1 /////////////////////////////////////////////////////////////////////////////
2 // Name:        timer.h
3 // Purpose:     interface of wxTimer
4 // Author:      wxWidgets team
5 // Licence:     wxWindows licence
6 /////////////////////////////////////////////////////////////////////////////
7 
8 // generate notifications periodically until the timer is stopped (default)
9 #define wxTIMER_CONTINUOUS false
10 
11 // only send the notification once and then stop the timer
12 #define wxTIMER_ONE_SHOT true
13 
14 wxEventType wxEVT_TIMER;
15 
16 
17 /**
18     @class wxTimer
19 
20     The wxTimer class allows you to execute code at specified intervals.
21     Its precision is platform-dependent, but in general will not be better than
22     @c 1ms nor worse than @c 1s.
23 
24     There are three different ways to use this class:
25 
26     - You may derive a new class from wxTimer and override the
27       wxTimer::Notify member to perform the required action.
28     - You may redirect the notifications to any wxEvtHandler derived object by
29       using the non-default constructor or wxTimer::SetOwner.
30       Then use the @c EVT_TIMER macro to connect it to the event handler which
31       will receive wxTimerEvent notifications.
32     - You may use a derived class and the @c EVT_TIMER macro to connect it to
33       an event handler defined in the derived class. If the default constructor
34       is used, the timer object will be its own owner object, since it is
35       derived from wxEvtHandler.
36 
37     In any case, you must start the timer with wxTimer::Start() after constructing
38     it before it actually starts sending notifications.
39     It can be stopped later with wxTimer::Stop().
40 
41     @note A timer can only be used from the main thread.
42 
43     @library{wxbase}
44     @category{misc}
45 
46     @see wxStopWatch
47 */
48 class wxTimer : public wxEvtHandler
49 {
50 public:
51     /**
52         Default constructor.
53         If you use it to construct the object and don't call SetOwner() later,
54         you must override Notify() method to process the notifications.
55     */
56     wxTimer();
57 
58     /**
59         Creates a timer and associates it with @a owner.
60         Please see SetOwner() for the description of parameters.
61     */
62     wxTimer(wxEvtHandler* owner, int id = -1);
63 
64     /**
65         Destructor. Stops the timer if it is running.
66     */
67     virtual ~wxTimer();
68 
69     /**
70         Returns the ID of the events generated by this timer.
71     */
72     int GetId() const;
73 
74     /**
75         Returns the current interval for the timer (in milliseconds).
76     */
77     int GetInterval() const;
78 
79     /**
80         Returns the current @e owner of the timer.
81 
82         If non-@NULL this is the event handler which will receive the
83         timer events (see wxTimerEvent) when the timer is running.
84     */
85     wxEvtHandler* GetOwner() const;
86 
87     /**
88         Returns @true if the timer is one shot, i.e.\ if it will stop after firing
89         the first notification automatically.
90     */
91     bool IsOneShot() const;
92 
93     /**
94         Returns @true if the timer is running, @false if it is stopped.
95     */
96     bool IsRunning() const;
97 
98     /**
99         This member should be overridden by the user if the default constructor was
100         used and SetOwner() wasn't called.
101 
102         Perform whatever action which is to be taken periodically here.
103 
104         Notice that throwing exceptions from this method is currently not
105         supported, use event-based timer handling approach if an exception can
106         be thrown while handling timer notifications.
107     */
108     virtual void Notify();
109 
110     /**
111         Associates the timer with the given @a owner object.
112 
113         When the timer is running, the owner will receive timer events (see wxTimerEvent)
114         with @a id equal to @a id specified here.
115     */
116     void SetOwner(wxEvtHandler* owner, int id = -1);
117 
118     /**
119         (Re)starts the timer. If @a milliseconds parameter is -1 (value by default),
120         the previous value is used. Returns @false if the timer could not be started,
121         @true otherwise (in MS Windows timers are a limited resource).
122 
123         If @a oneShot is @false (the default), the Notify() function will be called
124         repeatedly until the timer is stopped.
125         If @true, it will be called only once and the timer will stop automatically.
126 
127         To make your code more readable you may also use the following symbolic constants:
128         - wxTIMER_CONTINUOUS: Start a normal, continuously running, timer
129         - wxTIMER_ONE_SHOT: Start a one shot timer
130         Alternatively, use StartOnce().
131 
132         If the timer was already running, it will be stopped by this method before
133         restarting it.
134     */
135     virtual bool Start(int milliseconds = -1, bool oneShot = wxTIMER_CONTINUOUS);
136 
137     /**
138         Starts the timer for a once-only notification.
139 
140         This is a simple wrapper for Start() with @c wxTIMER_ONE_SHOT parameter.
141 
142         @since 2.9.5
143      */
144     bool StartOnce(int milliseconds = -1);
145 
146     /**
147         Stops the timer.
148     */
149     virtual void Stop();
150 };
151 
152 
153 /**
154    @class wxTimerRunner
155 
156    Starts the timer in its ctor, stops in the dtor.
157 */
158 class wxTimerRunner
159 {
160 public:
161     wxTimerRunner(wxTimer& timer);
162     wxTimerRunner(wxTimer& timer, int milli, bool oneShot = false);
163     void Start(int milli, bool oneShot = false);
164     ~wxTimerRunner();
165 };
166 
167 /**
168     @class wxTimerEvent
169 
170     wxTimerEvent object is passed to the event handler of timer events
171     (see wxTimer::SetOwner).
172 
173     For example:
174 
175     @code
176     class MyFrame : public wxFrame
177     {
178     public:
179         ...
180         void OnTimer(wxTimerEvent& event);
181 
182     private:
183         wxTimer m_timer;
184         wxDECLARE_EVENT_TABLE();
185     };
186 
187     wxBEGIN_EVENT_TABLE(MyFrame, wxFrame)
188         EVT_TIMER(TIMER_ID, MyFrame::OnTimer)
189     wxEND_EVENT_TABLE()
190 
191     MyFrame::MyFrame()
192            : m_timer(this, TIMER_ID)
193     {
194         m_timer.Start(1000);    // 1 second interval
195     }
196 
197     void MyFrame::OnTimer(wxTimerEvent& event)
198     {
199         // do whatever you want to do every second here
200     }
201     @endcode
202 
203     @library{wxbase}
204     @category{events}
205 
206     @see wxTimer
207 */
208 class wxTimerEvent : public wxEvent
209 {
210 public:
211     wxTimerEvent(wxTimer& timer);
212 
213     /**
214         Returns the interval of the timer which generated this event.
215     */
216     int GetInterval() const;
217 
218     /**
219         Returns the timer object which generated this event.
220     */
221     wxTimer& GetTimer() const;
222 };
223 
224