include/sfx2/itemwrapper.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
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   9  * This file incorporates work covered by the following license notice:
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  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #ifndef SFX_ITEMWRAPPER_HXX
  21 #define SFX_ITEMWRAPPER_HXX
  22
  23 #include "sal/config.h"
  24 #include "sfx2/dllapi.h"
  25 #include <svl/eitem.hxx>
  26 #include <svl/stritem.hxx>
  27 #include <svl/intitem.hxx>
  28 #include <svl/itemset.hxx>
  29
  30 // ============================================================================
  31
  32 namespace sfx {
  33
  34 // ============================================================================
  35 // Helpers
  36 // ============================================================================
  37
  38 class SFX2_DLLPUBLIC ItemWrapperHelper
  39 {
  40 public:
  41     /** Returns the WID of the passed SID in the item set. */
  42     static sal_uInt16       GetWhichId( const SfxItemSet& rItemSet, sal_uInt16 nSlot );
  43
  44     /** Returns true, if the passed item set supports the SID. */
  45     static bool         IsKnownItem( const SfxItemSet& rItemSet, sal_uInt16 nSlot );
  46
  47     /** Returns an item from an item set, if it is not in "don't know" state.
  48         @return  Pointer to item, or 0 if it has "don't know" state. */
  49     static const SfxPoolItem* GetUniqueItem( const SfxItemSet& rItemSet, sal_uInt16 nSlot );
  50
  51     /** Returns the default item from the pool of the passed item set. */
  52     static const SfxPoolItem& GetDefaultItem( const SfxItemSet& rItemSet, sal_uInt16 nSlot );
  53
  54     /** Removes an item from rDestSet, if it is default in rOldSet. */
  55     static void         RemoveDefaultItem( SfxItemSet& rDestSet, const SfxItemSet& rOldSet, sal_uInt16 nSlot );
  56 };
  57
  58 // ============================================================================
  59 // Item wrappers
  60 // ============================================================================
  61
  62 /** Base class wrapping a single item.
  63
  64     Objects of this class store the SID of an item. Exchanging data with the
  65     item is done with the virtual functions GetItemValue() and SetItemValue().
  66     Derived classes implement these functions according to the item type they
  67     work on.
  68
  69     The current tree of base classes/templates and standard item wrappers:
  70
  71     SingleItemWrapper< ItemT, ValueT >
  72      |
  73      +- ValueItemWrapper< ItemT, ValueT >   [1]
  74      |   |
  75      |   +- BoolItemWrapper   [1]
  76      |   +- Int16ItemWrapper   [1]
  77      |   +- UInt16ItemWrapper   [1]
  78      |   +- Int32ItemWrapper   [1]
  79      |   +- UInt32ItemWrapper   [1]
  80      |   +- StringItemWrapper   [1]
  81      |
  82      +- IdentItemWrapper< ItemT >   [1]
  83
  84     Notes:
  85     [1] Standard wrappers ready to use.
  86
  87     See documentation of class ItemConnectionBase for more details.
  88  */
  89 template< typename ItemT, typename ValueT >
  90 class SingleItemWrapper
  91 {
  92 public:
  93     typedef ItemT                               ItemType;
  94     typedef ValueT                              ItemValueType;
  95     typedef SingleItemWrapper< ItemT, ValueT >  SingleItemWrapperType;
  96
  97     inline explicit     SingleItemWrapper( sal_uInt16 nSlot ) : mnSlot( nSlot ) {}
  98
  99     virtual             ~SingleItemWrapper() {}
 100
 101     /** Returns the SID this wrapper works on. */
 102     inline sal_uInt16       GetSlotId() const { return mnSlot; }
 103
 104     /** Returns the item from an item set, if it is not in "don't know" state.
 105         @descr  Similar to ItemWrapperHelper::GetUniqueItem(), but works always
 106         with the own SID and returns the correct item type.
 107         @return Pointer to item, or 0 if it has "don't know" state. */
 108     const ItemT*        GetUniqueItem( const SfxItemSet& rItemSet ) const;
 109     /** Returns the default item from the pool of the passed item set.
