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     SetClippingRegion(wxPoint(0,0), m_window->GetClientSize());
 173 #endif // __WXUNIVERSAL__ || __WXWINCE__
 174 }
 175
 176 wxClientDCImpl::~wxClientDCImpl()
 177 {
 178 }
 179
 180 void wxClientDCImpl::DoGetSize(int *width, int *height) const
 181 {
 182     wxCHECK_RET( m_window, _T("wxClientDCImpl without a window?") );
 183
 184     m_window->GetClientSize(width, height);
 185 }
 186
 187 // ----------------------------------------------------------------------------
 188 // wxPaintDCImpl
 189 // ----------------------------------------------------------------------------
 190
 191 // VZ: initial implementation (by JACS) only remembered the last wxPaintDC
 192 //     created and tried to reuse it - this was supposed to take care of a
 193 //     situation when a derived class OnPaint() calls base class OnPaint()
 194 //     because in this case ::BeginPaint() shouldn't be called second time.
 195 //
 196 //     I'm not sure how useful this is, however we must remember the HWND
 197 //     associated with the last HDC as well - otherwise we may (and will!) try
 198 //     to reuse the HDC for another HWND which is a nice recipe for disaster.
 199 //
 200 //     So we store a list of windows for which we already have the DC and not
 201 //     just one single hDC. This seems to work, but I'm really not sure about
 202 //     the usefullness of the whole idea - IMHO it's much better to not call
 203 //     base class OnPaint() at all, or, if we really want to allow it, add a
 204 //     "wxPaintDC *" parameter to wxPaintEvent which should be used if it's
 205 //     !NULL instead of creating a new DC.
 206
 207 IMPLEMENT_ABSTRACT_CLASS(wxPaintDCImpl, wxClientDCImpl)
 208
 209 wxArrayDCInfo wxPaintDCImpl::ms_cache;
 210
 211 wxPaintDCImpl::wxPaintDCImpl( wxDC *owner ) :
 212    wxClientDCImpl( owner )
 213 {
 214 }
 215
 216 wxPaintDCImpl::wxPaintDCImpl( wxDC *owner, wxWindow *window ) :
 217    wxClientDCImpl( owner )
 218 {
 219     wxCHECK_RET( window, wxT("NULL canvas in wxPaintDCImpl ctor") );
 220
 221 #ifdef __WXDEBUG__
 222     if ( g_isPainting <= 0 )
 223     {
 224         wxFAIL_MSG( wxT("wxPaintDCImpl may be created only in EVT_PAINT handler!") );
 225
 226         return;
 227     }
 228 #endif // __WXDEBUG__
 229
 230     m_window = window;
 231
 232     // do we have a DC for this window in the cache?
 233     wxPaintDCInfo *info = FindInCache();
 234     if ( info )
 235     {
 236         m_hDC = info->hdc;
 237         info->count++;
 238     }
 239     else // not in cache, create a new one
 240     {
 241         m_hDC = (WXHDC)::BeginPaint(GetHwndOf(m_window), &g_paintStruct);
 242         if (m_hDC)
 243             ms_cache.Add(new wxPaintDCInfo(m_window, this));
 244     }
 245
 246     // Note: at this point m_hDC can be NULL under MicroWindows, when dragging.
 247     if (!GetHDC())
 248         return;
 249
 250     // (re)set the DC parameters.
