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 __WXDEBUG__
  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 // __WXDEBUG__
  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, _T("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     // default bg colour is pne of the window
 113     SetBackground(wxBrush(m_window->GetBackgroundColour(), wxSOLID));
 114
 115     // since we are a window dc we need to grab the palette from the window
 116 #if wxUSE_PALETTE
 117     InitializePalette();
 118 #endif
 119 }
 120
 121 void wxWindowDCImpl::DoGetSize(int *width, int *height) const
 122 {
 123     wxCHECK_RET( m_window, _T("wxWindowDCImpl without a window?") );
 124
 125     m_window->GetSize(width, height);
 126 }
 127
 128 // ----------------------------------------------------------------------------
 129 // wxClientDCImpl
 130 // ----------------------------------------------------------------------------
 131
 132 IMPLEMENT_ABSTRACT_CLASS(wxClientDCImpl, wxWindowDCImpl)
 133
 134 wxClientDCImpl::wxClientDCImpl( wxDC *owner ) :
 135    wxWindowDCImpl( owner )
 136 {
 137 }
 138
 139 wxClientDCImpl::wxClientDCImpl( wxDC *owner, wxWindow *window ) :
 140    wxWindowDCImpl( owner )
 141 {
 142     wxCHECK_RET( window, _T("invalid window in wxClientDCImpl") );
 143
 144     m_window = window;
 145     m_hDC = (WXHDC)::GetDC(GetHwndOf(window));
 146
 147     // m_bOwnsDC was already set to false in the base class ctor, so the DC
 148     // will be released (and not deleted) in ~wxDC
 149
 150     InitDC();
 151 }
 152
 153 void wxClientDCImpl::InitDC()
 154 {
 155     wxWindowDCImpl::InitDC();
 156
 157     // in wxUniv build we must manually do some DC adjustments usually
 158     // performed by Windows for us
 159     //
 160     // we also need to take the menu/toolbar manually into account under
 161     // Windows CE because they're just another control there, not anything
 162     // special as usually under Windows
 163 #if defined(__WXUNIVERSAL__) || defined(__WXWINCE__)
 164     wxPoint ptOrigin = m_window->GetClientAreaOrigin();
 165     if ( ptOrigin.x || ptOrigin.y )
 166     {
 167         // no need to shift DC origin if shift is null
 168         SetDeviceOrigin(ptOrigin.x, ptOrigin.y);
 169     }
 170
 171     // clip the DC to avoid overwriting the non client area
 172     wxSize size = m_window->GetClientSize();
 173     DoSetClippingRegion(0, 0, size.x, size.y);
 174 #endif // __WXUNIVERSAL__ || __WXWINCE__
 175 }
 176
 177 wxClientDCImpl::~wxClientDCImpl()
 178 {
 179 }
 180
 181 void wxClientDCImpl::DoGetSize(int *width, int *height) const
 182 {
 183     wxCHECK_RET( m_window, _T("wxClientDCImpl without a window?") );
 184
 185     m_window->GetClientSize(width, height);
 186 }
 187
 188 // ----------------------------------------------------------------------------
 189 // wxPaintDCImpl
 190 // ----------------------------------------------------------------------------
 191
 192 // VZ: initial implementation (by JACS) only remembered the last wxPaintDC
 193 //     created and tried to reuse it - this was supposed to take care of a
 194 //     situation when a derived class OnPaint() calls base class OnPaint()
 195 //     because in this case ::BeginPaint() shouldn't be called second time.
 196 //
 197 //     I'm not sure how useful this is, however we must remember the HWND
 198 //     associated with the last HDC as well - otherwise we may (and will!) try
 199 //     to reuse the HDC for another HWND which is a nice recipe for disaster.
 200 //
 201 //     So we store a list of windows for which we already have the DC and not
 202 //     just one single hDC. This seems to work, but I'm really not sure about
 203 //     the usefullness of the whole idea - IMHO it's much better to not call
 204 //     base class OnPaint() at all, or, if we really want to allow it, add a
 205 //     "wxPaintDC *" parameter to wxPaintEvent which should be used if it's
 206 //     !NULL instead of creating a new DC.
 207
 208 IMPLEMENT_ABSTRACT_CLASS(wxPaintDCImpl, wxClientDCImpl)
 209
 210 wxArrayDCInfo wxPaintDCImpl::ms_cache;
 211
 212 wxPaintDCImpl::wxPaintDCImpl( wxDC *owner ) :
 213    wxClientDCImpl( owner )
 214 {
 215 }
 216
 217 wxPaintDCImpl::wxPaintDCImpl( wxDC *owner, wxWindow *window ) :
 218    wxClientDCImpl( owner )
 219 {
 220     wxCHECK_RET( window, wxT("NULL canvas in wxPaintDCImpl ctor") );
 221
 222 #ifdef __WXDEBUG__
 223     if ( g_isPainting <= 0 )
 224     {
 225         wxFAIL_MSG( wxT("wxPaintDCImpl may be created only in EVT_PAINT handler!") );
 226
 227         return;
 228     }
 229 #endif // __WXDEBUG__
 230
 231     m_window = window;
 232
 233     // do we have a DC for this window in the cache?
