GtkEventControllerScroll
GtkEventControllerScroll — Event controller for scroll events
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Includes
#include <gtk/gtk.h>
Description
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 “scroll” signal (deltas in the
discrete case are multiples of 1).
In the case of continuous scroll events, GtkEventControllerScroll
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
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 “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
“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.
Types and Values
GtkEventControllerScroll
typedef struct _GtkEventControllerScroll GtkEventControllerScroll;
Property Details
The “flags” property
“flags” GtkEventControllerScrollFlags
The flags affecting event controller behavior
Owner: GtkEventControllerScroll
Flags: Read / Write
Since: 3.24
Signal Details
The “scroll-begin” signal
void
user_function (GtkEventControllerScroll *controller,
gpointer user_data)
Signals that a new scrolling operation has begun. It will
only be emitted on devices capable of it.
Flags: Run First
The “scroll-end” signal
void
user_function (GtkEventControllerScroll *controller,
gpointer user_data)
Signals that a new scrolling operation has finished. It will
only be emitted on devices capable of it.
Flags: Run First