src/msw/app.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/msw/app.cpp
   3 // Purpose:     wxApp
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     04/01/98
   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 #if defined(__BORLANDC__)
  24     #pragma hdrstop
  25 #endif
  26
  27 #ifndef WX_PRECOMP
  28     #include "wx/msw/wrapcctl.h"
  29     #include "wx/dynarray.h"
  30     #include "wx/frame.h"
  31     #include "wx/app.h"
  32     #include "wx/utils.h"
  33     #include "wx/gdicmn.h"
  34     #include "wx/pen.h"
  35     #include "wx/brush.h"
  36     #include "wx/cursor.h"
  37     #include "wx/icon.h"
  38     #include "wx/palette.h"
  39     #include "wx/dc.h"
  40     #include "wx/dialog.h"
  41     #include "wx/msgdlg.h"
  42     #include "wx/intl.h"
  43     #include "wx/crt.h"
  44     #include "wx/log.h"
  45     #include "wx/module.h"
  46 #endif
  47
  48 #include "wx/apptrait.h"
  49 #include "wx/filename.h"
  50 #include "wx/dynlib.h"
  51 #include "wx/evtloop.h"
  52 #include "wx/thread.h"
  53
  54 #include "wx/msw/private.h"
  55 #include "wx/msw/ole/oleutils.h"
  56 #include "wx/msw/private/timer.h"
  57
  58 #if wxUSE_TOOLTIPS
  59     #include "wx/tooltip.h"
  60 #endif // wxUSE_TOOLTIPS
  61
  62 // OLE is used for drag-and-drop, clipboard, OLE Automation..., but some
  63 // compilers don't support it (missing headers, libs, ...)
  64 #if defined(__GNUWIN32_OLD__) || defined(__SYMANTEC__)
  65     #undef wxUSE_OLE
  66
  67     #define  wxUSE_OLE 0
  68 #endif // broken compilers
  69
  70 #if defined(__POCKETPC__) || defined(__SMARTPHONE__)
  71     #include <ole2.h>
  72     #include <aygshell.h>
  73 #endif
  74
  75 #if wxUSE_OLE
  76     #include <ole2.h>
  77 #endif
  78
  79 #include <string.h>
  80 #include <ctype.h>
  81
  82 #include "wx/msw/missing.h"
  83
  84 // instead of including <shlwapi.h> which is not part of the core SDK and not
  85 // shipped at all with other compilers, we always define the parts of it we
  86 // need here ourselves
  87 //
  88 // NB: DLLVER_PLATFORM_WINDOWS will be defined if shlwapi.h had been somehow
  89 //     included already
  90 #ifndef DLLVER_PLATFORM_WINDOWS
  91     // hopefully we don't need to change packing as DWORDs should be already
  92     // correctly aligned
  93     struct DLLVERSIONINFO
  94     {
  95         DWORD cbSize;
  96         DWORD dwMajorVersion;                   // Major version
  97         DWORD dwMinorVersion;                   // Minor version
  98         DWORD dwBuildNumber;                    // Build number
  99         DWORD dwPlatformID;                     // DLLVER_PLATFORM_*
 100     };
 101
 102     typedef HRESULT (CALLBACK* DLLGETVERSIONPROC)(DLLVERSIONINFO *);
 103 #endif // defined(DLLVERSIONINFO)
 104
 105
 106 // ---------------------------------------------------------------------------
 107 // global variables
 108 // ---------------------------------------------------------------------------
 109
 110 #if !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
 111 extern void wxSetKeyboardHook(bool doIt);
 112 #endif
 113
 114 // NB: all "NoRedraw" classes must have the same names as the "normal" classes
 115 //     with NR suffix - wxWindow::MSWCreate() supposes this
 116 #ifdef __WXWINCE__
 117 WXDLLIMPEXP_CORE       wxChar *wxCanvasClassName;
 118 WXDLLIMPEXP_CORE       wxChar *wxCanvasClassNameNR;
 119 #else
 120 WXDLLIMPEXP_CORE const wxChar *wxCanvasClassName        = wxT("wxWindowClass");
 121 WXDLLIMPEXP_CORE const wxChar *wxCanvasClassNameNR      = wxT("wxWindowClassNR");
 122 #endif
 123 WXDLLIMPEXP_CORE const wxChar *wxMDIFrameClassName      = wxT("wxMDIFrameClass");
 124 WXDLLIMPEXP_CORE const wxChar *wxMDIFrameClassNameNoRedraw = wxT("wxMDIFrameClassNR");
 125 WXDLLIMPEXP_CORE const wxChar *wxMDIChildFrameClassName = wxT("wxMDIChildFrameClass");
 126 WXDLLIMPEXP_CORE const wxChar *wxMDIChildFrameClassNameNoRedraw = wxT("wxMDIChildFrameClassNR");
 127
 128 // ----------------------------------------------------------------------------
 129 // private functions
 130 // ----------------------------------------------------------------------------
 131
 132 LRESULT WXDLLEXPORT APIENTRY wxWndProc(HWND, UINT, WPARAM, LPARAM);
 133
 134 // ===========================================================================
 135 // wxGUIAppTraits implementation
 136 // ===========================================================================
 137
 138 // private class which we use to pass parameters from BeforeChildWaitLoop() to
 139 // AfterChildWaitLoop()
