Struct EventControllerScroll 

pub struct EventControllerScroll { /* private fields */ }

Available on crate feature v3_24 only.

EventControllerScroll is an event controller meant to handle scroll events from mice and touchpads. It is capable of handling both discrete and continuous scroll events, abstracting them both on the scroll signal (deltas in the discrete case are multiples of 1).

In the case of continuous scroll events, EventControllerScroll encloses all scroll events between two scroll-begin and scroll-end signals.

The behavior of the event controller can be modified by the flags given at creation time, or modified at a later point through set_flags() (e.g. because the scrolling conditions of the widget changed).

The controller can be set up to emit motion for either/both vertical and horizontal scroll events through EventControllerScrollFlags::VERTICAL, EventControllerScrollFlags::HORIZONTAL and GTK_EVENT_CONTROLLER_SCROLL_BOTH. If any axis is disabled, the respective scroll delta will be 0. Vertical scroll events will be translated to horizontal motion for the devices incapable of horizontal scrolling.

The event controller can also be forced to emit discrete events on all devices through EventControllerScrollFlags::DISCRETE. This can be used to implement discrete actions triggered through scroll events (e.g. switching across combobox options).

The EventControllerScrollFlags::KINETIC flag toggles the emission of the decelerate signal, emitted at the end of scrolling with two X/Y velocity arguments that are consistent with the motion that was received.

This object was added in 3.24.

Properties

flags

The flags affecting event controller behavior

Readable | Writeable

EventController

propagation-phase

The propagation phase at which this controller will handle events.

Readable | Writeable

widget

The widget receiving the GdkEvents that the controller will handle.

Readable | Writeable | Construct Only

Signals

decelerate

Emitted after scroll is finished if the EventControllerScrollFlags::KINETIC flag is set. vel_x and vel_y express the initial velocity that was imprinted by the scroll events. vel_x and vel_y are expressed in pixels/ms.

scroll

Signals that the widget should scroll by the amount specified by dx and dy.

scroll-begin

Signals that a new scrolling operation has begun. It will only be emitted on devices capable of it.

scroll-end

Signals that a new scrolling operation has finished. It will only be emitted on devices capable of it.

Implements

EventControllerExt, glib::ObjectExt

Implementations

impl EventControllerScroll

pub fn new( widget: &impl IsA<Widget>, flags: EventControllerScrollFlags, ) -> EventControllerScroll

Creates a new event controller that will handle scroll events for the given widget.

widget

a Widget

flags

behavior flags

Returns

a new EventControllerScroll

pub fn flags(&self) -> EventControllerScrollFlags

Gets the flags conditioning the scroll controller behavior.

Returns

the controller flags.

pub fn set_flags(&self, flags: EventControllerScrollFlags)

Sets the flags conditioning scroll controller behavior.

flags

behavior flags

pub fn connect_decelerate<F: Fn(&Self, f64, f64) + 'static>( &self, f: F, ) -> SignalHandlerId

Emitted after scroll is finished if the EventControllerScrollFlags::KINETIC flag is set. vel_x and vel_y express the initial velocity that was imprinted by the scroll events. vel_x and vel_y are expressed in pixels/ms.

vel_x

X velocity

vel_y

Y velocity

pub fn connect_scroll<F: Fn(&Self, f64, f64) + 'static>( &self, f: F, ) -> SignalHandlerId

Signals that the widget should scroll by the amount specified by dx and dy.

dx

X delta

dy

Y delta

pub fn connect_scroll_begin<F: Fn(&Self) + 'static>( &self, f: F, ) -> SignalHandlerId

Signals that a new scrolling operation has begun. It will only be emitted on devices capable of it.

pub fn connect_scroll_end<F: Fn(&Self) + 'static>( &self, f: F, ) -> SignalHandlerId

Signals that a new scrolling operation has finished. It will only be emitted on devices capable of it.

pub fn connect_flags_notify<F: Fn(&Self) + 'static>( &self, f: F, ) -> SignalHandlerId

Trait Implementations

impl Clone for EventControllerScroll

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EventControllerScroll

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

Formats the value using the given formatter.

impl Display for EventControllerScroll

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

Formats the value using the given formatter.

impl Eq for EventControllerScroll

impl HasParamSpec for EventControllerScroll

type ParamSpec = ParamSpecObject

type SetValue = EventControllerScroll

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(&str) -> ParamSpecObjectBuilder<'_, EventControllerScroll>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for EventControllerScroll

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl IsA<EventController> for EventControllerScroll

impl Ord for EventControllerScroll

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl ParentClassIs for EventControllerScroll

type Parent = EventController

impl<OT: ObjectType> PartialEq<OT> for EventControllerScroll

fn eq(&self, other: &OT) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<OT: ObjectType> PartialOrd<OT> for EventControllerScroll

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for EventControllerScroll

fn static_type() -> Type

Returns the type identifier of Self.