contrib/src/fl/antiflickpl.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        antiflickpl.cpp
   3 // Purpose:     Double-buffering plugin class for reducing flickering.
   4 // Author:      Aleksandras Gluchovas (@Lithuania)
   5 // Modified by:
   6 // Created:     23/10/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Aleksandras Gluchovas
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  13     #pragma implementation "antiflickpl.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20 #pragma hdrstop
  21 #endif
  22
  23 #ifndef WX_PRECOMP
  24 #include "wx/wx.h"
  25 #endif
  26
  27 #include "wx/fl/antiflickpl.h"
  28
  29 /***** Implementation for class cbAntiflickerPlugin *****/
  30
  31 IMPLEMENT_DYNAMIC_CLASS( cbAntiflickerPlugin, cbPluginBase )
  32
  33 BEGIN_EVENT_TABLE( cbAntiflickerPlugin, cbPluginBase )
  34
  35     EVT_PL_START_DRAW_IN_AREA  ( cbAntiflickerPlugin::OnStartDrawInArea  )
  36     EVT_PL_FINISH_DRAW_IN_AREA ( cbAntiflickerPlugin::OnFinishDrawInArea )
  37
  38 END_EVENT_TABLE()
  39
  40 // initialization of static members
  41
  42 int cbAntiflickerPlugin::mRefCount    = 0;
  43
  44 wxBitmap*   cbAntiflickerPlugin::mpVertBuf    = 0;
  45 wxBitmap*   cbAntiflickerPlugin::mpHorizBuf   = 0;
  46 wxMemoryDC* cbAntiflickerPlugin::mpVertBufDc  = 0;
  47 wxMemoryDC* cbAntiflickerPlugin::mpHorizBufDc = 0;
  48
  49 // constructors
  50
  51 cbAntiflickerPlugin::cbAntiflickerPlugin(void)
  52     : mpLRUBufDc  ( NULL ),
  53       mLRUArea    ( -1,-1, -1,-1 )
  54 {
  55     ++mRefCount;
  56 }
  57
  58 cbAntiflickerPlugin::cbAntiflickerPlugin( wxFrameLayout* pPanel, int paneMask )
  59
  60     : cbPluginBase( pPanel, paneMask ),
  61       mpLRUBufDc  ( NULL ),
  62       mLRUArea    ( -1,-1, -1,-1 )
  63 {
  64     ++mRefCount;
  65 }
  66
  67 cbAntiflickerPlugin::~cbAntiflickerPlugin()
  68 {
  69     if ( --mRefCount == 0 )
  70     {
  71         if ( mpHorizBuf )
  72         {
  73             mpHorizBufDc->SelectObject( wxNullBitmap );
  74             delete mpHorizBuf;
  75             delete mpHorizBufDc;
  76             mpHorizBuf   = 0;
  77             mpHorizBufDc = 0;
  78         }
  79
  80         if ( mpVertBuf )
  81         {
  82             mpVertBufDc->SelectObject( wxNullBitmap );
  83             delete mpVertBuf;
  84             delete mpVertBufDc;
  85             mpVertBuf   = 0;
  86             mpVertBufDc = 0;
  87         }
  88     }
  89 }
  90
  91 wxDC* cbAntiflickerPlugin::FindSuitableBuffer( const wxRect& forArea )
  92 {
  93     if ( mpVertBuf )
  94     {
  95         if ( mpVertBuf->GetHeight() >= forArea.height &&
  96              mpVertBuf->GetWidth()  >= forArea.width )
  97             return mpVertBufDc;
  98     }
  99     else
 100         if ( mpHorizBuf )
 101         {
 102             if ( mpHorizBuf->GetHeight() >= forArea.height &&
 103                  mpHorizBuf->GetWidth()  >= forArea.width )
 104                 return mpHorizBufDc;
 105         }
 106
 107     return 0;
 108 }
 109
 110 wxDC* cbAntiflickerPlugin::AllocNewBuffer( const wxRect& forArea )
 111 {
 112     // TBD:: preallocate bit larger bitmap at once, to avoid
 113     //       excessive realocations later
 114
 115     // check whether the given area is oriented horizontally
 116     // or vertically and choose corresponding bitmap to create or
 117     // recreate
 118
 119     if ( forArea.height > forArea.width )
 120     {
 121         wxSize prevDim( 0,0 );
 122
 123         if ( mpVertBuf )
 124         {
 125             prevDim.x = mpVertBuf->GetWidth();
