src/gtk/evtloop.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/gtk/evtloop.cpp
   3 // Purpose:     implements wxEventLoop for GTK+
   4 // Author:      Vadim Zeitlin
   5 // Created:     10.07.01
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2001 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   8 //              (c) 2013 Rob Bresalier, Vadim Zeitlin
   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/evtloop.h"
  28 #include "wx/evtloopsrc.h"
  29
  30 #ifndef WX_PRECOMP
  31     #include "wx/app.h"
  32     #include "wx/log.h"
  33 #endif // WX_PRECOMP
  34
  35 #include "wx/private/eventloopsourcesmanager.h"
  36 #include "wx/apptrait.h"
  37
  38 #include <gtk/gtk.h>
  39 #include <glib.h>
  40
  41 // ============================================================================
  42 // wxEventLoop implementation
  43 // ============================================================================
  44
  45 extern GtkWidget *wxGetRootWindow();
  46
  47 // ----------------------------------------------------------------------------
  48 // wxEventLoop running and exiting
  49 // ----------------------------------------------------------------------------
  50
  51 wxGUIEventLoop::wxGUIEventLoop()
  52 {
  53     m_exitcode = 0;
  54 }
  55
  56 int wxGUIEventLoop::DoRun()
  57 {
  58     guint loopLevel = gtk_main_level();
  59
  60     // This is placed inside of a loop to take into account nested
  61     // event loops.  For example, inside this event loop, we may receive
  62     // Exit() for a different event loop (which we are currently inside of)
  63     // That Exit() will cause this gtk_main() to exit so we need to re-enter it.
  64     while ( !m_shouldExit )
  65     {
  66         gtk_main();
  67     }
  68
  69     // Force the enclosing event loop to also exit to see if it is done in case
  70     // that event loop had Exit() called inside of the just ended loop. If it
  71     // is not time yet for that event loop to exit, it will be executed again
  72     // due to the while() loop on m_shouldExit().
  73     //
  74     // This is unnecessary if we are the top level loop, i.e. loop of level 0.
  75     if ( loopLevel )
  76     {
  77         gtk_main_quit();
  78     }
  79
  80     OnExit();
  81
  82     return m_exitcode;
  83 }
  84
  85 void wxGUIEventLoop::ScheduleExit(int rc)
  86 {
  87     wxCHECK_RET( IsInsideRun(), wxT("can't call ScheduleExit() if not started") );
  88
  89     m_exitcode = rc;
  90
  91     m_shouldExit = true;
  92
  93     gtk_main_quit();
  94 }
  95
  96 void wxGUIEventLoop::WakeUp()
  97 {
  98     // TODO: idle events handling should really be done by wxEventLoop itself
  99     //       but for now it's completely in gtk/app.cpp so just call there when
 100     //       we have wxTheApp and hope that it doesn't matter that we do
 101     //       nothing when we don't...
 102     if ( wxTheApp )
 103         wxTheApp->WakeUpIdle();
 104 }
 105
 106 // ----------------------------------------------------------------------------
 107 // wxEventLoop adding & removing sources
 108 // ----------------------------------------------------------------------------
 109
 110 #if wxUSE_EVENTLOOP_SOURCE
 111
 112 extern "C"
 113 {
 114 static gboolean wx_on_channel_event(GIOChannel *channel,
 115                                     GIOCondition condition,
 116                                     gpointer data)
 117 {
 118     wxUnusedVar(channel); // Unused if !wxUSE_LOG || !wxDEBUG_LEVEL
 119
 120     wxLogTrace(wxTRACE_EVT_SOURCE,
 121                "wx_on_channel_event, fd=%d, condition=%08x",
 122                g_io_channel_unix_get_fd(channel), condition);
 123
 124     wxEventLoopSourceHandler * const
 125         handler = static_cast<wxEventLoopSourceHandler *>(data);
 126
 127     if ( (condition & G_IO_IN) || (condition & G_IO_PRI) || (condition & G_IO_HUP) )
 128         handler->OnReadWaiting();
 129
 130     if (condition & G_IO_OUT)
 131         handler->OnWriteWaiting();
 132
 133     if ( (condition & G_IO_ERR) || (condition & G_IO_NVAL) )
 134         handler->OnExceptionWaiting();
 135
 136     // we never want to remove source here, so always return true
 137     //
 138     // The source may have been removed by the handler, so it may be
 139     // a good idea to return FALSE when the source has already been
 140     // removed.  However, that would involve somehow informing this function
 141     // that the source was removed, which is not trivial to implement
 142     // and handle all cases.  It has been found through testing
 143     // that if the source was removed by the handler, that even if we
 144     // return TRUE here, the source/callback will not get called again.
 145     return TRUE;
 146 }
 147 }
 148
 149 class wxGUIEventLoopSourcesManager : public wxEventLoopSourcesManagerBase
 150 {
 151 public:
 152     virtual wxEventLoopSource*
 153     AddSourceForFD(int fd, wxEventLoopSourceHandler *handler, int flags)
 154     {
 155         wxCHECK_MSG( fd != -1, NULL, "can't monitor invalid fd" );
 156
 157         int condition = 0;
 158         if ( flags & wxEVENT_SOURCE_INPUT )
 159             condition |= G_IO_IN | G_IO_PRI | G_IO_HUP;
 160         if ( flags & wxEVENT_SOURCE_OUTPUT )
 161             condition |= G_IO_OUT;
 162         if ( flags & wxEVENT_SOURCE_EXCEPTION )
 163             condition |= G_IO_ERR | G_IO_NVAL;
 164
 165         GIOChannel* channel = g_io_channel_unix_new(fd);
 166         const unsigned sourceId  = g_io_add_watch
 167                                    (
 168                                     channel,
 169                                     (GIOCondition)condition,
 170                                     &wx_on_channel_event,
 171                                     handler
 172                                    );
 173         // it was ref'd by g_io_add_watch() so we can unref it here
 174         g_io_channel_unref(channel);
 175
 176         if ( !sourceId )
 177             return NULL;
 178
 179         wxLogTrace(wxTRACE_EVT_SOURCE,
 180                    "Adding event loop source for fd=%d with GTK id=%u",
 181                    fd, sourceId);
 182
 183
 184         return new wxGTKEventLoopSource(sourceId, handler, flags);
 185     }
 186 };
 187
 188 wxEventLoopSourcesManagerBase* wxGUIAppTraits::GetEventLoopSourcesManager()
 189 {
 190     static wxGUIEventLoopSourcesManager s_eventLoopSourcesManager;
 191
 192     return &s_eventLoopSourcesManager;
 193 }
 194
 195 wxGTKEventLoopSource::~wxGTKEventLoopSource()
 196 {
 197     wxLogTrace(wxTRACE_EVT_SOURCE,
 198                "Removing event loop source with GTK id=%u", m_sourceId);
 199
 200     g_source_remove(m_sourceId);
 201 }
 202
 203 #endif // wxUSE_EVENTLOOP_SOURCE
 204
 205 // ----------------------------------------------------------------------------
 206 // wxEventLoop message processing dispatching
 207 // ----------------------------------------------------------------------------
 208
 209 bool wxGUIEventLoop::Pending() const
 210 {
 211     if ( wxTheApp )
 212     {
 213         // this avoids false positives from our idle source
 214         return wxTheApp->EventsPending();
 215     }
 216
 217     return gtk_events_pending() != 0;
 218 }
 219
 220 bool wxGUIEventLoop::Dispatch()
 221 {
 222     wxCHECK_MSG( IsRunning(), false, wxT("can't call Dispatch() if not running") );
 223
 224     // gtk_main_iteration() returns TRUE only if gtk_main_quit() was called
 225     return !gtk_main_iteration();
 226 }
 227
 228 extern "C" {
 229 static gboolean wx_event_loop_timeout(void* data)
 230 {
 231     bool* expired = static_cast<bool*>(data);
 232     *expired = true;
 233
 234     // return FALSE to remove this timeout
 235     return FALSE;
 236 }
 237 }
 238
 239 int wxGUIEventLoop::DispatchTimeout(unsigned long timeout)
 240 {
 241     bool expired = false;
 242     const unsigned id = g_timeout_add(timeout, wx_event_loop_timeout, &expired);
 243     bool quit = gtk_main_iteration() != 0;
 244
 245     if ( expired )
 246         return -1;
 247
 248     g_source_remove(id);
 249
 250     return !quit;
 251 }
 252
 253 //-----------------------------------------------------------------------------
 254 // YieldFor
 255 //-----------------------------------------------------------------------------
 256
 257 extern "C" {
 258 static void wxgtk_main_do_event(GdkEvent* event, void* data)
 259 {
 260     // categorize the GDK event according to wxEventCategory.
 261     // See http://library.gnome.org/devel/gdk/unstable/gdk-Events.html#GdkEventType
 262     // for more info.
 263
 264     // NOTE: GDK_* constants which were not present in the GDK2.0 can be tested for
 265     //       only at compile-time; when running the program (compiled with a recent GDK)
 266     //       on a system with an older GDK lib we can be sure there won't be problems
 267     //       because event->type will never assume those values corresponding to
 268     //       new event types (since new event types are always added in GDK with non
 269     //       conflicting values for ABI compatibility).
 270
 271     // Some events (currently only a single one) may be used for more than one
 272     // category, so we need 2 variables. The second one will remain "unknown"
 273     // in most cases.
 274     wxEventCategory cat = wxEVT_CATEGORY_UNKNOWN,
 275                     cat2 = wxEVT_CATEGORY_UNKNOWN;
 276     switch (event->type)
 277     {
 278     case GDK_SELECTION_REQUEST:
 279     case GDK_SELECTION_NOTIFY:
 280     case GDK_SELECTION_CLEAR:
 281     case GDK_OWNER_CHANGE:
 282         cat = wxEVT_CATEGORY_CLIPBOARD;
 283         break;
 284
 285     case GDK_KEY_PRESS:
 286     case GDK_KEY_RELEASE:
 287     case GDK_BUTTON_PRESS:
 288     case GDK_2BUTTON_PRESS:
 289     case GDK_3BUTTON_PRESS:
 290     case GDK_BUTTON_RELEASE:
 291     case GDK_SCROLL:        // generated from mouse buttons
 292     case GDK_CLIENT_EVENT:
 293         cat = wxEVT_CATEGORY_USER_INPUT;
 294         break;
 295
 296     case GDK_PROPERTY_NOTIFY:
 297         // This one is special: it can be used for UI purposes but also for
 298         // clipboard operations, so allow it in both cases (we probably could
 299         // examine the event itself to distinguish between the two cases but
 300         // this would be unnecessarily complicated).
 301         cat2 = wxEVT_CATEGORY_CLIPBOARD;
 302         // Fall through.
 303
 304     case GDK_PROXIMITY_IN:
 305     case GDK_PROXIMITY_OUT:
 306
 307     case GDK_MOTION_NOTIFY:
 308     case GDK_ENTER_NOTIFY:
 309     case GDK_LEAVE_NOTIFY:
 310     case GDK_VISIBILITY_NOTIFY:
 311
 312     case GDK_FOCUS_CHANGE:
 313     case GDK_CONFIGURE:
 314     case GDK_WINDOW_STATE:
 315     case GDK_SETTING:
 316     case GDK_DELETE:
 317     case GDK_DESTROY:
 318
 319     case GDK_EXPOSE:
 320 #ifndef __WXGTK3__
 321     case GDK_NO_EXPOSE:
 322 #endif
 323     case GDK_MAP:
 324     case GDK_UNMAP:
 325
 326     case GDK_DRAG_ENTER:
 327     case GDK_DRAG_LEAVE:
 328     case GDK_DRAG_MOTION:
 329     case GDK_DRAG_STATUS:
 330     case GDK_DROP_START:
 331     case GDK_DROP_FINISHED:
 332 #if GTK_CHECK_VERSION(2,8,0)
 333     case GDK_GRAB_BROKEN:
 334 #endif
 335 #if GTK_CHECK_VERSION(2,14,0)
 336     case GDK_DAMAGE:
 337 #endif
 338         cat = wxEVT_CATEGORY_UI;
 339         break;
 340
 341     default:
 342         cat = wxEVT_CATEGORY_UNKNOWN;
 343         break;
 344     }
 345
 346     wxGUIEventLoop* evtloop = static_cast<wxGUIEventLoop*>(data);
 347
 348     // is this event allowed now?
 349     if (evtloop->IsEventAllowedInsideYield(cat) ||
 350             (cat2 != wxEVT_CATEGORY_UNKNOWN &&
 351                 evtloop->IsEventAllowedInsideYield(cat2)))
 352     {
 353         // process it now
 354         gtk_main_do_event(event);
 355     }
 356     else if (event->type != GDK_NOTHING)
 357     {
 358         // process it later (but make a copy; the caller will free the event
 359         // pointer)
 360         evtloop->StoreGdkEventForLaterProcessing(gdk_event_copy(event));
 361     }
 362 }
 363 }
 364
 365 bool wxGUIEventLoop::YieldFor(long eventsToProcess)
 366 {
 367 #if wxUSE_THREADS
 368     if ( !wxThread::IsMain() )
 369     {
 370         // can't call gtk_main_iteration() from other threads like this
 371         return true;
 372     }
 373 #endif // wxUSE_THREADS
 374
 375     m_isInsideYield = true;
 376     m_eventsToProcessInsideYield = eventsToProcess;
 377
 378 #if wxUSE_LOG
 379     // disable log flushing from here because a call to wxYield() shouldn't
 380     // normally result in message boxes popping up &c
 381     wxLog::Suspend();
 382 #endif
 383
 384     // temporarily replace the global GDK event handler with our function, which
 385     // categorizes the events and using m_eventsToProcessInsideYield decides
 386     // if an event should be processed immediately or not
 387     // NOTE: this approach is better than using gdk_display_get_event() because
 388     //       gtk_main_iteration() does more than just calling gdk_display_get_event()
 389     //       and then call gtk_main_do_event()!
 390     //       In particular in this way we also process input from sources like
 391     //       GIOChannels (this is needed for e.g. wxGUIAppTraits::WaitForChild).
 392     gdk_event_handler_set(wxgtk_main_do_event, this, NULL);
 393     while (Pending())   // avoid false positives from our idle source
 394         gtk_main_iteration();
 395     gdk_event_handler_set ((GdkEventFunc)gtk_main_do_event, NULL, NULL);
 396
 397     // Process all pending events too, this is consistent with wxMSW behaviour
 398     // and the behaviour of wxGTK itself in the previous versions.
 399     if ( wxTheApp )
 400         wxTheApp->ProcessPendingEvents();
 401
 402     if (eventsToProcess != wxEVT_CATEGORY_CLIPBOARD)
 403     {
 404         // It's necessary to call ProcessIdle() to update the frames sizes which
 405         // might have been changed (it also will update other things set from
 406         // OnUpdateUI() which is a nice (and desired) side effect). But we
 407         // call ProcessIdle() only once since this is not meant for longish
 408         // background jobs (controlled by wxIdleEvent::RequestMore() and the
 409         // return value of Processidle().
 410         ProcessIdle();
 411     }
 412     //else: if we are inside ~wxClipboardSync() and we call ProcessIdle() and
 413     //      the user app contains an UI update handler which calls wxClipboard::IsSupported,
 414     //      then we fall into a never-ending loop...
 415
 416     // put all unprocessed GDK events back in the queue
 417     GdkDisplay* disp = gtk_widget_get_display(wxGetRootWindow());
 418     for (size_t i=0; i<m_arrGdkEvents.GetCount(); i++)
 419     {
 420         GdkEvent* ev = (GdkEvent*)m_arrGdkEvents[i];
 421
 422         // NOTE: gdk_display_put_event makes a copy of the event passed to it
 423         gdk_display_put_event(disp, ev);
 424         gdk_event_free(ev);
 425     }
 426
 427     m_arrGdkEvents.Clear();
 428
 429 #if wxUSE_LOG
 430     // let the logs be flashed again
 431     wxLog::Resume();
 432 #endif
 433
 434     m_isInsideYield = false;
 435
 436     return true;
 437 }