src/os2/dcclient.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dcclient.cpp
   3 // Purpose:     wxClientDC class
   4 // Author:      David Webster
   5 // Modified by:
   6 // Created:     09/21/99
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) David Webster
   9 // Licence:     wxWindows licence
  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 #include "wx/string.h"
  24 #include "wx/log.h"
  25 #include "wx/window.h"
  26
  27 #include "wx/os2/private.h"
  28
  29 #include "wx/dcclient.h"
  30
  31 // ----------------------------------------------------------------------------
  32 // array/list types
  33 // ----------------------------------------------------------------------------
  34
  35 struct WXDLLEXPORT wxPaintDCInfo
  36 {
  37     wxPaintDCInfo(wxWindow *win, wxDC *dc)
  38     {
  39         hwnd = win->GetHWND();
  40         hdc = dc->GetHDC();
  41         count = 1;
  42     }
  43
  44     WXHWND    hwnd;       // window for this DC
  45     WXHDC     hdc;        // the DC handle
  46     size_t    count;      // usage count
  47 };
  48
  49 #include "wx/arrimpl.cpp"
  50
  51 WX_DEFINE_OBJARRAY(wxArrayDCInfo);
  52
  53 // ----------------------------------------------------------------------------
  54 // macros
  55 // ----------------------------------------------------------------------------
  56
  57     IMPLEMENT_DYNAMIC_CLASS(wxWindowDC, wxDC)
  58     IMPLEMENT_DYNAMIC_CLASS(wxClientDC, wxWindowDC)
  59     IMPLEMENT_DYNAMIC_CLASS(wxPaintDC, wxWindowDC)
  60
  61 // ----------------------------------------------------------------------------
  62 // global variables
  63 // ----------------------------------------------------------------------------
  64
  65 static RECT        g_paintStruct;
  66
  67 #ifdef __WXDEBUG__
  68     // a global variable which we check to verify that wxPaintDC are only
  69     // created in resopnse to WM_PAINT message - doing this from elsewhere is a
  70     // common programming error among wxWindows programmers and might lead to
  71     // very subtle and difficult to debug refresh/repaint bugs.
  72     int g_isPainting = 0;
  73 #endif // __WXDEBUG__
  74
  75 // ===========================================================================
  76 // implementation
  77 // ===========================================================================
  78
  79 // ----------------------------------------------------------------------------
  80 // wxWindowDC
  81 // ----------------------------------------------------------------------------
  82
  83 wxWindowDC::wxWindowDC()
  84 {
  85   m_pCanvas = NULL;
  86 }
  87
  88 wxWindowDC::wxWindowDC(wxWindow *the_canvas)
  89 {
  90   m_pCanvas = the_canvas;
  91   m_hDC = (WXHDC) ::WinOpenWindowDC(GetWinHwnd(the_canvas) );
  92   m_nDCCount++;
  93   //
  94   // default under PM is that Window and Client DC's are the same
  95   // so we offer a separate Presentation Space to use for the
  96   // entire window.  Otherwise, calling BeginPaint will just create
  97   // chached-micro client presentation space
  98   //
  99    m_hPS = GpiCreatePS( m_hab
 100                        ,m_hDC
 101                        ,&m_PageSize
 102                        ,PU_PELS | GPIF_LONG | GPIA_ASSOC
 103                       );
 104   ::GpiAssociate(m_hPS, NULLHANDLE);
 105   ::GpiAssociate(m_hPS, m_hDC);
 106   SetBackground(wxBrush(m_pCanvas->GetBackgroundColour(), wxSOLID));
 107 }
 108
 109 wxWindowDC::~wxWindowDC()
 110 {
 111   if (m_pCanvas && m_hDC)
 112   {
 113     SelectOldObjects(m_hDC);
 114
 115     //
 116     // In PM one does not explicitly close or release an open WindowDC
 117     // They automatically close with the window, unless explicitly detached
 118     // but we need to destroy our PS
 119     //
 120     if(m_hPS)
 121     {
 122         ::GpiAssociate(m_hPS, NULLHANDLE);
 123         ::GpiDestroyPS(m_hPS);
 124     }
 125     m_hPS = NULLHANDLE;
 126     m_hDC = NULLHANDLE;
 127   }
 128
 129   m_nDCCount--;
 130 }
 131
 132 // ----------------------------------------------------------------------------
 133 // wxClientDC
 134 // ----------------------------------------------------------------------------
 135
 136 wxClientDC::wxClientDC()
 137 {
 138   m_pCanvas = NULL;
 139 }
 140
 141 wxClientDC::wxClientDC(wxWindow *the_canvas)
 142 {
 143     SIZEL                           vSizl = { 0,0};
 144
 145     m_pCanvas = the_canvas;
 146
 147     //
 148     // default under PM is that Window and Client DC's are the same
 149     //
 150     m_hDC = (WXHDC) ::WinOpenWindowDC(GetWinHwnd(the_canvas));
 151     m_hPS = ::GpiCreatePS( wxGetInstance()
 152                           ,m_hDC
 153                           ,&vSizl
 154                           ,PU_PELS | GPIF_LONG | GPIA_ASSOC
 155                          );
 156
 157     //
 158     // Default mode is BM_LEAVEALONE so we make no call Set the mix
 159     //
 160     SetBackground(wxBrush( m_pCanvas->GetBackgroundColour()
 161                           ,wxSOLID
 162                          )
 163                  );
 164 }
 165
 166 wxClientDC::~wxClientDC()
 167 {
 168   if ( m_pCanvas && GetHdc() )
 169   {
 170     SelectOldObjects(m_hDC);
 171
 172     // We don't explicitly release Device contexts in PM and
 173     // the cached micro PS is already gone
 174
 175     m_hDC = 0;
 176   }
 177 }
 178
 179 // ----------------------------------------------------------------------------
 180 // wxPaintDC
 181 // ----------------------------------------------------------------------------
 182
 183 // VZ: initial implementation (by JACS) only remembered the last wxPaintDC
 184 //     created and tried to reuse - this was supposed to take care of a
 185 //     situation when a derived class OnPaint() calls base class OnPaint()
 186 //     because in this case ::BeginPaint() shouldn't be called second time.