 126             prevDim.y = mpVertBuf->GetHeight();
 127
 128             mpVertBufDc->SelectObject( wxNullBitmap );
 129             delete mpVertBuf;
 130         }
 131         else
 132             mpVertBufDc = new wxMemoryDC();
 133
 134         mpVertBuf = new wxBitmap( int( wxMax(forArea.width,  prevDim.x ) ),
 135                                   int( wxMax(forArea.height, prevDim.y ) )
 136                                 );
 137
 138         mpVertBufDc->SelectObject( *mpVertBuf );
 139
 140         return mpVertBufDc;
 141     }
 142     else
 143     {
 144         wxSize prevDim( 0,0 );
 145
 146         if ( mpHorizBuf )
 147         {
 148             prevDim.x = mpHorizBuf->GetWidth();
 149             prevDim.y = mpHorizBuf->GetHeight();
 150
 151             mpHorizBufDc->SelectObject( wxNullBitmap );
 152             delete mpHorizBuf;
 153         }
 154         else
 155             mpHorizBufDc = new wxMemoryDC();
 156
 157         mpHorizBuf = new wxBitmap( int( wxMax(forArea.width,  prevDim.x ) ),
 158                                    int( wxMax(forArea.height, prevDim.y ) )
 159                                  );
 160
 161         mpHorizBufDc->SelectObject( *mpHorizBuf );
 162
 163         return mpHorizBufDc;
 164     }
 165 }
 166
 167 void cbAntiflickerPlugin::OnStartDrawInArea( cbStartDrawInAreaEvent& event )
 168 {
 169     wxASSERT( mpLRUBufDc == NULL ); // DBG:: see comments in OnFinishDrawInArea(..) method
 170
 171     // short-cut
 172     wxRect& area = event.mArea;
 173
 174     if ( event.mArea.width  < 0 ||
 175          event.mArea.height < 0 ) return;
 176
 177     // memorize given area
 178     mLRUArea.x      = area.x;
 179     mLRUArea.y      = area.y;
 180     mLRUArea.width  = area.width;
 181     mLRUArea.height = area.height;
 182
 183     wxDC* pBufDc = FindSuitableBuffer( area );
 184
 185     if ( !pBufDc )
 186         pBufDc = AllocNewBuffer( area );
 187
 188     pBufDc->SetDeviceOrigin( -area.x, -area.y );
 189
 190     pBufDc->SetClippingRegion( area.x,     area.y,
 191                                area.width, area.height );
 192
 193     wxClientDC clntDc( &mpLayout->GetParentFrame() );
 194
 195     (*event.mppDc) = pBufDc;
 196
 197     mpLRUBufDc = pBufDc; // memorize buffer, which will be flushed to screen
 198                          // upon "commiting" the drawing
 199
 200     /*
 201     // OLD STUFF::
 202     mpLRUBufDc->Blit( pos.x, pos.y, size.x, size.y,
 203                       &clntDc, pos.x, pos.y, wxCOPY );
 204                     */
 205 }
 206
 207 void cbAntiflickerPlugin::OnFinishDrawInArea( cbFinishDrawInAreaEvent& event )
 208 {
 209     wxRect& area = event.mArea;
 210
 211     if ( event.mArea.width  < 0 ||
 212          event.mArea.height < 0 ) return;
 213
 214     wxASSERT( mpLRUBufDc ); // DBG:: OnStartDrawInArea should be called first
 215
 216     // FOR NOW:: OnStartDrawInArea(..) should be immediately followed
 217     //           by OnFinishDrawInArea(..) for the same area
 218
 219     wxASSERT( mLRUArea.x      == area.x      );
 220     wxASSERT( mLRUArea.y      == area.y      );
 221     wxASSERT( mLRUArea.width  == area.width  );
 222     wxASSERT( mLRUArea.height == area.height );
 223
 224     wxClientDC clntDc( &mpLayout->GetParentFrame() );
 225
 226     // "commit" drawings in one-shot
 227     clntDc.Blit( area.x, area.y, area.width, area.height,
 228                  mpLRUBufDc, area.x, area.y, wxCOPY );
 229
 230     mpLRUBufDc->DestroyClippingRegion();
 231     mpLRUBufDc = 0;
 232 }
 233