use rtl::Reference in Ruler

instead of manual acquire/release

Change-Id: I7815a0a3c01fce57b4798ac1dbf501e20444c61d

include/svtools/ruler.hxx

@@ -21,6 +21,7 @@
 #define INCLUDED_SVTOOLS_RULER_HXX
 
 #include <svtools/svtdllapi.h>
+#include <rtl/ref.hxx>
 #include <tools/link.hxx>
 #include <tools/fract.hxx>
 #include <vcl/window.hxx>
@@ -660,7 +661,7 @@ private:
     std::unique_ptr<RulerSelection> mxCurrentHitTest;
     std::unique_ptr<RulerSelection> mxPreviousHitTest;
 
-    SvtRulerAccessible* pAccContext;
+    rtl::Reference<SvtRulerAccessible> mxAccContext;
 
     SVT_DLLPRIVATE void ImplVDrawLine(vcl::RenderContext& rRenderContext,  long nX1, long nY1, long nX2, long nY2 );
     SVT_DLLPRIVATE void ImplVDrawRect(vcl::RenderContext& rRenderContext, long nX1, long nY1, long nX2, long nY2 );

svtools/source/control/ruler.cxx

@@ -283,7 +283,6 @@ void Ruler::ImplInit( WinBits nWinBits )
         aDefSize.Width() = nDefHeight;
     SetOutputSizePixel( aDefSize );
     SetType(WINDOW_RULER);
-    pAccContext = nullptr;
 }
 
 Ruler::Ruler( vcl::Window* pParent, WinBits nWinStyle ) :
@@ -334,11 +333,7 @@ void Ruler::dispose()
     mpSaveData = nullptr;
     delete mpDragData;
     mpDragData = nullptr;
-    if( pAccContext )
-    {
-        pAccContext->release();
-        pAccContext = nullptr;
-    }
+    mxAccContext.clear();
     Window::dispose();
 }
 
@@ -2827,10 +2822,9 @@ uno::Reference< XAccessible > Ruler::CreateAccessible()
         {
             aStr = SvtResId(STR_SVT_ACC_RULER_VERT_NAME);
         }
-        pAccContext = new SvtRulerAccessible( xAccParent, *this, aStr );
-        pAccContext->acquire();
-        this->SetAccessible(pAccContext);
-        return pAccContext;
+        mxAccContext = new SvtRulerAccessible( xAccParent, *this, aStr );
+        this->SetAccessible(mxAccContext.get());
+        return mxAccContext.get();
     }
     else
         return uno::Reference< XAccessible >();