Fix scrolling to the bottom in wxTextCtrl::AppendText().

[wxWidgets.git] / interface / wx / evtloop.h

diff --git a/interface/wx/evtloop.h b/interface/wx/evtloop.h
index d4a7966a953bef405989b9f8e61dabfb4a608e07..4322ac08d0eefedd9fefac5cca88a34ef6734d79 100644 (file)
--- a/interface/wx/evtloop.h
+++ b/interface/wx/evtloop.h
@@ -12,13 +12,21 @@
 
     Base class for all event loop implementations.
 
 
     Base class for all event loop implementations.
 

+    An event loop is a class which queries the queue of native events sent
+    to the wxWidgets application and dispatches them to the appropriate
+    wxEvtHandlers.
+

     An object of this class is created by wxAppTraits::CreateEventLoop() and
     used by wxApp to run the main application event loop.
     An object of this class is created by wxAppTraits::CreateEventLoop() and
     used by wxApp to run the main application event loop.

+    Temporary event loops are usually created by wxDialog::ShowModal().
+
+    You can create your own event loop if you need, provided that you restore
+    the main event loop once yours is destroyed (see wxEventLoopActivator).

 
     @library{wxbase}
     @category{appmanagement}
 
 
     @library{wxbase}
     @category{appmanagement}
 

-    @see wxApp
+    @see wxApp, wxEventLoopActivator

 */
 class wxEventLoopBase
 {
 */
 class wxEventLoopBase
 {


@@ -37,15 +45,21 @@ public:
         Called by wxEventLoopActivator, use an instance of this class instead
         of calling this method directly to ensure that the previously active
         event loop is restored.
         Called by wxEventLoopActivator, use an instance of this class instead
         of calling this method directly to ensure that the previously active
         event loop is restored.

+
+        Results in a call to wxAppConsole::OnEventLoopEnter.

      */
     static void SetActive(wxEventLoopBase* loop);
 
      */
     static void SetActive(wxEventLoopBase* loop);
 

+    /**
+        Returns @true if this is the main loop executed by wxApp::OnRun().
+    */
+    bool IsMain() const;
+

 
     /**
 
     /**

-        Use this to check whether the event loop was successfully created
-        before using it
-     */
-    virtual bool IsOk() const;
+        @name Dispatch and processing
+    */
+    //@{

 
     /**
         Start the event loop, return the exit code when it is finished.
 
     /**
         Start the event loop, return the exit code when it is finished.


@@ -60,6 +74,21 @@ public:
      */
     virtual int Run() = 0;
 
      */
     virtual int Run() = 0;
 

+    /**
+        Return true if this event loop is currently running.
+
+        Notice that even if this event loop hasn't terminated yet but has just
+        spawned a nested (e.g. modal) event loop, this method would return
+        @false.
+     */
+    bool IsRunning() const;
+
+    /**
+        Use this to check whether the event loop was successfully created
+        before using it
+     */
+    virtual bool IsOk() const;
+

     /**
         Exit from the loop with the given exit code.
      */
     /**
         Exit from the loop with the given exit code.
      */


@@ -73,23 +102,40 @@ public:
     virtual bool Pending() const = 0;
 
     /**
     virtual bool Pending() const = 0;
 
     /**

-        Dispatch a single event.
+        Dispatches the next event in the windowing system event queue.
+        Blocks until an event appears if there are none currently
+        (use Pending() if this is not wanted).

 
 

-        If there are currently no events in the queue, blocks until an event
-        becomes available.
+        This can be used for programming event loops, e.g.

 
 

-        @return @false only if the event loop should terminate.
-     */
+        @code
+        while (evtloop->Pending())
+            evtloop->Dispatch();
+        @endcode
+
+        @return @false if the event loop should stop and @true otherwise.
+
+        @see Pending(), wxEventLoopBase
+    */

     virtual bool Dispatch() = 0;
 
     /**
     virtual bool Dispatch() = 0;
 
     /**

-        Return true if this event loop is currently running.
+        Dispatch an event but not wait longer than the specified timeout for
+        it.

