gtkmm: Gdk::Event Class Reference

Functions for handling events from the window system. More...

#include <gdkmm/event.h>

Public Types
enum class	Type { Type::DELETE , Type::MOTION_NOTIFY , Type::BUTTON_PRESS , Type::BUTTON_RELEASE , Type::KEY_PRESS , Type::KEY_RELEASE , Type::ENTER_NOTIFY , Type::LEAVE_NOTIFY , Type::FOCUS_CHANGE , Type::PROXIMITY_IN , Type::PROXIMITY_OUT , Type::DRAG_ENTER , Type::DRAG_LEAVE , Type::DRAG_MOTION , Type::DROP_START , Type::SCROLL , Type::GRAB_BROKEN , Type::TOUCH_BEGIN , Type::TOUCH_UPDATE , Type::TOUCH_END , Type::TOUCH_CANCEL , Type::TOUCHPAD_SWIPE , Type::TOUCHPAD_PINCH , Type::PAD_BUTTON_PRESS , Type::PAD_BUTTON_RELEASE , Type::PAD_RING , Type::PAD_STRIP , Type::PAD_GROUP_MODE , Type::TOUCHPAD_HOLD , Type::EVENT_LAST }
	Specifies the type of the event. More...

Public Member Functions
void	reference () const
	Increment the reference count for this object. More...

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

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

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

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

	Event ()=delete

	Event (const Event &)=delete

Event &	operator= (const Event &)=delete

Type	get_event_type () const
	Retrieves the type of the event. More...

Glib::RefPtr< Surface >	get_surface ()
	Extracts the surface associated with an event. More...

Glib::RefPtr< const Surface >	get_surface () const
	Extracts the surface associated with an event. More...

Glib::RefPtr< Seat >	get_seat ()
	Returns the seat that originated the event. More...

Glib::RefPtr< const Seat >	get_seat () const
	Returns the seat that originated the event. More...

Glib::RefPtr< Device >	get_device ()
	Returns the device of an event. More...

Glib::RefPtr< const Device >	get_device () const
	Returns the device of an event. More...

Glib::RefPtr< DeviceTool >	get_device_tool ()
	Returns a `Gdk::DeviceTool` representing the tool that caused the event. More...

Glib::RefPtr< const DeviceTool >	get_device_tool () const
	Returns a `Gdk::DeviceTool` representing the tool that caused the event. More...

guint32	get_time () const
	Returns the timestamp of event. More...

Glib::RefPtr< Display >	get_display ()
	Retrieves the display associated to the event. More...

Glib::RefPtr< const Display >	get_display () const
	Retrieves the display associated to the event. More...

const EventSequence *	get_event_sequence () const
	Returns the event sequence to which the event belongs. More...

ModifierType	get_modifier_state () const
	Returns the modifier state field of an event. More...

bool	get_position (double & x, double & y) const
	Extract the event surface relative x/y coordinates from an event. More...

std::vector< double >	get_axes () const
	Extracts all axis values from an event. More...

bool	get_axis (Gdk::AxisUse axis_use, double & value) const
	Extract the axis value for a particular axis use from an event structure. More...

bool	get_pointer_emulated () const
	Returns whether this event is an 'emulated' pointer event. More...

guint	get_button () const
	Extract the button number from a button event. More...

ScrollDirection	get_direction () const
	Extracts the direction of a scroll event. More...

void	get_deltas (double & delta_x, double & delta_y) const
	Extracts the scroll deltas of a scroll event. More...

ScrollUnit	get_scroll_unit () const
	Extracts the scroll delta unit of a scroll event. More...

bool	is_scroll_stop () const
	Check whether a scroll event is a stop scroll event. More...

guint	get_keyval () const
	Extracts the keyval from a key event. More...

guint	get_keycode () const
	Extracts the keycode from a key event. More...

