chart2/source/inc/WeakListenerAdapter.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  18  */
  19 #pragma once
  20
  21 #include <com/sun/star/lang/XEventListener.hpp>
  22 #include <com/sun/star/util/XModifyListener.hpp>
  23 #include <com/sun/star/view/XSelectionChangeListener.hpp>
  24 #include <cppuhelper/weakref.hxx>
  25 #include <cppuhelper/implbase.hxx>
  26
  27 namespace chart
  28 {
  29
  30 /** Adapter that enables adding listeners as weak UNO references.  Thus, adding
  31     an object as listener to a broadcaster does not increase its reference
  32     count.
  33
  34     <p>The helper class, of course, is held as hard reference at the
  35     broadcaster, but this should never be a problem as the adapter's life time
  36     depends on no other object.</p>
  37
  38     <p>Note that in order to remove an object as listener, you have to remove
  39     the same wrapper that you added, i.e., you should store the adapter as a
  40     member in the adapted class for later use.</p>
  41  */
  42 template< class Listener >
  43     class WeakListenerAdapter : public
  44     ::cppu::WeakImplHelper< Listener >
  45 {
  46 public:
  47     explicit WeakListenerAdapter( const css::uno::Reference< Listener > & xListener ) :
  48             m_xListener( xListener )
  49     {}
  50     explicit WeakListenerAdapter( const css::uno::WeakReference< Listener > & xListener ) :
  51             m_xListener( xListener )
  52     {}
  53
  54 protected:
  55     // ____ XEventListener (base of all listeners) ____
  56     virtual void SAL_CALL disposing(
  57         const css::lang::EventObject& Source ) override
  58     {
  59         css::uno::Reference< css::lang::XEventListener > xEventListener(
  60                   css::uno::Reference< Listener >( m_xListener), css::uno::UNO_QUERY );
  61         if( xEventListener.is())
  62             xEventListener->disposing( Source );
  63     }
  64
  65     css::uno::Reference< Listener > getListener() const
  66     {
  67         return m_xListener;
  68     }
  69
  70 private:
  71     css::uno::WeakReference< Listener > m_xListener;
  72 };
  73
  74 class WeakModifyListenerAdapter :
  75         public WeakListenerAdapter< css::util::XModifyListener >
  76 {
  77 public:
  78     explicit WeakModifyListenerAdapter(
  79         const css::uno::WeakReference< css::util::XModifyListener > & xListener );
  80     virtual ~WeakModifyListenerAdapter() override;
  81
  82 protected:
  83     // ____ XModifyListener ____
  84     virtual void SAL_CALL modified( const css::lang::EventObject& aEvent ) override;
  85 };
  86
  87 class WeakSelectionChangeListenerAdapter :
  88         public WeakListenerAdapter< css::view::XSelectionChangeListener >
  89 {
  90 public:
  91     explicit WeakSelectionChangeListenerAdapter(
  92         const css::uno::Reference< css::view::XSelectionChangeListener > & xListener );
  93     virtual ~WeakSelectionChangeListenerAdapter() override;
  94
  95 protected:
  96     // ____ XSelectionChangeListener ____
  97     virtual void SAL_CALL selectionChanged(
  98         const css::lang::EventObject& aEvent ) override;
  99 };
 100
 101 } //  namespace chart
 102
 103 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */