X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/954b8ae60391d18b87a604e7919c87c0c6ae208b..16d38102e8ad5534d185cc532b9aa8077a75e0a4:/docs/latex/wx/keyevent.tex diff --git a/docs/latex/wx/keyevent.tex b/docs/latex/wx/keyevent.tex index 1248ec89cf..0abdc667d4 100644 --- a/docs/latex/wx/keyevent.tex +++ b/docs/latex/wx/keyevent.tex @@ -2,6 +2,49 @@ This event class contains information about keypress (character) events. +Notice that there are three different kinds of keyboard events in wxWindows: +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 up one 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} wxWindows sample and pressing some keys +in any of the text controls shown in it. + +{\bf Note for Windows programmers:} The key and char events in wxWindows 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 wxWindows (unless it is used as an acclerator). + \wxheading{Derived from} \helpref{wxEvent}{wxevent} @@ -17,11 +60,10 @@ 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} @@ -83,51 +125,64 @@ Constructor. Currently, the only valid event types are wxEVT\_CHAR and wxEVT\_CH \membersection{wxKeyEvent::AltDown} -\func{bool}{AltDown}{\void} +\constfunc{bool}{AltDown}{\void} Returns TRUE if the Alt key was down at the time of the key event. \membersection{wxKeyEvent::ControlDown} -\func{bool}{ControlDown}{\void} +\constfunc{bool}{ControlDown}{\void} Returns TRUE if the control key was down at the time of the key event. +\membersection{wxKeyEvent::GetKeyCode} + +\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. + \membersection{wxKeyEvent::GetX} -\func{float}{GetX}{\void} +\constfunc{long}{GetX}{\void} Returns the X position of the event. \membersection{wxKeyEvent::GetY} -\func{float}{GetY}{\void} +\constfunc{long}{GetY}{\void} Returns the Y position of the event. -\membersection{wxKeyEvent::KeyCode} - -\func{long}{KeyCode}{\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. - \membersection{wxKeyEvent::MetaDown} -\func{bool}{MetaDown}{\void} +\constfunc{bool}{MetaDown}{\void} Returns TRUE if the Meta key was down at the time of the key event. -\membersection{wxKeyEvent::Position} +\membersection{wxKeyEvent::GetPosition} -\func{void}{Position}{\param{float *}{x}, \param{float *}{y}} +\constfunc{wxPoint}{GetPosition}{\void} + +\constfunc{void}{GetPosition}{\param{long *}{x}, \param{long *}{y}} Obtains the position at which the key was pressed. -\membersection{wxKeyEvent::ShiftDown} +\membersection{wxKeyEvent::HasModifiers} + +\constfunc{bool}{HasModifiers}{\void} + +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 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::ShiftDown}\label{wxkeyeventshiftdown} -\func{bool}{ShiftDown}{\void} +\constfunc{bool}{ShiftDown}{\void} Returns TRUE if the shift key was down at the time of the key event.