1wxUpdateUIEvent(3)         Erlang Module Definition         wxUpdateUIEvent(3)
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NAME

6       wxUpdateUIEvent - Functions for wxUpdateUIEvent class
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DESCRIPTION

9       This  class  is used for pseudo-events which are called by wxWidgets to
10       give an application the chance to update various  user  interface  ele‐
11       ments.
12
13       Without   update  UI  events,  an  application  has  to  work  hard  to
14       check/uncheck, enable/disable, show/hide, and set the text for elements
15       such  as menu items and toolbar buttons. The code for doing this has to
16       be mixed up with the code that is invoked when an action is invoked for
17       a menu item or button.
18
19       With update UI events, you define an event handler to look at the state
20       of the application and change UI elements accordingly.  wxWidgets  will
21       call  your  member  functions  in idle time, so you don't have to worry
22       where to call this code.
23
24       In addition to being a clearer and more  declarative  method,  it  also
25       means  you  don't  have  to  worry whether you're updating a toolbar or
26       menubar identifier. The same handler can update a menu item and toolbar
27       button, if the identifier is the same. Instead of directly manipulating
28       the menu or button, you call functions in the  event  object,  such  as
29       check/2.  wxWidgets  will  determine whether such a call has been made,
30       and which UI element to update.
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32       These events will work for popup menus as well as menubars. Just before
33       a menu is popped up, wxMenu::UpdateUI (not implemented in wx) is called
34       to process any UI events for the window that owns the menu.
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36       If you find that the overhead of UI update processing is affecting your
37       application, you can do one or both of the following:
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39       Note that although events are sent in idle time, defining a wxIdleEvent
40       handler for a window does not affect this because the events  are  sent
41       from  wxWindow::OnInternalIdle  (not implemented in wx) which is always
42       called in idle time.
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44       wxWidgets tries to optimize update events on some platforms. On Windows
45       and GTK+, events for menubar items are only sent when the menu is about
46       to be shown, and not in idle time.
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48       See: Overview events
49
50       This class is derived (and can use functions) from: wxCommandEvent  wx‐
51       Event
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53       wxWidgets docs: wxUpdateUIEvent
54

EVENTS

56       Use  wxEvtHandler:connect/3  with  wxUpdateUIEventType  to subscribe to
57       events of this type.
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DATA TYPES

60       wxUpdateUIEvent() = wx:wx_object()
61
62       wxUpdateUI() =
63           #wxUpdateUI{type = wxUpdateUIEvent:wxUpdateUIEventType()}
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65       wxUpdateUIEventType() = update_ui
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EXPORTS

68       canUpdate(Window) -> boolean()
69
70              Types:
71
72                 Window = wxWindow:wxWindow()
73
74              Returns true if it is appropriate  to  update  (send  UI  update
75              events to) this window.
76
77              This  function  looks  at  the  mode  used  (see setMode/1), the
78              wxWS_EX_PROCESS_UI_UPDATES  flag  in  window,  the  time  update
79              events  were last sent in idle time, and the update interval, to
80              determine whether events should be sent to this window  now.  By
81              default  this will always return true because the update mode is
82              initially wxUPDATE_UI_PROCESS_ALL and the interval is set to  0;
83              so  update events will be sent as often as possible. You can re‐
84              duce the frequency that events are sent  by  changing  the  mode
85              and/or setting an update interval.
86
87              See: resetUpdateTime/0, setUpdateInterval/1, setMode/1
88
89       check(This, Check) -> ok
90
91              Types:
92
93                 This = wxUpdateUIEvent()
94                 Check = boolean()
95
96              Check or uncheck the UI element.
97
98       enable(This, Enable) -> ok
99
100              Types:
101
102                 This = wxUpdateUIEvent()
103                 Enable = boolean()
104
105              Enable or disable the UI element.
106
107       show(This, Show) -> ok
108
109              Types:
110
111                 This = wxUpdateUIEvent()
112                 Show = boolean()
113
114              Show or hide the UI element.
115
116       getChecked(This) -> boolean()
117
118              Types:
119
120                 This = wxUpdateUIEvent()
121
122              Returns true if the UI element should be checked.
123
124       getEnabled(This) -> boolean()
125
126              Types:
127
128                 This = wxUpdateUIEvent()
129
130              Returns true if the UI element should be enabled.
131
132       getShown(This) -> boolean()
133
134              Types:
135
136                 This = wxUpdateUIEvent()
137
138              Returns true if the UI element should be shown.
139
140       getSetChecked(This) -> boolean()
141
142              Types:
143
144                 This = wxUpdateUIEvent()
145
146              Returns true if the application has called check/2.
147
148              For wxWidgets internal use only.
149
150       getSetEnabled(This) -> boolean()
151
152              Types:
153
154                 This = wxUpdateUIEvent()
155
156              Returns true if the application has called enable/2.
157
158              For wxWidgets internal use only.
159
160       getSetShown(This) -> boolean()
161
162              Types:
163
164                 This = wxUpdateUIEvent()
165
166              Returns true if the application has called show/2.
167
168              For wxWidgets internal use only.
169
170       getSetText(This) -> boolean()
171
172              Types:
173
174                 This = wxUpdateUIEvent()
175
176              Returns true if the application has called setText/2.
177
178              For wxWidgets internal use only.
179
180       getText(This) -> unicode:charlist()
181
182              Types:
183
184                 This = wxUpdateUIEvent()
185
186              Returns the text that should be set for the UI element.
187
188       getMode() -> wx:wx_enum()
189
190              Static  function returning a value specifying how wxWidgets will
191              send update events: to all windows, or only to those which spec‐
192              ify that they will process the events.
193
194              See: setMode/1
195
196       getUpdateInterval() -> integer()
197
198              Returns the current interval between updates in milliseconds.
199
200              The value -1 disables updates, 0 updates as frequently as possi‐
201              ble.
202
203              See: setUpdateInterval/1
204
205       resetUpdateTime() -> ok
206
207              Used internally to reset the last-updated time  to  the  current
208              time.
209
210              It is assumed that update events are normally sent in idle time,
211              so this is called at the end of idle processing.
212
213              See: canUpdate/1, setUpdateInterval/1, setMode/1
214
215       setMode(Mode) -> ok
216
217              Types:
218
219                 Mode = wx:wx_enum()
220
221              Specify how wxWidgets will send update events: to  all  windows,
222              or  only  to  those  which  specify  that  they will process the
223              events.
224
225       setText(This, Text) -> ok
226
227              Types:
228
229                 This = wxUpdateUIEvent()
230                 Text = unicode:chardata()
231
232              Sets the text for this UI element.
233
234       setUpdateInterval(UpdateInterval) -> ok
235
236              Types:
237
238                 UpdateInterval = integer()
239
240              Sets the interval between updates in milliseconds.
241
242              Set to -1 to disable updates, or to 0 to update as frequently as
243              possible. The default is 0.
244
245              Use  this to reduce the overhead of UI update events if your ap‐
246              plication has a lot of windows. If you set the value  to  -1  or
247              greater  than  0,  you may also need to call wxWindow:updateWin‐
248              dowUI/2 at appropriate points in your application, such as  when
249              a dialog is about to be shown.
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253wxWidgets team.                    wx 2.2.1                 wxUpdateUIEvent(3)