Struct gdk4::ScrollEvent

pub struct ScrollEvent(_);

An event related to a scrolling motion.

Implementations

impl ScrollEvent

pub fn upcast(self) -> Event

pub fn upcast_ref(&self) -> &Event

impl ScrollEvent

pub fn deltas(&self) -> (f64, f64)

Extracts the scroll deltas of a scroll event.

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

Returns

delta_x

return location for x scroll delta

delta_y

return location for y scroll delta

pub fn direction(&self) -> ScrollDirection

Extracts the direction of a scroll event.

Returns

the scroll direction of self

pub fn is_stop(&self) -> bool

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

Methods from Deref<Target = Event>

pub fn downcast_ref<T: EventKind>(&self) -> Option<&T>

pub fn angle<P: AsRef<Event>>(&self, event: P) -> Option<f64>

pub fn center<P: AsRef<Event>>(&self, event: P) -> Option<(f64, f64)>

pub fn distance<P: AsRef<Event>>(&self, event: P) -> Option<f64>

pub fn axis(&self, axis_use: AxisUse) -> Option<f64>

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

axis_use

the axis use to look for

Returns

true if the specified axis was found, otherwise false

value

location to store the value found

pub fn device(&self) -> Option<Device>

Returns the device of an event.

Returns

a Device

pub fn display(&self) -> Option<Display>

Retrieves the display associated to the self.

Returns

a Display

pub fn event_type(&self) -> EventType

Retrieves the type of the event.

Returns

a EventType

pub fn history(&self) -> Vec<TimeCoord>

Retrieves the history of the device that self is for, as a list of time and coordinates.

The history includes positions that are not delivered as separate events to the application because they occurred in the same frame as self.

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

Returns

an array of time and coordinates

pub fn modifier_state(&self) -> ModifierType

Returns the modifier state field of an event.

Returns

the modifier state of self

pub fn is_pointer_emulated(&self) -> bool

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

pub fn position(&self) -> Option<(f64, f64)>

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

Returns

x

location to put event surface x coordinate

y

location to put event surface y coordinate

pub fn seat(&self) -> Option<Seat>

Returns the seat that originated the event.

Returns

a Seat.

pub fn surface(&self) -> Option<Surface>

Extracts the surface associated with an event.

Returns

The Surface associated with the event

pub fn time(&self) -> u32

Returns the timestamp of self.

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

Returns

timestamp field from self

pub fn triggers_context_menu(&self) -> bool

Returns whether a 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.

Trait Implementations

impl AsRef<Event> for ScrollEvent

fn as_ref(&self) -> &Event

Performs the conversion.

impl Clone for ScrollEvent

fn clone(&self) -> ScrollEvent

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ScrollEvent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for ScrollEvent

type Target = Event

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Display for ScrollEvent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl StaticType for ScrollEvent

fn static_type() -> Type

Returns the type identifier of Self.