ModifierType	get_consumed_modifiers () const
	Extracts the consumed modifiers from a key event. More...

guint	get_layout () const
	Extracts the layout from a key event. More...

guint	get_level () const
	Extracts the shift level from a key event. More...

bool	is_modifier () const
	Extracts whether the key event is for a modifier key. More...

bool	get_focus_in () const
	Extracts whether this event is about focus entering or leaving the surface. More...

bool	get_touch_emulating_pointer () const
	Extracts whether a touch event is emulating a pointer event. More...

CrossingMode	get_crossing_mode () const
	Extracts the crossing mode from a crossing event. More...

NotifyType	get_crossing_detail () const
	Extracts the notify detail from a crossing event. More...

bool	get_crossing_focus () const
	Checks if the event surface is the focus surface. More...

TouchpadGesturePhase	get_touchpad_gesture_phase () const
	Extracts the touchpad gesture phase from a touchpad event. More...

guint	get_touchpad_n_fingers () const
	Extracts the number of fingers from a touchpad event. More...

void	get_touchpad_deltas (double & dx, double & dy) const
	Extracts delta information from a touchpad event. More...

double	get_touchpad_pinch_angle_delta () const
	Extracts the angle delta from a touchpad pinch event. More...

double	get_touchpad_pinch_scale () const
	Extracts the scale from a touchpad pinch event. More...

guint	get_pad_button () const
	Extracts information about the pressed button from a pad event. More...

void	get_pad_axis_value (guint & index, double & value) const
	Extracts the information from a pad strip or ring event. More...

void	get_pad_group_mode (guint & group, guint & mode) const
	Extracts group and mode information from a pad event. More...

Glib::RefPtr< Drop >	get_dnd_drop ()
	Gets the `Gdk::Drop` object from a DND event. More...

Glib::RefPtr< const Drop >	get_dnd_drop () const
	Gets the `Gdk::Drop` object from a DND event. More...

Glib::RefPtr< Surface >	get_grab_broken_grab_surface ()
	Extracts the grab surface from a grab broken event. More...

Glib::RefPtr< const Surface >	get_grab_broken_grab_surface () const
	Extracts the grab surface from a grab broken event. More...

bool	get_grab_broken_implicit () const
	Checks whether the grab broken event is for an implicit grab. More...

std::vector< TimeCoord >	get_history () const
	Retrieves the history of the event, as a vector of time and coordinates. More...

bool	triggers_context_menu () const
	Returns whether a `Gdk::Event` should trigger a context menu, according to platform conventions. More...

bool	get_distance (const Glib::RefPtr< const Event > & event2, double &distance) const
	Returns the distance between the event locations. More...

bool	get_angle (const Glib::RefPtr< const Event > & event2, double & angle) const
	Returns the relative angle from event1 to event2. More...

bool	get_center (const Glib::RefPtr< const Event > & event2, double & x, double & y) const
	Returns the point halfway between the events' positions. More...

KeyMatch	matches (guint keyval, ModifierType modifiers) const
	Matches a key event against a keyval and modifiers. More...

bool	get_match (guint & keyval, ModifierType & modifiers) const
	Gets a keyval and modifier combination that will match the event. More...

Protected Member Functions
void	operator delete (void *, std::size_t)

Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gdk::Event >	wrap (GdkEvent * object, bool take_copy=false)
	A Glib::wrap() method for this object. More...

Detailed Description

Functions for handling events from the window system.

In GTK applications the events are handled automatically by toplevel widgets and passed on to the event controllers of appropriate widgets, so these functions are rarely needed.

Key values are the codes which are sent whenever a key is pressed or released. The complete list of key values can be found in the gdk/gdkkeysyms.h header file. They are prefixed with GDK_KEY_.

Constructor & Destructor Documentation

◆ Event() [1/2]

Gdk::Event::Event ( )

delete

◆ Event() [2/2]

Gdk::Event::Event ( const Event & )

delete

Member Function Documentation

◆ get_angle()

bool Gdk::Event::get_angle	(	const Glib::RefPtr< const Event > &	event2,
		double &	angle
	)		const

Returns the relative angle from event1 to event2.

