guiWidgetsToolkit-class {gWidgets2} | R Documentation

## A class to record the toolkit a gui object uses

### Description

A class to record the toolkit a gui object uses

An observer can be observed

Handler is a special observer with obj and actino passed as first argument

Observable class sets up objects that can be observed. Inherited by template

This interface is inherited by the base GComponent classes in the toolkit implementations. The methods defined here are referenced by the S3 methods. For exampe, `svalue` dispatches to `get_value` or `get_index`.

Class for commands. Has methods do, redo, undo

Class for multple commands

A list with ptr. delegates call of do or undo to appropriate command

A reference class to create a model that monitors the global workspace. The class has method `update_state` and the "getting" methods `get_by_class`, `get_by_function` (filter), `get_changes`. Use with a `gtimer` instance to keep up to date with changes to the workspace.

Class for icons

### Arguments

`...` | passed to constructor

### Details

We combine both widget and container methods here. It isn't perfect, but they do share quite a bit. Perhaps, we could make the container class subclass the basic interface.

### Methods

`update(...)`

  Call self.

`update(...)`

  Call self.

`add_observer(o, signal = "DEFAULT")`

  Add an observer. Return id for block/remove/...

`block_observer(id)`

  Block observers. If o missing, block all

`block_observers()`

  Block all observers

`notify_observers(..., signal = "DEFAULT")`

  Call each non-blocked observer

`remove_observer(id)`

  Remove observer

`unblock_observer(id)`

  Unblock observer. If id missing, unblock global block

`unblock_observers()`

  Remove block of all observers. Keeps count, so may need to call again

`add_handler(signal, handler, action, ...)`

  Add a handler to be called for the event indicated by signal

`get_enabled()`

  is widget sensistive to user input

`get_index(drop = NULL, ...)`

  svalue; index=TRUE

`get_value(drop = NULL, ...)`

  Get main value of widget. From 'svalue' when index = FALSE or NULL

`set_enabled(value, ...)`

  specify with logical if widget is sensistive to user input

`set_value(value, ..., drop = NULL)`

  for 'svalue<-' when index = FALSE or NULL

`any_changes(...)`

  Report if any changes

`filter_names(f)`

  Filter the names by f

`get_by_class(classes = character(0))`

  Return objects matching any of classes

`get_by_function(f)`

  Filter objects by function f

`get_changes()`

  Return list of changes

`initialize(...)`

  Initialze state of cached objects

`pop_changes()`

  pop changes, reset

`update_state(...)`

  update cache of names/digests, then notify observers if there are changes

[Package gWidgets2 version 1.0-8 Index]