will cause the property named "property-b" of @object2 to be updated
every time method@GObject.set or the specific accessor changes the value of
the property "property-a" of @object1.
It is possible to create a bidirectional binding between two properties
of two gobject.object.ObjectG instances, so that if either property changes, the
other is updated as well, for instance:
It is also possible to set a custom transformation function (in both
directions, in case of a bidirectional binding) to apply a custom
transformation from the source value to the target value before
applying it; for instance, the following binding:
will keep the "value" property of the two adjustments in sync; the
@celsius_to_fahrenheit function will be called whenever the "value"
property of @adjustment1 changes and will transform the current value
of the property before applying it to the "value" property of @adjustment2.
Vice versa, the @fahrenheit_to_celsius function will be called whenever
the "value" property of @adjustment2 changes, and will transform the
current value of the property before applying it to the "value" property
of @adjustment1.
Note that #GBinding does not resolve cycles by itself; a cycle like
might lead to an infinite loop. The loop, in this particular case,
can be avoided if the objects emit the GObject::notify signal only
if the value has effectively been changed. A binding is implemented
using the GObject::notify signal, so it is susceptible to all the
various ways of blocking a signal emission, like func@GObject.signal_stop_emission
or func@GObject.signal_handler_block.
A binding will be severed, and the resources it allocates freed, whenever
either one of the gobject.object.ObjectG instances it refers to are finalized, or when
the #GBinding instance loses its last reference.
Bindings for languages with garbage collection can use
gobject.binding.Binding.unbind to explicitly release a binding between the source
and target properties, instead of relying on the last reference on the
binding, source, and target instances to drop.
gobject.object.ObjectG instance (or source) and another property on another gobject.object.ObjectG instance (or target).
Whenever the source property changes, the same value is applied to the target property; for instance, the following binding:
will cause the property named "property-b" of @object2 to be updated every time method@GObject.set or the specific accessor changes the value of the property "property-a" of @object1.
It is possible to create a bidirectional binding between two properties of two gobject.object.ObjectG instances, so that if either property changes, the other is updated as well, for instance:
will keep the two properties in sync.
It is also possible to set a custom transformation function (in both directions, in case of a bidirectional binding) to apply a custom transformation from the source value to the target value before applying it; for instance, the following binding:
will keep the "value" property of the two adjustments in sync; the @celsius_to_fahrenheit function will be called whenever the "value" property of @adjustment1 changes and will transform the current value of the property before applying it to the "value" property of @adjustment2.
Vice versa, the @fahrenheit_to_celsius function will be called whenever the "value" property of @adjustment2 changes, and will transform the current value of the property before applying it to the "value" property of @adjustment1.
Note that #GBinding does not resolve cycles by itself; a cycle like
might lead to an infinite loop. The loop, in this particular case, can be avoided if the objects emit the GObject::notify signal only if the value has effectively been changed. A binding is implemented using the GObject::notify signal, so it is susceptible to all the various ways of blocking a signal emission, like func@GObject.signal_stop_emission or func@GObject.signal_handler_block.
A binding will be severed, and the resources it allocates freed, whenever either one of the gobject.object.ObjectG instances it refers to are finalized, or when the #GBinding instance loses its last reference.
Bindings for languages with garbage collection can use gobject.binding.Binding.unbind to explicitly release a binding between the source and target properties, instead of relying on the last reference on the binding, source, and target instances to drop.