The relative angle is the angle between the X axis and the line through both events' positions. The rotation direction for positive angles is from the positive X axis towards the positive Y axis.

This assumes that both events have X/Y information. If not, this function returns false.

Parameters

event2	Second `Gdk::Event`.
angle	Return location for the relative angle between both events.

Returns: true if the angle could be calculated.

◆ get_axes()

std::vector< double > Gdk::Event::get_axes ( ) const

Extracts all axis values from an event.

Returns: A vector of values for all axes. An empty vector in case of failure.

◆ get_axis()

bool Gdk::Event::get_axis	(	Gdk::AxisUse	axis_use,
		double &	value
	)		const

Extract the axis value for a particular axis use from an event structure.

To find out which axes are used, use Gdk::DeviceTool::get_axes() on the device tool returned by get_device_tool().

Parameters

axis_use	The axis use to look for.
value	Location to store the value found.

Returns: true if the specified axis was found, otherwise false.

◆ get_button()

guint Gdk::Event::get_button ( ) const

Extract the button number from a button event.

Returns: The button of event.

◆ get_center()

bool Gdk::Event::get_center	(	const Glib::RefPtr< const Event > &	event2,
		double &	x,
		double &	y
	)		const

Returns the point halfway between the events' positions.

This assumes that both events have X/Y information. If not, this function returns false.

Parameters

event2	Second `Gdk::Event`.
x	Return location for the X coordinate of the center.
y	Return location for the Y coordinate of the center.

Returns: true if the center could be calculated.

◆ get_consumed_modifiers()

ModifierType Gdk::Event::get_consumed_modifiers ( ) const

Extracts the consumed modifiers from a key event.

Returns: The consumed modifiers or event.

◆ get_crossing_detail()

NotifyType Gdk::Event::get_crossing_detail ( ) const

Extracts the notify detail from a crossing event.

Returns: The notify detail of event.

◆ get_crossing_focus()

bool Gdk::Event::get_crossing_focus ( ) const

Checks if the event surface is the focus surface.

Returns: true if the surface is the focus surface.

◆ get_crossing_mode()

CrossingMode Gdk::Event::get_crossing_mode ( ) const

Extracts the crossing mode from a crossing event.

Returns: The mode of event.

◆ get_deltas()

void Gdk::Event::get_deltas	(	double &	delta_x,
		double &	delta_y
	)		const

Extracts the scroll deltas of a scroll event.

The deltas will be zero unless the scroll direction is Gdk::ScrollDirection::SMOOTH.

For the representation unit of these deltas, see get_unit().

Parameters

delta_x	Return location for x scroll delta.
delta_y	Return location for y scroll delta.

◆ get_device() [1/2]

Glib::RefPtr< Device > Gdk::Event::get_device ( )

Returns the device of an event.

Since gtkmm 3.94:

Returns: A Gdk::Device.

◆ get_device() [2/2]

Glib::RefPtr< const Device > Gdk::Event::get_device ( ) const

Returns the device of an event.

Since gtkmm 3.94:

Returns: A Gdk::Device.

◆ get_device_tool() [1/2]

Glib::RefPtr< DeviceTool > Gdk::Event::get_device_tool ( )

Returns a Gdk::DeviceTool representing the tool that caused the event.

If the was not generated by a device that supports different tools (such as a tablet), this function will return nullptr.

Note: the Gdk::DeviceTool will be constant during the application lifetime, if settings must be stored persistently across runs, see Gdk::DeviceTool::get_serial().

Returns: The current device tool.

◆ get_device_tool() [2/2]

Glib::RefPtr< const DeviceTool > Gdk::Event::get_device_tool ( ) const

Returns a Gdk::DeviceTool representing the tool that caused the event.

If the was not generated by a device that supports different tools (such as a tablet), this function will return nullptr.

Note: the Gdk::DeviceTool will be constant during the application lifetime, if settings must be stored persistently across runs, see Gdk::DeviceTool::get_serial().

Returns: The current device tool.

◆ get_direction()

ScrollDirection Gdk::Event::get_direction ( ) const

Extracts the direction of a scroll event.

