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1 \section{\class{wxKeyEvent}}\label{wxkeyevent}
2
3 This event class contains information about keypress (character) events.
4
5 Notice that there are three different kinds of keyboard events in wxWindows:
6 key down and up events and char events. The difference between the first two
7 is clear - the first corresponds to a key press and the second to a key
8 release - otherwise they are identical. Just note that if the key is
9 maintained in a pressed state you will typically get a lot of (automatically
10 generated) down events but only one up so it is wrong to assume that there is
11 one up event corresponding to each down one.
12
13 Both key events provide untranslated key codes while the char event carries
14 the translated one. The untranslated code for alphanumeric keys is always
15 an upper case value. For the other keys it is one of {\tt WXK\_XXX} values
16 from the \helpref{keycodes table}{keycodes}. The translated key is, in
17 general, the character the user expects to appear as the result of the key
18 combination when typing the text into a text entry zone, for example.
19
20 A few examples to clarify this (all assume that {\sc Caps Lock} is unpressed
21 and the standard US keyboard): when the {\tt 'A'} key is pressed, the key down
22 event key code is equal to {\tt ASCII A} $== 65$. But the char event key code
23 is {\tt ASCII a} $== 97$. On the other hand, if you press both {\sc Shift} and
24 {\tt 'A'} keys simultaneously , the key code in key down event will still be
25 just {\tt 'A'} while the char event key code parameter will now be {\tt 'A'}
26 as well.
27
28 Although in this simple case it is clear that the correct key code could be
29 found in the key down event handler by checking the value returned by
30 \helpref{ShiftDown()}{wxkeyeventshiftdown}, in general you should use
31 {\tt EVT\_CHAR} for this as for non alphanumeric keys the translation is
32 keyboard-layout dependent and can only be done properly by the system itself.
33
34 Another kind of translation is done when the control key is pressed: for
35 example, for {\sc Ctrl-A} key press the key down event still carries the
36 same key code {\tt 'a'} as usual but the char event will have key code of
37 $1$, the ASCII value of this key combination.
38
39 You may discover how the other keys on your system behave interactively by
40 running the \helpref{text}{sampletext} wxWindows sample and pressing some keys
41 in any of the text controls shown in it.
42
43 {\bf Note:} If a key down ({\tt EVT\_KEY\_DOWN}) event is caught and
44 the event handler does not call {\tt event.Skip()} then the coresponding
45 char event ({\tt EVT\_CHAR}) will not happen. This is by design and
46 enables the programs that handle both types of events to be a bit
47 simpler.
48
49 {\bf Note for Windows programmers:} The key and char events in wxWindows are
50 similar to but slightly different from Windows {\tt WM\_KEYDOWN} and
51 {\tt WM\_CHAR} events. In particular, Alt-x combination will generate a char
52 event in wxWindows (unless it is used as an accelerator).
53
54 {\bf Tip:} be sure to call {\tt event.Skip()} for events that you don't process in
55 key event function, otherwise menu shortcuts may cease to work under Windows.
56
57 \wxheading{Derived from}
58
59 \helpref{wxEvent}{wxevent}
60
61 \wxheading{Include files}
62
63 <wx/event.h>
64
65 \wxheading{Event table macros}
66
67 To process a key event, use these event handler macros to direct input to member
68 functions that take a wxKeyEvent argument.
69
70 \twocolwidtha{7cm}
71 \begin{twocollist}\itemsep=0pt
72 \twocolitem{{\bf EVT\_KEY\_DOWN(func)}}{Process a wxEVT\_KEY\_DOWN event (any key has been pressed).}
73 \twocolitem{{\bf EVT\_KEY\_UP(func)}}{Process a wxEVT\_KEY\_UP event (any key has been released).}
74 \twocolitem{{\bf EVT\_CHAR(func)}}{Process a wxEVT\_CHAR event.}
75 %\twocolitem{{\bf EVT\_CHAR\_HOOK(func)}}{Process a wxEVT\_CHAR\_HOOK event.}
76 \end{twocollist}%
77
78
79 \latexignore{\rtfignore{\wxheading{Members}}}
80
81 \membersection{wxKeyEvent::m\_altDown}
82
83 \member{bool}{m\_altDown}
84
85 true if the Alt key is pressed down.
86
87 \membersection{wxKeyEvent::m\_controlDown}
88
89 \member{bool}{m\_controlDown}
90
91 true if control is pressed down.