 140 struct ChildWaitLoopData
 141 {
 142     ChildWaitLoopData(wxWindowDisabler *wd_, wxWindow *winActive_)
 143     {
 144         wd = wd_;
 145         winActive = winActive_;
 146     }
 147
 148     wxWindowDisabler *wd;
 149     wxWindow *winActive;
 150 };
 151
 152 void *wxGUIAppTraits::BeforeChildWaitLoop()
 153 {
 154     /*
 155        We use a dirty hack here to disable all application windows (which we
 156        must do because otherwise the calls to wxYield() could lead to some very
 157        unexpected reentrancies in the users code) but to avoid losing
 158        focus/activation entirely when the child process terminates which would
 159        happen if we simply disabled everything using wxWindowDisabler. Indeed,
 160        remember that Windows will never activate a disabled window and when the
 161        last childs window is closed and Windows looks for a window to activate
 162        all our windows are still disabled. There is no way to enable them in
 163        time because we don't know when the childs windows are going to be
 164        closed, so the solution we use here is to keep one special tiny frame
 165        enabled all the time. Then when the child terminates it will get
 166        activated and when we close it below -- after reenabling all the other
 167        windows! -- the previously active window becomes activated again and
 168        everything is ok.
 169      */
 170     wxBeginBusyCursor();
 171
 172     // first disable all existing windows
 173     wxWindowDisabler *wd = new wxWindowDisabler;
 174
 175     // then create an "invisible" frame: it has minimal size, is positioned
 176     // (hopefully) outside the screen and doesn't appear on the taskbar
 177     wxWindow *winActive = new wxFrame
 178                     (
 179                         wxTheApp->GetTopWindow(),
 180                         wxID_ANY,
 181                         wxEmptyString,
 182                         wxPoint(32600, 32600),
 183                         wxSize(1, 1),
 184                         wxDEFAULT_FRAME_STYLE | wxFRAME_NO_TASKBAR
 185                     );
 186     winActive->Show();
 187
 188     return new ChildWaitLoopData(wd, winActive);
 189 }
 190
 191 void wxGUIAppTraits::AlwaysYield()
 192 {
 193     wxYield();
 194 }
 195
 196 void wxGUIAppTraits::AfterChildWaitLoop(void *dataOrig)
 197 {
 198     wxEndBusyCursor();
 199
 200     ChildWaitLoopData * const data = (ChildWaitLoopData *)dataOrig;
 201
 202     delete data->wd;
 203
 204     // finally delete the dummy frame and, as wd has been already destroyed and
 205     // the other windows reenabled, the activation is going to return to the
 206     // window which had had it before
 207     data->winActive->Destroy();
 208
 209     // also delete the temporary data object itself
 210     delete data;
 211 }
 212
 213 bool wxGUIAppTraits::DoMessageFromThreadWait()
 214 {
 215     // we should return false only if the app should exit, i.e. only if
 216     // Dispatch() determines that the main event loop should terminate
 217     wxEventLoopBase * const evtLoop = wxEventLoop::GetActive();
 218     if ( !evtLoop || !evtLoop->Pending() )
 219     {
 220         // no events means no quit event
 221         return true;
 222     }
 223
 224     return evtLoop->Dispatch();
 225 }
 226
 227 DWORD wxGUIAppTraits::WaitForThread(WXHANDLE hThread)
 228 {
 229     // if we don't have a running event loop, we shouldn't wait for the
 230     // messages as we never remove them from the message queue and so we enter
 231     // an infinite loop as MsgWaitForMultipleObjects() keeps returning
 232     // WAIT_OBJECT_0 + 1
 233     if ( !wxEventLoop::GetActive() )
 234         return DoSimpleWaitForThread(hThread);
 235
 236     return ::MsgWaitForMultipleObjects
 237              (
 238                1,                   // number of objects to wait for
 239                (HANDLE *)&hThread,  // the objects
 240                false,               // wait for any objects, not all
 241                INFINITE,            // no timeout
 242                QS_ALLINPUT |        // return as soon as there are any events
 243                QS_ALLPOSTMESSAGE
 244              );
 245 }
 246
 247 wxPortId wxGUIAppTraits::GetToolkitVersion(int *majVer, int *minVer) const
 248 {
 249     OSVERSIONINFO info;
 250     wxZeroMemory(info);
 251
 252     // on Windows, the toolkit version is the same of the OS version
 253     // as Windows integrates the OS kernel with the GUI toolkit.
