Gdk.Event.Touchpad_Event

Description

An event related to a gesture on a touchpad device.

Unlike touchscreens, where the windowing system sends basic sequences of begin, update, end events, and leaves gesture recognition to the clients, touchpad gestures are typically processed by the system, resulting in these events.

Gdk_Touchpad_Event

type Gdk_Touchpad_Event is new Gdk_Event with null record;

Gdk_Touchpad_Gesture_Phase

type Gdk_Touchpad_Gesture_Phase is (
   Phase_Begin,
   Phase_Update,
   Phase_End,
   Phase_Cancel);

Specifies the current state of a touchpad gesture.

All gestures are guaranteed to begin with an event with phase Gdk.Event.Touchpad_Event.Phase_Begin, followed by 0 or several events with phase Gdk.Event.Touchpad_Event.Phase_Update.

A finished gesture may have 2 possible outcomes, an event with phase Gdk.Event.Touchpad_Event.Phase_End will be emitted when the gesture is considered successful, this should be used as the hint to perform any permanent changes.

Cancelled gestures may be so for a variety of reasons, due to hardware or the compositor, or due to the gesture recognition layers hinting the gesture did not finish resolutely (eg. a 3rd finger being added during a pinch gesture). In these cases, the last event will report the phase Gdk.Event.Touchpad_Event.Phase_Cancel, this should be used as a hint to undo any visible/permanent changes that were done throughout the progress of the gesture.

Enumeration Literal

Phase_Begin

Phase_Update

Phase_End

Phase_Cancel

Gdk_Touchpad_Gesture_Phase_Properties

package Gdk_Touchpad_Gesture_Phase_Properties is
   new Generic_Internal_Discrete_Property (Gdk_Touchpad_Gesture_Phase);

Get_Deltas

procedure Get_Deltas
   (Self : Gdk.Event.Gdk_Event;
    Dx   : out Gdouble;
    Dy   : out Gdouble)

Extracts delta information from a touchpad event.

Parameters

Self

Dx

return location for x

Dy

return location for y

Get_Gesture_Phase

function Get_Gesture_Phase
   (Self : Gdk.Event.Gdk_Event) return Gdk_Touchpad_Gesture_Phase

Extracts the touchpad gesture phase from a touchpad event.

Parameters

Self

Return Value

the gesture phase of Event

Get_N_Fingers

function Get_N_Fingers (Self : Gdk.Event.Gdk_Event) return Guint

Extracts the number of fingers from a touchpad event.

Parameters

Self

Return Value

the number of fingers for Event

Get_Pinch_Angle_Delta

function Get_Pinch_Angle_Delta
   (Self : Gdk.Event.Gdk_Event) return Gdouble

Extracts the angle delta from a touchpad pinch event.

Parameters

Self

Return Value

the angle delta of Event

Get_Pinch_Scale

function Get_Pinch_Scale (Self : Gdk.Event.Gdk_Event) return Gdouble

Extracts the scale from a touchpad pinch event.

Parameters

Self

Return Value

the scale of Event

Get_Type

function Get_Type return Glib.GType

Return Value

Property_Gdk_Touchpad_Gesture_Phase

type Property_Gdk_Touchpad_Gesture_Phase is new Gdk_Touchpad_Gesture_Phase_Properties.Property;