 
 

-        Notice that even if this event loop hasn't terminated yet but has just
-        spawned a nested (e.g. modal) event loop, this method would return
-        @false.
+        If an event is received before the specified @a timeout expires, it is
+        processed and the function returns 1 normally or 0 if the event loop
+        should quite. Otherwise, i.e. if the timeout expires, the functions
+        returns -1 without processing any events.
+
+        @param timeout
+            The maximal time to wait for the events in milliseconds.
+
+        @return
+            1 if an event was processed, 0 if the event loop should quit or -1
+            if the timeout expired.

      */
      */

-    bool IsRunning() const;
+    virtual int DispatchTimeout(unsigned long timeout) = 0;

 
     /**
         Called by wxWidgets to wake up the event loop even if it is currently
 
     /**
         Called by wxWidgets to wake up the event loop even if it is currently


@@ -97,13 +143,105 @@ public:
      */
     virtual void WakeUp() = 0;
 
      */
     virtual void WakeUp() = 0;
 

+    //@}
+
+
+    /**
+        @name Idle handling
+    */
+    //@{
+
+    /**
+        Makes sure that idle events are sent again.
+    */
+    virtual void WakeUpIdle();
+
+    /**
+        This virtual function is called  when the application becomes idle and
+        normally just sends wxIdleEvent to all interested parties.
+
+        It should return @true if more idle events are needed, @false if not.
+    */
+    virtual bool ProcessIdle();
+
+    //@}
+
+
+    /**
+        @name Yield-related hooks
+    */
+    //@{
+
+    /**
+        Returns @true if called from inside Yield() or from inside YieldFor().
+    */
+    virtual bool IsYielding() const;
+
+    /**
+        Yields control to pending messages in the windowing system.
+
+        This can be useful, for example, when a time-consuming process writes to a
+        text window. Without an occasional yield, the text window will not be updated
+        properly, and on systems with cooperative multitasking, such as Windows 3.1
+        other processes will not respond.
+
+        Caution should be exercised, however, since yielding may allow the
+        user to perform actions which are not compatible with the current task.
+        Disabling menu items or whole menus during processing can avoid unwanted
+        reentrance of code: see ::wxSafeYield for a better function.
+        You can avoid unwanted reentrancies also using IsYielding().
+
+        Note that Yield() will not flush the message logs. This is intentional as
+        calling Yield() is usually done to quickly update the screen and popping up
+        a message box dialog may be undesirable. If you do wish to flush the log
+        messages immediately (otherwise it will be done during the next idle loop
+        iteration), call wxLog::FlushActive.
+
+        Calling Yield() recursively is normally an error and an assert failure is
+        raised in debug build if such situation is detected. However if the
+        @a onlyIfNeeded parameter is @true, the method will just silently
+        return @false instead.
+    */
+    bool Yield(bool onlyIfNeeded = false);
+
+    /**
+        Works like Yield() with @e onlyIfNeeded == @true, except that it allows
+        the caller to specify a mask of the ::wxEventCategory values which
+        indicates which events should be processed and which should instead
+        be "delayed" (i.e. processed by the main loop later).
+
+        Note that this is a safer alternative to Yield() since it ensures that
+        only the events you're interested to will be processed; i.e. this method
+        helps to avoid unwanted reentrancies.
+
+        Note that currently only wxMSW and wxGTK do support selective yield of
+        native events coming from the underlying GUI toolkit.
+        wxWidgets events posted using wxEvtHandler::AddPendingEvent or
+        wxEvtHandler::QueueEvent are instead selectively processed by all ports.
+
+        @see wxEvent::GetEventCategory
+    */
+    bool YieldFor(long eventsToProcess);
+
+    /**
+        Returns @true if the given event category is allowed inside
+        a YieldFor() call (i.e. compares the given category against the
+        last mask passed to YieldFor()).
+
+        @see wxEvent::GetEventCategory
+    */
+    virtual bool IsEventAllowedInsideYield(wxEventCategory cat) const;
+
+    //@}
+
+

 protected:
     /**
         This function is called before the event loop terminates, whether this
         happens normally (because of Exit() call) or abnormally (because of an
         exception thrown from inside the loop).
 
 protected:
     /**
         This function is called before the event loop terminates, whether this
         happens normally (because of Exit() call) or abnormally (because of an
         exception thrown from inside the loop).
 

-        Default version does nothing.
+        The default implementation calls wxAppConsole::OnEventLoopExit.

      */
     virtual void OnExit();
 };
      */
     virtual void OnExit();
 };