1\section{\class{wxEvent}}\label{wxevent} 2 3An event is a structure holding information about an event passed to a 4callback or member function. {\bf wxEvent} used to be a multipurpose 5event object, and is an abstract base class for other event classes (see below). 6 7For more information about events, see the \helpref{Event handling overview}{eventhandlingoverview}. 8 9\perlnote{In wxPerl custom event classes should be derived from 10\texttt{Wx::PlEvent} and \texttt{Wx::PlCommandEvent}.} 11 12\wxheading{Derived from} 13 14\helpref{wxObject}{wxobject} 15 16\wxheading{Include files} 17 18<wx/event.h> 19 20\wxheading{See also} 21 22\helpref{wxCommandEvent}{wxcommandevent},\rtfsp 23\helpref{wxMouseEvent}{wxmouseevent} 24 25\latexignore{\rtfignore{\wxheading{Members}}} 26 27 28\membersection{wxEvent::wxEvent}\label{wxeventctor} 29 30\func{}{wxEvent}{\param{int }{id = 0}, \param{wxEventType }{eventType = {\tt wxEVT\_NULL}}} 31 32Constructor. Should not need to be used directly by an application. 33 34 35\membersection{wxEvent::m\_propagationLevel}\label{wxeventmpropagationlevel} 36 37 38\member{int}{m\_propagationLevel} 39 40Indicates how many levels the event can propagate. This member is protected and 41should typically only be set in the constructors of the derived classes. It 42may be temporarily changed by \helpref{StopPropagation}{wxeventstoppropagation} 43and \helpref{ResumePropagation}{wxeventresumepropagation} and tested with 44\helpref{ShouldPropagate}{wxeventshouldpropagate}. 45 46The initial value is set to either {\tt wxEVENT\_PROPAGATE\_NONE} (by 47default) meaning that the event shouldn't be propagated at all or to 48{\tt wxEVENT\_PROPAGATE\_MAX} (for command events) meaning that it should be 49propagated as much as necessary. 50 51Any positive number means that the event should be propagated but no more than 52the given number of times. E.g. the propagation level may be set to $1$ to 53propagate the event to its parent only, but not to its grandparent. 54 55 56\membersection{wxEvent::Clone}\label{wxeventclone} 57 58\constfunc{virtual wxEvent*}{Clone}{\void} 59 60Returns a copy of the event. 61 62Any event that is posted to the wxWidgets event system for later action (via 63\helpref{wxEvtHandler::AddPendingEvent}{wxevthandleraddpendingevent} or 64\helpref{wxPostEvent}{wxpostevent}) must implement this method. All wxWidgets 65events fully implement this method, but any derived events implemented by the 66user should also implement this method just in case they (or some event 67derived from them) are ever posted. 68 69All wxWidgets events implement a copy constructor, so the easiest way of 70implementing the Clone function is to implement a copy constructor for 71a new event (call it MyEvent) and then define the Clone function like this: 72 73\begin{verbatim} 74 wxEvent *Clone(void) const { return new MyEvent(*this); } 75\end{verbatim} 76 77 78\membersection{wxEvent::GetEventObject}\label{wxeventgeteventobject} 79 80\func{wxObject*}{GetEventObject}{\void} 81 82Returns the object (usually a window) associated with the 83event, if any. 84 85 86\membersection{wxEvent::GetEventType}\label{wxeventgeteventtype} 87 88\func{wxEventType}{GetEventType}{\void} 89 90Returns the identifier of the given event type, 91such as \texttt{wxEVT\_COMMAND\_BUTTON\_CLICKED}. 92 93 94\membersection{wxEvent::GetId}\label{wxeventgetid} 95 96\constfunc{int}{GetId}{\void} 97 98Returns the identifier associated with this event, such as a button command id. 99 100 101\membersection{wxEvent::GetSkipped}\label{wxeventgetskipped} 102 103\constfunc{bool}{GetSkipped}{\void} 104 105Returns true if the event handler should be skipped, false otherwise. 106 107 108\membersection{wxEvent::GetTimestamp}\label{wxeventgettimestamp} 109 110\func{long}{GetTimestamp}{\void} 111 112Gets the timestamp for the event. The timestamp is the time in milliseconds 113since some fixed moment (\emph{not} necessarily the standard Unix Epoch, so 114only differences between the timestamps and not their absolute values usually 115make sense). 116 117 118\membersection{wxEvent::IsCommandEvent}\label{wxeventiscommandevent} 119 120\constfunc{bool}{IsCommandEvent}{\void} 121 122Returns true if the event is or is derived from 123\helpref{wxCommandEvent}{wxcommandevent} else it returns false. 124Note: Exists only for optimization purposes. 125 126 127\membersection{wxEvent::ResumePropagation}\label{wxeventresumepropagation} 128 129\func{void}{ResumePropagation}{\param{int }{propagationLevel}} 130 131Sets the propagation level to the given value (for example returned from an 132earlier call to \helpref{StopPropagation}{wxeventstoppropagation}). 133 134 135\membersection{wxEvent::SetEventObject}\label{wxeventseteventobject} 136 137\func{void}{SetEventObject}{\param{wxObject* }{object}} 138 139Sets the originating object. 140 141 142\membersection{wxEvent::SetEventType}\label{wxeventseteventtype} 143 144\func{void}{SetEventType}{\param{wxEventType }{type}} 145 146Sets the event type. 147 148 149\membersection{wxEvent::SetId}\label{wxeventsetid} 150 151\func{void}{SetId}{\param{int}{ id}} 152 153Sets the identifier associated with this event, such as a button command id. 154 155 156\membersection{wxEvent::SetTimestamp}\label{wxeventsettimestamp} 157 158\func{void}{SetTimestamp}{\param{long }{timeStamp}} 159 160Sets the timestamp for the event. 161 162 163\membersection{wxEvent::ShouldPropagate}\label{wxeventshouldpropagate} 164 165\constfunc{bool}{ShouldPropagate}{\void} 166 167Test if this event should be propagated or not, i.e. if the propagation level 168is currently greater than $0$. 169 170 171\membersection{wxEvent::Skip}\label{wxeventskip} 172 173\func{void}{Skip}{\param{bool}{ skip = true}} 174 175This method can be used inside an event handler to control whether further 176event handlers bound to this event will be called after the current one 177returns. Without Skip() (or equivalently if Skip(false) is used), 178the event will not be processed any more. If Skip(true) is called, the event 179processing system continues searching for a further handler function for this 180event, even though it has been processed already in the current handler. 181 182In general, it is recommended to skip all non-command events to allow the 183default handling to take place. The command events are, however, normally not 184skipped as usually a single command such as a button click or menu item 185selection must only be processed by one handler. 186 187 188\membersection{wxEvent::StopPropagation}\label{wxeventstoppropagation} 189 190\func{int}{StopPropagation}{\void} 191 192Stop the event from propagating to its parent window. 193 194Returns the old propagation level value which may be later passed to 195\helpref{ResumePropagation}{wxeventresumepropagation} to allow propagating the 196event again. 197 198