docs/latex/wx/event.tex

   1 \section{\class{wxEvent}}\label{wxevent}
   2
   3 An event is a structure holding information about an event passed to a
   4 callback or member function. {\bf wxEvent} used to be a multipurpose
   5 event object, and is an abstract base class for other event classes (see below).
   6
   7 For 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 \membersection{wxEvent::wxEvent}\label{wxeventctor}
  28
  29 \func{}{wxEvent}{\param{int }{id = 0}, \param{wxEventType }{eventType = {\tt wxEVT\_NULL}}}
  30
  31 Constructor. Should not need to be used directly by an application.
  32
  33 \membersection{wxEvent::m\_propagationLevel}\label{wxeventmpropagationlevel}
  34
  35 \member{int}{m\_propagationLevel}
  36
  37 Indicates how many levels the event can propagate. This member is protected and
  38 should typically only be set in the constructors of the derived classes. It
  39 may be temporarily changed by \helpref{StopPropagation}{wxeventstoppropagation}
  40 and \helpref{ResumePropagation}{wxeventresumepropagation} and tested with
  41 \helpref{ShouldPropagate}{wxeventshouldpropagate}.
  42
  43 The initial value is set to either {\tt wxEVENT\_PROPAGATE\_NONE} (by
  44 default) meaning that the event shouldn't be propagated at all or to
  45 {\tt wxEVENT\_PROPAGATE\_MAX} (for command events) meaning that it should be
  46 propagated as much as necessary.
  47
  48 Any positive number means that the event should be propagated but no more than
  49 the given number of times. E.g. the propagation level may be set to $1$ to
  50 propagate the event to its parent only, but not to its grandparent.
  51
  52 \membersection{wxEvent::Clone}\label{wxeventclone}
  53
  54 \constfunc{virtual wxEvent*}{Clone}{\void}
  55
  56 Returns a copy of the event.
  57
  58 Any event that is posted to the wxWidgets event system for later action (via
  59 \helpref{wxEvtHandler::AddPendingEvent}{wxevthandleraddpendingevent} or
  60 \helpref{wxPostEvent}{wxpostevent}) must implement this method. All wxWidgets
  61 events fully implement this method, but any derived events implemented by the
  62 user should also implement this method just in case they (or some event
  63 derived from them) are ever posted.
  64
  65 All wxWidgets events implement a copy constructor, so the easiest way of
  66 implementing the Clone function is to implement a copy constructor for
  67 a new event (call it MyEvent) and then define the Clone function like this:
  68
  69 \begin{verbatim}
  70     wxEvent *Clone(void) const { return new MyEvent(*this); }
  71 \end{verbatim}
  72
  73 \membersection{wxEvent::GetEventObject}\label{wxeventgeteventobject}
  74
  75 \func{wxObject*}{GetEventObject}{\void}
  76
  77 Returns the object (usually a window) associated with the
  78 event, if any.
  79
  80 \membersection{wxEvent::GetEventType}\label{wxeventgeteventtype}
  81
  82 \func{WXTYPE}{GetEventType}{\void}
  83
  84 Returns the identifier of the given event type,
  85 such as \texttt{wxEVT\_COMMAND\_BUTTON\_CLICKED}.
  86
  87 \membersection{wxEvent::GetId}\label{wxeventgetid}
  88
  89 \constfunc{int}{GetId}{\void}
  90
  91 Returns the identifier associated with this event, such as a button command id.
  92
  93 \membersection{wxEvent::GetSkipped}\label{wxeventgetskipped}
  94
  95 \constfunc{bool}{GetSkipped}{\void}
  96
  97 Returns true if the event handler should be skipped, false otherwise.
  98
  99 \membersection{wxEvent::GetTimestamp}\label{wxeventgettimestamp}
 100
 101 \func{long}{GetTimestamp}{\void}
 102
 103 Gets the timestamp for the event.
 104
 105 \membersection{wxEvent::IsCommandEvent}\label{wxeventiscommandevent}
 106
 107 \constfunc{bool}{IsCommandEvent}{\void}
 108
 109 Returns true if the event is or is derived from
 110 \helpref{wxCommandEvent}{wxcommandevent} else it returns false.
 111 Note: Exists only for optimization purposes.
 112
 113
 114 \membersection{wxEvent::ResumePropagation}\label{wxeventresumepropagation}
 115
 116 \func{void}{ResumePropagation}{\param{int }{propagationLevel}}
 117
 118 Sets the propagation level to the given value (for example returned from an
 119 earlier call to \helpref{StopPropagation}{wxeventstoppropagation}).
 120
 121
 122 \membersection{wxEvent::SetEventObject}\label{wxeventseteventobject}
 123
 124 \func{void}{SetEventObject}{\param{wxObject* }{object}}
 125
 126 Sets the originating object.
 127
 128 \membersection{wxEvent::SetEventType}\label{wxeventseteventtype}
 129
 130 \func{void}{SetEventType}{\param{WXTYPE }{typ}}
 131
 132 Sets the event type.
 133
 134 \membersection{wxEvent::SetId}\label{wxeventsetid}
 135
 136 \func{void}{SetId}{\param{int}{ id}}
 137
 138 Sets the identifier associated with this event, such as a button command id.
 139
 140 \membersection{wxEvent::SetTimestamp}\label{wxeventsettimestamp}
 141
 142 \func{void}{SetTimestamp}{\param{long }{timeStamp}}
 143
 144 Sets the timestamp for the event.
 145
 146 \membersection{wxEvent::ShouldPropagate}\label{wxeventshouldpropagate}
 147
 148 \constfunc{bool}{ShouldPropagate}{\void}
 149
 150 Test if this event should be propagated or not, i.e. if the propagation level
 151 is currently greater than $0$.
 152
 153 \membersection{wxEvent::Skip}\label{wxeventskip}
 154
 155 \func{void}{Skip}{\param{bool}{ skip = true}}
 156
 157 Called by an event handler, it controls whether additional event
 158 handlers bound to this event will be called after the current event
 159 handler returns.  Skip(false) (the default behavior) will prevent
 160 additional event handlers from being called and control will be
 161 returned to the sender of the event immediately after the current
 162 handler has finished.  Skip(true) will cause the event processing
 163 system to continue searching for a handler function for this event.
 164
 165
 166 \membersection{wxEvent::StopPropagation}\label{wxeventstoppropagation}
 167
 168 \func{int}{StopPropagation}{\void}
 169
 170 Stop the event from propagating to its parent window.
 171
 172 Returns the old propagation level value which may be later passed to
 173 \helpref{ResumePropagation}{wxeventresumepropagation} to allow propagating the
 174 event again.
 175