Package org.gnome.gtk

Class PadController

java.lang.Object
org.javagi.base.ProxyInstance
org.gnome.gobject.TypeInstance
org.gnome.gobject.GObject
org.gnome.gtk.EventController
org.gnome.gtk.PadController
All Implemented Interfaces:
Proxy
@Generated("io.github.jwharm.JavaGI") public class PadController extends EventController
Handles input from the pads found in drawing tablets.

Pads are the collection of buttons and tactile sensors often found around the stylus-sensitive area.

These buttons and sensors have no implicit meaning, and by default they perform no action. GtkPadController is provided to map those to Action objects, thus letting the application give them a more semantic meaning.

Buttons and sensors are not constrained to triggering a single action, some InputSource.TABLET_PAD devices feature multiple "modes". All these input elements have one current mode, which may determine the final action being triggered.

Pad devices often divide buttons and sensors into groups. All elements in a group share the same current mode, but different groups may have different modes. See DevicePad.getNGroups() and DevicePad.getGroupNModes(int).

Each of the actions that a given button/strip/ring performs for a given mode is defined by a Gtk.PadActionEntry. It contains an action name that will be looked up in the given ActionGroup and activated whenever the specified input element and mode are triggered.

A simple example of GtkPadController usage: Assigning button 1 in all modes and pad devices to an "invert-selection" action: 

GtkPadActionEntry *pad_actions[] = {
   { GTK_PAD_ACTION_BUTTON, 1, -1, "Invert selection", "pad-actions.invert-selection" },
   …
 };

 …
 action_group = g_simple_action_group_new ();
 action = g_simple_action_new ("pad-actions.invert-selection", NULL);
 g_signal_connect (action, "activate", on_invert_selection_activated, NULL);
 g_action_map_add_action (G_ACTION_MAP (action_group), action);
 …
 pad_controller = gtk_pad_controller_new (action_group, NULL);

The actions belonging to rings/strips/dials will be activated with a parameter of type G_VARIANT_TYPE_DOUBLE bearing the value of the given axis, it is required that those are made stateful and accepting this GVariantType. For rings the value is the angle of the ring position in degrees with 0 facing up. For strips the value is the absolute position on the strip, normalized to the [0.0, 1.0] range. For dials the value is the relative movement of the dial, normalized so that the value 120 represents one logical scroll wheel detent in the positive direction. Devices that support high-resolution scrolling may send events with fractions of 120 to signify a smaller motion.