X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/f6bcfd974ef26faf6f91a62cac09827e09463fd1..cba1c2ca127cbc8ce1aeb87b13b968caff0f995e:/docs/latex/wx/keyevent.tex diff --git a/docs/latex/wx/keyevent.tex b/docs/latex/wx/keyevent.tex index 34dfc6afd3..01a3ac89f2 100644 --- a/docs/latex/wx/keyevent.tex +++ b/docs/latex/wx/keyevent.tex @@ -2,6 +2,58 @@ This event class contains information about keypress (character) events. +Notice that there are three different kinds of keyboard events in wxWidgets: +key down and up events and char events. The difference between the first two +is clear - the first corresponds to a key press and the second to a key +release - otherwise they are identical. Just note that if the key is +maintained in a pressed state you will typically get a lot of (automatically +generated) down events but only one up so it is wrong to assume that there is +one up event corresponding to each down one. + +Both key events provide untranslated key codes while the char event carries +the translated one. The untranslated code for alphanumeric keys is always +an upper case value. For the other keys it is one of {\tt WXK\_XXX} values +from the \helpref{keycodes table}{keycodes}. The translated key is, in +general, the character the user expects to appear as the result of the key +combination when typing the text into a text entry zone, for example. + +A few examples to clarify this (all assume that {\sc Caps Lock} is unpressed +and the standard US keyboard): when the {\tt 'A'} key is pressed, the key down +event key code is equal to {\tt ASCII A} $== 65$. But the char event key code +is {\tt ASCII a} $== 97$. On the other hand, if you press both {\sc Shift} and +{\tt 'A'} keys simultaneously , the key code in key down event will still be +just {\tt 'A'} while the char event key code parameter will now be {\tt 'A'} +as well. + +Although in this simple case it is clear that the correct key code could be +found in the key down event handler by checking the value returned by +\helpref{ShiftDown()}{wxkeyeventshiftdown}, in general you should use +{\tt EVT\_CHAR} for this as for non alphanumeric keys the translation is +keyboard-layout dependent and can only be done properly by the system itself. + +Another kind of translation is done when the control key is pressed: for +example, for {\sc Ctrl-A} key press the key down event still carries the +same key code {\tt 'a'} as usual but the char event will have key code of +$1$, the ASCII value of this key combination. + +You may discover how the other keys on your system behave interactively by +running the \helpref{text}{sampletext} wxWidgets sample and pressing some keys +in any of the text controls shown in it. + +{\bf Note:} If a key down ({\tt EVT\_KEY\_DOWN}) event is caught and +the event handler does not call {\tt event.Skip()} then the corresponding +char event ({\tt EVT\_CHAR}) will not happen. This is by design and +enables the programs that handle both types of events to be a bit +simpler. + +{\bf Note for Windows programmers:} The key and char events in wxWidgets are +similar to but slightly different from Windows {\tt WM\_KEYDOWN} and +{\tt WM\_CHAR} events. In particular, Alt-x combination will generate a char +event in wxWidgets (unless it is used as an accelerator). + +{\bf Tip:} be sure to call {\tt event.Skip()} for events that you don't process in +key event function, otherwise menu shortcuts may cease to work under Windows. + \wxheading{Derived from} \helpref{wxEvent}{wxevent} @@ -17,128 +69,252 @@ functions that take a wxKeyEvent argument. \twocolwidtha{7cm} \begin{twocollist}\itemsep=0pt -\twocolitem{{\bf EVT\_CHAR(func)}}{Process a wxEVT\_CHAR event (a non-modifier key has been pressed).} \twocolitem{{\bf EVT\_KEY\_DOWN(func)}}{Process a wxEVT\_KEY\_DOWN event (any key has been pressed).} \twocolitem{{\bf EVT\_KEY\_UP(func)}}{Process a wxEVT\_KEY\_UP event (any key has been released).} \twocolitem{{\bf EVT\_CHAR(func)}}{Process a wxEVT\_CHAR event.} -\twocolitem{{\bf EVT\_CHAR\_HOOK(func)}}{Process a wxEVT\_CHAR\_HOOK event.} +%\twocolitem{{\bf EVT\_CHAR\_HOOK(func)}}{Process a wxEVT\_CHAR\_HOOK event.