EventControllerScroll

#GtkEventControllerScroll 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 #GtkEventControllerScroll::scroll signal (deltas in the discrete case are multiples of 1).

In the case of continuous scroll events, #GtkEventControllerScroll encloses all #GtkEventControllerScroll::scroll events between two #GtkEventControllerScroll::scroll-begin and #GtkEventControllerScroll::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_event_controller_scroll_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_EVENT_CONTROLLER_SCROLL_VERTICAL, #GTK_EVENT_CONTROLLER_SCROLL_HORIZONTAL and #GTK_EVENT_CONTROLLER_SCROLL_BOTH. If any axis is disabled, the respective #GtkEventControllerScroll::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 #GtkEventControllerScroll::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.

class EventControllerScroll : EventController {

protected

GtkEventControllerScroll* gtkEventControllerScroll;

GtkEventControllerScroll* getEventControllerScrollStruct(bool transferOwnership);

void* getStruct();

this(GtkEventControllerScroll* gtkEventControllerScroll, bool ownedRef);

static GType getType();

this(Widget widget, GtkEventControllerScrollFlags flags);

GtkEventControllerScrollFlags getFlags();

void setFlags(GtkEventControllerScrollFlags flags);

gulong addOnDecelerate(void delegate(double, double, EventControllerScroll) dlg, ConnectFlags connectFlags);

gulong addOnScroll(void delegate(double, double, EventControllerScroll) dlg, ConnectFlags connectFlags);

gulong addOnScrollBegin(void delegate(EventControllerScroll) dlg, ConnectFlags connectFlags);

gulong addOnScrollEnd(void delegate(EventControllerScroll) dlg, ConnectFlags connectFlags);

}

Constructors

this this(GtkEventControllerScroll* gtkEventControllerScroll, bool ownedRef): Sets our main struct and passes it to the parent class.
this this(Widget widget, GtkEventControllerScrollFlags flags): Creates a new event controller that will handle scroll events for the given @widget.

Members

Functions

addOnDecelerate gulong addOnDecelerate(void delegate(double, double, EventControllerScroll) dlg, ConnectFlags connectFlags): Emitted after scroll is finished if the #GTK_EVENT_CONTROLLER_SCROLL_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.
addOnScroll gulong addOnScroll(void delegate(double, double, EventControllerScroll) dlg, ConnectFlags connectFlags): Signals that the widget should scroll by the amount specified by @dx and @dy.
addOnScrollBegin gulong addOnScrollBegin(void delegate(EventControllerScroll) dlg, ConnectFlags connectFlags): Signals that a new scrolling operation has begun. It will only be emitted on devices capable of it.
addOnScrollEnd gulong addOnScrollEnd(void delegate(EventControllerScroll) dlg, ConnectFlags connectFlags): Signals that a new scrolling operation has finished. It will only be emitted on devices capable of it.
getEventControllerScrollStruct GtkEventControllerScroll* getEventControllerScrollStruct(bool transferOwnership): Get the main Gtk struct
getFlags GtkEventControllerScrollFlags getFlags(): Gets the flags conditioning the scroll controller behavior.
getStruct void* getStruct(): the main Gtk struct as a void*
setFlags void setFlags(GtkEventControllerScrollFlags flags): Sets the flags conditioning scroll controller behavior.

Static functions

getType GType getType()

Variables

gtkEventControllerScroll GtkEventControllerScroll* gtkEventControllerScroll;: the main Gtk struct

Inherited Members

From EventController

gtkEventController GtkEventController* gtkEventController;: the main Gtk struct
getEventControllerStruct GtkEventController* getEventControllerStruct(bool transferOwnership): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
getType GType getType()
getPropagationPhase GtkPropagationPhase getPropagationPhase(): Gets the propagation phase at which @controller handles events.
getWidget Widget getWidget(): Returns the #GtkWidget this controller relates to.
handleEvent bool handleEvent(Event event): Feeds an events into @controller, so it can be interpreted and the controller actions triggered.
reset void reset(): Resets the @controller to a clean state. Every interaction the controller did through #GtkEventController::handle-event will be dropped at this point.
setPropagationPhase void setPropagationPhase(GtkPropagationPhase phase): Sets the propagation phase at which a controller handles events.