name wxThreadEvent and YieldFor in wxProgressDialog and in thread overview; update the sample code to use new event macros; minor other changes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59002 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/doxygen/overviews/eventhandling.h

@@ -441,32 +441,10 @@ or unset this flag for the dialogs that have it on by default.
 Typically events that deal with a window as a window (size, motion,
 paint, mouse, keyboard, etc.) are sent only to the window.  Events
 that have a higher level of meaning or are generated by the window
-itself, (button click, menu select, tree expand, etc.) are command
+itself (button click, menu select, tree expand, etc.) are command
 events and are sent up to the parent to see if it is interested in the event.
-
+More precisely, as said above, all event classes @b not deriving from wxCommandEvent
-As mentioned above, only command events are recursively applied to the parents
+(see the wxEvent inheritance map) do @b not propagate upward.
-event handler in the library itself. As this quite often causes confusion for
-users, here is a list of system events that will @em not get sent to the
-parent's event handler:
-
-@li wxEvent: The event base class
-@li wxActivateEvent: A window or application activation event
-@li wxCloseEvent: A close window or end session event
-@li wxEraseEvent: An erase background event
-@li wxFocusEvent: A window focus event
-@li wxKeyEvent: A keypress event
-@li wxIdleEvent: An idle event
-@li wxInitDialogEvent: A dialog initialisation event
-@li wxJoystickEvent: A joystick event
-@li wxMenuEvent: A menu event
-@li wxMouseEvent: A mouse event
-@li wxMoveEvent: A move event
-@li wxPaintEvent: A paint event
-@li wxQueryLayoutInfoEvent: Used to query layout information
-@li wxSetCursorEvent: Used for special cursor processing based on current mouse position
-@li wxSizeEvent: A size event
-@li wxScrollWinEvent: A scroll event sent by a scrolled window (not a scroll bar)
-@li wxSysColourChangedEvent: A system colour change event
 
 In some cases, it might be desired by the programmer to get a certain number
 of system events in a parent window, for example all key events sent to, but not
@@ -763,7 +741,7 @@ your identifiers don't conflict accidentally.
 
 
 
-@subsection overview_events_macros Event Handling Summary
+@subsection overview_events_list List of wxWidgets events
 
 For the full list of event classes, please see the
 @ref group_class_events "event classes group page".

docs/doxygen/overviews/thread.h

@@ -13,10 +13,13 @@
 
 /**
 
-@page overview_thread Multithreading
+@page overview_thread Multithreading Overview
 
 Classes: wxThread, wxThreadHelper, wxMutex, wxCriticalSection, wxCondition, wxSemaphore
 
+
+@section overview_thread_intro When to use multiple threads
+
 wxWidgets provides a complete set of classes encapsulating objects necessary in
 multithreaded (MT) programs: the wxThread class itself and different
 synchronization objects: mutexes (see wxMutex) and critical sections (see
@@ -45,13 +48,17 @@ two possible implementation choices:
 - use wxIdleEvent (e.g. to perform a long calculation while updating a progress dialog)
 - do everything at once but call wxWindow::Update() or wxApp::YieldFor(wxEVT_CATEGORY_UI)
   periodically to update the screen.
+If instead you choose to use threads in your application, please read also
+the following sections of this overview.
 
-If instead you choose to use threads in your application, it is strongly recommended
+@section overview_thread_notes Important notes for multithreaded applications
+
+When writing a multi-threaded application, it is strongly recommended
 that <b>no secondary threads call GUI functions</b>.
 The design which uses one GUI thread and several worker threads which communicate
 with the main one using @b events is much more robust and will undoubtedly save you
 countless problems (example: under Win32 a thread can only access GDI objects such
-as pens, brushes, c created by itself and not by the other threads).
+as pens, brushes, device contexts created by itself and not by the other threads).
 
