X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/5fc0243835d4f6cbe586d85e3a6baa3c9c95fc7c..e1ea357c6725c152a7b93281b6ce5c6ad67f949e:/docs/latex/wx/tevent.tex diff --git a/docs/latex/wx/tevent.tex b/docs/latex/wx/tevent.tex index a69b2f5350..1dc49fd843 100644 --- a/docs/latex/wx/tevent.tex +++ b/docs/latex/wx/tevent.tex @@ -77,12 +77,16 @@ It may be noted that wxWindows' event processing system implements something very close to virtual methods in normal C++, i.e. it is possible to alter the behaviour of a class by overriding its event handling functions. In many cases this works even for changing the behaviour of native controls. -E.g. it is possible to filter out a number of key events sent by the +For example it is possible to filter out a number of key events sent by the system to a native text control by overriding wxTextCtrl and defining a -handler for key events using EVT_KEY_DOWN. This would in-deed prevent +handler for key events using EVT\_KEY\_DOWN. This would indeed prevent any key events from being sent to the native control - which might not be what is desired. In this case the event handler function has to call Skip() -so as to indicate that it did NOT handle the event at all. +so as to indicate that the search for the event handler should continue. + +To summarize, instead of explicitly calling the base class version as you +would have done with C++ virtual functions (i.e. {\it wxTextCtrl::OnChar()}), +you should instead call \helpref{Skip}{wxeventskip}. In practice, this would look like this if the derived text control only accepts 'a' to 'z' and 'A' to 'Z': @@ -107,7 +111,6 @@ void MyTextCtrl::OnChar(wxKeyEvent& event) wxBell(); } } - \end{verbatim} }% @@ -131,7 +134,9 @@ recursively applied to the parent window's event handler. If this returns TRUE, 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 @@ -153,15 +158,30 @@ events which will NOT get sent to the parent's event handler: \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}}{An 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} In some cases, it might be desired by the programmer to get a certain number -of system events in a parent window, e.g. all key events sent to, but not +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. + +\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} @@ -191,31 +211,87 @@ the original event handler. Use PushEventHandler/PopEventHandler to form a chain of event handlers, where each handler processes a different range of events independently from the other handlers. -\subsection{Event macros summary}\label{eventmacros} +\subsection{Window identifiers}\label{windowids} -\wxheading{Specifying an event table} +\index{identifiers}\index{wxID}Window identifiers are integers, and are used to uniquely determine window identity in the +event system (though you can use it for other purposes). In fact, identifiers do not need +to be unique across your entire application just so long as they are unique within a particular context you're interested +in, such as a frame and its children. You may use the wxID\_OK identifier, for example, on +any number of dialogs so long as you don't have several within the same dialog. -\twocolwidtha{8cm}% -\begin{twocollist}\itemsep=0pt -\twocolitem{\windowstyle{EVT\_CUSTOM(eventId, id, func)}}{Allows you to add a custom event table -entry by specifying the event identifier (such as wxEVT\_SIZE), the window identifier, -and a member function to call.} -\twocolitem{\windowstyle{EVT\_CUSTOM\_RANGE(eventId, id1, id2, func)}}{The same as EVT\_CUSTOM, -but responds to a range of window identifiers.} -\end{twocollist} +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 +to supply window ids at all times. Automatic generation of identifiers starts at 1 so may well conflict +with your own identifiers. + +The following standard identifiers are supplied. You can use wxID\_HIGHEST to determine the +number above which it is safe to define your own identifiers. Or, you can use identifiers below +wxID\_LOWEST. + +\begin{verbatim} +#define wxID_LOWEST 4999 + +#define wxID_OPEN 5000 +#define wxID_CLOSE 5001 +#define wxID_NEW 5002 +#define wxID_SAVE 5003 +#define wxID_SAVEAS 5004 +#define wxID_REVERT 5005 +#define wxID_EXIT 5006 +#define wxID_UNDO 5007 +#define wxID_REDO 5008 +#define wxID_HELP 5009 +#define wxID_PRINT 5010 +#define wxID_PRINT_SETUP 5011 +#define wxID_PREVIEW 5012 +#define wxID_ABOUT 5013 +#define wxID_HELP_CONTENTS 5014 +#define wxID_HELP_COMMANDS 5015 +#define wxID_HELP_PROCEDURES 5016 +#define wxID_HELP_CONTEXT 5017 + +#define wxID_CUT 5030 +#define wxID_COPY 5031 +#define wxID_PASTE 5032 +#define wxID_CLEAR 5033 +#define wxID_FIND 5034 +#define wxID_DUPLICATE 5035 +#define wxID_SELECTALL 5036 + +#define wxID_FILE1 5050 +#define wxID_FILE2 5051 +#define wxID_FILE3 5052 +#define wxID_FILE4 5053 +#define wxID_FILE5 5054 +#define wxID_FILE6 5055 +#define wxID_FILE7 5056 +#define wxID_FILE8 5057 +#define wxID_FILE9 5058 + +#define wxID_OK 5100 +#define wxID_CANCEL 5101 +#define wxID_APPLY 5102 +#define wxID_YES 5103 +#define wxID_NO 5104 +#define wxID_STATIC 5105 + +#define wxID_HIGHEST 5999 +\end{verbatim} + +\subsection{Event macros summary}\label{eventmacros} \wxheading{Generic event table macros} \twocolwidtha{8cm}% \begin{twocollist}\itemsep=0pt -\twocolitem{\windowstyle{EVT\_CUSTOM(eventId, id, func)}}{Allows you to add a custom event table +\twocolitem{\windowstyle{EVT\_CUSTOM(event, id, func)}}{Allows you to add a custom event table entry by specifying the event identifier (such as wxEVT\_SIZE), the window identifier, and a member function to call.} -\twocolitem{\windowstyle{EVT\_CUSTOM\_RANGE(eventId, id1, id2, func)}}{The same as EVT\_CUSTOM, +\twocolitem{\windowstyle{EVT\_CUSTOM\_RANGE(event, id1, id2, func)}}{The same as EVT\_CUSTOM, but responds to a range of window identifiers.} -\twocolitem{\windowstyle{EVT\_COMMAND(eventId, id, func)}}{The same as EVT\_CUSTOM, but +\twocolitem{\windowstyle{EVT\_COMMAND(id, event, func)}}{The same as EVT\_CUSTOM, but expects a member function with a wxCommandEvent argument.} -\twocolitem{\windowstyle{EVT\_COMMAND\_RANGE(eventId, id1, id2, func)}}{The same as EVT\_CUSTOM\_RANGE, but +\twocolitem{\windowstyle{EVT\_COMMAND\_RANGE(id1, id2, event, func)}}{The same as EVT\_CUSTOM\_RANGE, but expects a member function with a wxCommandEvent argument.} \end{twocollist} @@ -246,15 +322,17 @@ to handle dialog initialisation.} \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}.} +\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}