interface/wx/kbdstate.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/kbdstate.h
   3 // Purpose:     documentation of wxKeyboardState
   4 // Author:      wxWidgets team
   5 // Created:     2008-09-19
   6 // RCS-ID:      $Id$
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 /**
  11     Provides methods for testing the state of the keyboard modifier keys.
  12
  13     This class is used as a base class of wxKeyEvent and wxMouseState and,
  14     hence, indirectly, of wxMouseEvent, so its methods may be used to get
  15     information about the modifier keys which were pressed when the event
  16     occurred.
  17
  18     This class is implemented entirely inline in @<wx/kbdstate.h@> and thus has
  19     no linking requirements.
  20
  21     @nolibrary
  22     @category{events}
  23
  24     @see wxKeyEvent, wxMouseState
  25  */
  26 class wxKeyboardState
  27 {
  28 public:
  29     /**
  30         Constructor initializes the modifier key settings.
  31
  32         By default, no modifiers are active.
  33      */
  34     wxKeyboardState(bool controlDown = false,
  35                     bool shiftDown = false,
  36                     bool altDown = false,
  37                     bool metaDown = false);
  38
  39     /**
  40         Return the bit mask of all pressed modifier keys.
  41
  42         The return value is a combination of @c wxMOD_ALT, @c wxMOD_CONTROL,
  43         @c wxMOD_SHIFT and @c wxMOD_META bit masks. Additionally, @c wxMOD_NONE
  44         is defined as 0, i.e. corresponds to no modifiers (see HasModifiers())
  45         and @c wxMOD_CMD is either @c wxMOD_CONTROL (MSW and Unix) or
  46         @c wxMOD_META (Mac), see CmdDown().
  47         See ::wxKeyModifier for the full list of modifiers.
  48
  49         Notice that this function is easier to use correctly than, for example,
  50         ControlDown() because when using the latter you also have to remember to
  51         test that none of the other modifiers is pressed:
  52
  53         @code
  54         if ( ControlDown() && !AltDown() && !ShiftDown() && !MetaDown() )
  55             ... handle Ctrl-XXX ...
  56         @endcode
  57
  58         and forgetting to do it can result in serious program bugs (e.g. program
  59         not working with European keyboard layout where @c AltGr key which is
  60         seen by the program as combination of CTRL and ALT is used). On the
  61         other hand, you can simply write:
  62
  63         @code
  64         if ( GetModifiers() == wxMOD_CONTROL )
  65             ... handle Ctrl-XXX ...
  66         @endcode
  67
  68         with this function.
  69     */
  70     int GetModifiers() const;
  71
  72     /**
  73         Returns true if any modifiers at all are pressed.
  74
  75         This is equivalent to @c GetModifiers() @c != @c wxMOD_NONE.
  76      */
  77     bool HasModifiers() const;
  78
  79     /**
  80         Returns true if the Control key is pressed.
  81
  82         This function doesn't distinguish between right and left control keys.
  83
  84         In portable code you usually want to use CmdDown() to automatically
  85         test for the more frequently used Command key (and not the rarely used
  86         Control one) under Mac.
  87
  88         Notice that GetModifiers() should usually be used instead of this one.
  89      */
  90     bool ControlDown() const;
  91
  92     /**
  93         Returns true if the Shift key is pressed.
  94
  95         This function doesn't distinguish between right and left shift keys.
  96
  97         Notice that GetModifiers() should usually be used instead of this one.
  98      */
  99     bool ShiftDown() const;
 100
 101     /**
 102         Returns true if the Meta/Windows/Apple key is pressed.
 103
 104         This function tests the state of the key traditionally called Meta
 105         under Unix systems, Windows keys under MSW and Apple, or Command, key
 106         under Mac.
 107
 108         Notice that GetModifiers() should usually be used instead of this one.
 109
 110         @see CmdDown()
 111      */
 112     bool MetaDown() const;
 113
 114     /**
 115         Returns true if the Alt key is pressed.
 116
 117         Notice that GetModifiers() should usually be used instead of this one.
 118      */
 119     bool AltDown() const;
 120
 121     /**
 122         Returns true if the key used for command accelerators is pressed.
 123
 124         @c Cmd is a pseudo key which is Control for PC and Unix platforms but
 125         Apple (or Command) key under Macs: it makes often sense to use it
 126         instead of ControlDown() because @c Command key is used for the same
 127         thing under Mac as @c Control elsewhere (even though @c Control still
 128         exists, it is usually not used for the same purpose under Mac).
 129
 130         Notice that GetModifiers() should usually be used instead of this one.
 131      */
 132     bool CmdDown() const;
 133 };
 134