92
93 \membersection{wxKeyEvent::m\_keyCode}
94
95 \member{long}{m\_keyCode}
96
97 Virtual keycode. See \helpref{Keycodes}{keycodes} for a list of identifiers.
98
99 \membersection{wxKeyEvent::m\_metaDown}
100
101 \member{bool}{m\_metaDown}
102
103 true if the Meta key is pressed down.
104
105 \membersection{wxKeyEvent::m\_shiftDown}
106
107 \member{bool}{m\_shiftDown}
108
109 true if shift is pressed down.
110
111 \membersection{wxKeyEvent::m\_x}
112
113 \member{int}{m\_x}
114
115 X position of the event.
116
117 \membersection{wxKeyEvent::m\_y}
118
119 \member{int}{m\_y}
120
121 Y position of the event.
122
123 \membersection{wxKeyEvent::wxKeyEvent}
124
125 \func{}{wxKeyEvent}{\param{WXTYPE}{ keyEventType}}
126
127 Constructor. Currently, the only valid event types are wxEVT\_CHAR and wxEVT\_CHAR\_HOOK.
128
129 \membersection{wxKeyEvent::AltDown}
130
131 \constfunc{bool}{AltDown}{\void}
132
133 Returns true if the Alt key was down at the time of the key event.
134
135 \membersection{wxKeyEvent::ControlDown}
136
137 \constfunc{bool}{ControlDown}{\void}
138
139 Returns true if the control key was down at the time of the key event.
140
141 \membersection{wxKeyEvent::GetKeyCode}
142
143 \constfunc{int}{GetKeyCode}{\void}
144
145 Returns the virtual key code. ASCII events return normal ASCII values,
146 while non-ASCII events return values such as {\bf WXK\_LEFT} for the
147 left cursor key. See \helpref{Keycodes}{keycodes} for a full list of the virtual key codes.
148
149 \membersection{wxKeyEvent::GetRawKeyCode}
150
151 \constfunc{wxUint32}{GetRawKeyCode}{\void}
152
153 Returns the raw key code for this event. This is a platform-dependent scan code
154 which should only be used in advanced applications.
155
156 {\bf NB:} Currently the raw key codes are not supported by all ports, use
157 {\tt\#ifdef wxHAS\_RAW\_KEY\_CODES} to determine if this feature is available.
158
159 \membersection{wxKeyEvent::GetRawKeyFlags}
160
161 \constfunc{wxUint32}{GetRawKeyFlags}{\void}
162
163 Returns the low level key flags for this event. The flags are
164 platform-dependent and should only be used in advanced applications.
165
166 {\bf NB:} Currently the raw key flags are not supported by all ports, use
167 {\tt \#ifdef wxHAS\_RAW\_KEY\_CODES} to determine if this feature is available.
168
169 \membersection{wxKeyEvent::GetX}
170
171 \constfunc{long}{GetX}{\void}
172
173 Returns the X position (in client coordinates) of the event.
174
175 \membersection{wxKeyEvent::GetY}
176
177 \constfunc{long}{GetY}{\void}
178
179 Returns the Y (in client coordinates) position of the event.
180
181 \membersection{wxKeyEvent::MetaDown}
182
183 \constfunc{bool}{MetaDown}{\void}
184
185 Returns true if the Meta key was down at the time of the key event.
186
187 \membersection{wxKeyEvent::GetPosition}
188
189 \constfunc{wxPoint}{GetPosition}{\void}
190
191 \constfunc{void}{GetPosition}{\param{long *}{x}, \param{long *}{y}}
192
193 Obtains the position (in client coordinates) at which the key was pressed.
194
195 \membersection{wxKeyEvent::HasModifiers}
196
197 \constfunc{bool}{HasModifiers}{\void}
198
199 Returns true if either {\sc Ctrl} or {\sc Alt} keys was down
200 at the time of the key event. Note that this function does not take into
201 account neither {\sc Shift} nor {\sc Meta} key states (the reason for ignoring
202 the latter is that it is common for {\sc NumLock} key to be configured as
203 {\sc Meta} under X but the key presses even while {\sc NumLock} is on should
204 be still processed normally).
205
206 \membersection{wxKeyEvent::ShiftDown}\label{wxkeyeventshiftdown}
207
208 \constfunc{bool}{ShiftDown}{\void}
209
210 Returns true if the shift key was down at the time of the key event.
211