class Gtk::EventControllerScroll

Overview

Gtk::EventControllerScroll 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 Gtk::EventControllerScroll::#scroll signal. Deltas in the discrete case are multiples of 1.

In the case of continuous scroll events, Gtk::EventControllerScroll encloses all 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 Gtk::EventControllerScroll#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_EVENT_CONTROLLER_SCROLL_VERTICAL, %GTK_EVENT_CONTROLLER_SCROLL_HORIZONTAL and %GTK_EVENT_CONTROLLER_SCROLL_BOTH_AXES. If any axis is disabled, the respective 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_EVENT_CONTROLLER_SCROLL_DISCRETE. This can be used to implement discrete actions triggered through scroll events (e.g. switching across combobox options).

The %GTK_EVENT_CONTROLLER_SCROLL_KINETIC flag toggles the emission of the 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.

Defined in:

lib/gi-crystal/src/auto/gtk-4.0/event_controller_scroll.cr

Constructors

Class Method Summary

Instance Method Summary

Instance methods inherited from class Gtk::EventController

current_event : Gdk::Event? current_event, current_event_device : Gdk::Device? current_event_device, current_event_state : Gdk::ModifierType current_event_state, current_event_time : UInt32 current_event_time, name : String? name, name=(value : String) : String
name=(name : String?) : Nil name=, propagation_limit : Gtk::PropagationLimit propagation_limit, propagation_limit=(limit : Gtk::PropagationLimit) : Nil propagation_limit=, propagation_phase : Gtk::PropagationPhase propagation_phase, propagation_phase=(phase : Gtk::PropagationPhase) : Nil propagation_phase=, reset : Nil reset, static_name=(name : String?) : Nil static_name=, widget : Gtk::Widget widget

Constructor methods inherited from class Gtk::EventController

new
new(*, name : String? = nil, propagation_limit : Gtk::PropagationLimit? = nil, propagation_phase : Gtk::PropagationPhase? = nil, widget : Gtk::Widget? = nil) new

Class methods inherited from class Gtk::EventController

g_type : UInt64 g_type

Instance methods inherited from class GObject::Object

bind_property(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags) : GObject::Binding bind_property, bind_property_full(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags, transform_to : GObject::Closure, transform_from : GObject::Closure) : GObject::Binding bind_property_full, data(key : String) : Pointer(Void)? data, finalize finalize, freeze_notify : Nil freeze_notify, getv(names : Enumerable(String), values : Enumerable(_)) : Nil getv, notify(property_name : String) : Nil notify, notify_by_pspec(pspec : GObject::ParamSpec) : Nil notify_by_pspec, notify_signal notify_signal, property(property_name : String, value : _) : Nil property, qdata(quark : UInt32) : Pointer(Void)? qdata, ref_count : UInt32 ref_count, run_dispose : Nil run_dispose, set_data(key : String, data : Pointer(Void)?) : Nil set_data, set_property(property_name : String, value : _) : Nil set_property, steal_data(key : String) : Pointer(Void)? steal_data, steal_qdata(quark : UInt32) : Pointer(Void)? steal_qdata, thaw_notify : Nil thaw_notify, to_unsafe : Pointer(Void) to_unsafe, watch_closure(closure : GObject::Closure) : Nil watch_closure

Constructor methods inherited from class GObject::Object

cast(obj : GObject::Object) : self cast, cast?(obj : GObject::Object) : self? cast?, new(pointer : Pointer(Void), transfer : GICrystal::Transfer)
new new, newv(object_type : UInt64, parameters : Enumerable(GObject::Parameter)) : self newv

Class methods inherited from class GObject::Object

compat_control(what : UInt64, data : Pointer(Void)?) : UInt64 compat_control, g_type : UInt64 g_type, interface_find_property(g_iface : GObject::TypeInterface, property_name : String) : GObject::ParamSpec interface_find_property, interface_list_properties(g_iface : GObject::TypeInterface) : Enumerable(GObject::ParamSpec) interface_list_properties

Constructor Detail

def self.new(flags : Gtk::EventControllerScrollFlags) : self #

Creates a new event controller that will handle scroll events.


def self.new #

Initialize a new EventControllerScroll.


def self.new(*, flags : Gtk::EventControllerScrollFlags? = nil, name : String? = nil, propagation_limit : Gtk::PropagationLimit? = nil, propagation_phase : Gtk::PropagationPhase? = nil, widget : Gtk::Widget? = nil) #

Class Method Detail

def self.g_type : UInt64 #

Returns the type id (GType) registered in GLib type system.


Instance Method Detail

def decelerate_signal #

def flags : Gtk::EventControllerScrollFlags #

Gets the flags conditioning the scroll controller behavior.


def flags=(flags : Gtk::EventControllerScrollFlags) : Nil #

Sets the flags conditioning scroll controller behavior.


def scroll_begin_signal #

def scroll_end_signal #

def scroll_signal #

def unit : Gdk::ScrollUnit #

Gets the scroll unit of the last Gtk::EventControllerScroll::#scroll signal received.

Always returns %GDK_SCROLL_UNIT_WHEEL if the %GTK_EVENT_CONTROLLER_SCROLL_DISCRETE flag is set.