convert include/svx/dialcontrol.hxx from String to OUString

Change-Id: I6f35595305178ec10b19a9d5f499526d76e2b736

include/svx/dialcontrol.hxx

@@ -43,7 +43,7 @@ public:
     void                CopyBackground( const DialControlBmp& rSrc );
     void                DrawBackground( const Size& rSize, bool bEnabled );
     virtual void        DrawBackground();
-    virtual void        DrawElements( const String& rText, sal_Int32 nAngle );
+    virtual void        DrawElements( const OUString& rText, sal_Int32 nAngle );
 
 protected:
     Rectangle           maRect;

svx/source/dialog/dialcontrol.cxx

@@ -70,7 +70,7 @@ void DialControlBmp::DrawBackground( const Size& rSize, bool bEnabled )
     DrawBackground();
 }
 
-void DialControlBmp::DrawElements( const String& rText, sal_Int32 nAngle )
+void DialControlBmp::DrawElements( const OUString& rText, sal_Int32 nAngle )
 {
     double fAngle = nAngle * F_PI180 / 100.0;
     double fSin = sin( fAngle );
@@ -78,7 +78,7 @@ void DialControlBmp::DrawElements( const String& rText, sal_Int32 nAngle )
     double fWidth = GetTextWidth( rText ) / 2.0;
     double fHeight = GetTextHeight() / 2.0;
 
-    if ( rText.Len() > 0 )
+    if ( !rText.isEmpty() )
     {
         // rotated text
         Font aFont( GetFont() );