 234     wxPaintDCInfo *info = FindInCache();
 235     if ( info )
 236     {
 237         m_hDC = info->hdc;
 238         info->count++;
 239     }
 240     else // not in cache, create a new one
 241     {
 242         m_hDC = (WXHDC)::BeginPaint(GetHwndOf(m_window), &g_paintStruct);
 243         if (m_hDC)
 244             ms_cache.Add(new wxPaintDCInfo(m_window, this));
 245     }
 246
 247     // Note: at this point m_hDC can be NULL under MicroWindows, when dragging.
 248     if (!GetHDC())
 249         return;
 250
 251     // (re)set the DC parameters.
 252     InitDC();
 253
 254     // the HDC can have a clipping box (which we didn't set), make sure our
 255     // DoGetClippingBox() checks for it
 256     m_clipping = true;
 257 }
 258
 259 wxPaintDCImpl::~wxPaintDCImpl()
 260 {
 261     if ( m_hDC )
 262     {
 263         SelectOldObjects(m_hDC);
 264
 265         size_t index;
 266         wxPaintDCInfo *info = FindInCache(&index);
 267
 268         wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
 269
 270         if ( --info->count == 0 )
 271         {
 272             ::EndPaint(GetHwndOf(m_window), &g_paintStruct);
 273
 274             ms_cache.RemoveAt(index);
 275
 276             // Reduce the number of bogus reports of non-freed memory
 277             // at app exit
 278             if (ms_cache.IsEmpty())
 279                 ms_cache.Clear();
 280         }
 281         //else: cached DC entry is still in use
 282
 283         // prevent the base class dtor from ReleaseDC()ing it again
 284         m_hDC = 0;
 285     }
 286 }
 287
 288 wxPaintDCInfo *wxPaintDCImpl::FindInCache(size_t *index) const
 289 {
 290     wxPaintDCInfo *info = NULL;
 291     size_t nCache = ms_cache.GetCount();
 292     for ( size_t n = 0; n < nCache; n++ )
 293     {
 294         wxPaintDCInfo *info1 = &ms_cache[n];
 295         if ( info1->hwnd == m_window->GetHWND() )
 296         {
 297             info = info1;
 298             if ( index )
 299                 *index = n;
 300             break;
 301         }
 302     }
 303
 304     return info;
 305 }
 306
 307 // find the entry for this DC in the cache (keyed by the window)
 308 WXHDC wxPaintDCImpl::FindDCInCache(wxWindow* win)
 309 {
 310     size_t nCache = ms_cache.GetCount();
 311     for ( size_t n = 0; n < nCache; n++ )
 312     {
 313         wxPaintDCInfo *info = &ms_cache[n];
 314         if ( info->hwnd == win->GetHWND() )
 315         {
 316             return info->hdc;
 317         }
 318     }
 319     return 0;
 320 }
 321
 322 /*
 323  * wxPaintDCEx
 324  */
 325
 326 // TODO: don't duplicate wxPaintDCImpl code here!!
 327
 328 class wxPaintDCExImpl: public wxPaintDCImpl
 329 {
 330 public:
 331     wxPaintDCExImpl( wxDC *owner, wxWindow *window, WXHDC dc );
 332     ~wxPaintDCExImpl();
 333
 334     int m_saveState;
 335 };
 336
 337
 338 IMPLEMENT_ABSTRACT_CLASS(wxPaintDCEx,wxPaintDC)
 339
 340 wxPaintDCEx::wxPaintDCEx(wxWindow *window, WXHDC dc)
 341            : wxPaintDC(new wxPaintDCExImpl(this, window, dc))
 342 {
 343 }
 344
 345 wxPaintDCExImpl::wxPaintDCExImpl(wxDC *owner, wxWindow *window, WXHDC dc)
 346                : wxPaintDCImpl( owner )
 347 {
 348         wxCHECK_RET( dc, wxT("wxPaintDCEx requires an existing device context") );
 349
 350         m_saveState = 0;
 351
 352         m_window = window;
 353
 354         wxPaintDCInfo *info = FindInCache();
 355         if ( info )
 356         {
 357            m_hDC = info->hdc;
 358            info->count++;
 359         }
 360         else // not in cache, create a new one
 361         {
 362                 m_hDC = dc;
 363                 ms_cache.Add(new wxPaintDCInfo(m_window, this));
 364                 m_saveState = SaveDC((HDC) dc);
 365         }
 366 }
 367
 368 wxPaintDCExImpl::~wxPaintDCExImpl()
 369 {
 370         size_t index;
 371         wxPaintDCInfo *info = FindInCache(&index);
 372
 373         wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
 374
 375         if ( --info->count == 0 )
 376         {
 377                 RestoreDC((HDC) m_hDC, m_saveState);
 378                 ms_cache.RemoveAt(index);
 379
 380                 // Reduce the number of bogus reports of non-freed memory
 381                 // at app exit
 382                 if (ms_cache.IsEmpty())
 383                         ms_cache.Clear();
 384         }
 385         //else: cached DC entry is still in use
 386
 387         // prevent the base class dtor from ReleaseDC()ing it again
 388         m_hDC = 0;
 389 }
 390
 391