// Author: Vadim Zeitlin
// Modified by:
// Created: 01.06.01
-// RCS-ID: $Id$
// Copyright: (c) 2001 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
// Licence: wxWindows licence
///////////////////////////////////////////////////////////////////////////////
#ifndef _WX_EVTLOOP_H_
#define _WX_EVTLOOP_H_
-#ifdef __GNUG__
- #pragma interface "evtloop.h"
+#include "wx/event.h"
+#include "wx/utils.h"
+
+// TODO: implement wxEventLoopSource for MSW (it should wrap a HANDLE and be
+// monitored using MsgWaitForMultipleObjects())
+#if defined(__WXOSX__) || (defined(__UNIX__) && !defined(__WXMSW__))
+ #define wxUSE_EVENTLOOP_SOURCE 1
+#else
+ #define wxUSE_EVENTLOOP_SOURCE 0
+#endif
+
+#if wxUSE_EVENTLOOP_SOURCE
+ class wxEventLoopSource;
+ class wxEventLoopSourceHandler;
#endif
+/*
+ NOTE ABOUT wxEventLoopBase::YieldFor LOGIC
+ ------------------------------------------
+
+ The YieldFor() function helps to avoid re-entrancy problems and problems
+ caused by out-of-order event processing
+ (see "wxYield-like problems" and "wxProgressDialog+threading BUG" wx-dev threads).
+
+ The logic behind YieldFor() is simple: it analyzes the queue of the native
+ events generated by the underlying GUI toolkit and picks out and processes
+ only those matching the given mask.
+
+ It's important to note that YieldFor() is used to selectively process the
+ events generated by the NATIVE toolkit.
+ Events syntethized by wxWidgets code or by user code are instead selectively
+ processed thanks to the logic built into wxEvtHandler::ProcessPendingEvents().
+ In fact, when wxEvtHandler::ProcessPendingEvents gets called from inside a
+ YieldFor() call, wxEventLoopBase::IsEventAllowedInsideYield is used to decide
+ if the pending events for that event handler can be processed.
+ If all the pending events associated with that event handler result as "not processable",
+ the event handler "delays" itself calling wxEventLoopBase::DelayPendingEventHandler
+ (so it's moved: m_handlersWithPendingEvents => m_handlersWithPendingDelayedEvents).
+ Last, wxEventLoopBase::ProcessPendingEvents() before exiting moves the delayed
+ event handlers back into the list of handlers with pending events
+ (m_handlersWithPendingDelayedEvents => m_handlersWithPendingEvents) so that
+ a later call to ProcessPendingEvents() (possibly outside the YieldFor() call)
+ will process all pending events as usual.
+*/
+
// ----------------------------------------------------------------------------
-// wxEventLoop: a GUI event loop
+// wxEventLoopBase: interface for wxEventLoop
// ----------------------------------------------------------------------------
-class WXDLLEXPORT wxEventLoop
+class WXDLLIMPEXP_BASE wxEventLoopBase
{
public:
- // ctor
- wxEventLoop() { m_impl = NULL; }
+ // trivial, but needed (because of wxEventLoopBase) ctor
+ wxEventLoopBase();
// dtor
- virtual ~wxEventLoop();
+ virtual ~wxEventLoopBase() { }
+
+ // use this to check whether the event loop was successfully created before
+ // using it
+ virtual bool IsOk() const { return true; }
+
+ // returns true if this is the main loop
+ bool IsMain() const;
+
+#if wxUSE_EVENTLOOP_SOURCE
+ // create a new event loop source wrapping the given file descriptor and
+ // monitor it for events occurring on this descriptor in all event loops
+ static wxEventLoopSource *
+ AddSourceForFD(int fd, wxEventLoopSourceHandler *handler, int flags);
+#endif // wxUSE_EVENTLOOP_SOURCE
+
+ // dispatch&processing
+ // -------------------
// start the event loop, return the exit code when it is finished
+ //
+ // notice that wx ports should override DoRun(), this method is virtual
+ // only to allow overriding it in the user code for custom event loops
virtual int Run();
+ // is this event loop running now?
