X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/8e72b8b51770b59a83eb32f4d766b89f6c4dc615..eae0338fcb421ac03c0f78a0c0f30b9a766cdeec:/docs/latex/wx/event.tex?ds=inline diff --git a/docs/latex/wx/event.tex b/docs/latex/wx/event.tex index 5d4403d78f..fc016f23f2 100644 --- a/docs/latex/wx/event.tex +++ b/docs/latex/wx/event.tex @@ -4,6 +4,11 @@ An event is a structure holding information about an event passed to a callback or member function. {\bf wxEvent} used to be a multipurpose event object, and is an abstract base class for other event classes (see below). +For more information about events, see the \helpref{Event handling overview}{eventhandlingoverview}. + +\perlnote{In wxPerl custom event classes should be derived from +\texttt{Wx::PlEvent} and \texttt{Wx::PlCommandEvent}.} + \wxheading{Derived from} \helpref{wxObject}{wxobject} @@ -19,133 +24,176 @@ event object, and is an abstract base class for other event classes (see below). \latexignore{\rtfignore{\wxheading{Members}}} -\membersection{wxEvent::wxEvent} - -\func{}{wxEvent}{\param{int }{id = 0}} - -Constructor. Should not need to be used directly by an application. - -\membersection{wxEvent::m\_eventObject} - -\member{wxObject*}{m\_eventObject} - -The object (usually a window) that the event was generated from, -or should be sent to. -\membersection{wxEvent::m\_eventType} +\membersection{wxEvent::wxEvent}\label{wxeventctor} -\member{WXTYPE}{m\_eventType} +\func{}{wxEvent}{\param{int }{id = 0}, \param{wxEventType }{eventType = {\tt wxEVT\_NULL}}} -The type of the event, such as wxEVENT\_TYPE\_BUTTON\_COMMAND. - -\membersection{wxEvent::m\_id} +Constructor. Should not need to be used directly by an application. -\member{int}{m\_id} -Identifier for the window. +\membersection{wxEvent::m\_propagationLevel}\label{wxeventmpropagationlevel} -\membersection{wxEvent::m\_skipped} -\member{bool}{m\_skipped} +\member{int}{m\_propagationLevel} -Set to TRUE by {\bf Skip} if this event should be skipped. +Indicates how many levels the event can propagate. This member is protected and +should typically only be set in the constructors of the derived classes. It +may be temporarily changed by \helpref{StopPropagation}{wxeventstoppropagation} +and \helpref{ResumePropagation}{wxeventresumepropagation} and tested with +\helpref{ShouldPropagate}{wxeventshouldpropagate}. -\membersection{wxEvent::m\_timeStamp} +The initial value is set to either {\tt wxEVENT\_PROPAGATE\_NONE} (by +default) meaning that the event shouldn't be propagated at all or to +{\tt wxEVENT\_PROPAGATE\_MAX} (for command events) meaning that it should be +propagated as much as necessary. -\member{long}{m\_timeStamp} +Any positive number means that the event should be propagated but no more than +the given number of times. E.g. the propagation level may be set to $1$ to +propagate the event to its parent only, but not to its grandparent. -Timestamp for this event. \membersection{wxEvent::Clone}\label{wxeventclone} -\func{virtual wxEvent*}{Clone}{\void} const +\constfunc{virtual wxEvent*}{Clone}{\void} Returns a copy of the event. -Any event that is posted to the wxWindows event system for later action (via +Any event that is posted to the wxWidgets event system for later action (via \helpref{wxEvtHandler::AddPendingEvent}{wxevthandleraddpendingevent} or -\helpref{wxPostEvent}{wxpostevent}) must implement this method. All wxWindows +\helpref{wxPostEvent}{wxpostevent}) must implement this method. All wxWidgets events fully implement this method, but any derived events implemented by the user should also implement this method just in case they (or some event derived from them) are ever posted. -All wxWindows events implement a copy constructor, so the easiest way of +All wxWidgets events implement a copy constructor, so the easiest way of implementing the Clone function is to implement a copy constructor for a new event (call it MyEvent) and then define the Clone function like this: + \begin{verbatim} wxEvent *Clone(void) const { return new MyEvent(*this); } \end{verbatim} -\membersection{wxEvent::GetEventObject} + +\membersection{wxEvent::GetEventObject}\label{wxeventgeteventobject} \func{wxObject*}{GetEventObject}{\void} -Returns the object associated with the +Returns the object (usually a window) associated with the event, if any. -\membersection{wxEvent::GetEventType} -\func{WXTYPE}{GetEventType}{\void} +\membersection{wxEvent::GetEventType}\label{wxeventgeteventtype} + +\func{wxEventType}{GetEventType}{\void} Returns