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
  98                          return mpVertBufDc;
  99         }
 100         else
 101         if ( mpHorizBuf )
 102         {
 103                 if ( mpHorizBuf->GetHeight() >= forArea.height &&
 104                          mpHorizBuf->GetWidth()  >= forArea.width )
 105
 106                          return mpHorizBufDc;
 107         }
 108
 109         return 0;
 110 }
 111
 112 wxDC* cbAntiflickerPlugin::AllocNewBuffer( const wxRect& forArea )
 113 {
 114         // TBD:: preallocate bit larger bitmap at once, to avoid
 115         //       excessive realocations later
 116
 117         // check whether the given area is oriented horizontally
 118         // or vertically and choose corresponding bitmap to create or
 119         // recreate
 120
 121         if ( forArea.height > forArea.width )
 122         {
 123                 wxSize prevDim( 0,0 );
 124
 125                 if ( mpVertBuf )
 126                 {
 127                         prevDim.x = mpVertBuf->GetWidth();
 128                         prevDim.y = mpVertBuf->GetHeight();
 129
 130                         mpVertBufDc->SelectObject( wxNullBitmap );
 131                         delete mpVertBuf;
 132                 }
 133                 else
 134                         mpVertBufDc = new wxMemoryDC();
 135
 136                 mpVertBuf = new wxBitmap( int( wxMax(forArea.width,  prevDim.x ) ),
 137                                                                   int( wxMax(forArea.height, prevDim.y ) )
 138                                                                 );
 139
 140                 mpVertBufDc->SelectObject( *mpVertBuf );
 141
 142                 return mpVertBufDc;
 143         }
 144         else
 145         {
 146                 wxSize prevDim( 0,0 );
 147
 148                 if ( mpHorizBuf )
 149                 {
 150                         prevDim.x = mpHorizBuf->GetWidth();
 151                         prevDim.y = mpHorizBuf->GetHeight();
 152
 153                         mpHorizBufDc->SelectObject( wxNullBitmap );
 154                         delete mpHorizBuf;
 155                 }
 156                 else
 157                         mpHorizBufDc = new wxMemoryDC();
 158
 159                 mpHorizBuf = new wxBitmap( int( wxMax(forArea.width,  prevDim.x ) ),
 160                                                                    int( wxMax(forArea.height, prevDim.y ) )
 161                                                                  );
 162
 163                 mpHorizBufDc->SelectObject( *mpHorizBuf );
 164
 165                 return mpHorizBufDc;
 166         }
 167 }
 168
 169 void cbAntiflickerPlugin::OnStartDrawInArea( cbStartDrawInAreaEvent& event )
 170 {
 171         wxASSERT( mpLRUBufDc == NULL ); // DBG:: see comments in OnFinishDrawInArea(..) method
 172
 173         // short-cut
 174         wxRect& area = event.mArea;
 175
 176         if ( event.mArea.width  < 0 ||
 177                  event.mArea.height < 0 ) return;
 178
 179         // memorize given area
 180         mLRUArea.x      = area.x;
 181         mLRUArea.y      = area.y;
 182         mLRUArea.width  = area.width;
 183         mLRUArea.height = area.height;
 184
 185         wxDC* pBufDc = FindSuitableBuffer( area );
 186
 187         if ( !pBufDc )
 188
 189                 pBufDc = AllocNewBuffer( area );
 190
 191         pBufDc->SetDeviceOrigin( -area.x, -area.y );
 192
 193         pBufDc->SetClippingRegion( area.x,     area.y,
 194                                                            area.width, area.height );
 195
 196         wxClientDC clntDc( &mpLayout->GetParentFrame() );
 197
 198         (*event.mppDc) = pBufDc;
 199
 200         mpLRUBufDc = pBufDc; // memorize buffer, which will be flushed to screen
 201                              // upon "commiting" the drawing
 202
 203         /*
 204         // OLD STUFF::
 205         mpLRUBufDc->Blit( pos.x, pos.y, size.x, size.y,
 206                                       &clntDc, pos.x, pos.y, wxCOPY );
 207                                         */
 208 }
 209
 210 void cbAntiflickerPlugin::OnFinishDrawInArea( cbFinishDrawInAreaEvent& event )
 211 {
 212         wxRect& area = event.mArea;
 213
 214         if ( event.mArea.width  < 0 ||
 215                  event.mArea.height < 0 ) return;
 216
 217         wxASSERT( mpLRUBufDc ); // DBG:: OnStartDrawInArea should be called first
 218
 219         // FOR NOW:: OnStartDrawInArea(..) should be immediately followed
 220         //           by OnFinishDrawInArea(..) for the same area
 221
 222         wxASSERT( mLRUArea.x      == area.x      );
 223         wxASSERT( mLRUArea.y      == area.y      );
 224         wxASSERT( mLRUArea.width  == area.width  );
 225         wxASSERT( mLRUArea.height == area.height );
 226
 227         wxClientDC clntDc( &mpLayout->GetParentFrame() );
 228
 229         // "commit" drawings in one-shot
 230         clntDc.Blit( area.x, area.y, area.width, area.height,
 231                                  mpLRUBufDc, area.x, area.y, wxCOPY );
 232
 233         mpLRUBufDc->DestroyClippingRegion();
 234         mpLRUBufDc = 0;
 235 }
 236