+ //
+ // notice that even if this event loop hasn't terminated yet but has just
+ // spawned a nested (e.g. modal) event loop, this would return false
+ bool IsRunning() const;
+
// exit from the loop with the given exit code
+ //
+ // this can be only used to exit the currently running loop, use
+ // ScheduleExit() if this might not be the case
virtual void Exit(int rc = 0);
- // return TRUE if any events are available
- virtual bool Pending() const;
+ // ask the event loop to exit with the given exit code, can be used even if
+ // this loop is not running right now but the loop must have been started,
+ // i.e. Run() should have been already called
+ virtual void ScheduleExit(int rc = 0) = 0;
+
+ // return true if any events are available
+ virtual bool Pending() const = 0;
+
+ // dispatch a single event, return false if we should exit from the loop
+ virtual bool Dispatch() = 0;
+
+ // same as Dispatch() but doesn't wait for longer than the specified (in
+ // ms) timeout, return true if an event was processed, false if we should
+ // exit the loop or -1 if timeout expired
+ virtual int DispatchTimeout(unsigned long timeout) = 0;
+
+ // implement this to wake up the loop: usually done by posting a dummy event
+ // to it (can be called from non main thread)
+ virtual void WakeUp() = 0;
+
+
+ // idle handling
+ // -------------
+
+ // make sure that idle events are sent again
+ virtual void WakeUpIdle();
+
+ // this virtual function is called when the application
+ // becomes idle and by default it forwards to wxApp::ProcessIdle() and
+ // while it can be overridden in a custom event loop, you must call the
+ // base class version to ensure that idle events are still generated
+ //
+ // it should return true if more idle events are needed, false if not
+ virtual bool ProcessIdle();
+
+
+ // Yield-related hooks
+ // -------------------
+
+ // process all currently pending events right now
+ //
+ // it is an error to call Yield() recursively unless the value of
+ // onlyIfNeeded is true
+ //
+ // WARNING: this function is dangerous as it can lead to unexpected
+ // reentrancies (i.e. when called from an event handler it
+ // may result in calling the same event handler again), use
+ // with _extreme_ care or, better, don't use at all!
+ bool Yield(bool onlyIfNeeded = false);
+ virtual bool YieldFor(long eventsToProcess) = 0;
+
+ // returns true if the main thread is inside a Yield() call
+ virtual bool IsYielding() const
+ { return m_isInsideYield; }
+
+ // returns true if events of the given event category should be immediately
+ // processed inside a wxApp::Yield() call or rather should be queued for
+ // later processing by the main event loop
+ virtual bool IsEventAllowedInsideYield(wxEventCategory cat) const
+ { return (m_eventsToProcessInsideYield & cat) != 0; }
+
+ // no SafeYield hooks since it uses wxWindow which is not available when wxUSE_GUI=0
- // dispatch a single event, return FALSE if we should exit from the loop
- virtual bool Dispatch();
- // is the event loop running now?
- virtual bool IsRunning() const;
-
+ // active loop
+ // -----------
+
// return currently active (running) event loop, may be NULL
- static wxEventLoop *GetActive() { return ms_activeLoop; }
+ static wxEventLoopBase *GetActive() { return ms_activeLoop; }
// set currently active (running) event loop
- static void SetActive(wxEventLoop* loop) { ms_activeLoop = loop; }
+ static void SetActive(wxEventLoopBase* loop);
+
protected:
- // the pointer to the port specific implementation class
- class WXDLLEXPORT wxEventLoopImpl *m_impl;
+ // real implementation of Run()
+ virtual int DoRun() = 0;
+
+ // this function should be 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)
+ virtual void OnExit();
+
+ // Return true if we're currently inside our Run(), even if another nested
+ // event loop is currently running, unlike IsRunning() (which should have
+ // been really called IsActive() but it's too late to change this now).
+ bool IsInsideRun() const { return m_isInsideRun; }
+
+
// the pointer to currently active loop
- static wxEventLoop *ms_activeLoop;
+ static wxEventLoopBase *ms_activeLoop;
+
+ // should we exit the loop?