Returns: The scroll direction of event.

◆ get_display() [1/2]

Glib::RefPtr< Display > Gdk::Event::get_display ( )

Retrieves the display associated to the event.

Returns: A Gdk::Display.

◆ get_display() [2/2]

Glib::RefPtr< const Display > Gdk::Event::get_display ( ) const

Retrieves the display associated to the event.

Returns: A Gdk::Display.

◆ get_distance()

bool Gdk::Event::get_distance	(	const Glib::RefPtr< const Event > &	event2,
		double &	distance
	)		const

Returns the distance between the event locations.

This assumes that both events have X/Y information. If not, this function returns false.

Parameters

event2	Second `Gdk::Event`.
distance	Return location for the distance.

Returns: true if the distance could be calculated.

◆ get_dnd_drop() [1/2]

Glib::RefPtr< Drop > Gdk::Event::get_dnd_drop ( )

Gets the Gdk::Drop object from a DND event.

Returns: The drop.

◆ get_dnd_drop() [2/2]

Glib::RefPtr< const Drop > Gdk::Event::get_dnd_drop ( ) const

Gets the Gdk::Drop object from a DND event.

Returns: The drop.

◆ get_event_sequence()

const EventSequence * Gdk::Event::get_event_sequence ( ) const

Returns the event sequence to which the event belongs.

Related touch events are connected in a sequence. Other events typically don't have event sequence information.

Returns: The event sequence that the event belongs to.

◆ get_event_type()

Type Gdk::Event::get_event_type ( ) const

Retrieves the type of the event.

Returns: A Gdk::EventType.

◆ get_focus_in()

bool Gdk::Event::get_focus_in ( ) const

Extracts whether this event is about focus entering or leaving the surface.

Returns: true of the focus is entering.

◆ get_grab_broken_grab_surface() [1/2]

Glib::RefPtr< Surface > Gdk::Event::get_grab_broken_grab_surface ( )

Extracts the grab surface from a grab broken event.

Returns: The grab surface of event.

◆ get_grab_broken_grab_surface() [2/2]

Glib::RefPtr< const Surface > Gdk::Event::get_grab_broken_grab_surface ( ) const

Extracts the grab surface from a grab broken event.

Returns: The grab surface of event.

◆ get_grab_broken_implicit()

bool Gdk::Event::get_grab_broken_implicit ( ) const

Checks whether the grab broken event is for an implicit grab.

Returns: true if the an implicit grab was broken.

◆ get_history()

std::vector< TimeCoord > Gdk::Event::get_history ( ) const

Retrieves the history of the event, as a vector of time and coordinates.

The history includes events that are not delivered to the application because they occurred in the same frame as this event.

Note that only motion and scroll events record history, and motion events only if one of the mouse buttons is down.

Returns: A vector of time and coordinates.

◆ get_keycode()

guint Gdk::Event::get_keycode ( ) const

Extracts the keycode from a key event.

Returns: The keycode of event.

◆ get_keyval()

guint Gdk::Event::get_keyval ( ) const

Extracts the keyval from a key event.

Returns: The keyval of event.

◆ get_layout()

guint Gdk::Event::get_layout ( ) const

Extracts the layout from a key event.

Returns: The layout of event.

◆ get_level()

guint Gdk::Event::get_level ( ) const

Extracts the shift level from a key event.

Returns: The shift level of event.

◆ get_match()

bool Gdk::Event::get_match	(	guint &	keyval,
		ModifierType &	modifiers
	)		const

Gets a keyval and modifier combination that will match the event.

See matches().

Parameters

keyval	Return location for a keyval.
modifiers	Return location for modifiers.

Returns: true on success.

◆ get_modifier_state()

ModifierType Gdk::Event::get_modifier_state ( ) const

Returns the modifier state field of an event.

Returns: The modifier state of event.

◆ get_pad_axis_value()

void Gdk::Event::get_pad_axis_value	(	guint &	index,
		double &	value
	)		const

Extracts the information from a pad strip or ring event.

