gtkmm: Gtk::DragSource Class Reference

Event controller to initiate DND operations. More...

#include <gtkmm/dragsource.h>

Inheritance diagram for Gtk::DragSource:

[legend]

Public Member Functions
	DragSource (DragSource &&src) noexcept

DragSource &	operator= (DragSource &&src) noexcept

	~DragSource () noexcept override

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

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

GtkDragSource *	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

void	set_content (const Glib::RefPtr< Gdk::ContentProvider > &content)
	Sets a content provider on a `Gtk::DragSource`.

Glib::RefPtr< Gdk::ContentProvider >	get_content ()
	Gets the current content provider of a `Gtk::DragSource`.

Glib::RefPtr< const Gdk::ContentProvider >	get_content () const
	Gets the current content provider of a `Gtk::DragSource`.

void	set_actions (Gdk::DragAction actions)
	Sets the actions on the `Gtk::DragSource`.

Gdk::DragAction	get_actions () const
	Gets the actions that are currently set on the `Gtk::DragSource`.

void	set_icon (const Glib::RefPtr< const Gdk::Paintable > &paintable, int hot_x, int hot_y)
	Sets a paintable to use as icon during DND operations.

void	drag_cancel ()
	Cancels a currently ongoing drag operation.

Glib::RefPtr< Gdk::Drag >	get_drag ()
	Returns the underlying `Gdk::Drag` object for an ongoing drag.

Glib::RefPtr< const Gdk::Drag >	get_drag () const
	Returns the underlying `Gdk::Drag` object for an ongoing drag.

Glib::PropertyProxy< Glib::RefPtr< Gdk::ContentProvider > >	property_content ()
	The data that is offered by drag operations from this source.

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Gdk::ContentProvider > >	property_content () const
	The data that is offered by drag operations from this source.

Glib::PropertyProxy< Gdk::DragAction >	property_actions ()
	The actions that are supported by drag operations from the source.

Glib::PropertyProxy_ReadOnly< Gdk::DragAction >	property_actions () const
	The actions that are supported by drag operations from the source.

Glib::SignalProxy< Glib::RefPtr< Gdk::ContentProvider >(double, double)>	signal_prepare ()
	Only one signal handler is called.

Glib::SignalProxy< void(const Glib::RefPtr< Gdk::Drag > &)>	signal_drag_begin ()

Glib::SignalProxy< void(const Glib::RefPtr< Gdk::Drag > &, bool)>	signal_drag_end ()

Glib::SignalProxy< bool(const Glib::RefPtr< Gdk::Drag > &, Gdk::DragCancelReason)>	signal_drag_cancel ()

Public Member Functions inherited from Gtk::GestureSingle
	GestureSingle (GestureSingle &&src) noexcept

GestureSingle &	operator= (GestureSingle &&src) noexcept

	~GestureSingle () noexcept override

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

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

GtkGestureSingle *	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

bool	get_touch_only () const
	Returns `true` if the gesture is only triggered by touch events.

void	set_touch_only (bool touch_only=true)
	Sets whether to handle only touch events.

bool	get_exclusive () const
	Gets whether a gesture is exclusive.

void	set_exclusive (bool exclusive=true) const
	Sets whether gesture is exclusive.

unsigned int	get_button () const
	Returns the button number gesture listens for.

void	set_button (unsigned int button=0)
	Sets the button number gesture listens to.

unsigned int	get_current_button () const
	Returns the button number currently interacting with gesture, or 0 if there is none.

Gdk::EventSequence *	get_current_sequence ()
	Returns the event sequence currently interacting with gesture.

const Gdk::EventSequence *	get_current_sequence () const
	Returns the event sequence currently interacting with gesture.

Glib::PropertyProxy< bool >	property_touch_only ()
	Whether the gesture handles only touch events.

Glib::PropertyProxy_ReadOnly< bool >	property_touch_only () const
	Whether the gesture handles only touch events.

Glib::PropertyProxy< bool >	property_exclusive ()
	Whether the gesture is exclusive.

Glib::PropertyProxy_ReadOnly< bool >	property_exclusive () const
	Whether the gesture is exclusive.

Glib::PropertyProxy< unsigned int >	property_button ()
	Mouse button number to listen to, or 0 to listen for any button.

Glib::PropertyProxy_ReadOnly< unsigned int >	property_button () const
	Mouse button number to listen to, or 0 to listen for any button.

