Gtk.EventControllerScroll¶

Subclasses:: None

Methods¶

Inherited:: Gtk.EventController (13), GObject.Object (37)
Structs:: GObject.ObjectClass (5)

class	`new` (flags)
	`get_flags` ()
	`get_unit` ()
	`set_flags` (flags)

Virtual Methods¶

Inherited:: GObject.Object (7)

Properties¶

Inherited:: Gtk.EventController (4)

Name	Type	Flags	Short Description
`flags`	`Gtk.EventControllerScrollFlags`	r/w/en

Signals¶

Inherited:: GObject.Object (1)

Name	Short Description
`decelerate`	Emitted after scroll is finished if the `Gtk.EventControllerScrollFlags.KINETIC` flag is set.
`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.
`scroll-end`	Signals that a scrolling operation has finished.

Fields¶

Inherited:: GObject.Object (1)

Class Details¶

class Gtk.EventControllerScroll(**kwargs)¶

Bases:: Gtk.EventController
Abstract:: No
Structure:: Gtk.EventControllerScrollClass

GtkEventControllerScroll is an event controller that handles scroll events.

It is capable of handling both discrete and continuous scroll events from mice or touchpads, abstracting them both with the [signal`Gtk`.EventControllerScroll::scroll] signal. Deltas in the discrete case are multiples of 1.

In the case of continuous scroll events, GtkEventControllerScroll encloses all [signal`Gtk`.EventControllerScroll::scroll] emissions between two [signal`Gtk`.EventControllerScroll::scroll-begin] and [signal`Gtk`.EventControllerScroll::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 [method`Gtk`.EventControllerScroll.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 Gtk.EventControllerScrollFlags.VERTICAL, Gtk.EventControllerScrollFlags.HORIZONTAL and Gtk.EventControllerScrollFlags.BOTH_AXES. If any axis is disabled, the respective [signal`Gtk`.EventControllerScroll::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 Gtk.EventControllerScrollFlags.DISCRETE. This can be used to implement discrete actions triggered through scroll events (e.g. switching across combobox options).

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

classmethod new(flags)[source]¶

Parameters:: flags (Gtk.EventControllerScrollFlags) – flags affecting the controller behavior
Returns:: a new GtkEventControllerScroll
Return type:: Gtk.EventController

Creates a new event controller that will handle scroll events.

get_flags()[source]¶

Returns:: the controller flags.
Return type:: Gtk.EventControllerScrollFlags

Gets the flags conditioning the scroll controller behavior.

get_unit()[source]¶

Returns:: the scroll unit.
Return type:: Gdk.ScrollUnit

Gets the scroll unit of the last [signal`Gtk`.EventControllerScroll::scroll] signal received.

Always returns Gdk.ScrollUnit.WHEEL if the Gtk.EventControllerScrollFlags.DISCRETE flag is set.

New in version 4.8.

set_flags(flags)[source]¶

Parameters:: flags (Gtk.EventControllerScrollFlags) – flags affecting the controller behavior

Sets the flags conditioning scroll controller behavior.

Signal Details¶

Gtk.EventControllerScroll.signals.decelerate(event_controller_scroll, vel_x, vel_y)¶

Signal Name:

decelerate

Flags:

RUN_FIRST

Parameters:

event_controller_scroll (Gtk.EventControllerScroll) – The object which received the signal
vel_x (float) – X velocity
vel_y (float) – Y velocity

Emitted after scroll is finished if the Gtk.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.

Gtk.EventControllerScroll.signals.scroll(event_controller_scroll, dx, dy)¶

Signal Name:

scroll

Flags:

RUN_LAST

Parameters:

event_controller_scroll (Gtk.EventControllerScroll) – The object which received the signal
dx (float) – X delta
dy (float) – Y delta

Returns:

True if the scroll event was handled, False otherwise.

Return type:

bool

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

For the representation unit of the deltas, see [method`Gtk`.EventControllerScroll.get_unit].

Gtk.EventControllerScroll.signals.scroll_begin(event_controller_scroll)¶

Signal Name:: scroll-begin
Flags:: RUN_FIRST
Parameters:: event_controller_scroll (Gtk.EventControllerScroll) – The object which received the signal

Signals that a new scrolling operation has begun.

It will only be emitted on devices capable of it.

Gtk.EventControllerScroll.signals.scroll_end(event_controller_scroll)¶

Signal Name:: scroll-end
Flags:: RUN_FIRST
Parameters:: event_controller_scroll (Gtk.EventControllerScroll) – The object which received the signal

Signals that a scrolling operation has finished.

It will only be emitted on devices capable of it.

Property Details¶

Gtk.EventControllerScroll.props.flags¶

Name:: flags
Type:: Gtk.EventControllerScrollFlags
Default Value:: Gtk.EventControllerScrollFlags.NONE
Flags:: READABLE, WRITABLE, EXPLICIT_NOTIFY

The flags affecting event controller behavior.