.TH wxUpdateUIEvent 3erl "wx 2.2.1" "wxWidgets team." "Erlang Module Definition"
.SH NAME
wxUpdateUIEvent \- Functions for wxUpdateUIEvent class
.SH DESCRIPTION
.LP
This class is used for pseudo-events which are called by wxWidgets to give an application the chance to update various user interface elements\&.
.LP
Without update UI events, an application has to work hard to check/uncheck, enable/disable, show/hide, and set the text for elements such as menu items and toolbar buttons\&. The code for doing this has to be mixed up with the code that is invoked when an action is invoked for a menu item or button\&.
.LP
With update UI events, you define an event handler to look at the state of the application and change UI elements accordingly\&. wxWidgets will call your member functions in idle time, so you don\&'t have to worry where to call this code\&.
.LP
In addition to being a clearer and more declarative method, it also means you don\&'t have to worry whether you\&'re updating a toolbar or menubar identifier\&. The same handler can update a menu item and toolbar button, if the identifier is the same\&. Instead of directly manipulating the menu or button, you call functions in the event object, such as \fIcheck/2\fR\&\&. wxWidgets will determine whether such a call has been made, and which UI element to update\&.
.LP
These events will work for popup menus as well as menubars\&. Just before a menu is popped up, \fIwxMenu::UpdateUI\fR\& (not implemented in wx) is called to process any UI events for the window that owns the menu\&.
.LP
If you find that the overhead of UI update processing is affecting your application, you can do one or both of the following:
.LP
Note that although events are sent in idle time, defining a \fIwxIdleEvent\fR\& handler for a window does not affect this because the events are sent from \fIwxWindow::OnInternalIdle\fR\& (not implemented in wx) which is always called in idle time\&.
.LP
wxWidgets tries to optimize update events on some platforms\&. On Windows and GTK+, events for menubar items are only sent when the menu is about to be shown, and not in idle time\&.
.LP
See: Overview events 
.LP
This class is derived (and can use functions) from: \fIwxCommandEvent\fR\& \fIwxEvent\fR\&
.LP
wxWidgets docs: wxUpdateUIEvent
.SH "EVENTS"

.LP
Use \fIwxEvtHandler:connect/3\fR\& with \fIwxUpdateUIEventType\fR\& to subscribe to events of this type\&.
.SH DATA TYPES
.nf

\fBwxUpdateUIEvent()\fR\& = wx:wx_object()
.br
.fi
.nf

\fBwxUpdateUI()\fR\& = 
.br
    #wxUpdateUI{type = wxUpdateUIEvent:wxUpdateUIEventType()}
.br
.fi
.nf

\fBwxUpdateUIEventType()\fR\& = update_ui
.br
.fi
.SH EXPORTS
.LP
.nf

.B
canUpdate(Window) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Window = wxWindow:wxWindow()
.br
.RE
.RE
.RS
.LP
Returns true if it is appropriate to update (send UI update events to) this window\&.
.LP
This function looks at the mode used (see \fIsetMode/1\fR\&), the wxWS_EX_PROCESS_UI_UPDATES flag in \fIwindow\fR\&, the time update events were last sent in idle time, and the update interval, to determine whether events should be sent to this window now\&. By default this will always return true because the update mode is initially wxUPDATE_UI_PROCESS_ALL and the interval is set to 0; so update events will be sent as often as possible\&. You can reduce the frequency that events are sent by changing the mode and/or setting an update interval\&.
.LP
See: \fIresetUpdateTime/0\fR\&, \fIsetUpdateInterval/1\fR\&, \fIsetMode/1\fR\& 
.RE

.LP
.nf

.B
check(This, Check) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
Check = boolean()
.br
.RE
.RE
.RS
.LP
Check or uncheck the UI element\&.
.RE

.LP
.nf

.B
enable(This, Enable) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
Enable = boolean()
.br
.RE
.RE
.RS
.LP
Enable or disable the UI element\&.
.RE

.LP
.nf

.B
show(This, Show) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
Show = boolean()
.br
.RE
.RE
.RS
.LP
Show or hide the UI element\&.
.RE

.LP
.nf

.B
getChecked(This) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
.RE
.RE
.RS
.LP
Returns true if the UI element should be checked\&.
.RE

.LP
.nf

.B
getEnabled(This) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
.RE
.RE
.RS
.LP
Returns true if the UI element should be enabled\&.
.RE

.LP
.nf

.B
getShown(This) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
.RE
.RE
.RS
.LP
Returns true if the UI element should be shown\&.
.RE

.LP
.nf

.B
getSetChecked(This) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
.RE
.RE
.RS
.LP
Returns true if the application has called \fIcheck/2\fR\&\&.
.LP
For wxWidgets internal use only\&.
.RE

.LP
.nf

.B
getSetEnabled(This) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
.RE
.RE
.RS
.LP
Returns true if the application has called \fIenable/2\fR\&\&.
.LP
For wxWidgets internal use only\&.
.RE

.LP
.nf

.B
getSetShown(This) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
.RE
.RE
.RS
.LP
Returns true if the application has called \fIshow/2\fR\&\&.
.LP
For wxWidgets internal use only\&.
.RE

.LP
.nf

.B
getSetText(This) -> boolean()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
.RE
.RE
.RS
.LP
Returns true if the application has called \fIsetText/2\fR\&\&.
.LP
For wxWidgets internal use only\&.
.RE

.LP
.nf

.B
getText(This) -> unicode:charlist()
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
.RE
.RE
.RS
.LP
Returns the text that should be set for the UI element\&.
.RE

.LP
.nf

.B
getMode() -> wx:wx_enum()
.br
.fi
.br
.RS
.LP
Static function returning a value specifying how wxWidgets will send update events: to all windows, or only to those which specify that they will process the events\&.
.LP
See: \fIsetMode/1\fR\& 
.RE

.LP
.nf

.B
getUpdateInterval() -> integer()
.br
.fi
.br
.RS
.LP
Returns the current interval between updates in milliseconds\&.
.LP
The value -1 disables updates, 0 updates as frequently as possible\&.
.LP
See: \fIsetUpdateInterval/1\fR\& 
.RE

.LP
.nf

.B
resetUpdateTime() -> ok
.br
.fi
.br
.RS
.LP
Used internally to reset the last-updated time to the current time\&.
.LP
It is assumed that update events are normally sent in idle time, so this is called at the end of idle processing\&.
.LP
See: \fIcanUpdate/1\fR\&, \fIsetUpdateInterval/1\fR\&, \fIsetMode/1\fR\& 
.RE

.LP
.nf

.B
setMode(Mode) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
Mode = wx:wx_enum()
.br
.RE
.RE
.RS
.LP
Specify how wxWidgets will send update events: to all windows, or only to those which specify that they will process the events\&.
.RE

.LP
.nf

.B
setText(This, Text) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
This = wxUpdateUIEvent()
.br
Text = unicode:chardata()
.br
.RE
.RE
.RS
.LP
Sets the text for this UI element\&.
.RE

.LP
.nf

.B
setUpdateInterval(UpdateInterval) -> ok
.br
.fi
.br
.RS
.LP
Types:

.RS 3
UpdateInterval = integer()
.br
.RE
.RE
.RS
.LP
Sets the interval between updates in milliseconds\&.
.LP
Set to -1 to disable updates, or to 0 to update as frequently as possible\&. The default is 0\&.
.LP
Use this to reduce the overhead of UI update events if your application has a lot of windows\&. If you set the value to -1 or greater than 0, you may also need to call \fIwxWindow:updateWindowUI/2\fR\& at appropriate points in your application, such as when a dialog is about to be shown\&.
.RE