src/msw/evtloop.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        msw/evtloop.cpp
   3 // Purpose:     implements wxEventLoop for MSW
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     01.06.01
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2001 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // License:     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 #ifndef WX_PRECOMP
  28     #if wxUSE_GUI
  29         #include "wx/window.h"
  30     #endif
  31     #include "wx/app.h"
  32 #endif //WX_PRECOMP
  33
  34 #include "wx/evtloop.h"
  35 #include "wx/thread.h"
  36 #include "wx/except.h"
  37 #include "wx/ptr_scpd.h"
  38 #include "wx/msw/private.h"
  39
  40 #if wxUSE_GUI
  41     #include "wx/tooltip.h"
  42     #if wxUSE_THREADS
  43         // define the list of MSG strutures
  44         WX_DECLARE_LIST(MSG, wxMsgList);
  45
  46         #include "wx/listimpl.cpp"
  47
  48         WX_DEFINE_LIST(wxMsgList)
  49     #endif // wxUSE_THREADS
  50 #endif //wxUSE_GUI
  51
  52 #if wxUSE_BASE
  53
  54 // ============================================================================
  55 // wxMSWEventLoopBase implementation
  56 // ============================================================================
  57
  58 // ----------------------------------------------------------------------------
  59 // ctor/dtor
  60 // ----------------------------------------------------------------------------
  61
  62 wxMSWEventLoopBase::wxMSWEventLoopBase()
  63 {
  64     m_shouldExit = false;
  65     m_exitcode = 0;
  66 }
  67
  68 // ----------------------------------------------------------------------------
  69 // wxEventLoop message processing dispatching
  70 // ----------------------------------------------------------------------------
  71
  72 bool wxMSWEventLoopBase::Pending() const
  73 {
  74     MSG msg;
  75     return ::PeekMessage(&msg, 0, 0, 0, PM_NOREMOVE) != 0;
  76 }
  77
  78 bool wxMSWEventLoopBase::GetNextMessage(WXMSG* msg)
  79 {
  80     wxCHECK_MSG( IsRunning(), false, _T("can't get messages if not running") );
  81
  82     const BOOL rc = ::GetMessage(msg, NULL, 0, 0);
  83
  84     if ( rc == 0 )
  85     {
  86         // got WM_QUIT
  87         return false;
  88     }
  89
  90     if ( rc == -1 )
  91     {
  92         // should never happen, but let's test for it nevertheless
  93         wxLogLastError(wxT("GetMessage"));
  94
  95         // still break from the loop
  96         return false;
  97     }
  98
  99     return true;
 100 }
 101
 102 int wxMSWEventLoopBase::GetNextMessageTimeout(WXMSG *msg, unsigned long timeout)
 103 {
 104     // MsgWaitForMultipleObjects() won't notice any input which was already
 105     // examined (e.g. using PeekMessage()) but not yet removed from the queue
 106     // so we need to remove any immediately messages manually
 107     //
 108     // NB: using MsgWaitForMultipleObjectsEx() could simplify the code here but
 109     //     it is not available in very old Windows versions
 110     if ( !::PeekMessage(msg, 0, 0, 0, PM_REMOVE) )
 111     {
 112         // we use this function just in order to not block longer than the
 113         // given timeout, so we don't pass any handles to it at all
 114         DWORD rc = ::MsgWaitForMultipleObjects
 115                      (
 116                         0, NULL,
 117                         FALSE,
 118                         timeout,
 119                         QS_ALLINPUT
 120                      );
 121
 122         switch ( rc )
 123         {
 124             default:
 125                 wxLogDebug("unexpected MsgWaitForMultipleObjects() return "
 126                            "value %lu", rc);
 127                 // fall through
 128
 129             case WAIT_TIMEOUT:
 130                 return -1;
 131
 132             case WAIT_OBJECT_0:
 133                 if ( !::PeekMessage(msg, 0, 0, 0, PM_REMOVE) )
 134                 {
 135                     // somehow it may happen that MsgWaitForMultipleObjects()
 136                     // returns true but there are no messages -- just treat it
 137                     // the same as timeout then
 138                     return -1;
 139                 }
 140                 break;
 141         }
 142     }
 143
 144     return msg->message != WM_QUIT;
 145 }
 146
 147
 148 #endif // wxUSE_BASE
 149
 150 #if wxUSE_GUI
 151
 152 // ============================================================================
 153 // GUI wxEventLoop implementation
 154 // ============================================================================
 155
 156 wxWindowMSW *wxGUIEventLoop::ms_winCritical = NULL;
 157
 158 bool wxGUIEventLoop::IsChildOfCriticalWindow(wxWindowMSW *win)
 159 {
 160     while ( win )
 161     {
 162         if ( win == ms_winCritical )
 163             return true;
 164
 165         win = win->GetParent();
 166     }
 167
 168     return false;
 169 }
 170
 171 bool wxGUIEventLoop::PreProcessMessage(WXMSG *msg)
 172 {
 173     HWND hwnd = msg->hwnd;
 174     wxWindow *wndThis = wxGetWindowFromHWND((WXHWND)hwnd);
 175     wxWindow *wnd;
 176
 177     // this might happen if we're in a modeless dialog, or if a wx control has
 178     // children which themselves were not created by wx (i.e. wxActiveX control children)
 179     if ( !wndThis )
 180     {
 181         while ( hwnd && (::GetWindowLong(hwnd, GWL_STYLE) & WS_CHILD ))
 182         {
 183             hwnd = ::GetParent(hwnd);
 184
 185             // If the control has a wx parent, break and give the parent a chance
 186             // to process the window message
 187             wndThis = wxGetWindowFromHWND((WXHWND)hwnd);
 188             if (wndThis != NULL)
 189                 break;
 190         }
 191
 192         if ( !wndThis )
 193         {
 194             // this may happen if the event occurred in a standard modeless dialog (the
 195             // only example of which I know of is the find/replace dialog) - then call
 196             // IsDialogMessage() to make TAB navigation in it work
 197
 198             // NOTE: IsDialogMessage() just eats all the messages (i.e. returns true for
 199             // them) if we call it for the control itself
 200             return hwnd && ::IsDialogMessage(hwnd, msg) != 0;
 201         }
 202     }
 203
 204     if ( !AllowProcessing(wndThis) )
 205     {
 206         // not a child of critical window, so we eat the event but take care to
 207         // stop an endless stream of WM_PAINTs which would have resulted if we
 208         // didn't validate the invalidated part of the window
 209         if ( msg->message == WM_PAINT )
 210             ::ValidateRect(hwnd, NULL);
 211
 212         return true;
 213     }
 214
 215 #if wxUSE_TOOLTIPS
 216     // we must relay WM_MOUSEMOVE events to the tooltip ctrl if we want it to
 217     // popup the tooltip bubbles
 218     if ( msg->message == WM_MOUSEMOVE )
 219     {
 220         // we should do it if one of window children has an associated tooltip
 221         // (and not just if the window has a tooltip itself)
 222         if ( wndThis->HasToolTips() )
 223             wxToolTip::RelayEvent((WXMSG *)msg);
 224     }
 225 #endif // wxUSE_TOOLTIPS
 226
 227     // allow the window to prevent certain messages from being
 228     // translated/processed (this is currently used by wxTextCtrl to always
 229     // grab Ctrl-C/V/X, even if they are also accelerators in some parent)
 230     if ( !wndThis->MSWShouldPreProcessMessage((WXMSG *)msg) )
 231     {
 232         return false;
 233     }
 234
 235     // try translations first: the accelerators override everything
 236     for ( wnd = wndThis; wnd; wnd = wnd->GetParent() )
 237     {
 238         if ( wnd->MSWTranslateMessage((WXMSG *)msg))
 239             return true;
 240
 241         // stop at first top level window, i.e. don't try to process the key
 242         // strokes originating in a dialog using the accelerators of the parent
 243         // frame - this doesn't make much sense
 244         if ( wnd->IsTopLevel() )
 245             break;
 246     }
 247
 248     // now try the other hooks (kbd navigation is handled here)
 249     for ( wnd = wndThis; wnd; wnd = wnd->GetParent() )
 250     {
 251         if ( wnd->MSWProcessMessage((WXMSG *)msg) )
 252             return true;
 253
 254         // also stop at first top level window here, just as above because
 255         // if we don't do this, pressing ESC on a modal dialog shown as child
 256         // of a modal dialog with wxID_CANCEL will cause the parent dialog to
