chart2/source/inc/WeakListenerAdapter.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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   9  * This file incorporates work covered by the following license notice:
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  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19 #pragma once
  20
  21 #include <com/sun/star/lang/XEventListener.hpp>
  22 #include <com/sun/star/view/XSelectionChangeListener.hpp>
  23 #include <cppuhelper/weakref.hxx>
  24 #include <cppuhelper/implbase.hxx>
  25
  26 namespace chart
  27 {
  28
  29 /** Adapter that enables adding listeners as weak UNO references.  Thus, adding
  30     an object as listener to a broadcaster does not increase its reference
  31     count.
  32
  33     <p>The helper class, of course, is held as hard reference at the
  34     broadcaster, but this should never be a problem as the adapter's life time
  35     depends on no other object.</p>
  36
  37     <p>Note that in order to remove an object as listener, you have to remove
  38     the same wrapper that you added, i.e., you should store the adapter as a
  39     member in the adapted class for later use.</p>
  40  */
  41 template< class Listener >
  42     class WeakListenerAdapter : public
  43     ::cppu::WeakImplHelper< Listener >
  44 {
  45 public:
  46     explicit WeakListenerAdapter( const css::uno::Reference< Listener > & xListener ) :
  47             m_xListener( xListener )
  48     {}
  49
  50 protected:
  51     // ____ XEventListener (base of all listeners) ____
  52     virtual void SAL_CALL disposing(
  53         const css::lang::EventObject& Source ) override
  54     {
  55         css::uno::Reference< css::lang::XEventListener > xEventListener(
  56                   css::uno::Reference< Listener >( m_xListener), css::uno::UNO_QUERY );
  57         if( xEventListener.is())
  58             xEventListener->disposing( Source );
  59     }
  60
  61     css::uno::Reference< Listener > getListener() const
  62     {
  63         return m_xListener;
  64     }
  65
  66 private:
  67     css::uno::WeakReference< Listener > m_xListener;
  68 };
  69
  70 class WeakSelectionChangeListenerAdapter final :
  71         public WeakListenerAdapter< css::view::XSelectionChangeListener >
  72 {
  73 public:
  74     explicit WeakSelectionChangeListenerAdapter(
  75         const css::uno::Reference< css::view::XSelectionChangeListener > & xListener );
  76     virtual ~WeakSelectionChangeListenerAdapter() override;
  77
  78 protected:
  79     // ____ XSelectionChangeListener ____
  80     virtual void SAL_CALL selectionChanged(
  81         const css::lang::EventObject& aEvent ) override;
  82 };
  83
  84 } //  namespace chart
  85
  86 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */