src/msw/dcclient.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/msw/dcclient.cpp
   3 // Purpose:     wxClientDC class
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     01/02/97
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   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 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #include "wx/dcclient.h"
  28 #include "wx/msw/dcclient.h"
  29
  30 #ifndef WX_PRECOMP
  31     #include "wx/string.h"
  32     #include "wx/log.h"
  33     #include "wx/window.h"
  34 #endif
  35
  36 #include "wx/msw/private.h"
  37
  38 // ----------------------------------------------------------------------------
  39 // array/list types
  40 // ----------------------------------------------------------------------------
  41
  42 struct WXDLLEXPORT wxPaintDCInfo
  43 {
  44     wxPaintDCInfo(wxWindow *win, wxPaintDCImpl *dc)
  45     {
  46         hwnd = win->GetHWND();
  47         hdc = dc->GetHDC();
  48         count = 1;
  49     }
  50
  51     WXHWND    hwnd;       // window for this DC
  52     WXHDC     hdc;        // the DC handle
  53     size_t    count;      // usage count
  54 };
  55
  56 #include "wx/arrimpl.cpp"
  57
  58 WX_DEFINE_OBJARRAY(wxArrayDCInfo)
  59
  60 // ----------------------------------------------------------------------------
  61 // macros
  62 // ----------------------------------------------------------------------------
  63
  64 // ----------------------------------------------------------------------------
  65 // global variables
  66 // ----------------------------------------------------------------------------
  67
  68 static PAINTSTRUCT g_paintStruct;
  69
  70 #ifdef wxHAS_PAINT_DEBUG
  71     // a global variable which we check to verify that wxPaintDC are only
  72     // created in response to WM_PAINT message - doing this from elsewhere is a
  73     // common programming error among wxWidgets programmers and might lead to
  74     // very subtle and difficult to debug refresh/repaint bugs.
  75     int g_isPainting = 0;
  76 #endif // wxHAS_PAINT_DEBUG
  77
  78 // ===========================================================================
  79 // implementation
  80 // ===========================================================================
  81
  82 // ----------------------------------------------------------------------------
  83 // wxMSWWindowDCImpl
  84 // ----------------------------------------------------------------------------
  85
  86 IMPLEMENT_ABSTRACT_CLASS(wxWindowDCImpl, wxMSWDCImpl)
  87
  88 wxWindowDCImpl::wxWindowDCImpl( wxDC *owner ) :
  89    wxMSWDCImpl( owner )
  90 {
  91 }
  92
  93 wxWindowDCImpl::wxWindowDCImpl( wxDC *owner, wxWindow *window ) :
  94    wxMSWDCImpl( owner )
  95 {
  96     wxCHECK_RET( window, wxT("invalid window in wxWindowDCImpl") );
  97
  98     m_window = window;
  99     m_hDC = (WXHDC) ::GetWindowDC(GetHwndOf(m_window));
 100
 101     // m_bOwnsDC was already set to false in the base class ctor, so the DC
 102     // will be released (and not deleted) in ~wxDC
 103     InitDC();
 104 }
 105
 106 void wxWindowDCImpl::InitDC()
 107 {
 108     // the background mode is only used for text background and is set in
 109     // DrawText() to OPAQUE as required, otherwise always TRANSPARENT,
 110     ::SetBkMode(GetHdc(), TRANSPARENT);
 111
 112     // since we are a window dc we need to grab the palette from the window
 113 #if wxUSE_PALETTE
 114     InitializePalette();
 115 #endif
 116 }
 117
 118 void wxWindowDCImpl::DoGetSize(int *width, int *height) const
 119 {
 120     wxCHECK_RET( m_window, wxT("wxWindowDCImpl without a window?") );
 121
 122     m_window->GetSize(width, height);
 123 }
 124
 125 // ----------------------------------------------------------------------------
 126 // wxClientDCImpl
 127 // ----------------------------------------------------------------------------
 128
 129 IMPLEMENT_ABSTRACT_CLASS(wxClientDCImpl, wxWindowDCImpl)
 130
 131 wxClientDCImpl::wxClientDCImpl( wxDC *owner ) :
 132    wxWindowDCImpl( owner )
 133 {
 134 }
 135
 136 wxClientDCImpl::wxClientDCImpl( wxDC *owner, wxWindow *window ) :
 137    wxWindowDCImpl( owner )
 138 {
 139     wxCHECK_RET( window, wxT("invalid window in wxClientDCImpl") );
 140
 141     m_window = window;
 142     m_hDC = (WXHDC)::GetDC(GetHwndOf(window));
 143
 144     // m_bOwnsDC was already set to false in the base class ctor, so the DC
 145     // will be released (and not deleted) in ~wxDC
 146
 147     InitDC();
 148 }
 149
 150 void wxClientDCImpl::InitDC()
 151 {
 152     wxWindowDCImpl::InitDC();
 153
 154     // in wxUniv build we must manually do some DC adjustments usually
 155     // performed by Windows for us
 156     //
 157     // we also need to take the menu/toolbar manually into account under
 158     // Windows CE because they're just another control there, not anything
 159     // special as usually under Windows
 160 #if defined(__WXUNIVERSAL__) || defined(__WXWINCE__)
 161     wxPoint ptOrigin = m_window->GetClientAreaOrigin();
 162     if ( ptOrigin.x || ptOrigin.y )
 163     {
 164         // no need to shift DC origin if shift is null
 165         SetDeviceOrigin(ptOrigin.x, ptOrigin.y);
 166     }
 167
 168     // clip the DC to avoid overwriting the non client area
 169     wxSize size = m_window->GetClientSize();
 170     DoSetClippingRegion(0, 0, size.x, size.y);
 171 #endif // __WXUNIVERSAL__ || __WXWINCE__
 172 }
 173
 174 wxClientDCImpl::~wxClientDCImpl()
 175 {
 176 }
 177
 178 void wxClientDCImpl::DoGetSize(int *width, int *height) const
 179 {
 180     wxCHECK_RET( m_window, wxT("wxClientDCImpl without a window?") );
 181
 182     m_window->GetClientSize(width, height);
 183 }
 184
 185 // ----------------------------------------------------------------------------
 186 // wxPaintDCImpl
 187 // ----------------------------------------------------------------------------
 188
 189 // VZ: initial implementation (by JACS) only remembered the last wxPaintDC
 190 //     created and tried to reuse it - this was supposed to take care of a
 191 //     situation when a derived class OnPaint() calls base class OnPaint()
 192 //     because in this case ::BeginPaint() shouldn't be called second time.
 193 //
 194 //     I'm not sure how useful this is, however we must remember the HWND
 195 //     associated with the last HDC as well - otherwise we may (and will!) try
 196 //     to reuse the HDC for another HWND which is a nice recipe for disaster.
 197 //
 198 //     So we store a list of windows for which we already have the DC and not
 199 //     just one single hDC. This seems to work, but I'm really not sure about
 200 //     the usefullness of the whole idea - IMHO it's much better to not call
 201 //     base class OnPaint() at all, or, if we really want to allow it, add a
 202 //     "wxPaintDC *" parameter to wxPaintEvent which should be used if it's
 203 //     !NULL instead of creating a new DC.
 204
 205 IMPLEMENT_ABSTRACT_CLASS(wxPaintDCImpl, wxClientDCImpl)
 206
 207 wxArrayDCInfo wxPaintDCImpl::ms_cache;
 208
 209 wxPaintDCImpl::wxPaintDCImpl( wxDC *owner ) :
 210    wxClientDCImpl( owner )
 211 {
 212 }
 213
 214 wxPaintDCImpl::wxPaintDCImpl( wxDC *owner, wxWindow *window ) :
 215    wxClientDCImpl( owner )
 216 {
 217     wxCHECK_RET( window, wxT("NULL canvas in wxPaintDCImpl ctor") );
 218
 219 #ifdef wxHAS_PAINT_DEBUG
 220     if ( g_isPainting <= 0 )
 221     {
 222         wxFAIL_MSG( wxT("wxPaintDCImpl may be created only in EVT_PAINT handler!") );
 223
 224         return;
 225     }
 226 #endif // wxHAS_PAINT_DEBUG
 227
 228     m_window = window;
 229
 230     // do we have a DC for this window in the cache?
 231     wxPaintDCInfo *info = FindInCache();
 232     if ( info )
 233     {
 234         m_hDC = info->hdc;
 235         info->count++;
 236     }
 237     else // not in cache, create a new one
 238     {
 239         // see comments in src/msw/window.cpp where this is defined
 240         extern bool wxDidCreatePaintDC;
 241
 242         wxDidCreatePaintDC = true;
 243
 244         m_hDC = (WXHDC)::BeginPaint(GetHwndOf(m_window), &g_paintStruct);
 245         if (m_hDC)
 246             ms_cache.Add(new wxPaintDCInfo(m_window, this));
 247     }
 248
 249     // Note: at this point m_hDC can be NULL under MicroWindows, when dragging.
 250     if (!GetHDC())
 251         return;
 252
 253     // (re)set the DC parameters.
 254     InitDC();
 255
 256     // the HDC can have a clipping box (which we didn't set), make sure our
 257     // DoGetClippingBox() checks for it
 258     m_clipping = true;
 259 }
 260
 261 wxPaintDCImpl::~wxPaintDCImpl()
 262 {
 263     if ( m_hDC )
 264     {
 265         SelectOldObjects(m_hDC);
 266
 267         size_t index;
 268         wxPaintDCInfo *info = FindInCache(&index);
 269
 270         wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
 271
 272         if ( --info->count == 0 )
 273         {
 274             ::EndPaint(GetHwndOf(m_window), &g_paintStruct);
 275
 276             ms_cache.RemoveAt(index);
 277
 278             // Reduce the number of bogus reports of non-freed memory
 279             // at app exit
 280             if (ms_cache.IsEmpty())
 281                 ms_cache.Clear();
 282         }
 283         //else: cached DC entry is still in use
 284
 285         // prevent the base class dtor from ReleaseDC()ing it again
 286         m_hDC = 0;
 287     }
 288 }
 289
 290 wxPaintDCInfo *wxPaintDCImpl::FindInCache(size_t *index) const
 291 {
 292     wxPaintDCInfo *info = NULL;
 293     size_t nCache = ms_cache.GetCount();
 294     for ( size_t n = 0; n < nCache; n++ )
 295     {
 296         wxPaintDCInfo *info1 = &ms_cache[n];
 297         if ( info1->hwnd == m_window->GetHWND() )
 298         {
 299             info = info1;
 300             if ( index )
 301                 *index = n;
 302             break;
 303         }
 304     }
 305
 306     return info;
 307 }
 308
 309 // find the entry for this DC in the cache (keyed by the window)
 310 WXHDC wxPaintDCImpl::FindDCInCache(wxWindow* win)
 311 {
 312     size_t nCache = ms_cache.GetCount();
 313     for ( size_t n = 0; n < nCache; n++ )
 314     {
 315         wxPaintDCInfo *info = &ms_cache[n];
 316         if ( info->hwnd == win->GetHWND() )
 317         {
 318             return info->hdc;
 319         }
 320     }
 321     return 0;
 322 }
 323
 324 /*
 325  * wxPaintDCEx
 326  */
 327
 328 // TODO: don't duplicate wxPaintDCImpl code here!!
 329
 330 class wxPaintDCExImpl: public wxPaintDCImpl
 331 {
 332 public:
 333     wxPaintDCExImpl( wxDC *owner, wxWindow *window, WXHDC dc );
 334     ~wxPaintDCExImpl();
 335
 336     int m_saveState;
 337 };
 338
 339
 340 IMPLEMENT_ABSTRACT_CLASS(wxPaintDCEx,wxPaintDC)
 341
 342 wxPaintDCEx::wxPaintDCEx(wxWindow *window, WXHDC dc)
 343            : wxPaintDC(new wxPaintDCExImpl(this, window, dc))
 344 {
 345 }
 346
 347 wxPaintDCExImpl::wxPaintDCExImpl(wxDC *owner, wxWindow *window, WXHDC dc)
 348                : wxPaintDCImpl( owner )
 349 {
 350         wxCHECK_RET( dc, wxT("wxPaintDCEx requires an existing device context") );
 351
 352         m_saveState = 0;
 353
 354         m_window = window;
 355
 356         wxPaintDCInfo *info = FindInCache();
 357         if ( info )
 358         {
 359            m_hDC = info->hdc;
 360            info->count++;
 361         }
 362         else // not in cache, create a new one
 363         {
 364                 m_hDC = dc;
 365                 ms_cache.Add(new wxPaintDCInfo(m_window, this));
 366                 m_saveState = SaveDC((HDC) dc);
 367         }
 368 }
 369
 370 wxPaintDCExImpl::~wxPaintDCExImpl()
 371 {
 372         size_t index;
 373         wxPaintDCInfo *info = FindInCache(&index);
 374
 375         wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
 376
 377         if ( --info->count == 0 )
 378         {
 379                 RestoreDC((HDC) m_hDC, m_saveState);
 380                 ms_cache.RemoveAt(index);
 381
 382                 // Reduce the number of bogus reports of non-freed memory
 383                 // at app exit
 384                 if (ms_cache.IsEmpty())
 385                         ms_cache.Clear();
 386         }
 387         //else: cached DC entry is still in use
 388
 389         // prevent the base class dtor from ReleaseDC()ing it again
 390         m_hDC = 0;
 391 }
 392
 393