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