Public Member Functions inherited from Gtk::Gesture
	Gesture (Gesture &&src) noexcept

Gesture &	operator= (Gesture &&src) noexcept

	~Gesture () noexcept override

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

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

GtkGesture *	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

Glib::RefPtr< Gdk::Device >	get_device ()
	Returns the logical `Gdk::Device` that is currently operating on gesture.

Glib::RefPtr< const Gdk::Device >	get_device () const
	Returns the logical `Gdk::Device` that is currently operating on gesture.

bool	set_state (EventSequenceState state)
	Sets the state of all sequences that gesture is currently interacting with.

EventSequenceState	get_sequence_state (Gdk::EventSequence *sequence) const
	Returns the sequence state, as seen by gesture.

bool	set_sequence_state (Gdk::EventSequence *sequence, EventSequenceState state)
	Sets the state of sequence in gesture.

std::vector< const Gdk::EventSequence * >	get_sequences () const
	Returns the list of Gdk::EventSequences currently being interpreted.

Gdk::EventSequence *	get_last_updated_sequence ()
	Returns the `Gdk::EventSequence` that was last updated on gesture.

const Gdk::EventSequence *	get_last_updated_sequence () const
	Returns the `Gdk::EventSequence` that was last updated on gesture.

bool	handles_sequence (Gdk::EventSequence *sequence) const
	Returns `true` if gesture is currently handling events corresponding to sequence.

Glib::RefPtr< Gdk::Event >	get_last_event (Gdk::EventSequence *sequence)
	Returns the last event that was processed for sequence.

Glib::RefPtr< const Gdk::Event >	get_last_event (Gdk::EventSequence *sequence) const
	Returns the last event that was processed for sequence.

bool	get_point (Gdk::EventSequence *sequence, double &x, double &y) const
	If sequence is currently being interpreted by gesture, returns `true` and fills in x and y with the last coordinates stored for that event sequence.

bool	get_bounding_box (Gdk::Rectangle &rect) const
	If there are touch sequences being currently handled by gesture, returns `true` and fills in rect with the bounding box containing all active touches.

bool	get_bounding_box_center (double &x, double &y) const
	If there are touch sequences being currently handled by gesture, returns `true` and fills in x and y with the center of the bounding box containing all active touches.

bool	is_active () const
	Returns `true` if the gesture is currently active.

bool	is_recognized () const
	Returns `true` if the gesture is currently recognized.

void	group (const Glib::RefPtr< Gesture > &group_gesture)
	Adds gesture to the same group than group_gesture.

void	ungroup ()
	Separates gesture into an isolated group.

std::vector< Glib::RefPtr< Gesture > >	get_group ()
	Returns all gestures in the group of gesture.

std::vector< Glib::RefPtr< const Gesture > >	get_group () const
	Returns all gestures in the group of gesture.

bool	is_grouped_with (const Glib::RefPtr< Gesture > &other) const
	Returns `true` if both gestures pertain to the same group.

Glib::SignalProxy< void(Gdk::EventSequence *)>	signal_begin ()

Glib::SignalProxy< void(Gdk::EventSequence *)>	signal_end ()

Glib::SignalProxy< void(Gdk::EventSequence *)>	signal_update ()

Glib::SignalProxy< void(Gdk::EventSequence *)>	signal_cancel ()

Glib::SignalProxy< void(Gdk::EventSequence *, EventSequenceState)>	signal_sequence_state_changed ()

Glib::PropertyProxy_ReadOnly< unsigned int >	property_n_points () const
	The number of touch points that trigger recognition on this gesture.

Public Member Functions inherited from Gtk::EventController
	EventController (EventController &&src) noexcept

EventController &	operator= (EventController &&src) noexcept

	~EventController () noexcept override

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

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

GtkEventController *	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

Widget *	get_widget ()
	Returns the `Gtk::Widget` this controller relates to.

const Widget *	get_widget () const
	Returns the `Gtk::Widget` this controller relates to.

void	reset ()
	Resets the controller to a clean state.

PropagationPhase	get_propagation_phase () const
	Gets the propagation phase at which controller handles events.

void	set_propagation_phase (PropagationPhase phase)
	Sets the propagation phase at which a controller handles events.

PropagationLimit	get_propagation_limit () const
	Gets the propagation limit of the event controller.

void	set_propagation_limit (PropagationLimit limit)
	Sets the event propagation limit on the event controller.

