Method

GtkExpressionwatch

Declaration [src]

GtkExpressionWatch*
gtk_expression_watch (
  GtkExpression* self,
  GObject* this_,
  GtkExpressionNotify notify,
  gpointer user_data,
  GDestroyNotify user_destroy
)

Description [src]

Watch the given expression for changes.

The notify function will be called whenever the evaluation of self may have changed.

GTK cannot guarantee that the evaluation did indeed change when the notify gets invoked, but it guarantees the opposite: When it did in fact change, the notify will be invoked.

Parameters

`this_`	`GObject`
	The `this` argument to watch.
	The argument can be `NULL`.
	The data is owned by the caller of the function.
`notify`	`GtkExpressionNotify`
	Callback to invoke when the expression changes.
`user_data`	`gpointer`
	User data to pass to the `notify` callback.
	The argument can be `NULL`.
	The data is owned by the caller of the function.
`user_destroy`	`GDestroyNotify`
	Destroy notify for `user_data`

Return value

Returns:	`GtkExpressionWatch`
	The newly installed watch. Note that the only reference held to the watch will be released when the watch is unwatched which can happen automatically, and not just via `gtk_expression_watch_unwatch()`. You should call `gtk_expression_watch_ref()` if you want to keep the watch around.
	The data is owned by the instance.