docs/latex/wx/upduievt.tex

   1 \section{\class{wxUpdateUIEvent}}\label{wxupdateuievent}
   2
   3 This class is used for pseudo-events which are called by wxWindows
   4 to give an application the chance to update various user interface elements.
   5
   6 \wxheading{Derived from}
   7
   8 \helpref{wxCommandEvent}{wxcommandevent}\\
   9 \helpref{wxEvent}{wxevent}\\
  10 \helpref{wxObject}{wxobject}
  11
  12 \wxheading{Include files}
  13
  14 <wx/event.h>
  15
  16 \wxheading{Event table macros}
  17
  18 To process an update event, use these event handler macros to direct input to member
  19 functions that take a wxUpdateUIEvent argument.
  20
  21 \twocolwidtha{7cm}
  22 \begin{twocollist}\itemsep=0pt
  23 \twocolitem{{\bf EVT\_UPDATE\_UI(id, func)}}{Process a wxEVT\_UPDATE\_UI event for the command with the given id.}
  24 \twocolitem{{\bf EVT\_UPDATE\_UI\_RANGE(id1, id2, func)}}{Process a wxEVT\_UPDATE\_UI event for any command with id included in the given range.}
  25 \end{twocollist}%
  26
  27 \wxheading{Remarks}
  28
  29 Without update UI events, an application has to work hard to check/uncheck, enable/disable,
  30 and set the text for elements such as menu items and toolbar buttons.
  31 The code for doing this has to be mixed up with the code that is invoked when
  32 an action is invoked for a menu item or button.
  33
  34 With update UI events, you define an event handler to look at the state of
  35 the application and change UI elements accordingly. wxWindows will call your
  36 member functions in idle time, so you don't have to worry where to call this code.
  37 In addition to being a clearer and more declarative method, it also means you
  38 don't have to worry whether you're updating a toolbar or menubar identifier.
  39 The same handler can update a menu item and toolbar button, if the identifier is the same.
  40
  41 Instead of directly manipulating the menu or button, you call functions in the event
  42 object, such as \helpref{wxUpdateUIEvent::Check}{wxupdateuieventcheck}. wxWindows
  43 will determine whether such a call has been made, and which UI element to update.
  44
  45 These events will work for popup menus as well as menubars. Just before a menu is popped
  46 up, \helpref{wxMenu::UpdateUI}{wxmenuupdateui} is called to process any UI events for
  47 the window that owns the menu.
  48
  49 \wxheading{See also}
  50
  51 \helpref{Event handling overview}{eventhandlingoverview}
  52
  53 \latexignore{\rtfignore{\wxheading{Members}}}
  54
  55 \membersection{wxUpdateUIEvent::wxUpdateUIEvent}
  56
  57 \func{}{wxUpdateUIEvent}{\param{wxWindowID }{commandId = 0}}
  58
  59 Constructor.
  60
  61 \membersection{wxUpdateUIEvent::m\_checked}
  62
  63 \member{bool}{m\_checked}
  64
  65 true if the element should be checked, false otherwise.
  66
  67 \membersection{wxUpdateUIEvent::m\_enabled}
  68
  69 \member{bool}{m\_checked}
  70
  71 true if the element should be enabled, false otherwise.
  72
  73 \membersection{wxUpdateUIEvent::m\_setChecked}
  74
  75 \member{bool}{m\_setChecked}
  76
  77 true if the application has set the {\bf m\_checked} member.
  78
  79 \membersection{wxUpdateUIEvent::m\_setEnabled}
  80
  81 \member{bool}{m\_setEnabled}
  82
  83 true if the application has set the {\bf m\_enabled} member.
  84
  85 \membersection{wxUpdateUIEvent::m\_setText}
  86
  87 \member{bool}{m\_setText}
  88
  89 true if the application has set the {\bf m\_text} member.
  90
  91 \membersection{wxUpdateUIEvent::m\_text}
  92
  93 \member{wxString}{m\_text}
  94
  95 Holds the text with which the the application wishes to
  96 update the UI element.
  97
  98 \membersection{wxUpdateUIEvent::Check}\label{wxupdateuieventcheck}
  99
 100 \func{void}{Check}{\param{bool}{ check}}
 101
 102 Check or uncheck the UI element.
 103
 104 \membersection{wxUpdateUIEvent::Enable}\label{wxupdateuieventenable}
 105
 106 \func{void}{Enable}{\param{bool}{ enable}}
 107
 108 Enable or disable the UI element.
 109
 110 \membersection{wxUpdateUIEvent::GetChecked}\label{wxupdateuieventgetchecked}
 111
 112 \constfunc{bool}{GetChecked}{\void}
 113
 114 Returns true if the UI element should be checked.
 115
 116 \membersection{wxUpdateUIEvent::GetEnabled}\label{wxupdateuieventgetenabled}
 117
 118 \constfunc{bool}{GetEnabled}{\void}
 119
 120 Returns true if the UI element should be enabled.
 121
 122 \membersection{wxUpdateUIEvent::GetSetChecked}\label{wxupdateuieventgetsetchecked}
 123
 124 \constfunc{bool}{GetSetChecked}{\void}
 125
 126 Returns true if the application has called {\bf SetChecked}. For wxWindows internal use only.
 127
 128 \membersection{wxUpdateUIEvent::GetSetEnabled}\label{wxupdateuieventgetsetenabled}
 129
 130 \constfunc{bool}{GetSetEnabled}{\void}
 131
 132 Returns true if the application has called {\bf SetEnabled}. For wxWindows internal use only.
 133
 134 \membersection{wxUpdateUIEvent::GetSetText}\label{wxupdateuieventgetsettext}
 135
 136 \constfunc{bool}{GetSetText}{\void}
 137
 138 Returns true if the application has called {\bf SetText}. For wxWindows internal use only.
 139
 140 \membersection{wxUpdateUIEvent::GetText}\label{wxupdateuieventgettext}
 141
 142 \constfunc{wxString}{GetText}{\void}
 143
 144 Returns the text that should be set for the UI element.
 145
 146 \membersection{wxUpdateUIEvent::SetText}\label{wxupdateuieventsettext}
 147
 148 \func{void}{SetText}{\param{const wxString\&}{ text}}
 149
 150 Sets the text for this UI element.
 151