 187 //
 188 //     I'm not sure how useful this is, however we must remember the HWND
 189 //     associated with the last HDC as well - otherwise we may (and will!) try
 190 //     to reuse the HDC for another HWND which is a nice recipe for disaster.
 191 //
 192 //     So we store a list of windows for which we already have the DC and not
 193 //     just one single hDC. This seems to work, but I'm really not sure about
 194 //     the usefullness of the whole idea - IMHO it's much better to not call
 195 //     base class OnPaint() at all, or, if we really want to allow it, add a
 196 //     "wxPaintDC *" parameter to wxPaintEvent which should be used if it's
 197 //     !NULL instead of creating a new DC.
 198
 199 wxArrayDCInfo wxPaintDC::ms_cache;
 200
 201 wxPaintDC::wxPaintDC()
 202 {
 203     m_pCanvas = NULL;
 204     m_hDC = 0;
 205 }
 206
 207 wxPaintDC::wxPaintDC(
 208   wxWindow*                         pCanvas
 209 )
 210 {
 211     wxCHECK_RET(pCanvas, wxT("NULL canvas in wxPaintDC ctor"));
 212
 213 #ifdef __WXDEBUG__
 214     if (g_isPainting <= 0)
 215     {
 216         wxFAIL_MSG( wxT("wxPaintDC may be created only in EVT_PAINT handler!") );
 217         return;
 218     }
 219 #endif // __WXDEBUG__
 220
 221     m_pCanvas = pCanvas;
 222
 223     //
 224     // Do we have a DC for this window in the cache?
 225     //
 226     wxPaintDCInfo*                  pInfo = FindInCache();
 227
 228     if (pInfo)
 229     {
 230         m_hDC = pInfo->hdc;
 231         pInfo->count++;
 232     }
 233     else // not in cache, create a new one
 234     {
 235         HPS                         hPS;
 236
 237         hPS = ::WinBeginPaint( GetWinHwnd(m_pCanvas)
 238                               ,NULLHANDLE
 239                               ,&g_paintStruct
 240                              );
 241         if(hPS)
 242         {
 243             m_hOldPS = m_hPS;
 244             m_hPS = hPS;
 245         }
 246         m_bIsPaintTime   = TRUE;
 247         m_hDC = (WXHDC) -1; // to satisfy those anonizmous efforts
 248         m_vRclPaint = g_paintStruct;
 249         ms_cache.Add(new wxPaintDCInfo(m_pCanvas, this));
 250     }
 251     SetBackground(wxBrush(m_pCanvas->GetBackgroundColour(), wxSOLID));
 252 }
 253
 254 wxPaintDC::~wxPaintDC()
 255 {
 256     if ( m_hDC )
 257     {
 258         SelectOldObjects(m_hDC);
 259
 260         size_t index;
 261         wxPaintDCInfo *info = FindInCache(&index);
 262
 263         wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
 264
 265         if ( !--info->count )
 266         {
 267             ::WinEndPaint(m_hPS);
 268             m_hPS          = m_hOldPS;
 269             m_bIsPaintTime = FALSE;
 270             ms_cache.Remove(index);
 271         }
 272         //else: cached DC entry is still in use
 273
 274         // prevent the base class dtor from ReleaseDC()ing it again
 275         m_hDC = 0;
 276     }
 277 }
 278
 279 wxPaintDCInfo *wxPaintDC::FindInCache(size_t *index) const
 280 {
 281     wxPaintDCInfo *info = NULL;
 282     size_t nCache = ms_cache.GetCount();
 283     for ( size_t n = 0; n < nCache; n++ )
 284     {
 285         info = &ms_cache[n];
 286         if ( info->hwnd == m_pCanvas->GetHWND() )
 287         {
 288             if ( index )
 289                 *index = n;
 290             break;
 291         }
 292     }
 293
 294     return info;
 295 }