // other style is used for them.
+    int f = item->GetFlag();
+    if ( grow )
+    {
+        f &= ~wxALIGN_CENTER_VERTICAL;
+        f |= wxGROW;
+    }
+    else
+    {
+        f &= ~wxGROW;
+        f |= wxALIGN_CENTER_VERTICAL;
+    }
+
+    item->SetFlag(f);
+}
+
 // ----------------------------------------------------------------------------
 // wxPickerBase - event handlers
 // ----------------------------------------------------------------------------