the identifier of the given event type, -such as wxEVENT\_TYPE\_BUTTON\_COMMAND. +such as \texttt{wxEVT\_COMMAND\_BUTTON\_CLICKED}. -\membersection{wxEvent::GetId} -\func{int}{GetId}{\void} +\membersection{wxEvent::GetId}\label{wxeventgetid} -Returns the identifier associated with this event, such as a button command id. +\constfunc{int}{GetId}{\void} -\membersection{wxEvent::GetObjectType} +Returns the identifier associated with this event, such as a button command id. -\func{WXTYPE}{GetObjectType}{\void} -Returns the type of the object associated with the -event, such as wxTYPE\_BUTTON. +\membersection{wxEvent::GetSkipped}\label{wxeventgetskipped} -\membersection{wxEvent::GetSkipped} +\constfunc{bool}{GetSkipped}{\void} -\func{bool}{GetSkipped}{\void} +Returns true if the event handler should be skipped, false otherwise. -Returns TRUE if the event handler should be skipped, FALSE otherwise. -\membersection{wxEvent::GetTimestamp} +\membersection{wxEvent::GetTimestamp}\label{wxeventgettimestamp} \func{long}{GetTimestamp}{\void} -Gets the timestamp for the event. +Gets the timestamp for the event. The timestamp is the time in milliseconds +since some fixed moment (\emph{not} necessarily the standard Unix Epoch, so +only differences between the timestamps and not their absolute values usually +make sense). + + +\membersection{wxEvent::IsCommandEvent}\label{wxeventiscommandevent} + +\constfunc{bool}{IsCommandEvent}{\void} + +Returns true if the event is or is derived from +\helpref{wxCommandEvent}{wxcommandevent} else it returns false. +Note: Exists only for optimization purposes. -\membersection{wxEvent::SetEventObject} + +\membersection{wxEvent::ResumePropagation}\label{wxeventresumepropagation} + +\func{void}{ResumePropagation}{\param{int }{propagationLevel}} + +Sets the propagation level to the given value (for example returned from an +earlier call to \helpref{StopPropagation}{wxeventstoppropagation}). + + +\membersection{wxEvent::SetEventObject}\label{wxeventseteventobject} \func{void}{SetEventObject}{\param{wxObject* }{object}} Sets the originating object. -\membersection{wxEvent::SetEventType} -\func{void}{SetEventType}{\param{WXTYPE }{typ}} +\membersection{wxEvent::SetEventType}\label{wxeventseteventtype} + +\func{void}{SetEventType}{\param{wxEventType }{type}} Sets the event type. -\membersection{wxEvent::SetId} + +\membersection{wxEvent::SetId}\label{wxeventsetid} \func{void}{SetId}{\param{int}{ id}} Sets the identifier associated with this event, such as a button command id. -\membersection{wxEvent::SetTimestamp} + +\membersection{wxEvent::SetTimestamp}\label{wxeventsettimestamp} \func{void}{SetTimestamp}{\param{long }{timeStamp}} Sets the timestamp for the event. -Sets the originating object. + +\membersection{wxEvent::ShouldPropagate}\label{wxeventshouldpropagate} + +\constfunc{bool}{ShouldPropagate}{\void} + +Test if this event should be propagated or not, i.e. if the propagation level +is currently greater than $0$. + \membersection{wxEvent::Skip}\label{wxeventskip} -\func{void}{Skip}{\param{bool}{ skip = TRUE}} +\func{void}{Skip}{\param{bool}{ skip = true}} + +This method can be called by an event handler and controls whether additional +event handlers bound to this event will be called after the current event +handler returns. The default behavior is equivalent to calling Skip(false) +(which is, hence, usually unnecessary) and will prevent additional event +handlers from being called and control will be returned to the sender of the +event immediately after the current handler has finished. If Skip(true) is +called, the event processing system continues searching for a handler +function for this event as if the current handler didn't exist. + +In general, it is recommended to skip all non-command events to allow the +default handling to take place. The command events are, however, normally not +skipped as usually a single command such as a button click or menu item +selection must only be processed by one handler. + + +\membersection{wxEvent::StopPropagation}\label{wxeventstoppropagation} + +\func{int}{StopPropagation}{\void} + +Stop the event from propagating to its parent window. -Called by an event handler to tell the event system that the -event handler should be skipped, and the next valid handler used -instead. +Returns the old propagation level value which may be later passed to +\helpref{ResumePropagation}{wxeventresumepropagation} to allow propagating the +event again.