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 // ----------------------------------------------------------------------------
  37 // private classes
  38 // ----------------------------------------------------------------------------
  39
  40 // this class is used by wxHtmlListBox to cache the parsed representation of
  41 // the items to avoid doing it anew each time an item must be drawn
  42 //
  43 // TODO: extend the class to cache more than item
  44 class wxHtmlListBoxCache
  45 {
  46 public:
  47     wxHtmlListBoxCache() { m_cell = NULL; }
  48     ~wxHtmlListBoxCache() { delete m_cell; }
  49
  50     // returns true if we already have this item cached
  51     bool Has(size_t n) const { return m_cell && n == m_item; }
  52
  53     // ensure that the item is cached
  54     void Store(size_t n, wxHtmlCell *cell)
  55     {
  56         m_item = n;
  57
  58         delete m_cell;
  59         m_cell = cell;
  60     }
  61
  62     // return the cached cell for this index or NULL if none
  63     wxHtmlCell *Get(size_t n) const
  64     {
  65         // we could be reading uninitialized m_item here but the code is still
  66         // correct
  67         return n == m_item ? m_cell : NULL;
  68     }
  69
  70 private:
  71     // the parsed representation of the cached item or NULL
  72     wxHtmlCell *m_cell;
  73
  74     // the index of the currently cached item (only valid if m_cell != NULL)
  75     size_t m_item;
  76 };
  77
  78 // ============================================================================
  79 // implementation
  80 // ============================================================================
  81
  82 // ----------------------------------------------------------------------------
  83 // wxHtmlListBox creation
  84 // ----------------------------------------------------------------------------
  85
  86 void wxHtmlListBox::Init()
  87 {
  88     m_htmlParser = NULL;
  89     m_cache = new wxHtmlListBoxCache;
  90 }
  91
  92 bool wxHtmlListBox::Create(wxWindow *parent,
  93                            wxWindowID id,
  94                            const wxPoint& pos,
  95                            const wxSize& size,
  96                            size_t countItems,
  97                            long style,
  98                            const wxString& name)
  99 {
 100     return wxVListBox::Create(parent, id, pos, size, countItems, style, name);
 101 }
 102
 103 wxHtmlListBox::~wxHtmlListBox()
 104 {
 105     delete m_cache;
 106     if ( m_htmlParser )
 107     {
 108         delete m_htmlParser->GetDC();
 109         delete m_htmlParser;
 110     }
 111 }
 112
 113 // ----------------------------------------------------------------------------
 114 // wxHtmlListBox items markup
 115 // ----------------------------------------------------------------------------
 116
 117 wxString wxHtmlListBox::OnGetItemMarkup(size_t n) const
 118 {
 119     // we don't even need to wrap the value returned by OnGetItem() inside
 120     // "<html><body>" and "</body></html>" because wxHTML can parse it even
 121     // without these tags
 122     return OnGetItem(n);
 123 }
 124
 125 void wxHtmlListBox::CacheItem(size_t n) const
 126 {
 127     if ( !m_cache->Has(n) )
 128     {
 129         if ( !m_htmlParser )
 130         {
 131             wxHtmlListBox *self = wxConstCast(this, wxHtmlListBox);
 132
 133             self->m_htmlParser = new wxHtmlWinParser;
 134             m_htmlParser->SetDC(new wxClientDC(self));
 135         }
 136
 137         wxHtmlContainerCell *cell = (wxHtmlContainerCell *)m_htmlParser->
 138                 Parse(OnGetItemMarkup(n));
 139         wxCHECK_RET( cell, _T("wxHtmlParser::Parse() returned NULL?") );
 140
 141         cell->Layout(GetClientSize().x);
 142
 143         m_cache->Store(n, cell);
 144     }
 145 }
 146
 147 // ----------------------------------------------------------------------------
 148 // wxHtmlListBox implementation of wxVListBox pure virtuals
 149 // ----------------------------------------------------------------------------
 150
 151 void wxHtmlListBox::OnDrawItem(wxDC& dc, const wxRect& rect, size_t n) const
 152 {
 153     CacheItem(n);
 154
 155     wxHtmlCell *cell = m_cache->Get(n);
 156     wxCHECK_RET( cell, _T("this cell should be cached!") );
 157
 158     // draw the selected cell in selected state
 159     if ( IsSelected(n) )
 160     {
 161         wxHtmlSelection htmlSel;
 162         htmlSel.Set(wxPoint(0, 0), cell, wxPoint(INT_MAX, INT_MAX), cell);
 163         wxHtmlRenderingState htmlRendState(&htmlSel);
 164         htmlRendState.SetSelectionState(wxHTML_SEL_IN);
 165         cell->Draw(dc, rect.x, rect.y, 0, INT_MAX, htmlRendState);
 166     }
 167     else
 168     {
 169         // note that we can't stop drawing exactly at the window boundary as then
 170         // even the visible cells part could be not drawn, so always draw the
 171         // entire cell
 172         wxHtmlRenderingState htmlRendState(NULL);
 173         cell->Draw(dc, rect.x, rect.y, 0, INT_MAX, htmlRendState);
 174     }
 175 }
 176
 177 wxCoord wxHtmlListBox::OnMeasureItem(size_t n) const
 178 {
 179     CacheItem(n);
 180
 181     wxHtmlCell *cell = m_cache->Get(n);
 182     wxCHECK_MSG( cell, 0, _T("this cell should be cached!") );
 183
 184     return cell->GetHeight() + cell->GetDescent();
 185 }
 186