 110         @descr  Similar to ItemWrapperHelper::GetDefaultItem(), but works
 111         always with the own SID and returns the correct item type. */
 112     const ItemT&        GetDefaultItem( const SfxItemSet& rItemSet ) const;
 113
 114     /** Derived classes return the value of the passed item. */
 115     virtual ValueT      GetItemValue( const ItemT& rItem ) const = 0;
 116     /** Derived classes set the value at the passed item. */
 117     virtual void        SetItemValue( ItemT& rItem, ValueT aValue ) const = 0;
 118
 119 private:
 120     sal_uInt16              mnSlot;     /// The SID of this item wrapper.
 121 };
 122
 123 // ============================================================================
 124
 125 /** An item wrapper usable for most types of items.
 126
 127     The item type must support the following functions:
 128     - ValueT ItemT::GetValue() const
 129     - void ItemT::SetValue( ValueT )
 130
 131     The template parameter InternalValueT can be used to specify the internal
 132     value type of the item, if it differs from ValueT. This parameter has to be
 133     used to prevent compiler warnings.
 134  */
 135 template< typename ItemT, typename ValueT, typename InternalValueT = ValueT >
 136 class ValueItemWrapper : public SingleItemWrapper< ItemT, ValueT >
 137 {
 138 public:
 139     inline explicit     ValueItemWrapper( sal_uInt16 nSlot ) :
 140                             SingleItemWrapper< ItemT, ValueT >( nSlot ) {}
 141
 142     virtual             ~ValueItemWrapper() {}
 143
 144     virtual ValueT      GetItemValue( const ItemT& rItem ) const
 145                             { return static_cast< ValueT >( rItem.GetValue() ); }
 146     virtual void        SetItemValue( ItemT& rItem, ValueT aValue ) const
 147                             { rItem.SetValue( static_cast< InternalValueT >( aValue ) ); }
 148 };
 149
 150 // ----------------------------------------------------------------------------
 151
 152 typedef ValueItemWrapper< SfxBoolItem,   sal_Bool >          BoolItemWrapper;
 153 typedef ValueItemWrapper< SfxInt16Item,  sal_Int16 >         Int16ItemWrapper;
 154 typedef ValueItemWrapper< SfxUInt16Item, sal_uInt16 >        UInt16ItemWrapper;
 155 typedef ValueItemWrapper< SfxInt32Item,  sal_Int32 >         Int32ItemWrapper;
 156 typedef ValueItemWrapper< SfxUInt32Item, sal_uInt32 >        UInt32ItemWrapper;
 157 typedef ValueItemWrapper< SfxStringItem, const String& > StringItemWrapper;
 158
 159 // ============================================================================
 160
 161 /** An item wrapper that uses the item itself as value. */
 162 template< typename ItemT >
 163 class IdentItemWrapper : public SingleItemWrapper< ItemT, const ItemT& >
 164 {
 165 public:
 166     inline explicit     IdentItemWrapper( sal_uInt16 nSlot ) :
 167                             SingleItemWrapper< ItemT, const ItemT& >( nSlot ) {}
 168
 169     virtual             ~IdentItemWrapper() {}
 170
 171     virtual const ItemT& GetItemValue( const ItemT& rItem ) const
 172                             { return rItem; }
 173     virtual void        SetItemValue( ItemT& rItem, const ItemT& rValue ) const
 174                             { rItem = rValue; }
 175 };
 176
 177 // ============================================================================
 178
 179
 180 // ============================================================================
 181 //               ***  Implementation of template functions  ***
 182 // ============================================================================
 183
 184 // ============================================================================
 185 // Item wrappers
 186 // ============================================================================
 187
 188 template< typename ItemT, typename ValueT >
 189 const ItemT* SingleItemWrapper< ItemT, ValueT >::GetUniqueItem( const SfxItemSet& rItemSet ) const
 190 {
 191     return static_cast< const ItemT* >( ItemWrapperHelper::GetUniqueItem( rItemSet, mnSlot ) );
 192 }
 193
 194 template< typename ItemT, typename ValueT >
 195 const ItemT& SingleItemWrapper< ItemT, ValueT >::GetDefaultItem( const SfxItemSet& rItemSet ) const
 196 {
 197     return static_cast< const ItemT& >( ItemWrapperHelper::GetDefaultItem( rItemSet, mnSlot ) );
 198 }
 199
 200 // ============================================================================
 201
 202 } // namespace sfx
 203
 204 #endif
 205
 206 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */