implement the wxGTK selective yield with a different approach: rather than getting the events ourselves and fetching them to gtk_main_do_event(), install our own wxgtk_main_do_event() to filter them (closes #10320 -- see bug reported in comment 19)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59541 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/evtloop.h

@@ -15,6 +15,8 @@
 // wxGUIEventLoop for wxGTK
 // ----------------------------------------------------------------------------
 
+typedef union  _GdkEvent        GdkEvent;
+
 class WXDLLIMPEXP_CORE wxGUIEventLoop : public wxEventLoopBase
 {
 public:
@@ -28,6 +30,9 @@ public:
     virtual void WakeUp();
     virtual bool YieldFor(long eventsToProcess);
 
+    void StoreGdkEventForLaterProcessing(GdkEvent* ev)
+        { m_arrGdkEvents.Add(ev); }
+    
 protected:
 
     // the exit code of this event loop

src/gtk/evtloop.cpp

@@ -133,37 +133,8 @@ int wxGUIEventLoop::DispatchTimeout(unsigned long timeout)
 // YieldFor
 //-----------------------------------------------------------------------------
 
-bool wxGUIEventLoop::YieldFor(long eventsToProcess)
+static void wxgtk_main_do_event(GdkEvent *event, wxGUIEventLoop* evtloop)
 {
-#if wxUSE_THREADS
-    if ( !wxThread::IsMain() )
-    {
-        // can't call gtk_main_iteration() from other threads like this
-        return true;
-    }
-#endif // wxUSE_THREADS
-
-    m_isInsideYield = true;
-    m_eventsToProcessInsideYield = eventsToProcess;
-
-#if wxUSE_LOG
-    // disable log flushing from here because a call to wxYield() shouldn't
-    // normally result in message boxes popping up &c
-    wxLog::Suspend();
-#endif
-
-    // NOTE: gtk_main_iteration() doesn't allow us to filter events, so we
-    //       rather use gtk_main_do_event() after filtering the events at
-    //       GDK level
-
-    GdkDisplay* disp = gtk_widget_get_display(wxGetRootWindow());
-
-    // gdk_display_get_event() will transform X11 events into GDK events
-    // and will queue all of them in the display (private) structure;
-    // finally it will "unqueue" the last one and return it to us
-    GdkEvent* event = gdk_display_get_event(disp);
-    while (event)
-    {
     // categorize the GDK event according to wxEventCategory.
     // See http://library.gnome.org/devel/gdk/unstable/gdk-Events.html#GdkEventType
     // for more info.
@@ -190,7 +161,6 @@ bool wxGUIEventLoop::YieldFor(long eventsToProcess)
         cat = wxEVT_CATEGORY_USER_INPUT;
         break;
 
-
     case GDK_PROXIMITY_IN:
     case GDK_PROXIMITY_OUT:
 
@@ -211,7 +181,6 @@ bool wxGUIEventLoop::YieldFor(long eventsToProcess)
     case GDK_NO_EXPOSE:
     case GDK_MAP:
     case GDK_UNMAP:
-        //case GDK_DAMAGE:
 
     case GDK_DRAG_ENTER:
     case GDK_DRAG_LEAVE:
@@ -228,14 +197,45 @@ bool wxGUIEventLoop::YieldFor(long eventsToProcess)
         break;
     }
 
-        if (eventsToProcess & cat)
+    // is this event allowed now?
+    if (evtloop->IsEventAllowedInsideYield(cat))
         gtk_main_do_event(event);         // process it now
-        else
+    else if (event->type != GDK_NOTHING)
-            m_arrGdkEvents.Add(event);      // process it later
+        evtloop->StoreGdkEventForLaterProcessing(gdk_event_copy(event));
+            // process it later (but make a copy; the caller will free the event pointer)
+}
 
-        // get next event
+bool wxGUIEventLoop::YieldFor(long eventsToProcess)
-        event = gdk_display_get_event(disp);
+{
+#if wxUSE_THREADS
+    if ( !wxThread::IsMain() )
+    {
+        // can't call gtk_main_iteration() from other threads like this
+        return true;
     }
+#endif // wxUSE_THREADS
+
+    m_isInsideYield = true;
+    m_eventsToProcessInsideYield = eventsToProcess;
+
+#if wxUSE_LOG
+    // disable log flushing from here because a call to wxYield() shouldn't
+    // normally result in message boxes popping up &c
+    wxLog::Suspend();
+#endif
+
+    // temporarily replace the global GDK event handler with our function, which
+    // categorizes the events and using m_eventsToProcessInsideYield decides
+    // if an event should be processed immediately or not
+    // NOTE: this approach is better than using gdk_display_get_event() because
+    //       gtk_main_iteration() does more than just calling gdk_display_get_event()
+    //       and then call gtk_main_do_event()!
+    //       In particular in this way we also process input from sources like
+    //       GIOChannels (this is needed for e.g. wxGUIAppTraits::WaitForChild).
+    gdk_event_handler_set ((GdkEventFunc)wxgtk_main_do_event, this, NULL);
+    while (Pending())   // avoid false positives from our idle source
+        gtk_main_iteration();
+    gdk_event_handler_set ((GdkEventFunc)gtk_main_do_event, NULL, NULL);
 
     if (eventsToProcess != wxEVT_CATEGORY_CLIPBOARD)
     {
@@ -252,6 +252,7 @@ bool wxGUIEventLoop::YieldFor(long eventsToProcess)
     //      then we fall into a never-ending loop...
 
     // put all unprocessed GDK events back in the queue
+    GdkDisplay* disp = gtk_widget_get_display(wxGetRootWindow());
     for (size_t i=0; i<m_arrGdkEvents.GetCount(); i++)
     {
         GdkEvent* ev = (GdkEvent*)m_arrGdkEvents[i];