 251     InitDC();
 252
 253     // the HDC can have a clipping box (which we didn't set), make sure our
 254     // DoGetClippingBox() checks for it
 255     m_clipping = true;
 256 }
 257
 258 wxPaintDCImpl::~wxPaintDCImpl()
 259 {
 260     if ( m_hDC )
 261     {
 262         SelectOldObjects(m_hDC);
 263
 264         size_t index;
 265         wxPaintDCInfo *info = FindInCache(&index);
 266
 267         wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
 268
 269         if ( --info->count == 0 )
 270         {
 271             ::EndPaint(GetHwndOf(m_window), &g_paintStruct);
 272
 273             ms_cache.RemoveAt(index);
 274
 275             // Reduce the number of bogus reports of non-freed memory
 276             // at app exit
 277             if (ms_cache.IsEmpty())
 278                 ms_cache.Clear();
 279         }
 280         //else: cached DC entry is still in use
 281
 282         // prevent the base class dtor from ReleaseDC()ing it again
 283         m_hDC = 0;
 284     }
 285 }
 286
 287 wxPaintDCInfo *wxPaintDCImpl::FindInCache(size_t *index) const
 288 {
 289     wxPaintDCInfo *info = NULL;
 290     size_t nCache = ms_cache.GetCount();
 291     for ( size_t n = 0; n < nCache; n++ )
 292     {
 293         wxPaintDCInfo *info1 = &ms_cache[n];
 294         if ( info1->hwnd == m_window->GetHWND() )
 295         {
 296             info = info1;
 297             if ( index )
 298                 *index = n;
 299             break;
 300         }
 301     }
 302
 303     return info;
 304 }
 305
 306 // find the entry for this DC in the cache (keyed by the window)
 307 WXHDC wxPaintDCImpl::FindDCInCache(wxWindow* win)
 308 {
 309     size_t nCache = ms_cache.GetCount();
 310     for ( size_t n = 0; n < nCache; n++ )
 311     {
 312         wxPaintDCInfo *info = &ms_cache[n];
 313         if ( info->hwnd == win->GetHWND() )
 314         {
 315             return info->hdc;
 316         }
 317     }
 318     return 0;
 319 }
 320
 321 /*
 322  * wxPaintDCEx
 323  */
 324
 325 // TODO: don't duplicate wxPaintDCImpl code here!!
 326
 327 class wxPaintDCExImpl: public wxPaintDCImpl
 328 {
 329 public:
 330     wxPaintDCExImpl( wxDC *owner, wxWindow *window, WXHDC dc );
 331     ~wxPaintDCExImpl();
 332
 333     int m_saveState;
 334 };
 335
 336
 337 IMPLEMENT_ABSTRACT_CLASS(wxPaintDCEx,wxPaintDC)
 338
 339 wxPaintDCEx::wxPaintDCEx(wxWindow *window, WXHDC dc)
 340            : wxPaintDC(new wxPaintDCExImpl(this, window, dc))
 341 {
 342 }
 343
 344 wxPaintDCExImpl::wxPaintDCExImpl(wxDC *owner, wxWindow *window, WXHDC dc)
 345                : wxPaintDCImpl( owner )
 346 {
 347         wxCHECK_RET( dc, wxT("wxPaintDCEx requires an existing device context") );
 348
 349         m_saveState = 0;
 350
 351         m_window = window;
 352
 353         wxPaintDCInfo *info = FindInCache();
 354         if ( info )
 355         {
 356            m_hDC = info->hdc;
 357            info->count++;
 358         }
 359         else // not in cache, create a new one
 360         {
 361                 m_hDC = dc;
 362                 ms_cache.Add(new wxPaintDCInfo(m_window, this));
 363                 m_saveState = SaveDC((HDC) dc);
 364         }
 365 }
 366
 367 wxPaintDCExImpl::~wxPaintDCExImpl()
 368 {
 369         size_t index;
 370         wxPaintDCInfo *info = FindInCache(&index);
 371
 372         wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
 373
 374         if ( --info->count == 0 )
 375         {
 376                 RestoreDC((HDC) m_hDC, m_saveState);
 377                 ms_cache.RemoveAt(index);
 378
 379                 // Reduce the number of bogus reports of non-freed memory
 380                 // at app exit
 381                 if (ms_cache.IsEmpty())
 382                         ms_cache.Clear();
 383         }
 384         //else: cached DC entry is still in use
 385
 386         // prevent the base class dtor from ReleaseDC()ing it again
 387         m_hDC = 0;
 388 }
 389
 390