 254     info.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
 255     if ( ::GetVersionEx(&info) )
 256     {
 257         if ( majVer )
 258             *majVer = info.dwMajorVersion;
 259         if ( minVer )
 260             *minVer = info.dwMinorVersion;
 261     }
 262
 263 #if defined(__WXHANDHELD__) || defined(__WXWINCE__)
 264     return wxPORT_WINCE;
 265 #else
 266     return wxPORT_MSW;
 267 #endif
 268 }
 269
 270 #if wxUSE_TIMER
 271
 272 wxTimerImpl *wxGUIAppTraits::CreateTimerImpl(wxTimer *timer)
 273 {
 274     return new wxMSWTimerImpl(timer);
 275 }
 276
 277 #endif // wxUSE_TIMER
 278
 279 wxEventLoopBase* wxGUIAppTraits::CreateEventLoop()
 280 {
 281     return new wxEventLoop;
 282 }
 283
 284 // ===========================================================================
 285 // wxApp implementation
 286 // ===========================================================================
 287
 288 int wxApp::m_nCmdShow = SW_SHOWNORMAL;
 289
 290 // ---------------------------------------------------------------------------
 291 // wxWin macros
 292 // ---------------------------------------------------------------------------
 293
 294 IMPLEMENT_DYNAMIC_CLASS(wxApp, wxEvtHandler)
 295
 296 BEGIN_EVENT_TABLE(wxApp, wxEvtHandler)
 297     EVT_IDLE(wxApp::OnIdle)
 298     EVT_END_SESSION(wxApp::OnEndSession)
 299     EVT_QUERY_END_SESSION(wxApp::OnQueryEndSession)
 300 END_EVENT_TABLE()
 301
 302 // class to ensure that wxAppBase::CleanUp() is called if our Initialize()
 303 // fails
 304 class wxCallBaseCleanup
 305 {
 306 public:
 307     wxCallBaseCleanup(wxApp *app) : m_app(app) { }
 308     ~wxCallBaseCleanup() { if ( m_app ) m_app->wxAppBase::CleanUp(); }
 309
 310     void Dismiss() { m_app = NULL; }
 311
 312 private:
 313     wxApp *m_app;
 314 };
 315
 316 //// Initialize
 317 bool wxApp::Initialize(int& argc, wxChar **argv)
 318 {
 319     if ( !wxAppBase::Initialize(argc, argv) )
 320         return false;
 321
 322     // ensure that base cleanup is done if we return too early
 323     wxCallBaseCleanup callBaseCleanup(this);
 324
 325 #ifdef __WXWINCE__
 326     wxString tmp = GetAppName();
 327     tmp += wxT("ClassName");
 328     wxCanvasClassName = wxStrdup( tmp.wc_str() );
 329     tmp += wxT("NR");
 330     wxCanvasClassNameNR = wxStrdup( tmp.wc_str() );
 331     HWND hWnd = FindWindow( wxCanvasClassNameNR, NULL );
 332     if (hWnd)
 333     {
 334         SetForegroundWindow( (HWND)(((DWORD)hWnd)|0x01) );
 335         return false;
 336     }
 337 #endif
 338
 339 #if !defined(__WXMICROWIN__)
 340     InitCommonControls();
 341 #endif // !defined(__WXMICROWIN__)
 342
 343 #if defined(__SMARTPHONE__) || defined(__POCKETPC__)
 344     SHInitExtraControls();
 345 #endif
 346
 347 #ifndef __WXWINCE__
 348     // Don't show a message box if a function such as SHGetFileInfo
 349     // fails to find a device.
 350     SetErrorMode(SEM_FAILCRITICALERRORS|SEM_NOOPENFILEERRORBOX);
 351 #endif
 352
 353     wxOleInitialize();
 354
 355     RegisterWindowClasses();
 356
 357     wxWinHandleHash = new wxWinHashTable(wxKEY_INTEGER, 100);
 358
 359 #if !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
 360     wxSetKeyboardHook(true);
 361 #endif
 362
 363     callBaseCleanup.Dismiss();
 364
 365     return true;
 366 }
 367
 368 // ---------------------------------------------------------------------------
 369 // RegisterWindowClasses
 370 // ---------------------------------------------------------------------------
 371
 372 // TODO we should only register classes really used by the app. For this it
 373 //      would be enough to just delay the class registration until an attempt
 374 //      to create a window of this class is made.
 375 bool wxApp::RegisterWindowClasses()
 376 {
 377     WNDCLASS wndclass;
 378     wxZeroMemory(wndclass);
 379
 380     // for each class we register one with CS_(V|H)REDRAW style and one
 381     // without for windows created with wxNO_FULL_REDRAW_ON_REPAINT flag
 382     static const long styleNormal = CS_HREDRAW | CS_VREDRAW | CS_DBLCLKS;
 383     static const long styleNoRedraw = CS_DBLCLKS;
 384
 385     // the fields which are common to all classes
 386     wndclass.lpfnWndProc   = (WNDPROC)wxWndProc;
 387     wndclass.hInstance     = wxhInstance;
 388     wndclass.hCursor       = ::LoadCursor((HINSTANCE)NULL, IDC_ARROW);
 389
 390     // register the class for all normal windows
 391     wndclass.hbrBackground = (HBRUSH)(COLOR_BTNFACE + 1);
 392     wndclass.lpszClassName = wxCanvasClassName;
 393     wndclass.style         = styleNormal;
 394
 395     if ( !RegisterClass(&wndclass) )
 396     {
 397         wxLogLastError(wxT("RegisterClass(frame)"));
 398     }
 399
 400     // "no redraw" frame
 401     wndclass.lpszClassName = wxCanvasClassNameNR;
 402     wndclass.style         = styleNoRedraw;
 403
 404     if ( !RegisterClass(&wndclass) )
 405     {
 406         wxLogLastError(wxT("RegisterClass(no redraw frame)"));
 407     }
 408
 409     // Register the MDI frame window class.
 410     wndclass.hbrBackground = (HBRUSH)NULL; // paint MDI frame ourselves
 411     wndclass.lpszClassName = wxMDIFrameClassName;
 412     wndclass.style         = styleNormal;
 413
 414     if ( !RegisterClass(&wndclass) )
 415     {
 416         wxLogLastError(wxT("RegisterClass(MDI parent)"));
 417     }
 418
 419     // "no redraw" MDI frame
 420     wndclass.lpszClassName = wxMDIFrameClassNameNoRedraw;
 421     wndclass.style         = styleNoRedraw;
 422
 423     if ( !RegisterClass(&wndclass) )
 424     {
 425         wxLogLastError(wxT("RegisterClass(no redraw MDI parent frame)"));
 426     }
 427
 428     // Register the MDI child frame window class.
 429     wndclass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
 430     wndclass.lpszClassName = wxMDIChildFrameClassName;
 431     wndclass.style         = styleNormal;
 432
 433     if ( !RegisterClass(&wndclass) )
 434     {
 435         wxLogLastError(wxT("RegisterClass(MDI child)"));
 436     }
 437
 438     // "no redraw" MDI child frame
 439     wndclass.lpszClassName = wxMDIChildFrameClassNameNoRedraw;
 440     wndclass.style         = styleNoRedraw;
 441
 442     if ( !RegisterClass(&wndclass) )
 443     {
 444         wxLogLastError(wxT("RegisterClass(no redraw MDI child)"));
 445     }
 446
 447     return true;
 448 }
 449
 450 // ---------------------------------------------------------------------------
 451 // UnregisterWindowClasses
 452 // ---------------------------------------------------------------------------
 453
 454 bool wxApp::UnregisterWindowClasses()
 455 {
 456     bool retval = true;
 457
 458 #ifndef __WXMICROWIN__
 459     // MDI frame window class.
 460     if ( !::UnregisterClass(wxMDIFrameClassName, wxhInstance) )
 461     {
 462         wxLogLastError(wxT("UnregisterClass(MDI parent)"));
 463
 464         retval = false;
 465     }
 466
 467     // "no redraw" MDI frame
 468     if ( !::UnregisterClass(wxMDIFrameClassNameNoRedraw, wxhInstance) )
 469     {
 470         wxLogLastError(wxT("UnregisterClass(no redraw MDI parent frame)"));
 471
 472         retval = false;
 473     }
 474
 475     // MDI child frame window class.
 476     if ( !::UnregisterClass(wxMDIChildFrameClassName, wxhInstance) )
 477     {
 478         wxLogLastError(wxT("UnregisterClass(MDI child)"));
 479
 480         retval = false;
 481     }
 482
 483     // "no redraw" MDI child frame
 484     if ( !::UnregisterClass(wxMDIChildFrameClassNameNoRedraw, wxhInstance) )
 485     {
 486         wxLogLastError(wxT("UnregisterClass(no redraw MDI child)"));
 487
 488         retval = false;
 489     }
 490
 491     // canvas class name
 492     if ( !::UnregisterClass(wxCanvasClassName, wxhInstance) )
 493     {
 494         wxLogLastError(wxT("UnregisterClass(canvas)"));
 495
 496         retval = false;
 497     }
 498
 499     if ( !::UnregisterClass(wxCanvasClassNameNR, wxhInstance) )
 500     {
 501         wxLogLastError(wxT("UnregisterClass(no redraw canvas)"));
 502
 503         retval = false;
 504     }
 505 #endif // __WXMICROWIN__
 506
 507     return retval;
 508 }
 509
 510 void wxApp::CleanUp()
 511 {
 512     // all objects pending for deletion must be deleted first, otherwise we
 513     // would crash when they use wxWinHandleHash (and UnregisterWindowClasses()
 514     // call wouldn't succeed as long as any windows still exist), so call the
 515     // base class method first and only then do our clean up
 516     wxAppBase::CleanUp();
 517
 518 #if !defined(__WXMICROWIN__) && !defined(__WXWINCE__)
 519     wxSetKeyboardHook(false);
 520 #endif
 521
 522     wxOleUninitialize();
 523
 524     // for an EXE the classes are unregistered when it terminates but DLL may
 525     // be loaded several times (load/unload/load) into the same process in
 526     // which case the registration will fail after the first time if we don't
 527     // unregister the classes now
 528     UnregisterWindowClasses();
 529
 530     delete wxWinHandleHash;
 531     wxWinHandleHash = NULL;
 532
 533 #ifdef __WXWINCE__
 534     free( wxCanvasClassName );
 535     free( wxCanvasClassNameNR );
 536 #endif
 537 }
 538
 539 // ----------------------------------------------------------------------------
 540 // wxApp ctor/dtor
 541 // ----------------------------------------------------------------------------
 542
 543 wxApp::wxApp()
 544 {
 545     m_printMode = wxPRINT_WINDOWS;
 546 }
 547
 548 wxApp::~wxApp()
 549 {
 550 }
 551
 552 // ----------------------------------------------------------------------------
 553 // wxApp idle handling
 554 // ----------------------------------------------------------------------------
 555
 556 void wxApp::OnIdle(wxIdleEvent& WXUNUSED(event))
 557 {
 558 #if wxUSE_DC_CACHEING
 559     // automated DC cache management: clear the cached DCs and bitmap
 560     // if it's likely that the app has finished with them, that is, we
 561     // get an idle event and we're not dragging anything.
