glibmm: Gio::AsyncResult Class Reference

Provides a base class for implementing asynchronous function results. More...

#include </home/kjell/checkout/gnome/glibmm/gio/giomm/asyncresult.h>

Inheritance diagram for Gio::AsyncResult:

Public Member Functions

 AsyncResult (AsyncResult&& src) noexcept
 
AsyncResultoperator= (AsyncResult&& src) noexcept
 
 ~AsyncResult () noexcept override
 
GAsyncResult* gobj ()
 Provides access to the underlying C GObject. More...

 
const GAsyncResult* gobj () const
 Provides access to the underlying C GObject. More...

 
Glib::RefPtr< Glib::ObjectBaseget_source_object_base ()
 
Glib::RefPtr< const Glib::ObjectBaseget_source_object_base () const
 
bool is_tagged (gpointer source_tag) const
 Checks if res has the given source_tag (generally a function pointer indicating the function res was created by). More...

 
- Public Member Functions inherited from Glib::Interface
 Interface ()
 A Default constructor. More...

 
 Interface (Interface&& src) noexcept
 
Interfaceoperator= (Interface&& src) noexcept
 
 Interface (const Glib::Interface_Class& interface_class)
 Called by constructors of derived classes. More...

 
 Interface (GObject* castitem)
 Called by constructors of derived classes. More...

 
 ~Interface () noexcept override
 
 Interface (const Interface&)=delete
 
Interfaceoperator= (const Interface&)=delete
 
GObject* gobj ()
 
const GObject* gobj () const
 
- Public Member Functions inherited from Glib::ObjectBase
 ObjectBase (const ObjectBase&)=delete
 
ObjectBaseoperator= (const ObjectBase&)=delete
 
void set_property_value (const Glib::ustring& property_name, const Glib::ValueBase& value)
 You probably want to use a specific property_*() accessor method instead. More...

 
void get_property_value (const Glib::ustring& property_name, Glib::ValueBase& value) const
 You probably want to use a specific property_*() accessor method instead. More...

 
template<class PropertyType >
void set_property (const Glib::ustring& property_name, const PropertyType& value)
 You probably want to use a specific property_*() accessor method instead. More...

 
template<class PropertyType >
void get_property (const Glib::ustring& property_name, PropertyType& value) const
 You probably want to use a specific property_*() accessor method instead. More...

 
template<class PropertyType >
PropertyType get_property (const Glib::ustring& property_name) const
 You probably want to use a specific property_*() accessor method instead. More...

 
sigc::connection connect_property_changed (const Glib::ustring& property_name, const sigc::slot< void()>& slot)
 You can use the signal_changed() signal of the property proxy instead. More...

 
sigc::connection connect_property_changed (const Glib::ustring& property_name, sigc::slot< void()>&& slot)
 You can use the signal_changed() signal of the property proxy instead. More...

 
void freeze_notify ()
 Increases the freeze count on object. More...

 
void thaw_notify ()
 Reverts the effect of a previous call to freeze_notify(). More...

 
virtual void reference () const
 Increment the reference count for this object. More...

 
virtual void unreference () const
 Decrement the reference count for this object. More...

 
GObject* gobj ()
 Provides access to the underlying C GObject. More...

 
const GObject* gobj () const
 Provides access to the underlying C GObject. More...

 
GObject* gobj_copy () const
 Give a ref-ed copy to someone. Use for direct struct access. More...

 
- Public Member Functions inherited from sigc::trackable
 trackable () noexcept
 
 trackable (const trackable &src) noexcept
 
 trackable (trackable &&src) noexcept
 
 ~trackable ()
 
void add_destroy_notify_callback (notifiable *data, func_destroy_notify func) const
 
void notify_callbacks ()
 
trackableoperator= (const trackable &src)
 
trackableoperator= (trackable &&src) noexcept
 
void remove_destroy_notify_callback (notifiable *data) const
 

Static Public Member Functions

static void add_interface (GType gtype_implementer)
 
static GType get_type ()
 Get the GType for this class, for use with the underlying GObject type system. More...

 

Protected Member Functions

 AsyncResult ()
 You should derive from this class to use it. More...

 
virtual Glib::RefPtr< Glib::ObjectBaseget_source_object_vfunc ()
 
virtual bool is_tagged_vfunc (gpointer source_tag)
 
- Protected Member Functions inherited from Glib::ObjectBase
 ObjectBase ()
 This default constructor is called implicitly from the constructor of user-derived classes, even if, for instance, Gtk::Button calls a different ObjectBase constructor. More...

 
 ObjectBase (const char* custom_type_name)
 A derived constructor always overrides this choice. More...

 
 ObjectBase (const std::type_info& custom_type_info)
 This constructor is a special feature to allow creation of derived types on the fly, without having to use g_object_new() manually. More...

