X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/5f445b310b239ea4d26996d4384899c66aa833c5..e2478fde622a16d25c66690af353dfdc37e7b582:/docs/latex/wx/timer.tex diff --git a/docs/latex/wx/timer.tex b/docs/latex/wx/timer.tex index 4560342c9d..88ecf4940b 100644 --- a/docs/latex/wx/timer.tex +++ b/docs/latex/wx/timer.tex @@ -1,13 +1,34 @@ \section{\class{wxTimer}}\label{wxtimer} -The wxTimer class allows you to execute code at specified intervals. To -use it, derive a new class and override the {\bf Notify} member to -perform the required action. Start with {\bf Start}, stop with {\bf -Stop}, it's as simple as that. +The wxTimer class allows you to execute code at specified intervals. Its +precision is platform-dependent, but in general will not be better than 1ms nor +worse than 1s. + +There are two different ways to use this class: + +\begin{enumerate} +\item You may derive a new class from wxTimer and override the +\helpref{Notify}{wxtimernotify} member to perform the required action. +\item Or you may redirect the notifications to any +\helpref{wxEvtHandler}{wxevthandler} derived object by using the non default +constructor or \helpref{SetOwner}{wxtimersetowner}. Then use the {\tt EVT\_TIMER} +macro to connect it to the event handler which will receive +\helpref{wxTimerEvent}{wxtimerevent} notifications. +\item Or you may use a derived class and the {\tt EVT\_TIMER} +macro to connect it to an event handler defined in the derived class. +If the default constructor is used, the timer object will be its +own owner object, since it is derived from wxEvtHandler. +\end{enumerate} + +In any case, you must start the timer with \helpref{Start}{wxtimerstart} +after constructing it before it actually starts sending notifications. It can +be stopped later with \helpref{Stop}{wxtimerstop}. + +{\bf NB:} note that timer can only be used from the main thread currently. \wxheading{Derived from} -\helpref{wxObject}{wxobject} +\helpref{wxEvtHandler}{wxevthandler} \wxheading{Include files} @@ -19,89 +40,136 @@ Stop}, it's as simple as that. \latexignore{\rtfignore{\wxheading{Members}}} -\membersection{wxTimer::wxTimer} +\membersection{wxTimer::wxTimer}\label{wxtimerwxtimer} \func{}{wxTimer}{\void} -Constructor. +Default constructor. If you use it to construct the object and don't call +\helpref{SetOwner}{wxtimersetowner} later, you must override +\helpref{Notify}{wxtimernotify} method to process the notifications. + +\func{}{wxTimer}{\param{wxEvtHandler *}{owner}, \param{int }{id = -1}} + +Creates a timer and associates it with {\it owner}. Please see +\helpref{SetOwner}{wxtimersetowner} for the description of parameters. \membersection{wxTimer::\destruct{wxTimer}} \func{}{\destruct{wxTimer}}{\void} -Destructor. Stops the timer if activated. +Destructor. Stops the timer if it is running. + +\membersection{wxTimer::GetInterval}\label{wxtimergetinterval} + +\constfunc{int}{GetInterval}{\void} + +Returns the current interval for the timer (in milliseconds). + +\membersection{wxTimer::IsOneShot}\label{wxtimerisoneshot} -\membersection{wxTimer::Interval} +\constfunc{bool}{IsOneShot}{\void} -\func{int}{Interval}{\void} +Returns {\tt true} if the timer is one shot, i.e.\ if it will stop after firing the +first notification automatically. -Returns the current interval for the timer. +\membersection{wxTimer::IsRunning}\label{wxtimerisrunning} -\membersection{wxTimer::Notify} +\constfunc{bool}{IsRunning}{\void} + +Returns {\tt true} if the timer is running, {\tt false} if it is stopped. + +\membersection{wxTimer::Notify}\label{wxtimernotify} \func{void}{Notify}{\void} -This member should be overridden by the user. It is called on timeout. +This member should be overridden by the user if the default constructor was +used and \helpref{SetOwner}{wxtimersetowner} wasn't called. -\membersection{wxTimer::Start} +Perform whatever action which is to be taken periodically here. -\func{bool}{Start}{\param{int}{ milliseconds = -1}, \param{bool}{ oneShot=FALSE}} +\membersection{wxTimer::SetOwner}\label{wxtimersetowner} -(Re)starts the timer. If {\it milliseconds}\/ is absent or -1, the -previous value is used. Returns FALSE if the timer could not be started, -TRUE otherwise (in MS Windows timers are a limited resource). +\func{void}{SetOwner}{\param{wxEvtHandler *}{owner}, \param{int }{id = -1}} -If {\it oneShot} is FALSE (the default), the Notify function will be repeatedly -called. If TRUE, Notify will be called only once. +Associates the timer with the given {\it owner}\/ object. When the timer is +running, the owner will receive \helpref{timer events}{wxtimerevent} with +id equal to {\it id}\/ specified here. -\membersection{wxTimer::Stop} +\membersection{wxTimer::Start}\label{wxtimerstart} -\func{void}{Stop}{\void} +\func{bool}{Start}{\param{int}{milliseconds = -1}, \param{bool }{oneShot = {\tt false}}} -Stops the timer. +(Re)starts the timer. If {\it milliseconds}\/ parameter is -1 (value by default), +the previous value is used. Returns {\tt false} if the timer could not be started, +{\tt true} otherwise (in MS Windows timers are a limited resource). -\section{\class{wxStopWatch}}\label{wxstopwatch} +If {\it oneShot}\/ is {\tt false} (the default), the \helpref{Notify}{wxtimernotify} +function will be called repeatedly until the timer is stopped. If {\tt true}, +it will be called only once and the timer will stop automatically. To make your +code more readable you may also use the following symbolic constants +\twocolwidtha{5cm}% +\begin{twocollist}\itemsep=0pt +\twocolitem{wxTIMER\_CONTINUOUS}{Start a normal, continuously running, timer} +\twocolitem{wxTIMER\_ONE\_SHOT}{Start a one shot timer} +\end{twocollist} -The wxStopWatch class allow you to measure time intervalls. -\wxheading{Include files} +If the timer was already running, it will be stopped by this method before +restarting it. - +\membersection{wxTimer::Stop}\label{wxtimerstop} -\wxheading{See also} +\func{void}{Stop}{\void} -\helpref{::wxStartTimer}{wxstarttimer}, \helpref{::wxGetElapsedTime}{wxgetelapsedtime}, \helpref{wxTimer}{wxtimer} +Stops the timer. -\latexignore{\rtfignore{\wxheading{Members}}} +\section{\class{wxTimerEvent}}\label{wxtimerevent} -\membersection{wxStopWatch::wxStopWatch} +wxTimerEvent object is passed to the event handler of timer events. -\func{}{wxStopWatch}{\void} +For example: -Constructor. This starts the stop watch. +\begin{verbatim} +class MyFrame : public wxFrame +{ +public: + ... + void OnTimer(wxTimerEvent& event); -\membersection{wxStopWatch::Pause}\label{wxstopwatchpause} +private: + wxTimer m_timer; +}; -\func{void}{Pause}{\void} +BEGIN_EVENT_TABLE(MyFrame, wxFrame) + EVT_TIMER(TIMER_ID, MyFrame::OnTimer) +END_EVENT_TABLE() -Pauses the stop watch. Call \helpref{wxStopWatch::Resume}{wxstopwatchresume} to resume -time measuring again. +MyFrame::MyFrame() + : m_timer(this, TIMER_ID) +{ + m_timer.Start(1000); // 1 second interval +} -\membersection{wxStopWatch::Start} +void MyFrame::OnTimer(wxTimerEvent& event) +{ + // do whatever you want to do every second here +} -\func{void}{Start}{\param{long}{ milliseconds = 0}} +\end{verbatim} -(Re)starts the stop watch with a given initial value. +\wxheading{Include files} -\membersection{wxStopWatch::Resume}\label{wxstopwatchresume} + + +\wxheading{See also} -\func{void}{Resume}{\void} +\helpref{wxTimer}{wxtimer} + +\latexignore{\rtfignore{\wxheading{Members}}} -Resumes the stop watch after having been paused with \helpref{wxStopWatch::Pause}{wxstopwatchpause}. +\membersection{wxTimerEvent::GetInterval}\label{wxtimereventgetinterval} -\membersection{wxStopWatch::Time} +\constfunc{int}{GetInterval}{\void} -\func{long}{Time}{\void}\label{wxstopwatchtime} +Returns the interval of the timer which generated this event. -Returns the time in milliseconds since the start (or restart) or the last call of -\helpref{wxStopWatch::Pause}{wxstopwatchpause}.