Glib::ustring	get_name () const
	Gets the name of controller.

void	set_name (const Glib::ustring & name)
	Sets a name on the controller that can be used for debugging.

Glib::RefPtr< const Gdk::Event >	get_current_event () const
	Returns the event that is currently being handled by the controller.

guint32	get_current_event_time () const
	Returns the timestamp of the event that is currently being handled by the controller.

Glib::RefPtr< Gdk::Device >	get_current_event_device ()
	Returns the device of the event that is currently being handled by the controller.

Glib::RefPtr< const Gdk::Device >	get_current_event_device () const
	Returns the event that is currently being handled by the controller.

Gdk::ModifierType	get_current_event_state () const
	Returns the modifier state of the event that is currently being handled by the controller.

Glib::PropertyProxy_ReadOnly< Widget * >	property_widget () const
	The widget receiving the `Gdk::Events` that the controller will handle.

Glib::PropertyProxy< PropagationPhase >	property_propagation_phase ()
	The propagation phase at which this controller will handle events.

Glib::PropertyProxy_ReadOnly< PropagationPhase >	property_propagation_phase () const
	The propagation phase at which this controller will handle events.

Glib::PropertyProxy< PropagationLimit >	property_propagation_limit ()
	The limit for which events this controller will handle.

Glib::PropertyProxy_ReadOnly< PropagationLimit >	property_propagation_limit () const
	The limit for which events this controller will handle.

Glib::PropertyProxy< Glib::ustring >	property_name ()
	The name for this controller, typically used for debugging purposes.

Glib::PropertyProxy_ReadOnly< Glib::ustring >	property_name () const
	The name for this controller, typically used for debugging purposes.

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

static Glib::RefPtr< DragSource >	create ()

Static Public Member Functions inherited from Gtk::GestureSingle
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Static Public Member Functions inherited from Gtk::Gesture
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Static Public Member Functions inherited from Gtk::EventController
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Protected Member Functions
	DragSource ()

Protected Member Functions inherited from Gtk::GestureSingle
	GestureSingle ()
	There is no create() method that corresponds to this constructor, because only derived classes shall be created.

Protected Member Functions inherited from Gtk::Gesture
	Gesture ()
	There is no create() method that corresponds to this constructor, because only derived classes shall be created.

Protected Member Functions inherited from Gtk::EventController
	EventController ()
	There is no create() method that corresponds to this constructor, because only derived classes shall be created.

Related Symbols
(Note that these are not member symbols.)
Glib::RefPtr< Gtk::DragSource >	wrap (GtkDragSource *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Related Symbols inherited from Gtk::GestureSingle
Glib::RefPtr< Gtk::GestureSingle >	wrap (GtkGestureSingle *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Related Symbols inherited from Gtk::Gesture
Glib::RefPtr< Gtk::Gesture >	wrap (GtkGesture *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Related Symbols inherited from Gtk::EventController
Glib::RefPtr< Gtk::EventController >	wrap (GtkEventController *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

Event controller to initiate DND operations.

Gtk::DragSource is an auxiliary object that is used to initiate Drag-And-Drop operations. It can be set up with the necessary ingredients for a DND operation ahead of time. This includes the source for the data that is being transferred, in the form of a Gdk::ContentProvider, the desired action, and the icon to use during the drag operation. After setting it up, the drag source must be added to a widget as an event controller, using Gtk::Widget::add_controller().

Setting up the content provider and icon ahead of time only makes sense when the data does not change. More commonly, you will want to set them up just in time. To do so, Gtk::DragSource has signal_prepare() and signal_drag_begin(). The prepare signal is emitted before a drag is started, and can be used to set the content provider and actions that the drag should be started with. The drag-begin signal is emitted after the Gdk::Drag object has been created, and can be used to set up the drag icon.

During the DND operation, Gtk::DragSource emits signals that can be used to obtain updates about the status of the operation, but it is not normally necessary to connect to any signals, except for one case: when the supported actions include Gdk::DragAction::MOVE, you need to listen for signal_drag_end() and delete the data after it has been transferred.

Since gtkmm 3.96:

Constructor & Destructor Documentation

◆ DragSource() [1/2]

Gtk::DragSource::DragSource ( DragSource && src )

noexcept

◆ ~DragSource()

Gtk::DragSource::~DragSource ( )

overridenoexcept

◆ DragSource() [2/2]

Gtk::DragSource::DragSource ( )

protected

Member Function Documentation

◆ create()

static Glib::RefPtr< DragSource > Gtk::DragSource::create ( )

static

◆ drag_cancel()

void Gtk::DragSource::drag_cancel ( )

Cancels a currently ongoing drag operation.

