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
These events will work for popup menus as well as menubars. Just before a menu is popped up,
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
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.
See:
This class is derived (and can use functions) from:
wxWidgets docs:
Use
Returns true if it is appropriate to update (send UI update events to) this window.
This function looks at the mode used (see
See:
Check or uncheck the UI element.
Enable or disable the UI element.
Show or hide the UI element.
Returns true if the UI element should be checked.
Returns true if the UI element should be enabled.
Returns true if the UI element should be shown.
Returns true if the application has called
For wxWidgets internal use only.
Returns true if the application has called
For wxWidgets internal use only.
Returns true if the application has called
For wxWidgets internal use only.
Returns true if the application has called
For wxWidgets internal use only.
Returns the text that should be set for the UI element.
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.
See:
Returns the current interval between updates in milliseconds.
The value -1 disables updates, 0 updates as frequently as possible.
See:
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:
Specify how wxWidgets will send update events: to all windows, or only to those which specify that they will process the events.
Sets the text for this UI element.
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