 For communication between secondary threads and the main thread, you may use
 wxEvtHandler::QueueEvent or its short version ::wxQueueEvent. These functions
@@ -62,6 +69,19 @@ synchronization classes to implement the solution which suits your needs
 yourself. In particular, please note that it is not enough to derive
 your class from wxThread and wxEvtHandler to send messages to it: in fact, this
 does not work at all.
+You're instead encouraged to use wxThreadHelper as it greatly simplifies the
+communication and the sharing of resources.
+
+You should also look at the wxThread docs for important notes about secondary
+threads and their deletion.
+
+Last, remember that if wxEventLoopBase::YieldFor() is used directly or indirectly
+(e.g. through wxProgressDialog) in your code, then you may have both re-entrancy
+problems and also problems caused by the processing of events out of order.
+To resolve the last problem wxThreadEvent can be used: thanks to its implementation
+of the wxThreadEvent::GetEventCategory function wxThreadEvent classes in fact
+do not get processed by wxEventLoopBase::YieldFor() unless you specify the
+@c wxEVT_CATEGORY_THREAD flag.
 
 See also the @sample{thread} for a sample showing some simple interactions
 between the main and secondary threads.

interface/wx/event.h

@@ -147,6 +147,7 @@ public:
 
     /**
         Returns a generic category for this event.
+        wxEvent implementation returns @c wxEVT_CATEGORY_UI by default.
 
         This function is used to selectively process events in wxEventLoopBase::YieldFor.
     */
@@ -2030,6 +2031,11 @@ public:
     This event class contains information about command events, which originate
     from a variety of simple controls.
 
+    Note that wxCommandEvents and wxCommandEvent-derived event classes by default
+    and unlike other wxEvent-derived classes propagate upward from the source
+    window (the window which emits the event) up to the first parent which processes
+    the event. Be sure to read @ref overview_events_propagation.
+
     More complex controls, such as wxTreeCtrl, have separate command event classes.
 
     @beginEventTable{wxCommandEvent}
@@ -2534,6 +2540,12 @@ public:
     This class adds some simple functionalities to wxCommandEvent coinceived
     for inter-threads communications.
 
+    This event is not natively emitted by any control/class: this is just
+    an helper class for the user.
+    Its most important feature is the GetEventCategory() implementation which
+    allows thread events to @b NOT be processed by wxEventLoopBase::YieldFor calls
+    (unless the @c wxEVT_CATEGORY_THREAD is specified - which is never in wx code).
+
     @library{wxcore}
     @category{events}
 

interface/wx/progdlg.h

@@ -10,9 +10,16 @@
     @class wxProgressDialog
 
     This class represents a dialog that shows a short message and a
-    progress bar. Optionally, it can display ABORT and SKIP buttons,
+    progress bar. Optionally, it can display ABORT and SKIP buttons, and
     the elapsed, remaining and estimated time for the end of the progress.
 
+    Note that you must be aware that wxProgressDialog internally calls
+    wxEventLoopBase::YieldFor with @c wxEVT_CATEGORY_UI and @c wxEVT_CATEGORY_USER_INPUT
+    and this may cause unwanted re-entrancies or the out-of-order processing
+    of pending events (to help preventing the last problem if you're using
+    wxProgressDialog in a multi-threaded application you should be sure to use
+    wxThreadEvent for your inter-threads communications).
+
     @beginStyleTable
     @style{wxPD_APP_MODAL}
            Make the progress dialog modal. If this flag is not given, it is

interface/wx/thread.h

@@ -279,7 +279,7 @@ public:
 
     Example:
     @code
-        extern const wxEventType wxEVT_COMMAND_MYTHREAD_UPDATE;
+        wxDECLARE_EVENT(wxEVT_COMMAND_MYTHREAD_UPDATE, wxThreadEvent);
 
         class MyFrame : public wxFrame, public wxThreadHelper
         {
@@ -298,7 +298,7 @@ public:
 
             ...
             void DoStartALongTask();
-            void OnThreadUpdate(wxCommandEvent& evt);
+            void OnThreadUpdate(wxThreadEvent& evt);
             void OnClose(wxCloseEvent& evt);
             ...
 
@@ -312,7 +312,7 @@ public:
             DECLARE_EVENT_TABLE()
         };
 
-        DEFINE_EVENT_TYPE(wxEVT_COMMAND_MYTHREAD_UPDATE)
+        wxDEFINE_EVENT(wxEVT_COMMAND_MYTHREAD_UPDATE, wxThreadEvent)
         BEGIN_EVENT_TABLE(MyFrame, wxFrame)
             EVT_COMMAND(wxID_ANY, wxEVT_COMMAND_MYTHREAD_UPDATE, MyFrame::OnThreadUpdate)
             EVT_CLOSE(MyFrame::OnClose)
@@ -364,7 +364,7 @@ public:
 