+ bool m_shouldExit;
+
+ // YieldFor() helpers:
+ bool m_isInsideYield;
+ long m_eventsToProcessInsideYield;
+
+private:
+ // this flag is set on entry into Run() and reset before leaving it
+ bool m_isInsideRun;
+
+ wxDECLARE_NO_COPY_CLASS(wxEventLoopBase);
+};
+
+#if defined(__WINDOWS__) || defined(__WXMAC__) || defined(__WXDFB__) || (defined(__UNIX__) && !defined(__WXOSX__))
+
+// this class can be used to implement a standard event loop logic using
+// Pending() and Dispatch()
+//
+// it also handles idle processing automatically
+class WXDLLIMPEXP_BASE wxEventLoopManual : public wxEventLoopBase
+{
+public:
+ wxEventLoopManual();
+
+ // sets the "should exit" flag and wakes up the loop so that it terminates
+ // soon
+ virtual void ScheduleExit(int rc = 0);
+
+protected:
+ // enters a loop calling OnNextIteration(), Pending() and Dispatch() and
+ // terminating when Exit() is called
+ virtual int DoRun();
+
+ // may be overridden to perform some action at the start of each new event
+ // loop iteration
+ virtual void OnNextIteration() { }
+
+
+ // the loop exit code
+ int m_exitcode;
+
+private:
+ // process all already pending events and dispatch a new one (blocking
+ // until it appears in the event queue if necessary)
+ //
+ // returns the return value of Dispatch()
+ bool ProcessEvents();
+
+ wxDECLARE_NO_COPY_CLASS(wxEventLoopManual);
+};
+
+#endif // platforms using "manual" loop
+
+// we're moving away from old m_impl wxEventLoop model as otherwise the user
+// code doesn't have access to platform-specific wxEventLoop methods and this
+// can sometimes be very useful (e.g. under MSW this is necessary for
+// integration with MFC) but currently this is not done for all ports yet (e.g.
+// wxX11) so fall back to the old wxGUIEventLoop definition below for them
+
+#if defined(__DARWIN__)
+ // CoreFoundation-based event loop is currently in wxBase so include it in
+ // any case too (although maybe it actually shouldn't be there at all)
+ #include "wx/osx/core/evtloop.h"
+#endif
+
+// include the header defining wxConsoleEventLoop
+#if defined(__UNIX__) && !defined(__WXMSW__)
+ #include "wx/unix/evtloop.h"
+#elif defined(__WINDOWS__)
+ #include "wx/msw/evtloopconsole.h"
+#endif
+
+#if wxUSE_GUI
+
+// include the appropriate header defining wxGUIEventLoop
+
+#if defined(__WXMSW__)
+ #include "wx/msw/evtloop.h"
+#elif defined(__WXCOCOA__)
+ #include "wx/cocoa/evtloop.h"
+#elif defined(__WXOSX__)
+ #include "wx/osx/evtloop.h"
+#elif defined(__WXDFB__)
+ #include "wx/dfb/evtloop.h"
+#elif defined(__WXGTK20__)
+ #include "wx/gtk/evtloop.h"
+#else // other platform
+
+#include "wx/stopwatch.h" // for wxMilliClock_t
+
+class WXDLLIMPEXP_FWD_CORE wxEventLoopImpl;
+
+class WXDLLIMPEXP_CORE wxGUIEventLoop : public wxEventLoopBase
+{
+public:
+ wxGUIEventLoop() { m_impl = NULL; }
+ virtual ~wxGUIEventLoop();
+
+ virtual void ScheduleExit(int rc = 0);
+ virtual bool Pending() const;
+ virtual bool Dispatch();
+ virtual int DispatchTimeout(unsigned long timeout)
+ {
+ // TODO: this is, of course, horribly inefficient and a proper wait with
+ // timeout should be implemented for all ports natively...
