gObjectGet(obj, ..., drop = T)
"["(obj, value, ...)
gObjectSet(obj, ...)
"["(obj, propNames) <- value
"[["(obj, member, where = parent.frame())
"[["(obj, member) <- value
"$"(x, member)
"$"(obj, member) <- value
gObject(type, ...)
gObjectNew(type, ...)
gObjectSetData(obj, key, data = NULL)
gObjectGetData(obj, key)
gObjectGetSignals(obj)
gObjectGetPropInfo(obj, parents = TRUE, collapse = TRUE)
gTypeGetPropInfo(type)
"names"(x)
interface(obj)
gObjectParentClass(obj)GObjectTRUE to
return the element from the list, instead of the list with just that element.GObjectGObjectGObject for which the property names are to be
retrievedgObjectGet and gObjectGetData, respectively.
gObjectNew returns a new instance of the specified type.
gObjectGetPropInfo and gTypeGetPropInfo return a named list
(or list of lists if collapse is FALSE) of
properties (GParamSpecs) belonging to the GObject type and
its parents (unless parents is FALSE).
gObjectGetSignals gets a list of signal ids with names for the signals supported by the object.
gObjectParentClass returns a pointer to the parent class of the object.
GObject has a type, known as a GType. Like all
object-oriented paradigms, types may be (in this case singly) inherited.
Thus, every GObject has a type that descends from the common
GObject type. GObjects may also implement interfaces. The
interfaces implemented by a particular object may be found in the
interfaces attribute of an R object representing a GObject,
for which, as you might expect, inherits("GObject") returns TRUE.
To conveniently access this attribute, use interface.A GObject is usually constructed with the constructor belonging
to a particular subtype (for example, gtkWindowNew constructs a
GtkWindow). It is also possible to use gObjectNew
to construct an instance of GObject with the given type and properties.
The properties of a GObject are name-value pairs that may be retrieved
and set using gObjectGet and gObjectSet, respectively.
Whenever specifying properties as arguments in RGtk2, name the arguments with
the property name and give the desired property value as the actual argument.
For example, gObjectSet(window, modal = T) to make a window modal. For
convenience, the [.GObject and [<-.GObject functions may be used
to get and set properties, respectively. For example,
window["modal"] <- T. Properties help describe the state of an
object and are convenient for many reasons, including the ability to register
handlers that are invoked when a property changes. They are also associated
with metadata that describe their purpose and allow runtime checking of
constraints, such as the data type or range in the case of a numeric type.
This notification occurs via GObject signals, which are named hooks for
which callbacks may be registered. The event driven system of GTK+ depends on
signals for coordinating objects in response to both user and programmatic events.
You can use gSignalConnect to connect an R function to a signal.
When new GObject classes are defined in R, they may provide additional fields
and methods. [[.GObject and [[<-.GObject get and set, respectively,
those members, depending on permissions: private members are only available
to methods of the defining class, and protected only to subclasses of the
defining class. If [[ fails to find an R-defined member, it searches
for a C field and then a GObject property. [[<- first tries to set a
GObject property before looking
for an R member to ensure that properties are set through the proper channel.
Note that the bindings of public fields and public and protected methods are
locked, so they cannot be changed using [[<-. $<-.GObject serves
as a synonym of [[<-.GObject, but $.GObject first checks for a
function (see $.RGtkObject) before falling back to the behavior
of [[.GObject.
Finally, arbitrary R objects can be stored in a GObject under a specific key
for later retrieval. This can be achieved with gObjectSetData and
gObjectGetData, respectively. This is similar to attributes in R, with
a major difference being that changes occur in the external GObject,
transcending the local R object.
GObjects also offer some introspection capabilities. gObjectGetPropInfo
and gObjectGetSignals provide a list of supported properties and signals, respectively.
names.GObject lists the available properties for an object.
It is hoped that in the future methods and fields may also be introspected.
GType
GSignal