src/generic/htmllbox.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        generic/htmllbox.cpp
   3 // Purpose:     implementation of wxHtmlListBox
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     31.05.03
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
   9 // License:     wxWindows license
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #ifndef WX_PRECOMP
  28     #include "wx/dcclient.h"
  29 #endif //WX_PRECOMP
  30
  31 #include "wx/htmllbox.h"
  32
  33 #include "wx/html/htmlcell.h"
  34 #include "wx/html/winpars.h"
  35
  36 // this hack forces the linker to always link in m_* files
  37 #include "wx/html/forcelnk.h"
  38 FORCE_WXHTML_MODULES()
  39
  40 // ----------------------------------------------------------------------------
  41 // private classes
  42 // ----------------------------------------------------------------------------
  43
  44 // this class is used by wxHtmlListBox to cache the parsed representation of
  45 // the items to avoid doing it anew each time an item must be drawn
  46 class wxHtmlListBoxCache
  47 {
  48 public:
  49     wxHtmlListBoxCache()
  50     {
  51         for ( size_t n = 0; n < SIZE; n++ )
  52         {
  53             m_items[n] = (size_t)-1;
  54             m_cells[n] = NULL;
  55         }
  56
  57         m_next = 0;
  58     }
  59
  60     ~wxHtmlListBoxCache()
  61     {
  62         for ( size_t n = 0; n < SIZE; n++ )
  63         {
  64             delete m_cells[n];
  65         }
  66     }
  67
  68     // completely invalidate the cache
  69     void Clear()
  70     {
  71         for ( size_t n = 0; n < SIZE; n++ )
  72         {
  73             m_items[n] = (size_t)-1;
  74             delete m_cells[n];
  75             m_cells[n] = NULL;
  76         }
  77     }
  78
  79     // return the cached cell for this index or NULL if none
  80     wxHtmlCell *Get(size_t item) const
  81     {
  82         for ( size_t n = 0; n < SIZE; n++ )
  83         {
  84             if ( m_items[n] == item )
  85                 return m_cells[n];
  86         }
  87
  88         return NULL;
  89     }
  90
  91     // returns true if we already have this item cached
  92     bool Has(size_t item) const { return Get(item) != NULL; }
  93
  94     // ensure that the item is cached
  95     void Store(size_t item, wxHtmlCell *cell)
  96     {
  97         delete m_cells[m_next];
  98         m_cells[m_next] = cell;
  99         m_items[m_next] = item;
 100
 101         // advance to the next item wrapping around if there are no more
 102         if ( ++m_next == SIZE )
 103             m_next = 0;
 104     }
 105
 106 private:
 107     // the max number of the items we cache
 108     enum { SIZE = 50 };
 109
 110     // the index of the LRU (oldest) cell
 111     size_t m_next;
 112
 113     // the parsed representation of the cached item or NULL
 114     wxHtmlCell *m_cells[SIZE];
 115
 116     // the index of the currently cached item (only valid if m_cells != NULL)
 117     size_t m_items[SIZE];
 118 };
 119
 120 // ----------------------------------------------------------------------------
 121 // event tables
 122 // ----------------------------------------------------------------------------
 123
 124 BEGIN_EVENT_TABLE(wxHtmlListBox, wxVListBox)
 125     EVT_SIZE(wxHtmlListBox::OnSize)
 126 END_EVENT_TABLE()
 127
 128 // ============================================================================
 129 // implementation
 130 // ============================================================================
 131
 132 // ----------------------------------------------------------------------------
 133 // wxHtmlListBox creation
 134 // ----------------------------------------------------------------------------
 135
 136 void wxHtmlListBox::Init()
 137 {
 138     m_htmlParser = NULL;
