added null pointer check and assert

[wxWidgets.git] / docs / latex / wx / tevent.tex

diff --git a/docs/latex/wx/tevent.tex b/docs/latex/wx/tevent.tex
index e615864ac3c1d08938c929cad229c8b260c4856e..7468d45803e380c3dd43826aa1927c1f7a59126d 100644 (file)
--- a/docs/latex/wx/tevent.tex
+++ b/docs/latex/wx/tevent.tex
@@ -268,8 +268,9 @@ defining the appropriate event table, and then call
 \rtfsp\helpref{wxWindow::SetEventHandler}{wxwindowseteventhandler} (or, preferably,
 \rtfsp\helpref{wxWindow::PushEventHandler}{wxwindowpusheventhandler}) to make this
 event handler the object that responds to events. This way, you can avoid
-a lot of class derivation, and use the same event handler object to
-handle events from instances of different classes. If you ever have to call a window's event handler
+a lot of class derivation, and use instances of the same event handler class (but different
+objects as the same event handler object shouldn't be used more than once) to
+handle events from instances of different widget classes. If you ever have to call a window's event handler
 manually, use the GetEventHandler function to retrieve the window's event handler and use that
 to call the member function. By default, GetEventHandler returns a pointer to the window itself
 unless an application has redirected event handling using SetEventHandler or PushEventHandler.
@@ -449,7 +450,7 @@ DEFINE_EVENT_TYPE(name)
 \end{verbatim}
 
 You can ignore the {\it value} parameter of the DECLARE\_EVENT\_TYPE macro
-since it used only for backwards compatibility with wxWidgets 2.0.x based
+since it is used only for backwards compatibility with wxWidgets 2.0.x based
 applications where you have to give the event type ID an explicit value.
 
 See also the \helpref{event sample}{sampleevent} for an example of code
@@ -526,9 +527,7 @@ Under certain circumstances, it will be required to define your own event
 class e.g. for sending more complex data from one place to another. Apart
 from defining your event class, you will also need to define your own
 event table macro (which is quite long). Watch out to put in enough
-casts to the inherited event function. Here is an example, taken mostly
-from the {\it wxPlot} library, which is in the {\it contrib} section of
-the wxWidgets sources.
+casts to the inherited event function. Here is an example:
 
 {\small%
 \begin{verbatim}
@@ -551,7 +550,7 @@ private:
     wxPlotCurve   *m_curve;
 };
 
-DECLARE_EVENT_MACRO( wxEVT_PLOT_ACTION, -1 )
+DECLARE_EVENT_TYPE( wxEVT_PLOT_ACTION, -1 )
 
 typedef void (wxEvtHandler::*wxPlotEventFunction)(wxPlotEvent&);