                 // VERY IMPORTANT: do not call any GUI function inside this
                 //                 function; rather use wxQueueEvent():
-                wxQueueEvent(this, new wxCommandEvent(wxEVT_COMMAND_MYTHREAD_UPDATE));
+                wxQueueEvent(this, new wxThreadEvent(wxEVT_COMMAND_MYTHREAD_UPDATE));
                     // we used pointer 'this' assuming it's safe; see OnClose()
             }
 
@@ -386,7 +386,7 @@ public:
             Destroy();
         }
 
-        void MyFrame::OnThreadUpdate(wxCommandEvent&evt)
+        void MyFrame::OnThreadUpdate(wxThreadEvent& evt)
         {
             // ...do something... e.g. m_pGauge->Pulse();
 
@@ -399,7 +399,7 @@ public:
     @library{wxbase}
     @category{threading}
 
-    @see wxThread
+    @see wxThread, wxThreadEvent
 */
 class wxThreadHelper
 {
@@ -631,8 +631,8 @@ enum
 
     @code
     // declare a new type of event, to be used by our MyThread class:
-    extern const wxEventType wxEVT_COMMAND_MYTHREAD_COMPLETED;
+    wxDECLARE_EVENT(wxEVT_COMMAND_MYTHREAD_COMPLETED, wxThreadEvent);
-    extern const wxEventType wxEVT_COMMAND_MYTHREAD_UPDATE;
+    wxDECLARE_EVENT(wxEVT_COMMAND_MYTHREAD_UPDATE, wxThreadEvent);
     class MyFrame;
 
     class MyThread : public wxThread
@@ -669,7 +669,8 @@ enum
         // a resume routine would be nearly identic to DoPauseThread()
         void DoResumeThread() { ... }
 
-        void OnThreadCompletion(wxCommandEvent&);
+        void OnThreadUpdate(wxThreadEvent&);
+        void OnThreadCompletion(wxThreadEvent&);
         void OnClose(wxCloseEvent&);
 
     protected:
@@ -686,8 +687,8 @@ enum
         EVT_COMMAND(wxID_ANY, wxEVT_COMMAND_MYTHREAD_COMPLETED, MyFrame::OnThreadCompletion)
     END_EVENT_TABLE()
 
-    DEFINE_EVENT_TYPE(wxEVT_COMMAND_MYTHREAD_COMPLETED)
+    wxDEFINE_EVENT(wxEVT_COMMAND_MYTHREAD_COMPLETED, wxThreadEvent)
-    DEFINE_EVENT_TYPE(wxEVT_COMMAND_MYTHREAD_UPDATE)
+    wxDEFINE_EVENT(wxEVT_COMMAND_MYTHREAD_UPDATE, wxThreadEvent)
 
     void MyFrame::DoStartThread()
     {
@@ -721,13 +722,13 @@ enum
         {
             // ... do a bit of work...
 
-            wxQueueEvent(m_pHandler, new wxCommandEvent(wxEVT_COMMAND_MYTHREAD_UPDATE));
+            wxQueueEvent(m_pHandler, new wxThreadEvent(wxEVT_COMMAND_MYTHREAD_UPDATE));
         }
 
         // signal the event handler that this thread is going to be destroyed
         // NOTE: here we assume that using the m_pHandler pointer is safe,
         //       (in this case this is assured by the MyFrame destructor)
-        wxQueueEvent(m_pHandler, new wxCommandEvent(wxEVT_COMMAND_MYTHREAD_COMPLETED));
+        wxQueueEvent(m_pHandler, new wxThreadEvent(wxEVT_COMMAND_MYTHREAD_COMPLETED));
 
         return (wxThread::ExitCode)0;     // success
     }
@@ -740,12 +741,12 @@ enum
         m_pHandler->m_pThread = NULL;
     }
 
-    void MyFrame::OnThreadCompletion(wxCommandEvent&)
+    void MyFrame::OnThreadCompletion(wxThreadEvent&)
     {
         wxMessageOutputDebug().Printf("MYFRAME: MyThread exited!\n");
     }
 
-    void MyFrame::OnThreadUpdate(wxCommandEvent&)
+    void MyFrame::OnThreadUpdate(wxThreadEvent&)
     {
         wxMessageOutputDebug().Printf("MYFRAME: MyThread update...\n");
     }