 562     if (!::GetKeyState(MK_LBUTTON) && !::GetKeyState(MK_MBUTTON) && !::GetKeyState(MK_RBUTTON))
 563         wxMSWDCImpl::ClearCache();
 564 #endif // wxUSE_DC_CACHEING
 565 }
 566
 567 void wxApp::WakeUpIdle()
 568 {
 569     // Send the top window a dummy message so idle handler processing will
 570     // start up again.  Doing it this way ensures that the idle handler
 571     // wakes up in the right thread (see also wxWakeUpMainThread() which does
 572     // the same for the main app thread only)
 573     wxWindow *topWindow = wxTheApp->GetTopWindow();
 574     if ( topWindow )
 575     {
 576         if ( !::PostMessage(GetHwndOf(topWindow), WM_NULL, 0, 0) )
 577         {
 578             // should never happen
 579             wxLogLastError(wxT("PostMessage(WM_NULL)"));
 580         }
 581     }
 582 }
 583
 584 // ----------------------------------------------------------------------------
 585 // other wxApp event hanlders
 586 // ----------------------------------------------------------------------------
 587
 588 void wxApp::OnEndSession(wxCloseEvent& WXUNUSED(event))
 589 {
 590     if (GetTopWindow())
 591         GetTopWindow()->Close(true);
 592 }
 593
 594 // Default behaviour: close the application with prompts. The
 595 // user can veto the close, and therefore the end session.
 596 void wxApp::OnQueryEndSession(wxCloseEvent& event)
 597 {
 598     if (GetTopWindow())
 599     {
 600         if (!GetTopWindow()->Close(!event.CanVeto()))
 601             event.Veto(true);
 602     }
 603 }
 604
 605 // ----------------------------------------------------------------------------
 606 // system DLL versions
 607 // ----------------------------------------------------------------------------
 608
 609 #if wxUSE_DYNLIB_CLASS
 610
 611 namespace
 612 {
 613
 614 // helper function: retrieve the DLL version by using DllGetVersion(), returns
 615 // 0 if the DLL doesn't export such function
 616 int CallDllGetVersion(wxDynamicLibrary& dll)
 617 {
 618     // now check if the function is available during run-time
 619     wxDYNLIB_FUNCTION( DLLGETVERSIONPROC, DllGetVersion, dll );
 620     if ( !pfnDllGetVersion )
 621         return 0;
 622
 623     DLLVERSIONINFO dvi;
 624     dvi.cbSize = sizeof(dvi);
 625
 626     HRESULT hr = (*pfnDllGetVersion)(&dvi);
 627     if ( FAILED(hr) )
 628     {
 629         wxLogApiError(_T("DllGetVersion"), hr);
 630
 631         return 0;
 632     }
 633
 634     return 100*dvi.dwMajorVersion + dvi.dwMinorVersion;
 635 }
 636
 637 } // anonymous namespace
 638
 639 /* static */
 640 int wxApp::GetComCtl32Version()
 641 {
 642     // cache the result
 643     //
 644     // NB: this is MT-ok as in the worst case we'd compute s_verComCtl32 twice,
 645     //     but as its value should be the same both times it doesn't matter
 646     static int s_verComCtl32 = -1;
 647
 648     if ( s_verComCtl32 == -1 )
 649     {
 650         // we're prepared to handle the errors
 651         wxLogNull noLog;
 652
 653         // the DLL should really be available
 654         wxDynamicLibrary dllComCtl32(_T("comctl32.dll"), wxDL_VERBATIM);
 655         if ( !dllComCtl32.IsLoaded() )
 656         {
 657             s_verComCtl32 = 0;
 658             return 0;
 659         }
 660
 661         // try DllGetVersion() for recent DLLs
 662         s_verComCtl32 = CallDllGetVersion(dllComCtl32);
 663
 664         // if DllGetVersion() is unavailable either during compile or
 665         // run-time, try to guess the version otherwise
 666         if ( !s_verComCtl32 )
 667         {
 668             // InitCommonControlsEx is unique to 4.70 and later
 669             void *pfn = dllComCtl32.GetSymbol(_T("InitCommonControlsEx"));
 670             if ( !pfn )
 671             {
 672                 // not found, must be 4.00
 673                 s_verComCtl32 = 400;
 674             }
 675             else // 4.70+
 676             {
 677                 // many symbols appeared in comctl32 4.71, could use any of
 678                 // them except may be DllInstall()
 679                 pfn = dllComCtl32.GetSymbol(_T("InitializeFlatSB"));
 680                 if ( !pfn )
 681                 {
 682                     // not found, must be 4.70
 683                     s_verComCtl32 = 470;
 684                 }
 685                 else
 686                 {
 687                     // found, must be 4.71 or later
 688                     s_verComCtl32 = 471;
 689                 }
 690             }
 691         }
 692     }
 693
 694     return s_verComCtl32;
 695 }
 696
 697 /* static */
 698 int wxApp::GetShell32Version()
 699 {
 700     static int s_verShell32 = -1;
 701     if ( s_verShell32 == -1 )
 702     {
 703         // we're prepared to handle the errors
 704         wxLogNull noLog;
 705
 706         wxDynamicLibrary dllShell32(_T("shell32.dll"), wxDL_VERBATIM);
 707         if ( dllShell32.IsLoaded() )
 708         {
 709             s_verShell32 = CallDllGetVersion(dllShell32);
 710
 711             if ( !s_verShell32 )
 712             {
 713                 // there doesn't seem to be any way to distinguish between 4.00
 714                 // and 4.70 (starting from 4.71 we have DllGetVersion()) so
 715                 // just assume it is 4.0
 716                 s_verShell32 = 400;
 717             }
 718         }
 719         else // failed load the DLL?
