include/wx/selstore.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/selstore.h
   3 // Purpose:     wxSelectionStore stores selected items in a control
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     08.06.03 (extracted from src/generic/listctrl.cpp)
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2000-2003 Vadim Zeitlin <vadim@wxwidgets.org>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_SELSTORE_H_
  13 #define _WX_SELSTORE_H_
  14
  15 #include "wx/dynarray.h"
  16
  17 // ----------------------------------------------------------------------------
  18 // wxSelectedIndices is just a sorted array of indices
  19 // ----------------------------------------------------------------------------
  20
  21 inline int CMPFUNC_CONV wxSizeTCmpFn(size_t n1, size_t n2)
  22 {
  23     return (int)(n1 - n2);
  24 }
  25
  26 WX_DEFINE_SORTED_EXPORTED_ARRAY_CMP_SIZE_T(size_t,
  27                                            wxSizeTCmpFn,
  28                                            wxSelectedIndices);
  29
  30 // ----------------------------------------------------------------------------
  31 // wxSelectionStore is used to store the selected items in the virtual
  32 // controls, i.e. it is well suited for storing even when the control contains
  33 // a huge (practically infinite) number of items.
  34 //
  35 // Of course, internally it still has to store the selected items somehow (as
  36 // an array currently) but the advantage is that it can handle the selection
  37 // of all items (common operation) efficiently and that it could be made even
  38 // smarter in the future (e.g. store the selections as an array of ranges +
  39 // individual items) without changing its API.
  40 // ----------------------------------------------------------------------------
  41
  42 class WXDLLEXPORT wxSelectionStore
  43 {
  44 public:
  45     wxSelectionStore() : m_itemsSel(wxSizeTCmpFn) { Init(); }
  46
  47     // set the total number of items we handle
  48     void SetItemCount(size_t count) { m_count = count; }
  49
  50     // special case of SetItemCount(0)
  51     void Clear() { m_itemsSel.Clear(); m_count = 0; m_defaultState = false; }
  52
  53     // must be called when a new item is inserted/added
  54     void OnItemAdd(size_t WXUNUSED(item)) { wxFAIL_MSG( _T("TODO") ); }
  55
  56     // must be called when an item is deleted
  57     void OnItemDelete(size_t item);
  58
  59     // select one item, use SelectRange() insted if possible!
  60     //
  61     // returns true if the items selection really changed
  62     bool SelectItem(size_t item, bool select = true);
  63
  64     // select the range of items
  65     //
  66     // return true and fill the itemsChanged array with the indices of items
  67     // which have changed state if "few" of them did, otherwise return false
  68     // (meaning that too many items changed state to bother counting them
  69     // individually)
  70     bool SelectRange(size_t itemFrom, size_t itemTo,
  71                      bool select = true,
  72                      wxArrayInt *itemsChanged = NULL);
  73
  74     // return true if the given item is selected
  75     bool IsSelected(size_t item) const;
  76
  77     // return the total number of selected items
  78     size_t GetSelectedCount() const
  79     {
  80         return m_defaultState ? m_count - m_itemsSel.GetCount()
  81                               : m_itemsSel.GetCount();
  82     }
  83
  84 private:
  85     // (re)init
  86     void Init() { m_defaultState = false; }
  87
  88     // the total number of items we handle
  89     size_t m_count;
  90
  91     // the default state: normally, false (i.e. off) but maybe set to true if
  92     // there are more selected items than non selected ones - this allows to
  93     // handle selection of all items efficiently
  94     bool m_defaultState;
  95
  96     // the array of items whose selection state is different from default
  97     wxSelectedIndices m_itemsSel;
  98
  99     DECLARE_NO_COPY_CLASS(wxSelectionStore)
 100 };
 101
 102
 103 #endif // _WX_SELSTORE_H_
 104