 257         // be closed, for example
 258         if ( wnd->IsTopLevel() )
 259             break;
 260     }
 261
 262     // no special preprocessing for this message, dispatch it normally
 263     return false;
 264 }
 265
 266 void wxGUIEventLoop::ProcessMessage(WXMSG *msg)
 267 {
 268     // give us the chance to preprocess the message first
 269     if ( !PreProcessMessage(msg) )
 270     {
 271         // if it wasn't done, dispatch it to the corresponding window
 272         ::TranslateMessage(msg);
 273         ::DispatchMessage(msg);
 274     }
 275 }
 276
 277 bool wxGUIEventLoop::Dispatch()
 278 {
 279     MSG msg;
 280     if ( !GetNextMessage(&msg) )
 281         return false;
 282
 283 #if wxUSE_THREADS
 284     wxASSERT_MSG( wxThread::IsMain(),
 285                   wxT("only the main thread can process Windows messages") );
 286
 287     static bool s_hadGuiLock = true;
 288     static wxMsgList s_aSavedMessages;
 289
 290     // if a secondary thread owning the mutex is doing GUI calls, save all
 291     // messages for later processing - we can't process them right now because
 292     // it will lead to recursive library calls (and we're not reentrant)
 293     if ( !wxGuiOwnedByMainThread() )
 294     {
 295         s_hadGuiLock = false;
 296
 297         // leave out WM_COMMAND messages: too dangerous, sometimes
 298         // the message will be processed twice
 299         if ( !wxIsWaitingForThread() || msg.message != WM_COMMAND )
 300         {
 301             MSG* pMsg = new MSG(msg);
 302             s_aSavedMessages.Append(pMsg);
 303         }
 304
 305         return true;
 306     }
 307     else
 308     {
 309         // have we just regained the GUI lock? if so, post all of the saved
 310         // messages
 311         //
 312         // FIXME of course, it's not _exactly_ the same as processing the
 313         //       messages normally - expect some things to break...
 314         if ( !s_hadGuiLock )
 315         {
 316             s_hadGuiLock = true;
 317
 318             wxMsgList::compatibility_iterator node = s_aSavedMessages.GetFirst();
 319             while (node)
 320             {
 321                 MSG* pMsg = node->GetData();
 322                 s_aSavedMessages.Erase(node);
 323
 324                 ProcessMessage(pMsg);
 325                 delete pMsg;
 326
 327                 node = s_aSavedMessages.GetFirst();
 328             }
 329         }
 330     }
 331 #endif // wxUSE_THREADS
 332
 333     ProcessMessage(&msg);
 334
 335     return true;
 336 }
 337
 338 int wxGUIEventLoop::DispatchTimeout(unsigned long timeout)
 339 {
 340     MSG msg;
 341     int rc = GetNextMessageTimeout(&msg, timeout);
 342     if ( rc != 1 )
 343         return rc;
 344
 345     ProcessMessage(&msg);
 346
 347     return 1;
 348 }
 349
 350 void wxGUIEventLoop::OnNextIteration()
 351 {
 352 #if wxUSE_THREADS
 353     wxMutexGuiLeaveOrEnter();
 354 #endif // wxUSE_THREADS
 355 }
 356
 357 void wxGUIEventLoop::WakeUp()
 358 {
 359     ::PostMessage(NULL, WM_NULL, 0, 0);
 360 }
 361
 362 #else // !wxUSE_GUI
 363
 364 #if wxUSE_CONSOLE_EVENTLOOP
 365
 366 void wxConsoleEventLoop::OnNextIteration()
 367 {
 368     if ( wxTheApp )
 369         wxTheApp->ProcessPendingEvents();
 370 }
 371
 372 void wxConsoleEventLoop::WakeUp()
 373 {
 374 #if wxUSE_THREADS
 375     wxWakeUpMainThread();
 376 #endif
 377 }
 378
 379 void wxConsoleEventLoop::ProcessMessage(WXMSG *msg)
 380 {
 381     if ( msg->message == WM_TIMER )
 382     {
 383         TIMERPROC proc = (TIMERPROC)msg->lParam;
 384         if ( proc )
 385             (*proc)(NULL, 0, msg->wParam, 0);
 386     }
 387     else
 388     {
 389         ::DispatchMessage(msg);
 390     }
 391 }
 392
 393 bool wxConsoleEventLoop::Dispatch()
 394 {
 395     MSG msg;
 396     if ( !GetNextMessage(&msg) )
 397         return false;
 398
 399     ProcessMessage(&msg);
 400
 401     return !m_shouldExit;
 402 }
 403
 404 int wxConsoleEventLoop::DispatchTimeout(unsigned long timeout)
 405 {
 406     MSG msg;
 407     int rc = GetNextMessageTimeout(&msg, timeout);
 408     if ( rc != 1 )
 409         return rc;
 410
 411     ProcessMessage(&msg);
 412
 413     return !m_shouldExit;
 414 }
 415
 416 #endif // wxUSE_CONSOLE_EVENTLOOP
 417
 418 #endif //wxUSE_GUI