// key code is within legal range. we call event.Skip() so the
// event can be processed either in the base wxWindows class
// or the native control.
-
- event.Skip();
+
+ event.Skip();
}
else
{
// illegal key hit. we don't call event.Skip() so the
// event is not processed anywhere else.
-
+
wxBell();
}
}
\item Finally, {\bf ProcessEvent} is called on the wxApp object.
\end{enumerate}
+{\bf Pay close attention to Step 5.} People often overlook or get
+confused by this powerful feature of the wxWindows event processing
+system. To put it a different way, events derived either directly or
+indirectly from wxCommandEvent will travel up the containment
+hierarchy from child to parent until an event handler is found that
+doesn't call event.Skip(). Events not derived from wxCommandEvent are
+sent only to the window they occurred in and then stop.
+
+Typically events that deal with a window as a window (size, motion,
+paint, mouse, keyboard, etc.) are sent only to the window. Events
+that have a higher level of meaning and/or are generated by the window
+itself, (button click, menu select, tree expand, etc.) are command
+events and are sent up to the parent to see if it is interested in the
+event.
+
Note that your application may wish to override ProcessEvent to redirect processing of
events. This is done in the document/view framework, for example, to allow event handlers
-to be defined in the document or view.
+to be defined in the document or view. To test for command events (which will probably
+be the only events you wish to redirect), you may use wxEvent::IsCommandEvent for
+efficiency, instead of using the slower run-time type system.
As mentioned above, only command events are recursively applied to the parents event
handler. As this quite often causes confusion for users, here is a list of system
\twocolitem{\helpref{wxPaintEvent}{wxpaintevent}}{A paint event}
\twocolitem{\helpref{wxQueryLayoutInfoEvent}{wxquerylayoutinfoevent}}{Used to query layout information}
\twocolitem{\helpref{wxSizeEvent}{wxsizeevent}}{A size event}
+\twocolitem{\helpref{wxScrollWinEvent}{wxscrollwinevent}}{A scroll event sent by a scrolled window (not a scroll bar)}
\twocolitem{\helpref{wxSysColourChangedEvent}{wxsyscolourchangedevent}}{A system colour change event}
\twocolitem{\helpref{wxUpdateUIEvent}{wxupdateuievent}}{A user interface update event}
\end{twocollist}
of system events in a parent window, for example all key events sent to, but not
used by, the native controls in a dialog. In this case, a special event handler
will have to be written that will override ProcessEvent() in order to pass
-all events (or any selection of them) to the parent window. See next section.
+all events (or any selection of them) to the parent window.
+
+% VZ: it doesn't work like this, but just in case we ever reenable this
+% behaviour, I leave it here
+%
+% \subsection{Redirection of command events to the window with the focus}
+%
+% The usual upward search through the window hierarchy for command event
+% handlers does not always meet an application's requirements. Say you have two
+% wxTextCtrl windows in a frame, plus a toolbar with Cut, Copy and Paste
+% buttons. To avoid the need to define event handlers in the frame
+% and redirect them explicitly to the window with the focus, command events
+% are sent to the window with the focus first, for
+% menu and toolbar command and UI update events only. This means that
+% each window can handle its own commands and UI updates independently. In
+% fact wxTextCtrl can handle Cut, Copy, Paste, Undo and Redo commands and UI update
+% requests, so no extra coding is required to support them in your menus and
+% toolbars.
\subsection{Pluggable event handlers}
any number of dialogs so long as you don't have several within the same dialog.
If you pass -1 to a window constructor, an identifier will be generated for you, but beware:
-if things don't respond in the way they should, it could be because of an id conflict. It's safer
+if things don't respond in the way they should, it could be because of an id conflict. It is safer
to supply window ids at all times. Automatic generation of identifiers starts at 1 so may well conflict
with your own identifiers.
\twocolitem{\helpref{wxDropFilesEvent}{wxdropfilesevent}}{The EVT\_DROP\_FILES macros handles
file drop events.}
\twocolitem{\helpref{wxEraseEvent}{wxeraseevent}}{The EVT\_ERASE\_BACKGROUND macro is used to handle window erase requests.}
-\twocolitem{\helpref{wxFocusEvent}{wxfocusevent}}{The EVT\_SET\_FOCUS and EVT\_KILL\_FOCUS macros are used to handle keybaord focus events.}
+\twocolitem{\helpref{wxFocusEvent}{wxfocusevent}}{The EVT\_SET\_FOCUS and EVT\_KILL\_FOCUS macros are used to handle keyboard focus events.}
\twocolitem{\helpref{wxKeyEvent}{wxkeyevent}}{EVT\_CHAR and EVT\_CHAR\_HOOK macros handle keyboard
input for any window.}
\twocolitem{\helpref{wxIdleEvent}{wxidleevent}}{The EVT\_IDLE macro handle application idle events
\twocolitem{\helpref{wxMouseEvent}{wxmouseevent}}{Mouse event macros can handle either individual
mouse events or all mouse events.}
\twocolitem{\helpref{wxMoveEvent}{wxmoveevent}}{The EVT\_MOVE macro is used to handle a window move.}
-\twocolitem{\helpref{wxUpdateUIEvent}{wxupdateuievent}}{The EVT\_UPDATE\_UI macro is used to handle user interface
-update pseudo-events, which are generated to give the application the chance to update the visual state of menus,
-toolbars and controls.}
\twocolitem{\helpref{wxPaintEvent}{wxpaintevent}}{The EVT\_PAINT macro is used to handle window paint requests.}
-\twocolitem{\helpref{wxScrollEvent}{wxscrollevent}}{These macros are used to handle scroll events from
-windows, \helpref{wxScrollBar}{wxscrollbar}, and \helpref{wxSpinButton}{wxspinbutton}.}
+\twocolitem{\helpref{wxScrollEvent}{wxscrollevent}}{These macros are used to handle scroll events from
+\helpref{wxScrollBar}{wxscrollbar}, \helpref{wxSlider}{wxslider},and \helpref{wxSpinButton}{wxspinbutton}.}
\twocolitem{\helpref{wxSizeEvent}{wxsizeevent}}{The EVT\_SIZE macro is used to handle a window resize.}
+\twocolitem{\helpref{wxSplitterEvent}{wxsplitterevent}}{The EVT\_SPLITTER\_SASH\_POS\_CHANGED, EVT\_SPLITTER\_UNSPLIT
+and EVT\_SPLITTER\_DOUBLECLICKED macros are used to handle the various splitter window events.}
\twocolitem{\helpref{wxSysColourChangedEvent}{wxsyscolourchangedevent}}{The EVT\_SYS\_COLOUR\_CHANGED macro is used to handle
events informing the application that the user has changed the system colours (Windows only).}
\twocolitem{\helpref{wxTreeEvent}{wxtreeevent}}{These macros handle \helpref{wxTreeCtrl}{wxtreectrl} events.}
+\twocolitem{\helpref{wxUpdateUIEvent}{wxupdateuievent}}{The EVT\_UPDATE\_UI macro is used to handle user interface
+update pseudo-events, which are generated to give the application the chance to update the visual state of menus,
+toolbars and controls.}
\end{twocollist}
projects / wxWidgets.git / blobdiff