◆ get_actions()

Gdk::DragAction Gtk::DragSource::get_actions ( ) const

Gets the actions that are currently set on the Gtk::DragSource.

Returns: The actions set on source.

◆ get_content() [1/2]

Glib::RefPtr< Gdk::ContentProvider > Gtk::DragSource::get_content ( )

Gets the current content provider of a Gtk::DragSource.

Returns: The Gdk::ContentProvider of source.

◆ get_content() [2/2]

Glib::RefPtr< const Gdk::ContentProvider > Gtk::DragSource::get_content ( ) const

Gets the current content provider of a Gtk::DragSource.

Returns: The Gdk::ContentProvider of source.

◆ get_drag() [1/2]

Glib::RefPtr< Gdk::Drag > Gtk::DragSource::get_drag ( )

Returns the underlying Gdk::Drag object for an ongoing drag.

Returns: The Gdk::Drag of the current drag operation.

◆ get_drag() [2/2]

Glib::RefPtr< const Gdk::Drag > Gtk::DragSource::get_drag ( ) const

Returns the underlying Gdk::Drag object for an ongoing drag.

Returns: The Gdk::Drag of the current drag operation.

◆ get_type()

static GType Gtk::DragSource::get_type ( )

static

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

◆ gobj() [1/2]

GtkDragSource * Gtk::DragSource::gobj ( )

inline

Provides access to the underlying C GObject.

◆ gobj() [2/2]

const GtkDragSource * Gtk::DragSource::gobj ( ) const

inline

Provides access to the underlying C GObject.

◆ gobj_copy()

GtkDragSource * Gtk::DragSource::gobj_copy ( )

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

◆ operator=()

DragSource & Gtk::DragSource::operator= ( DragSource && src )

noexcept

◆ property_actions() [1/2]

Glib::PropertyProxy< Gdk::DragAction > Gtk::DragSource::property_actions ( )

The actions that are supported by drag operations from the source.

Note that you must handle the signal_drag_end() signal if the actions include Gdk::DragAction::MOVE.

Default value: Gdk::DragAction::COPY

Returns: A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

◆ property_actions() [2/2]

Glib::PropertyProxy_ReadOnly< Gdk::DragAction > Gtk::DragSource::property_actions ( ) const

The actions that are supported by drag operations from the source.

Note that you must handle the signal_drag_end() signal if the actions include Gdk::DragAction::MOVE.

Default value: Gdk::DragAction::COPY

Returns: A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ property_content() [1/2]

Glib::PropertyProxy< Glib::RefPtr< Gdk::ContentProvider > > Gtk::DragSource::property_content ( )

The data that is offered by drag operations from this source.

Returns: A PropertyProxy that allows you to get or set the value of the property, or receive notification when the value of the property changes.

◆ property_content() [2/2]

Glib::PropertyProxy_ReadOnly< Glib::RefPtr< Gdk::ContentProvider > > Gtk::DragSource::property_content ( ) const

The data that is offered by drag operations from this source.

Returns: A PropertyProxy_ReadOnly that allows you to get the value of the property, or receive notification when the value of the property changes.

◆ set_actions()

void Gtk::DragSource::set_actions ( Gdk::DragAction actions )

Sets the actions on the Gtk::DragSource.

During a DND operation, the actions are offered to potential drop targets. If actions include Gdk::DragAction::MOVE, you need to listen to the signal_drag_end() signal and handle delete_data being true.

This function can be called before a drag is started, or in a handler for the signal_prepare() signal.

Parameters

actions The actions to offer.

◆ set_content()

void Gtk::DragSource::set_content ( const Glib::RefPtr< Gdk::ContentProvider > & content )

Sets a content provider on a Gtk::DragSource.

When the data is requested in the cause of a DND operation, it will be obtained from the content provider.

This function can be called before a drag is started, or in a handler for the signal_prepare() signal.

You may consider setting the content provider back to nullptr in a signal_drag_end() signal handler.

Parameters

content A Gdk::ContentProvider.