} \end{twocollist}% -\wxheading{See also} - -\helpref{wxWindow::OnChar}{wxwindowonchar}, -\helpref{wxWindow::OnCharHook}{wxwindowoncharhook}, -\helpref{wxWindow::OnKeyDown}{wxwindowonkeydown}, -\helpref{wxWindow::OnKeyUp}{wxwindowonkeyup} \latexignore{\rtfignore{\wxheading{Members}}} -\membersection{wxKeyEvent::m\_altDown} + +\membersection{wxKeyEvent::m\_altDown}\label{wxkeyeventmaltdown} \member{bool}{m\_altDown} -TRUE if the Alt key is pressed down. +\textbf{Deprecated: } Please use \helpref{GetModifiers}{wxkeyeventgetmodifiers} +instead! + +true if the Alt key is pressed down. -\membersection{wxKeyEvent::m\_controlDown} + +\membersection{wxKeyEvent::m\_controlDown}\label{wxkeyeventmcontroldown} \member{bool}{m\_controlDown} -TRUE if control is pressed down. +\textbf{Deprecated: } Please use \helpref{GetModifiers}{wxkeyeventgetmodifiers} +instead! + +true if control is pressed down. -\membersection{wxKeyEvent::m\_keyCode} + +\membersection{wxKeyEvent::m\_keyCode}\label{wxkeyeventmkeycode} \member{long}{m\_keyCode} +\textbf{Deprecated: } Please use \helpref{GetKeyCode}{wxkeyeventgetkeycode} +instead! + Virtual keycode. See \helpref{Keycodes}{keycodes} for a list of identifiers. -\membersection{wxKeyEvent::m\_metaDown} + +\membersection{wxKeyEvent::m\_metaDown}\label{wxkeyeventmmetadown} \member{bool}{m\_metaDown} -TRUE if the Meta key is pressed down. +\textbf{Deprecated: } Please use \helpref{GetModifiers}{wxkeyeventgetmodifiers} +instead! + +true if the Meta key is pressed down. -\membersection{wxKeyEvent::m\_shiftDown} + +\membersection{wxKeyEvent::m\_shiftDown}\label{wxkeyeventmshiftdown} \member{bool}{m\_shiftDown} -TRUE if shift is pressed down. +\textbf{Deprecated: } Please use \helpref{GetModifiers}{wxkeyeventgetmodifiers} +instead! + +true if shift is pressed down. -\membersection{wxKeyEvent::m\_x} + +\membersection{wxKeyEvent::m\_x}\label{wxkeyeventmx} \member{int}{m\_x} +\textbf{Deprecated: } Please use \helpref{GetX}{wxkeyeventgetx} instead! + X position of the event. -\membersection{wxKeyEvent::m\_y} + +\membersection{wxKeyEvent::m\_y}\label{wxkeyeventmy} \member{int}{m\_y} +\textbf{Deprecated: } Please use \helpref{GetY}{wxkeyeventgety} instead! + Y position of the event. -\membersection{wxKeyEvent::wxKeyEvent} + +\membersection{wxKeyEvent::wxKeyEvent}\label{wxkeyeventctor} \func{}{wxKeyEvent}{\param{WXTYPE}{ keyEventType}} Constructor. Currently, the only valid event types are wxEVT\_CHAR and wxEVT\_CHAR\_HOOK. -\membersection{wxKeyEvent::AltDown} + +\membersection{wxKeyEvent::AltDown}\label{wxkeyeventaltdown} \constfunc{bool}{AltDown}{\void} -Returns TRUE if the Alt key was down at the time of the key event. +Returns true if the Alt key was down at the time of the key event. + +Notice that \helpref{GetModifiers}{wxkeyeventgetmodifiers} is easier to use +correctly than this function so you should consider using it in new code. + + +\membersection{wxKeyEvent::CmdDown}\label{wxkeyeventcmddown} + +\constfunc{bool}{CmdDown}{\void} + +\textsc{Cmd} is a pseudo key which is the same as Control for PC and Unix +platforms but the special \textsc{Apple} (a.k.a as \textsc{Command}) key under +Macs: it makes often sense to use it instead of, say, ControlDown() because Cmd +key is used for the same thing under Mac as Ctrl elsewhere (but Ctrl still +exists, just not used for this purpose under Mac). So for non-Mac platforms +this is the same as \helpref{ControlDown()}{wxkeyeventcontroldown} and under +Mac this is the same as \helpref{MetaDown()}{wxkeyeventmetadown}. + -\membersection{wxKeyEvent::ControlDown} +\membersection{wxKeyEvent::ControlDown}\label{wxkeyeventcontroldown} \constfunc{bool}{ControlDown}{\void} -Returns TRUE if the control key was down at the time of the key event. +Returns true if the control key was down at the time of the key event. -\membersection{wxKeyEvent::GetKeyCode} +Notice that \helpref{GetModifiers}{wxkeyeventgetmodifiers} is easier to use +correctly than this function so you should consider using it in new code. + + +\membersection{wxKeyEvent::GetKeyCode}\label{wxkeyeventgetkeycode} \constfunc{int}{GetKeyCode}{\void} Returns the virtual key code. ASCII events return normal ASCII values, while non-ASCII events return values such as {\bf WXK\_LEFT} for the -left cursor key. See \helpref{Keycodes}{keycodes} for a full list of the virtual key codes. +left cursor key. See \helpref{Keycodes}{keycodes} for a full list of +the virtual key codes. -\membersection{wxKeyEvent::GetX} +Note that in Unicode build, the returned value is meaningful only if the +user entered a character that can be represented in current locale's default +charset. You can obtain the corresponding Unicode character using +\helpref{GetUnicodeKey}{wxkeyeventgetunicodekey}. -\constfunc{long}{GetX}{\void} -Returns the X position of the