+ const wxMilliClock_t timeEnd = wxGetLocalTimeMillis() + timeout;
+ for ( ;; )
+ {
+ if ( Pending() )
+ return Dispatch();
+
+ if ( wxGetLocalTimeMillis() >= timeEnd )
+ return -1;
+ }
+ }
+ virtual void WakeUp() { }
+ virtual bool YieldFor(long eventsToProcess);
+
+protected:
+ virtual int DoRun();
+
+ // the pointer to the port specific implementation class
+ wxEventLoopImpl *m_impl;
+
+ wxDECLARE_NO_COPY_CLASS(wxGUIEventLoop);
};
+#endif // platforms
+
+#endif // wxUSE_GUI
+
+#if wxUSE_GUI
+ // we use a class rather than a typedef because wxEventLoop is
+ // forward-declared in many places
+ class wxEventLoop : public wxGUIEventLoop { };
+#else // !wxUSE_GUI
+ // we can't define wxEventLoop differently in GUI and base libraries so use
+ // a #define to still allow writing wxEventLoop in the user code
+ #if wxUSE_CONSOLE_EVENTLOOP && (defined(__WINDOWS__) || defined(__UNIX__))
+ #define wxEventLoop wxConsoleEventLoop
+ #else // we still must define it somehow for the code below...
+ #define wxEventLoop wxEventLoopBase
+ #endif
+#endif
+
+inline bool wxEventLoopBase::IsRunning() const { return GetActive() == this; }
+
+#if wxUSE_GUI && !defined(__WXOSX__)
+// ----------------------------------------------------------------------------
+// wxModalEventLoop
+// ----------------------------------------------------------------------------
+
+// this is a naive generic implementation which uses wxWindowDisabler to
+// implement modality, we will surely need platform-specific implementations
+// too, this generic implementation is here only temporarily to see how it
+// works
+class WXDLLIMPEXP_CORE wxModalEventLoop : public wxGUIEventLoop
+{
+public:
+ wxModalEventLoop(wxWindow *winModal)
+ {
+ m_windowDisabler = new wxWindowDisabler(winModal);
+ }
+
+protected:
+ virtual void OnExit()
+ {
+ delete m_windowDisabler;
+ m_windowDisabler = NULL;
+
+ wxGUIEventLoop::OnExit();
+ }
+
+private:
+ wxWindowDisabler *m_windowDisabler;
+};
+
+#endif //wxUSE_GUI
+
+// ----------------------------------------------------------------------------
+// wxEventLoopActivator: helper class for wxEventLoop implementations
+// ----------------------------------------------------------------------------
+
+// this object sets the wxEventLoop given to the ctor as the currently active
+// one and unsets it in its dtor, this is especially useful in presence of
+// exceptions but is more tidy even when we don't use them
+class wxEventLoopActivator
+{
+public:
+ wxEventLoopActivator(wxEventLoopBase *evtLoop)
+ {
+ m_evtLoopOld = wxEventLoopBase::GetActive();
+ wxEventLoopBase::SetActive(evtLoop);
+ }
+
+ ~wxEventLoopActivator()
+ {
+ // restore the previously active event loop
+ wxEventLoopBase::SetActive(m_evtLoopOld);
+ }
+
+private:
+ wxEventLoopBase *m_evtLoopOld;
+};
+
+#if wxUSE_CONSOLE_EVENTLOOP
+
+class wxEventLoopGuarantor
+{
+public:
+ wxEventLoopGuarantor()
+ {
+ m_evtLoopNew = NULL;
+ if (!wxEventLoop::GetActive())
+ {
+ m_evtLoopNew = new wxEventLoop;
+ wxEventLoop::SetActive(m_evtLoopNew);
+ }
+ }
+
+ ~wxEventLoopGuarantor()
+ {
+ if (m_evtLoopNew)
+ {
+ wxEventLoop::SetActive(NULL);
+ delete m_evtLoopNew;
+ }
+ }
+
+private:
+ wxEventLoop *m_evtLoopNew;
+};
+
+#endif // wxUSE_CONSOLE_EVENTLOOP
+
#endif // _WX_EVTLOOP_H_
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