docs/latex/wx/timer.tex

   1 \section{\class{wxTimer}}\label{wxtimer}
   2
   3 The wxTimer class allows you to execute code at specified intervals. Its
   4 precision is platform-dependent, but in general will not be better than 1ms nor
   5 worse than 1s.
   6
   7 There are two different ways to use this class:
   8
   9 \begin{enumerate}
  10 \item You may derive a new class from wxTimer and override the
  11 \helpref{Notify}{wxtimernotify} member to perform the required action.
  12 \item Or you may redirect the notifications to any
  13 \helpref{wxEvtHandler}{wxevthandler} derived object by using the non default
  14 constructor or \helpref{SetOwner}{wxtimersetowner}. Then use {\tt EVT\_TIMER}
  15 macro to connect it to the event handler which will receive
  16 \helpref{wxTimerEvent}{wxtimerevent} notifications.
  17 \end{enumerate}
  18
  19 In any case, you must start the timer with \helpref{Start}{wxtimerstart}
  20 after constructing it before it actually starts sending notifications. It can
  21 be stopped later with \helpref{Stop}{wxtimerstop}.
  22
  23 \wxheading{Derived from}
  24
  25 \helpref{wxObject}{wxobject}
  26
  27 \wxheading{Include files}
  28
  29 <wx/timer.h>
  30
  31 \wxheading{See also}
  32
  33 \helpref{::wxStartTimer}{wxstarttimer}, \helpref{::wxGetElapsedTime}{wxgetelapsedtime}, \helpref{wxStopWatch}{wxstopwatch}
  34
  35 \latexignore{\rtfignore{\wxheading{Members}}}
  36
  37 \membersection{wxTimer::wxTimer}\label{wxtimerwxtimer}
  38
  39 \func{}{wxTimer}{\void}
  40
  41 Default constructor. If you use it to construct the object and don't call
  42 \helpref{SetOwner}{wxtimersetowner} later, you must override
  43 \helpref{Notify}{wxtimernotify} method to process the notifications.
  44
  45 \func{}{wxTimer}{\param{wxEvtHandler *}{owner}, \param{int }{id = -1}}
  46
  47 Creates a timer and associates it with {\it owner}. Please see
  48 \helpref{SetOwner}{wxtimersetowner} for the description of parameters.
  49
  50 \membersection{wxTimer::\destruct{wxTimer}}
  51
  52 \func{}{\destruct{wxTimer}}{\void}
  53
  54 Destructor. Stops the timer if it is running.
  55
  56 \membersection{wxTimer::GetInterval}{wxtimergetinterval}
  57
  58 \constfunc{int}{GetInterval}{\void}
  59
  60 Returns the current interval for the timer (in milliseconds).
  61
  62 \membersection{wxTimer::IsOneShot}\label{wxtimerisoneshot}
  63
  64 \constfunc{bool}{IsOneShot}{\void}
  65
  66 Returns TRUE if the timer is one shot, i.e. if it will stop after firing the
  67 first notification automatically.
  68
  69 \membersection{wxTimer::IsRunning}\label{wxtimerisrunning}
  70
  71 \constfunc{bool}{IsRunning}{\void}
  72
  73 Returns TRUE if the timer is running, FALSE if it is stopped.
  74
  75 \membersection{wxTimer::Notify}\label{wxtimernotify}
  76
  77 \func{void}{Notify}{\void}
  78
  79 This member should be overridden by the user if the default constructor was
  80 used and \helpref{SetOwner}{wxtimersetowner} wasn't called.
  81
  82 Perform whatever action which is to be taken periodically here.
  83
  84 \membersection{wxTimer::SetOwner}\label{wxtimersetowner}
  85
  86 \func{void}{SetOwner}{\param{wxEvtHandler *}{owner}, \param{int }{id = -1}}
  87
  88 Associates the timer with the given {\it owner} object. When the timer is
  89 running, the owner will receive \helpref{timer events}{wxtimerevent} with
  90 id equal to {\it id} specified here.
  91
  92 \membersection{wxTimer::Start}\label{wxtimerstart}
  93
  94 \func{bool}{Start}{\param{int}{ milliseconds = -1}, \param{bool}{ oneShot=FALSE}}
  95
  96 (Re)starts the timer. If {\it milliseconds} parameter is -1 (value by default),
  97 the previous value is used. Returns FALSE if the timer could not be started,
  98 TRUE otherwise (in MS Windows timers are a limited resource).
  99
 100 If {\it oneShot} is FALSE (the default), the \helpref{Notify}{wxtimernotify}
 101 function will be called repeatedly until the timer is stopped. If TRUE,
 102 it will be called only once and the timer will stop automatically.
 103
 104 If the timer was already running, it will be stopped by this method before
 105 restarting it.
 106
 107 \membersection{wxTimer::Stop}\label{wxtimerstop}
 108
 109 \func{void}{Stop}{\void}
 110
 111 Stops the timer.
 112
 113 \section{\class{wxTimerEvent}}\label{wxtimerevent}
 114
 115 wxTimerEvent object is passed to the event handler of timer events.
 116
 117 For example:
 118
 119 \begin{verbatim}
 120 class MyFrame : public wxFrame
 121 {
 122 public:
 123     ...
 124     void OnTimer(wxTimerEvent& event);
 125
 126 private:
 127     wxTimer m_timer;
 128 };
 129
 130 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 131     EVT_TIMER(TIMER_ID, MyFrame::OnTimer)
 132 END_EVENT_TABLE()
 133
 134 MyFrame::MyFrame()
 135        : m_timer(this, TIMER_ID)
 136 {
 137     m_timer.Start(1000);    // 1 second interval
 138 }
 139
 140 void MyFrame::OnTimer(wxTimerEvent& event)
 141 {
 142     // do whatever you want to do every second here
 143 }
 144
 145 \end{verbatim}
 146
 147 \wxheading{Include files}
 148
 149 <wx/timer.h>
 150
 151 \wxheading{See also}
 152
 153 \helpref{wxTimer}{wxtimer}
 154
 155 \latexignore{\rtfignore{\wxheading{Members}}}
 156
 157 \membersection{wxTimerEvent::GetInterval}\label{wxtimereventgetinterval}
 158
 159 \constfunc{int}{GetInterval}{\void}
 160
 161 Returns the interval of the timer which generated this event.
 162