 139     m_cache = new wxHtmlListBoxCache;
 140 }
 141
 142 bool wxHtmlListBox::Create(wxWindow *parent,
 143                            wxWindowID id,
 144                            const wxPoint& pos,
 145                            const wxSize& size,
 146                            size_t countItems,
 147                            long style,
 148                            const wxString& name)
 149 {
 150     return wxVListBox::Create(parent, id, pos, size, countItems, style, name);
 151 }
 152
 153 wxHtmlListBox::~wxHtmlListBox()
 154 {
 155     delete m_cache;
 156     if ( m_htmlParser )
 157     {
 158         delete m_htmlParser->GetDC();
 159         delete m_htmlParser;
 160     }
 161 }
 162
 163 // ----------------------------------------------------------------------------
 164 // wxHtmlListBox items markup
 165 // ----------------------------------------------------------------------------
 166
 167 wxString wxHtmlListBox::OnGetItemMarkup(size_t n) const
 168 {
 169     // we don't even need to wrap the value returned by OnGetItem() inside
 170     // "<html><body>" and "</body></html>" because wxHTML can parse it even
 171     // without these tags
 172     return OnGetItem(n);
 173 }
 174
 175 // ----------------------------------------------------------------------------
 176 // wxHtmlListBox cache handling
 177 // ----------------------------------------------------------------------------
 178
 179 void wxHtmlListBox::CacheItem(size_t n) const
 180 {
 181     if ( !m_cache->Has(n) )
 182     {
 183         if ( !m_htmlParser )
 184         {
 185             wxHtmlListBox *self = wxConstCast(this, wxHtmlListBox);
 186
 187             self->m_htmlParser = new wxHtmlWinParser;
 188             m_htmlParser->SetDC(new wxClientDC(self));
 189         }
 190
 191         wxHtmlContainerCell *cell = (wxHtmlContainerCell *)m_htmlParser->
 192                 Parse(OnGetItemMarkup(n));
 193         wxCHECK_RET( cell, _T("wxHtmlParser::Parse() returned NULL?") );
 194
 195         cell->Layout(GetClientSize().x - 2*GetMargins().x);
 196
 197         m_cache->Store(n, cell);
 198     }
 199 }
 200
 201 void wxHtmlListBox::OnSize(wxSizeEvent& event)
 202 {
 203     // we need to relayout all the cached cells
 204     m_cache->Clear();
 205
 206     event.Skip();
 207 }
 208
 209 void wxHtmlListBox::RefreshAll()
 210 {
 211     m_cache->Clear();
 212
 213     wxVListBox::RefreshAll();
 214 }
 215
 216 // ----------------------------------------------------------------------------
 217 // wxHtmlListBox implementation of wxVListBox pure virtuals
 218 // ----------------------------------------------------------------------------
 219
 220 void wxHtmlListBox::OnDrawItem(wxDC& dc, const wxRect& rect, size_t n) const
 221 {
 222     CacheItem(n);
 223
 224     wxHtmlCell *cell = m_cache->Get(n);
 225     wxCHECK_RET( cell, _T("this cell should be cached!") );
 226
 227     wxHtmlRenderingState htmlRendState;
 228
 229     // draw the selected cell in selected state
 230     if ( IsSelected(n) )
 231     {
 232         wxHtmlSelection htmlSel;
 233         htmlSel.Set(wxPoint(0, 0), cell, wxPoint(INT_MAX, INT_MAX), cell);
 234         htmlRendState.SetSelection(&htmlSel);
 235         htmlRendState.SetSelectionState(wxHTML_SEL_IN);
 236     }
 237
 238     // note that we can't stop drawing exactly at the window boundary as then
 239     // even the visible cells part could be not drawn, so always draw the
 240     // entire cell
 241     cell->Draw(dc, rect.x, rect.y, 0, INT_MAX, htmlRendState);
 242 }
 243
 244 wxCoord wxHtmlListBox::OnMeasureItem(size_t n) const
 245 {
 246     CacheItem(n);
 247
 248     wxHtmlCell *cell = m_cache->Get(n);
 249     wxCHECK_MSG( cell, 0, _T("this cell should be cached!") );
 250
 251     return cell->GetHeight() + cell->GetDescent();
 252 }
 253