src/mgl/evtloop.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        mgl/evtloop.cpp
   3 // Purpose:     implements wxEventLoop for MGL
   4 // Author:      Vaclav Slavik
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) 2001 SciTech Software, Inc. (www.scitechsoft.com)
   7 // License:     wxWindows license
   8 ///////////////////////////////////////////////////////////////////////////////
   9
  10 // ----------------------------------------------------------------------------
  11 // headers
  12 // ----------------------------------------------------------------------------
  13
  14 #ifdef __GNUG__
  15     #pragma implementation "evtloop.h"
  16 #endif
  17
  18 // For compilers that support precompilation, includes "wx.h".
  19 #include "wx/wxprec.h"
  20
  21 #ifdef __BORLANDC__
  22     #pragma hdrstop
  23 #endif
  24
  25 #ifndef WX_PRECOMP
  26     #include "wx/window.h"
  27     #include "wx/app.h"
  28     #include "wx/thread.h"
  29 #endif //WX_PRECOMP
  30
  31 #include "wx/evtloop.h"
  32
  33 #include "wx/mgl/private.h"
  34
  35 // ----------------------------------------------------------------------------
  36 // wxEventLoopImpl
  37 // ----------------------------------------------------------------------------
  38
  39 class WXDLLEXPORT wxEventLoopImpl
  40 {
  41 public:
  42     // ctor
  43     wxEventLoopImpl()
  44         {
  45             SetExitCode(0);
  46             SetKeepLooping(TRUE);
  47         }
  48
  49     // process a message
  50     void ProcessEvent(event_t *evt);
  51
  52     // generate an idle message, return TRUE if more idle time requested
  53     bool SendIdleMessage();
  54
  55     // set/get the exit code
  56     void SetExitCode(int exitcode) { m_exitcode = exitcode; }
  57     int GetExitCode() const { return m_exitcode; }
  58
  59     void SetKeepLooping(bool k) { m_keepLooping = k; }
  60     bool GetKeepLooping() const { return m_keepLooping; }
  61
  62 private:
  63
  64     // the exit code of the event loop
  65     int m_exitcode;
  66     // FALSE if the loop should end
  67     bool m_keepLooping;
  68 };
  69
  70 // ============================================================================
  71 // wxEventLoopImpl implementation
  72 // ============================================================================
  73
  74 void wxEventLoopImpl::ProcessEvent(event_t *evt)
  75 {
  76     MGL_wmProcessEvent(g_winMng, evt);
  77 }
  78
  79 bool wxEventLoopImpl::SendIdleMessage()
  80 {
  81     wxIdleEvent event;
  82
  83     return wxTheApp->ProcessEvent(event) && event.MoreRequested();
  84 }
  85
  86 // ============================================================================
  87 // wxEventLoop implementation
  88 // ============================================================================
  89
  90 // ----------------------------------------------------------------------------
  91 // wxEventLoop running and exiting
  92 // ----------------------------------------------------------------------------
  93
  94 wxEventLoop::~wxEventLoop()
  95 {
  96     wxASSERT_MSG( !m_impl, _T("should have been deleted in Run()") );
  97 }
  98
  99 bool wxEventLoop::IsRunning() const
 100 {
 101     return m_impl != NULL;
 102 }
 103
 104 int wxEventLoop::Run()
 105 {
 106     // event loops are not recursive, you need to create another loop!
 107     wxCHECK_MSG( !IsRunning(), -1, _T("can't reenter a message loop") );
 108
 109     m_impl = new wxEventLoopImpl;
 110
 111     for ( ;; )
 112     {
 113 #if wxUSE_THREADS
 114         //wxMutexGuiLeaveOrEnter(); // FIXME_MGL - huh?
 115 #endif // wxUSE_THREADS
 116
 117         // generate and process idle events for as long as we don't have
 118         // anything else to do
 119         while ( !Pending() && m_impl->SendIdleMessage() ) {}
 120
 121         // a message came or no more idle processing to do, sit in Dispatch()
 122         // waiting for the next message
 123         if ( !Dispatch() )
 124         {
 125             // app terminated
 126             break;
 127         }
 128     }
 129
 130     int exitcode = m_impl->GetExitCode();
 131     delete m_impl;
 132     m_impl = NULL;
 133
 134     return exitcode;
 135 }
 136
 137 void wxEventLoop::Exit(int rc)
 138 {
 139     wxCHECK_RET( IsRunning(), _T("can't call Exit() if not running") );
 140
 141     m_impl->SetExitCode(rc);
 142     m_impl->SetKeepLooping(FALSE);
 143 }
 144
 145 // ----------------------------------------------------------------------------
 146 // wxEventLoop message processing dispatching
 147 // ----------------------------------------------------------------------------
 148
 149 bool wxEventLoop::Pending() const
 150 {
 151     event_t evt;
 152     return EVT_peekNext(&evt, EVT_EVERYEVT);
 153 }
 154
 155 bool wxEventLoop::Dispatch()
 156 {
 157     wxCHECK_MSG( IsRunning(), FALSE, _T("can't call Dispatch() if not running") );
 158
 159     event_t evt;
 160     ibool rc = EVT_getNext(&evt, EVT_EVERYEVT);
 161
 162     if ( !rc )
 163     {
 164         wxLogError(_T("events queue empty even though Pending() returned true"));
 165         return FALSE;
 166     }
 167
 168     // FIXME_MGL -- there must be some way to programatically exit
 169     // the loop, like WM_QUIT under Windows -- perhaps we need custom
 170     // event to indicate this??
 171
 172     m_impl->ProcessEvent(&evt);
 173
 174     return m_impl->GetKeepLooping();
 175 }
 176