 
 ObjectBase (ObjectBase&& src) noexcept
 
ObjectBaseoperator= (ObjectBase&& src) noexcept
 
virtual ~ObjectBase () noexcept=0
 
void initialize (GObject* castitem)
 
void initialize_move (GObject* castitem, Glib::ObjectBase* previous_wrapper)
 

Related Functions

(Note that these are not member functions.)

Glib::RefPtr< Gio::AsyncResultwrap (GAsyncResult* object, bool take_copy=false)
 A Glib::wrap() method for this object. More...

 

Additional Inherited Members

- Public Types inherited from sigc::trackable
typedef internal::func_destroy_notify func_destroy_notify
 
- Public Types inherited from sigc::notifiable
typedef internal::func_destroy_notify func_destroy_notify
 

Detailed Description

Provides a base class for implementing asynchronous function results.

Asynchronous operations are broken up into two separate operations which are chained together by a SlotAsyncReady. To begin an asynchronous operation, provide a SlotAsyncReady to the asynchronous function. This callback will be triggered when the operation has completed, and will be passed an AsyncResult instance filled with the details of the operation's success or failure, the object the asynchronous function was started for and any error codes returned. The asynchronous callback function is then expected to call the corresponding "_finish()" function with the object the function was called for, and the AsyncResult instance.

The purpose of the "_finish()" function is to take the generic result of type AsyncResult and return the specific result that the operation in question yields (e.g. a FileEnumerator for an "enumerate children" operation). If the result or error status of the operation is not needed, there is no need to call the "_finish()" function and GIO will take care of cleaning up the result and error information after the SlotAsyncReady returns. You may also store the AsyncResult and call "_finish()" later.

Example of a typical asynchronous operation flow:

void _theoretical_frobnitz_async(const Glib::RefPtr<Theoretical>& t,
const SlotAsyncReady& slot);
gboolean _theoretical_frobnitz_finish(const Glib::RefPtr<Theoretical>& t,
const Glib::RefPtr<AsyncResult>& result);
static void
on_frobnitz_result(Glib::RefPtr<AsyncResult>& result)
{
Glib::RefPtr<Glib::Object> source_object = result->get_source_object();
bool success = _theoretical_frobnitz_finish(source_object, res);
if (success)
std::cout << "Hurray" << std::endl;
else
std::cout << "Uh oh!" << std::endl;
...
}
int main (int argc, void *argv[])
{
...
_theoretical_frobnitz_async (theoretical_data,
sigc::ptr_fun(&on_frobnitz_result) );
...
}

The async function could also take an optional Glib::Cancellable object, allowing the calling function to cancel the asynchronous operation.

The callback for an asynchronous operation is called only once, and is always called, even in the case of a cancelled operation. On cancellation, the result is an ERROR_CANCELLED error.

Since glibmm 2.16:

Constructor & Destructor Documentation

Gio::AsyncResult::AsyncResult ( )
protected

You should derive from this class to use it.

Gio::AsyncResult::AsyncResult ( AsyncResult&&  src)
noexcept
Gio::AsyncResult::~AsyncResult ( )
overridenoexcept

Member Function Documentation

static void Gio::AsyncResult::add_interface ( GType  gtype_implementer)
static
Glib::RefPtr<Glib::ObjectBase> Gio::AsyncResult::get_source_object_base ( )
Glib::RefPtr<const Glib::ObjectBase> Gio::AsyncResult::get_source_object_base ( ) const
virtual Glib::RefPtr<Glib::ObjectBase> Gio::AsyncResult::get_source_object_vfunc ( )
protectedvirtual
static GType Gio::AsyncResult::get_type ( )
static

Get the GType for this class, for use with the underlying GObject type system.

GAsyncResult* Gio::AsyncResult::gobj ( )
inline

Provides access to the underlying C GObject.

const GAsyncResult* Gio::AsyncResult::gobj ( ) const
inline

Provides access to the underlying C GObject.

bool Gio::AsyncResult::is_tagged ( gpointer  source_tag) const

Checks if res has the given source_tag (generally a function pointer indicating the function res was created by).

Since glibmm 2.34:
Parameters
source_tagAn application-defined tag.
Returns
true if res has the indicated source_tag, false if not.
virtual bool Gio::AsyncResult::is_tagged_vfunc ( gpointer  source_tag)
protectedvirtual
AsyncResult& Gio::AsyncResult::operator= ( AsyncResult&&  src)
noexcept

Friends And Related Function Documentation

Glib::RefPtr< Gio::AsyncResult > wrap ( GAsyncResult *  object,
bool  take_copy = false 
)
related

A Glib::wrap() method for this object.

Parameters
objectThe C instance.
take_copyFalse if the result should take ownership of the C instance. True if it should take a new copy or ref.
Returns
A C++ instance that wraps this C instance.