src/mgl/evtloop.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/mgl/evtloop.cpp
   3 // Purpose:     implements wxEventLoop for MGL
   4 // Author:      Vaclav Slavik
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) 2001-2002 SciTech Software, Inc. (www.scitechsoft.com)
   7 // Licence:     wxWindows licence
   8 ///////////////////////////////////////////////////////////////////////////////
   9
  10 // ----------------------------------------------------------------------------
  11 // headers
  12 // ----------------------------------------------------------------------------
  13
  14 // For compilers that support precompilation, includes "wx.h".
  15 #include "wx/wxprec.h"
  16
  17 #ifdef __BORLANDC__
  18     #pragma hdrstop
  19 #endif
  20
  21 #ifndef WX_PRECOMP
  22     #include "wx/window.h"
  23     #include "wx/app.h"
  24     #include "wx/thread.h"
  25     #include "wx/timer.h"
  26 #endif //WX_PRECOMP
  27
  28 #include "wx/evtloop.h"
  29
  30 #include "wx/generic/private/timer.h"
  31 #include "wx/mgl/private.h"
  32
  33 // ----------------------------------------------------------------------------
  34 // wxEventLoopImpl
  35 // ----------------------------------------------------------------------------
  36
  37 class WXDLLEXPORT wxEventLoopImpl
  38 {
  39 public:
  40     // ctor
  41     wxEventLoopImpl()
  42         {
  43             SetExitCode(0);
  44             SetKeepLooping(true);
  45         }
  46
  47     // process an event
  48     void Dispatch();
  49
  50     // generate an idle event, return true if more idle time requested
  51     bool SendIdleEvent();
  52
  53     // set/get the exit code
  54     void SetExitCode(int exitcode) { m_exitcode = exitcode; }
  55     int GetExitCode() const { return m_exitcode; }
  56
  57     void SetKeepLooping(bool k) { m_keepLooping = k; }
  58     bool GetKeepLooping() const { return m_keepLooping; }
  59
  60 private:
  61
  62     // the exit code of the event loop
  63     int m_exitcode;
  64     // false if the loop should end
  65     bool m_keepLooping;
  66 };
  67
  68 // ============================================================================
  69 // wxEventLoopImpl implementation
  70 // ============================================================================
  71
  72 void wxEventLoopImpl::Dispatch()
  73 {
  74     event_t evt;
  75
  76     // VS: The code below is equal to MGL's EVT_halt implementation, with
  77     //     two things added: sleeping (busy waiting is stupid, let's make CPU's
  78     //     life a bit easier) and timers updating.
  79
  80     // EVT_halt(&evt, EVT_EVERYEVT);
  81     for (;;)
  82     {
  83 #if wxUSE_TIMER
  84         wxGenericTimerImpl::NotifyTimers();
  85 #endif
  86         MGL_wmUpdateDC(g_winMng);
  87
  88         EVT_pollJoystick();
  89         if ( EVT_getNext(&evt, EVT_EVERYEVT) ) break;
  90         PM_sleep(10);
  91     }
  92     // end of EVT_halt
  93
  94     MGL_wmProcessEvent(g_winMng, &evt);
  95 }
  96
  97 bool wxEventLoopImpl::SendIdleEvent()
  98 {
  99     return wxTheApp->ProcessIdle();
 100 }
 101
 102 // ============================================================================
 103 // wxGUIEventLoop implementation
 104 // ============================================================================
 105
 106 // ----------------------------------------------------------------------------
 107 // wxGUIEventLoop running and exiting
 108 // ----------------------------------------------------------------------------
 109
 110 wxGUIEventLoop::~wxGUIEventLoop()
 111 {
 112     wxASSERT_MSG( !m_impl, wxT("should have been deleted in Run()") );
 113 }
 114
 115 int wxGUIEventLoop::Run()
 116 {
 117     // event loops are not recursive, you need to create another loop!
 118     wxCHECK_MSG( !IsRunning(), -1, wxT("can't reenter a message loop") );
 119
 120     m_impl = new wxEventLoopImpl;
 121
 122     wxEventLoopActivator activate(this);
 123
 124     for ( ;; )
 125     {
 126 #if wxUSE_THREADS
 127         //wxMutexGuiLeaveOrEnter(); // FIXME_MGL - huh?
 128 #endif // wxUSE_THREADS
 129
 130         // generate and process idle events for as long as we don't have
 131         // anything else to do
 132         while ( !Pending() && m_impl->SendIdleEvent() ) {}
 133
 134         // a message came or no more idle processing to do, sit in Dispatch()
 135         // waiting for the next message
 136         if ( !Dispatch() )
 137         {
 138             // app terminated
 139             break;
 140         }
 141     }
 142
 143     OnExit();
 144
 145     int exitcode = m_impl->GetExitCode();
 146     wxDELETE(m_impl);
 147
 148     return exitcode;
 149 }
 150
 151 void wxGUIEventLoop::Exit(int rc)
 152 {
 153     wxCHECK_RET( IsRunning(), wxT("can't call Exit() if not running") );
 154
 155     m_impl->SetExitCode(rc);
 156     m_impl->SetKeepLooping(false);
 157
 158     // Send a dummy event so that the app won't block in EVT_halt if there
 159     // are no user-generated events in the queue:
 160     EVT_post(0, EVT_USEREVT, 0, 0);
 161 }
 162
 163 // ----------------------------------------------------------------------------
 164 // wxEventLoop message processing dispatching
 165 // ----------------------------------------------------------------------------
 166
 167 bool wxGUIEventLoop::Pending() const
 168 {
 169     // update the display here, so that wxYield refreshes display and
 170     // changes take effect immediately, not after emptying events queue:
 171     MGL_wmUpdateDC(g_winMng);
 172
 173     // is there an event in the queue?
 174     event_t evt;
 175     return (bool)(EVT_peekNext(&evt, EVT_EVERYEVT));
 176 }
 177
 178 bool wxGUIEventLoop::Dispatch()
 179 {
 180     wxCHECK_MSG( IsRunning(), false, wxT("can't call Dispatch() if not running") );
 181
 182     m_impl->Dispatch();
 183     return m_impl->GetKeepLooping();
 184 }
 185
 186
 187 //-----------------------------------------------------------------------------
 188 // wxYield
 189 //-----------------------------------------------------------------------------
 190
 191 bool wxGUIEventLoop::YieldFor(long eventsToProcess)
 192 {
 193 #if wxUSE_THREADS
 194     if ( !wxThread::IsMain() )
 195     {
 196         // can't process events from other threads, MGL is thread-unsafe
 197         return true;
 198     }
 199 #endif // wxUSE_THREADS
 200
 201     m_isInsideYield = true;
 202     m_eventsToProcessInsideYield = eventsToProcess;
 203
 204     wxLog::Suspend();
 205
 206     // TODO: implement event filtering using the eventsToProcess mask
 207
 208     while (Pending())
 209         Dispatch();
 210
 211     /* it's necessary to call ProcessIdle() to update the frames sizes which
 212        might have been changed (it also will update other things set from
 213        OnUpdateUI() which is a nice (and desired) side effect) */
 214     while (wxTheApp->ProcessIdle()) { }
 215
 216     wxLog::Resume();
 217
 218     m_isInsideYield = false;
 219
 220     return true;
 221 }