Parameters

index	Return location for the axis index.
value	Return location for the axis value.

◆ get_pad_button()

guint Gdk::Event::get_pad_button ( ) const

Extracts information about the pressed button from a pad event.

Returns: The button of event.

◆ get_pad_group_mode()

void Gdk::Event::get_pad_group_mode	(	guint &	group,
		guint &	mode
	)		const

Extracts group and mode information from a pad event.

Parameters

group	Return location for the group.
mode	Return location for the mode.

◆ get_pointer_emulated()

bool Gdk::Event::get_pointer_emulated ( ) const

Returns whether this event is an 'emulated' pointer event.

Emulated pointer events typically originate from a touch events.

Returns: true if this event is emulated.

◆ get_position()

bool Gdk::Event::get_position	(	double &	x,
		double &	y
	)		const

Extract the event surface relative x/y coordinates from an event.

This position is in surface coordinates.

Parameters

x	Location to put event surface x coordinate.
y	Location to put event surface y coordinate.

◆ get_scroll_unit()

ScrollUnit Gdk::Event::get_scroll_unit ( ) const

Extracts the scroll delta unit of a scroll event.

The unit will always be Gdk::ScrollUnit::WHEEL if the scroll direction is not Gdk::ScrollDirection::SMOOTH.

Since gtkmm 4.8:

Returns: The scroll unit.

◆ get_seat() [1/2]

Glib::RefPtr< Seat > Gdk::Event::get_seat ( )

Returns the seat that originated the event.

Returns: A Gdk::Seat.

◆ get_seat() [2/2]

Glib::RefPtr< const Seat > Gdk::Event::get_seat ( ) const

Returns the seat that originated the event.

Returns: A Gdk::Seat.

◆ get_surface() [1/2]

Glib::RefPtr< Surface > Gdk::Event::get_surface ( )

Extracts the surface associated with an event.

Returns: The Gdk::Surface associated with the event.

◆ get_surface() [2/2]

Glib::RefPtr< const Surface > Gdk::Event::get_surface ( ) const

Extracts the surface associated with an event.

Returns: The Gdk::Surface associated with the event.

◆ get_time()

guint32 Gdk::Event::get_time ( ) const

Returns the timestamp of event.

Not all events have timestamps. In that case, this function returns GDK_CURRENT_TIME.

Returns: Timestamp field from event.

◆ get_touch_emulating_pointer()

bool Gdk::Event::get_touch_emulating_pointer ( ) const

Extracts whether a touch event is emulating a pointer event.

Returns: true if event is emulating.

◆ get_touchpad_deltas()

void Gdk::Event::get_touchpad_deltas	(	double &	dx,
		double &	dy
	)		const

Extracts delta information from a touchpad event.

Parameters

dx	Return location for x.
dy	Return location for y.

◆ get_touchpad_gesture_phase()

TouchpadGesturePhase Gdk::Event::get_touchpad_gesture_phase ( ) const

Extracts the touchpad gesture phase from a touchpad event.

Returns: The gesture phase of event.

◆ get_touchpad_n_fingers()

guint Gdk::Event::get_touchpad_n_fingers ( ) const

Extracts the number of fingers from a touchpad event.

Returns: The number of fingers for event.

◆ get_touchpad_pinch_angle_delta()

double Gdk::Event::get_touchpad_pinch_angle_delta ( ) const

Extracts the angle delta from a touchpad pinch event.

Returns: The angle delta of event.

◆ get_touchpad_pinch_scale()

double Gdk::Event::get_touchpad_pinch_scale ( ) const

Extracts the scale from a touchpad pinch event.

Returns: The scale of event.

◆ gobj() [1/2]

GdkEvent * Gdk::Event::gobj ( )

Provides access to the underlying C instance.

◆ gobj() [2/2]

const GdkEvent * Gdk::Event::gobj ( ) const

Provides access to the underlying C instance.

◆ gobj_copy()

GdkEvent * Gdk::Event::gobj_copy ( ) const

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

◆ is_modifier()

bool Gdk::Event::is_modifier ( ) const

Extracts whether the key event is for a modifier key.