 720         {
 721             s_verShell32 = 0;
 722         }
 723     }
 724
 725     return s_verShell32;
 726 }
 727
 728 #else // !wxUSE_DYNLIB_CLASS
 729
 730 /* static */
 731 int wxApp::GetComCtl32Version()
 732 {
 733     return 0;
 734 }
 735
 736 /* static */
 737 int wxApp::GetShell32Version()
 738 {
 739     return 0;
 740 }
 741
 742 #endif // wxUSE_DYNLIB_CLASS/!wxUSE_DYNLIB_CLASS
 743
 744 // ----------------------------------------------------------------------------
 745 // Yield to incoming messages
 746 // ----------------------------------------------------------------------------
 747
 748 bool wxApp::Yield(bool onlyIfNeeded)
 749 {
 750     // MT-FIXME
 751     static bool s_inYield = false;
 752
 753 #if wxUSE_LOG
 754     // disable log flushing from here because a call to wxYield() shouldn't
 755     // normally result in message boxes popping up &c
 756     wxLog::Suspend();
 757 #endif // wxUSE_LOG
 758
 759     if ( s_inYield )
 760     {
 761         if ( !onlyIfNeeded )
 762         {
 763             wxFAIL_MSG( wxT("wxYield called recursively" ) );
 764         }
 765
 766         return false;
 767     }
 768
 769     s_inYield = true;
 770
 771     // we don't want to process WM_QUIT from here - it should be processed in
 772     // the main event loop in order to stop it
 773     MSG msg;
 774     while ( PeekMessage(&msg, (HWND)0, 0, 0, PM_NOREMOVE) &&
 775             msg.message != WM_QUIT )
 776     {
 777 #if wxUSE_THREADS
 778         wxMutexGuiLeaveOrEnter();
 779 #endif // wxUSE_THREADS
 780
 781         if ( !wxTheApp->Dispatch() )
 782             break;
 783     }
 784
 785     // if there are pending events, we must process them.
 786     ProcessPendingEvents();
 787
 788 #if wxUSE_LOG
 789     // let the logs be flashed again
 790     wxLog::Resume();
 791 #endif // wxUSE_LOG
 792
 793     s_inYield = false;
 794
 795     return true;
 796 }
 797
 798 #if wxUSE_EXCEPTIONS
 799
 800 // ----------------------------------------------------------------------------
 801 // exception handling
 802 // ----------------------------------------------------------------------------
 803
 804 bool wxApp::OnExceptionInMainLoop()
 805 {
 806     // ask the user about what to do: use the Win32 API function here as it
 807     // could be dangerous to use any wxWidgets code in this state
 808     switch (
 809             ::MessageBox
 810               (
 811                 NULL,
 812                 _T("An unhandled exception occurred. Press \"Abort\" to \
 813 terminate the program,\r\n\
 814 \"Retry\" to exit the program normally and \"Ignore\" to try to continue."),
 815                 _T("Unhandled exception"),
 816                 MB_ABORTRETRYIGNORE |
 817                 MB_ICONERROR|
 818                 MB_TASKMODAL
 819               )
 820            )
 821     {
 822         case IDABORT:
 823             throw;
 824
 825         default:
 826             wxFAIL_MSG( _T("unexpected MessageBox() return code") );
 827             // fall through
 828
 829         case IDRETRY:
 830             return false;
 831
 832         case IDIGNORE:
 833             return true;
 834     }
 835 }
 836
 837 #endif // wxUSE_EXCEPTIONS