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_

Type: GObject

The this argument to watch.

The argument can be NULL.

The data is owned by the caller of the method.

notify

Type: GtkExpressionNotify

Callback to invoke when the expression changes.

user_data

Type: gpointer

User data to pass to the notify callback.

The argument can be NULL.

The data is owned by the caller of the method.

user_destroy

Type: GDestroyNotify

Destroy notify for user_data.

Return value

Type: 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 returned data is owned by the instance.