/GTK 3.24


GtkPadController — Controller for drawing tablet pads


GActionGroup * action-group Read / Write / Construct Only
GdkDevice * pad Read / Write / Construct Only

Types and Values

Object Hierarchy

    ╰── GtkEventController
        ╰── GtkPadController


#include <gtk/gtk.h>


GtkPadController is an event controller for the pads found in drawing tablets (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, this event controller is provided to map those to GAction objects, thus letting the application give those a more semantic meaning.

Buttons and sensors are not constrained to triggering a single action, some GDK_SOURCE_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 gdk_device_pad_get_n_groups() and gdk_device_pad_get_group_n_modes().

Each of the actions that a given button/strip/ring performs for a given mode is defined by GtkPadActionEntry, it contains an action name that will be looked up in the given GActionGroup 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 (window, action_group, NULL);

The actions belonging to rings/strips 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.


gtk_pad_controller_new ()

GtkPadController *
gtk_pad_controller_new (GtkWindow *window,
                        GActionGroup *group,
                        GdkDevice *pad);

Creates a new GtkPadController that will associate events from pad to actions. A NULL pad may be provided so the controller manages all pad devices generically, it is discouraged to mix GtkPadController objects with NULL and non-NULL pad argument on the same window , as execution order is not guaranteed.

The GtkPadController is created with no mapped actions. In order to map pad events to actions, use gtk_pad_controller_set_action_entries() or gtk_pad_controller_set_action().



a GtkWindow


GActionGroup to trigger actions from


A GDK_SOURCE_TABLET_PAD device, or NULL to handle all pads.



A newly created GtkPadController

Since: 3.22

gtk_pad_controller_set_action_entries ()

gtk_pad_controller_set_action_entries (GtkPadController *controller,
                                       const GtkPadActionEntry *entries,
                                       gint n_entries);

This is a convenience function to add a group of action entries on controller . See GtkPadActionEntry and gtk_pad_controller_set_action().



a GtkPadController


the action entries to set on controller .

[array length=n_entries]


the number of elements in entries

Since: 3.22

gtk_pad_controller_set_action ()

gtk_pad_controller_set_action (GtkPadController *controller,
                               GtkPadActionType type,
                               gint index,
                               gint mode,
                               const gchar *label,
                               const gchar *action_name);

Adds an individual action to controller . This action will only be activated if the given button/ring/strip number in index is interacted while the current mode is mode . -1 may be used for simple cases, so the action is triggered on all modes.

The given label should be considered user-visible, so internationalization rules apply. Some windowing systems may be able to use those for user feedback.



a GtkPadController


the type of pad feature that will trigger this action


the 0-indexed button/ring/strip number that will trigger this action


the mode that will trigger this action, or -1 for all modes.


Human readable description of this action, this string should be deemed user-visible.


action name that will be activated in the GActionGroup

Since: 3.22

Types and Values


typedef struct _GtkPadController GtkPadController;

enum GtkPadActionType

The type of a pad action.



Action is triggered by a pad button


Action is triggered by a pad ring


Action is triggered by a pad strip

struct GtkPadActionEntry

struct GtkPadActionEntry {
  GtkPadActionType type;
  gint index;
  gint mode;
  gchar *label;
  gchar *action_name;

Struct defining a pad action entry.


GtkPadActionType type;

the type of pad feature that will trigger this action entry.

gint index;

the 0-indexed button/ring/strip number that will trigger this action entry.

gint mode;

the mode that will trigger this action entry, or -1 for all modes.

gchar *label;

Human readable description of this action entry, this string should be deemed user-visible.

gchar *action_name;

action name that will be activated in the GActionGroup.

Property Details

The “action-group” property

  “action-group”             GActionGroup *

Action group to launch actions from.

Owner: GtkPadController

Flags: Read / Write / Construct Only

The “pad” property

  “pad”                      GdkDevice *

Pad device to control.

Owner: GtkPadController

Flags: Read / Write / Construct Only

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Licensed under the GNU Lesser General Public License version 2.1 or later.