◆ set_icon()

void Gtk::DragSource::set_icon	(	const Glib::RefPtr< const Gdk::Paintable > &	paintable,
		int	hot_x,
		int	hot_y
	)

Sets a paintable to use as icon during DND operations.

The hotspot coordinates determine the point on the icon that gets aligned with the hotspot of the cursor.

If paintable is nullptr, a default icon is used.

This function can be called before a drag is started, or in a signal_prepare() or signal_drag_begin() signal handler.

Parameters

paintable	The `Gdk::Paintable` to use as icon.
hot_x	The hotspot X coordinate on the icon.
hot_y	The hotspot Y coordinate on the icon.

◆ signal_drag_begin()

Glib::SignalProxy< void(const Glib::RefPtr< Gdk::Drag > &)> Gtk::DragSource::signal_drag_begin ( )

Slot Prototype:: void on_my_drag_begin(const Glib::RefPtr<Gdk::Drag>& drag)

Flags: Run Last

Emitted on the drag source when a drag is started.

It can be used to e.g. set a custom drag icon with Gtk::DragSource::set_icon().

Parameters

drag	The `Gdk::Drag` object.

◆ signal_drag_cancel()

Glib::SignalProxy< bool(const Glib::RefPtr< Gdk::Drag > &, Gdk::DragCancelReason)> Gtk::DragSource::signal_drag_cancel ( )

Slot Prototype:: bool on_my_drag_cancel(const Glib::RefPtr<Gdk::Drag>& drag, Gdk::DragCancelReason reason)

Flags: Run Last

Emitted on the drag source when a drag has failed.

The signal handler may handle a failed drag operation based on the type of error. It should return true if the failure has been handled and the default "drag operation failed" animation should not be shown.

Parameters

drag	The `Gdk::Drag` object.
reason	Information on why the drag failed.

Returns: true if the failed drag operation has been already handled.

◆ signal_drag_end()

Glib::SignalProxy< void(const Glib::RefPtr< Gdk::Drag > &, bool)> Gtk::DragSource::signal_drag_end ( )

Slot Prototype:: void on_my_drag_end(const Glib::RefPtr<Gdk::Drag>& drag, bool delete_data)

Flags: Run Last

Emitted on the drag source when a drag is finished.

A typical reason to connect to this signal is to undo things done in signal_prepare() or signal_drag_begin() handlers.

Parameters

drag	The `Gdk::Drag` object.
delete_data	`true` if the drag was performing Gdk::DragAction::MOVE, and the data should be deleted.

◆ signal_prepare()

Glib::SignalProxy< Glib::RefPtr< Gdk::ContentProvider >(double, double)> Gtk::DragSource::signal_prepare ( )

Only one signal handler is called.

If you connect a handler, it must be called before (instead of) the default handler, otherwise it won't be called. Set the after parameter in connect() to false.

Slot Prototype:: Glib::RefPtr<Gdk::ContentProvider> on_my_prepare(double x, double y)

Flags: Run Last

Emitted when a drag is about to be initiated.

It returns the Gdk::ContentProvider to use for the drag that is about to start. The default handler for this signal returns the value of the property_content() property, so if you set up that property ahead of time, you don't need to connect to this signal.

Parameters

x	The X coordinate of the drag starting point.
y	The Y coordinate of the drag starting point.

Returns: A Gdk::ContentProvider.

Friends And Related Symbol Documentation

◆ wrap()

Glib::RefPtr< Gtk::DragSource > wrap	(	GtkDragSource *	object,
		bool	take_copy = `false`
	)

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

Parameters

object	The C instance.
take_copy	False 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.

Public Member Functions

Static Public Member Functions

Protected Member Functions

Related Symbols

Detailed Description

Constructor & Destructor Documentation

◆ DragSource() [1/2]

◆ ~DragSource()

◆ DragSource() [2/2]

Member Function Documentation

◆ create()

◆ drag_cancel()

◆ get_actions()

◆ get_content() [1/2]

◆ get_content() [2/2]

◆ get_drag() [1/2]

◆ get_drag() [2/2]

◆ get_type()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ operator=()

◆ property_actions() [1/2]

◆ property_actions() [2/2]

◆ property_content() [1/2]

◆ property_content() [2/2]

◆ set_actions()

◆ set_content()

◆ set_icon()

◆ signal_drag_begin()

◆ signal_drag_cancel()

◆ signal_drag_end()

◆ signal_prepare()

Friends And Related Symbol Documentation

◆ wrap()