Returns: true if the event is for a modifier key.

◆ is_scroll_stop()

bool Gdk::Event::is_scroll_stop ( ) const

Check whether a scroll event is a stop scroll event.

Scroll sequences with smooth scroll information may provide a stop scroll event once the interaction with the device finishes, e.g. by lifting a finger. This stop scroll event is the signal that a widget may trigger kinetic scrolling based on the current velocity.

Stop scroll events always have a delta of 0/0.

Returns: true if the event is a scroll stop event.

◆ matches()

KeyMatch Gdk::Event::matches	(	guint	keyval,
		ModifierType	modifiers
	)		const

Matches a key event against a keyval and modifiers.

This is typically used to trigger keyboard shortcuts such as Ctrl-C.

Partial matches are possible where the combination matches if the currently active group is ignored.

Note that we ignore Caps Lock for matching.

Parameters

keyval	The keyval to match.
modifiers	The modifiers to match.

Returns: A Gdk::KeyMatch value describing whether event matches.

◆ operator delete()

void Gdk::Event::operator delete	(	void *	,
		std::size_t
	)

protected

◆ operator=()

Event & Gdk::Event::operator= ( const Event & )

delete

◆ reference()

void Gdk::Event::reference ( ) const

Increment the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

◆ triggers_context_menu()

bool Gdk::Event::triggers_context_menu ( ) const

Returns whether a Gdk::Event should trigger a context menu, according to platform conventions.

The right mouse button typically triggers context menus.

This function should always be used instead of simply checking for event->button == GDK_BUTTON_SECONDARY.

Returns: true if the event should trigger a context menu.

◆ unreference()

void Gdk::Event::unreference ( ) const

Decrement the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

Friends And Related Function Documentation

◆ wrap()

Glib::RefPtr< Gdk::Event > wrap	(	GdkEvent *	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 Types

Public Member Functions

Protected Member Functions

Related Functions

Detailed Description

Constructor & Destructor Documentation

◆ Event() [1/2]

◆ Event() [2/2]

Member Function Documentation

◆ get_angle()

◆ get_axes()

◆ get_axis()

◆ get_button()

◆ get_center()

◆ get_consumed_modifiers()

◆ get_crossing_detail()

◆ get_crossing_focus()

◆ get_crossing_mode()

◆ get_deltas()

◆ get_device() [1/2]

◆ get_device() [2/2]

◆ get_device_tool() [1/2]

◆ get_device_tool() [2/2]

◆ get_direction()

◆ get_display() [1/2]

◆ get_display() [2/2]

◆ get_distance()

◆ get_dnd_drop() [1/2]

◆ get_dnd_drop() [2/2]

◆ get_event_sequence()

◆ get_event_type()

◆ get_focus_in()

◆ get_grab_broken_grab_surface() [1/2]

◆ get_grab_broken_grab_surface() [2/2]

◆ get_grab_broken_implicit()

◆ get_history()

◆ get_keycode()

◆ get_keyval()

◆ get_layout()

◆ get_level()

◆ get_match()

◆ get_modifier_state()

◆ get_pad_axis_value()

◆ get_pad_button()

◆ get_pad_group_mode()

◆ get_pointer_emulated()

◆ get_position()

◆ get_scroll_unit()

◆ get_seat() [1/2]

◆ get_seat() [2/2]

◆ get_surface() [1/2]

◆ get_surface() [2/2]

◆ get_time()

◆ get_touch_emulating_pointer()

◆ get_touchpad_deltas()

◆ get_touchpad_gesture_phase()

◆ get_touchpad_n_fingers()

◆ get_touchpad_pinch_angle_delta()

◆ get_touchpad_pinch_scale()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ is_modifier()

◆ is_scroll_stop()

◆ matches()

◆ operator delete()

◆ operator=()

◆ reference()

◆ triggers_context_menu()

◆ unreference()

Friends And Related Function Documentation

◆ wrap()