Class: Wx::UpdateUIEvent

Inherits:
CommandEvent show all
Defined in:
lib/wx/doc/gen/events.rb

Overview

This class is used for pseudo-events which are called by wxWidgets to give an application the chance to update various user interface elements.

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. 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. 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 #check. wxWidgets will determine whether such a call has been made, and which UI element to update. These events will work for popup menus as well as menubars. Just before a menu is popped up, Menu::UpdateUI is called to process any UI events for the window that owns the menu. If you find that the overhead of UI update processing is affecting your application, you can do one or both of the following:

Note that although events are sent in idle time, defining a IdleEvent handler for a window does not affect this because the events are sent from Window#on_internal_idle which is always called in idle time. 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.

Events using this class

The following event-handler methods redirect the events to member method or handler blocks for UpdateUIEvent events. Event handler methods:

Category: Events

See Also:

  • and Event Handling

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from CommandEvent

#client_data, #client_data=, #get_client_data, #get_client_object, #get_int, #get_selection, #get_string, #is_checked, #is_selection, #set_client_data, #set_client_object, #set_extra_long, #set_int, #set_string

Methods inherited from Event

#clone, #get_event_category, #get_event_object, #get_event_type, #get_id, #get_skipped, #get_timestamp, #is_command_event, #resume_propagation, #set_event_object, #set_event_type, #set_id, #set_timestamp, #should_propagate, #skip, #stop_propagation

Methods inherited from Object

#clone, #dup, #is_same_as, #un_share

Constructor Details

#initialize(commandId = 0) ⇒ Wx::UpdateUIEvent

Constructor.

Parameters:

  • commandId (Integer) (defaults to: 0) 


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# File 'lib/wx/doc/gen/events.rb', line 2138

def initialize(commandId=0) end

Class Method Details

.can_update(window) ⇒ Boolean

Returns true if it is appropriate to update (send UI update events to) this window.

This function looks at the mode used (see set_mode), the WS_EX_PROCESS_UI_UPDATES flag in window, 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 Wx::UpdateUIMode::UPDATE_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.

Parameters:

Returns:

  • (Boolean)

See Also:



2230
 
# File 'lib/wx/doc/gen/events.rb', line 2230

def self.can_update(window) end

.get_mode ⇒ Wx::UpdateUIMode

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.

Returns:

See Also:



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# File 'lib/wx/doc/gen/events.rb', line 2237

def self.get_mode; end

.get_update_interval ⇒ Integer

Returns the current interval between updates in milliseconds.

The value -1 disables updates, 0 updates as frequently as possible.

Returns:

  • (Integer)

See Also:



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# File 'lib/wx/doc/gen/events.rb', line 2244

def self.get_update_interval; end

.reset_update_time ⇒ void

This method returns an undefined value.

Used internally to reset the last-updated time to the current time.

It is assumed that update events are normally sent in idle time, so this is called at the end of idle processing.

See Also:



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# File 'lib/wx/doc/gen/events.rb', line 2253

def self.reset_update_time; end

.set_mode(mode) ⇒ void

This method returns an undefined value.

Specify how wxWidgets will send update events: to all windows, or only to those which specify that they will process the events.

Parameters:



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# File 'lib/wx/doc/gen/events.rb', line 2258

def self.set_mode(mode) end

.set_update_interval(updateInterval) ⇒ void

This method returns an undefined value.

Sets the interval between updates in milliseconds.

Set to -1 to disable updates, or to 0 to update as frequently as possible. The default is 0. 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 Window#update_window_ui at appropriate points in your application, such as when a dialog is about to be shown.

Parameters:

  • updateInterval (Integer) 


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# File 'lib/wx/doc/gen/events.rb', line 2266

def self.set_update_interval(updateInterval) end

Instance Method Details

#check(check) ⇒ void

This method returns an undefined value.

Check or uncheck the UI element.

Parameters:

  • check (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2143

def check(check) end

#enable(enable) ⇒ void

This method returns an undefined value.

Enable or disable the UI element.

Parameters:

  • enable (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2148

def enable(enable) end

#get_checked ⇒ Boolean Also known as: checked

Returns true if the UI element should be checked.

Returns:

  • (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2152

def get_checked; end

#get_enabled ⇒ Boolean Also known as: enabled

Returns true if the UI element should be enabled.

Returns:

  • (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2157

def get_enabled; end

#get_set_checked ⇒ Boolean Also known as: set_checked

Returns true if the application has called #check.

For wxWidgets internal use only.

Returns:

  • (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2178

def get_set_checked; end

#get_set_enabled ⇒ Boolean Also known as: set_enabled

Returns true if the application has called #enable.

For wxWidgets internal use only.

Returns:

  • (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2185

def get_set_enabled; end

#get_set_shown ⇒ Boolean Also known as: set_shown

Returns true if the application has called #show.

For wxWidgets internal use only.

Returns:

  • (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2192

def get_set_shown; end

#get_set_text ⇒ Boolean

Returns true if the application has called #set_text.

For wxWidgets internal use only.

Returns:

  • (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2199

def get_set_text; end

#get_shown ⇒ Boolean Also known as: shown

Returns true if the UI element should be shown.

Returns:

  • (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2203

def get_shown; end

#get_text ⇒ String Also known as: text

Returns the text that should be set for the UI element.

Returns:

  • (String) 


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# File 'lib/wx/doc/gen/events.rb', line 2208

def get_text; end

#is_checkable ⇒ Boolean Also known as: checkable?

Returns true if the UI element can be checked.

For the event handlers that can be used for multiple items, not all of which can be checked, this method can be useful to determine whether to call #check on the event object or not, i.e. the main use case for this method is:

def on_update_ui(event)
    ....
    if event.is_checkable
      event.check(...some condition...)
  end

Returns:

  • (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2171

def is_checkable; end

#set_text(text) ⇒ void Also known as: text=

This method returns an undefined value.

Sets the text for this UI element.

Parameters:

  • text (String) 


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# File 'lib/wx/doc/gen/events.rb', line 2214

def set_text(text) end

#show(show) ⇒ void

This method returns an undefined value.

Show or hide the UI element.

Parameters:

  • show (Boolean) 


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# File 'lib/wx/doc/gen/events.rb', line 2220

def show(show) end