event. +\membersection{wxKeyEvent::GetModifiers}\label{wxkeyeventgetmodifiers} -\membersection{wxKeyEvent::GetY} +\constfunc{int}{GetModifiers}{\void} -\constfunc{long}{GetY}{\void} +Return the bitmask of modifier keys which were pressed when this event +happened. See \helpref{key modifier constants}{keymodifiers} for the full list +of modifiers. -Returns the Y position of the event. +Notice that this function is easier to use correctly than, for example, +\helpref{ControlDown}{wxkeyeventcontroldown} because when using the latter you +also have to remember to test that none of the other modifiers is pressed: -\membersection{wxKeyEvent::MetaDown} +\begin{verbatim} + if ( ControlDown() && !AltDown() && !ShiftDown() && !MetaDown() ) + ... handle Ctrl-XXX ... +\end{verbatim} -\constfunc{bool}{MetaDown}{\void} +and forgetting to do it can result in serious program bugs (e.g. program not +working with European keyboard layout where \textsc{AltGr} key which is seen by +the program as combination of \textsc{Ctrl} and \textsc{Alt} is used). On the +other hand, you can simply write + +\begin{verbatim} + if ( GetModifiers() == wxMOD_CONTROL ) + ... handle Ctrl-XXX ... +\end{verbatim} -Returns TRUE if the Meta key was down at the time of the key event. +with this function. -\membersection{wxKeyEvent::GetPosition} + +\membersection{wxKeyEvent::GetPosition}\label{wxkeyeventgetposition} \constfunc{wxPoint}{GetPosition}{\void} \constfunc{void}{GetPosition}{\param{long *}{x}, \param{long *}{y}} -Obtains the position at which the key was pressed. +Obtains the position (in client coordinates) at which the key was pressed. + -\membersection{wxKeyEvent::HasModifiers} +\membersection{wxKeyEvent::GetRawKeyCode}\label{wxkeyeventgetrawkeycode} + +\constfunc{wxUint32}{GetRawKeyCode}{\void} + +Returns the raw key code for this event. This is a platform-dependent scan code +which should only be used in advanced applications. + +{\bf NB:} Currently the raw key codes are not supported by all ports, use +{\tt\#ifdef wxHAS\_RAW\_KEY\_CODES} to determine if this feature is available. + + +\membersection{wxKeyEvent::GetRawKeyFlags}\label{wxkeyeventgetrawkeyflags} + +\constfunc{wxUint32}{GetRawKeyFlags}{\void} + +Returns the low level key flags for this event. The flags are +platform-dependent and should only be used in advanced applications. + +{\bf NB:} Currently the raw key flags are not supported by all ports, use +{\tt \#ifdef wxHAS\_RAW\_KEY\_CODES} to determine if this feature is available. + + +\membersection{wxKeyEvent::GetUnicodeKey}\label{wxkeyeventgetunicodekey} + +\constfunc{wxChar}{GetUnicodeKey}{\void} + +Returns the Unicode character corresponding to this key event. + +This function is only available in Unicode build, i.e. when +\texttt{wxUSE\_UNICODE} is $1$. + + +\membersection{wxKeyEvent::GetX}\label{wxkeyeventgetx} + +\constfunc{long}{GetX}{\void} + +Returns the X position (in client coordinates) of the event. + + +\membersection{wxKeyEvent::GetY}\label{wxkeyeventgety} + +\constfunc{long}{GetY}{\void} + +Returns the Y (in client coordinates) position of the event. + + +\membersection{wxKeyEvent::HasModifiers}\label{wxkeyeventhasmodifiers} \constfunc{bool}{HasModifiers}{\void} -Returns TRUE if either of {\sc Ctrl}, {\sc Alt} or {\sc Meta} keys was down +Returns true if either {\sc Ctrl} or {\sc Alt} keys was down at the time of the key event. Note that this function does not take into -account the {\sc Shift} key state. +account neither {\sc Shift} nor {\sc Meta} key states (the reason for ignoring +the latter is that it is common for {\sc NumLock} key to be configured as +{\sc Meta} under X but the key presses even while {\sc NumLock} is on should +be still processed normally). + + +\membersection{wxKeyEvent::MetaDown}\label{wxkeyeventmetadown} + +\constfunc{bool}{MetaDown}{\void} + +Returns true if the Meta key was down at the time of the key event. + +Notice that \helpref{GetModifiers}{wxkeyeventgetmodifiers} is easier to use +correctly than this function so you should consider using it in new code. + -\membersection{wxKeyEvent::ShiftDown} +\membersection{wxKeyEvent::ShiftDown}\label{wxkeyeventshiftdown} \constfunc{bool}{ShiftDown}{\void} -Returns TRUE if the shift key was down at the time of the key event. +Returns true if the shift key was down at the time of the key event. +Notice that \helpref{GetModifiers}{wxkeyeventgetmodifiers} is easier to use +correctly than this function so you should consider using it in new code.