gdk: Add GdkDevicePad

This is an interface meant to be implemented by the "pad" devices.
This device-specific interface exposes the mapping of all pad features,
it allows retrieving:
- The number of buttons/rings/strips
- The number of groups
- The number of modes a group has
- Whether a given button/ring/strip belongs to a given group

https://bugzilla.gnome.org/show_bug.cgi?id=770026

docs/reference/gdk/gdk-docs.sgml

@@ -25,6 +25,7 @@
     <xi:include href="xml/gdkseat.xml" />
     <xi:include href="xml/gdkmonitor.xml" />
     <xi:include href="xml/gdkdevice.xml" />
+    <xi:include href="xml/gdkdevicepad.xml" />
     <xi:include href="xml/regions.xml" />
     <xi:include href="xml/pixbufs.xml" />
     <xi:include href="xml/rgba_colors.xml" />

docs/reference/gdk/gdk3-sections.txt

@@ -796,6 +796,25 @@ gdk_device_type_get_type
 GDK_MAX_TIMECOORD_AXES
 </SECTION>
 
+<SECTION>
+<TITLE>GdkDevicePad</TITLE>
+<FILE>gdkdevicepad</FILE>
+GdkDevicePad
+GdkDevicePadFeature
+gdk_device_pad_get_n_groups
+gdk_device_pad_get_group_n_modes
+gdk_device_pad_get_n_features
+gdk_device_pad_get_feature_group
+
+<SUBSECTION Standard>
+GDK_TYPE_DEVICE_PAD
+GDK_DEVICE_PAD
+GDK_IS_DEVICE_PAD
+
+<SUBSECTION Private>
+gdk_device_pad_get_type
+</SECTION>
+
 <SECTION>
 <TITLE>GdkSeat</TITLE>
 <FILE>gdkseat</FILE>

docs/reference/gdk/gdk3.types

@@ -4,6 +4,7 @@ gdk_app_launch_context_get_type
 gdk_cursor_get_type
 gdk_device_get_type
 gdk_device_manager_get_type
+gdk_device_pad_get_type
 gdk_display_get_type
 gdk_display_manager_get_type
 gdk_drag_context_get_type

gdk/Makefile.am

@@ -71,6 +71,7 @@ gdk_public_h_sources = 				\
 	gdkcairo.h				\
 	gdkcursor.h				\
 	gdkdevice.h				\
+	gdkdevicepad.h				\
 	gdkdevicetool.h				\
 	gdkdevicemanager.h			\
 	gdkdisplay.h				\
@@ -114,6 +115,7 @@ gdk_private_headers = 				\
 	gdkcursorprivate.h			\
 	gdkdevicemanagerprivate.h		\
 	gdkdeviceprivate.h			\
+	gdkdevicepadprivate.h			\
 	gdkdevicetoolprivate.h			\
 	gdkdisplaymanagerprivate.h		\
 	gdkdisplayprivate.h			\
@@ -144,6 +146,7 @@ gdk_c_sources = 				\
 	gdkcursor.c				\
 	gdkdeprecated.c				\
 	gdkdevice.c				\
+	gdkdevicepad.c				\
 	gdkdevicetool.c				\
 	gdkdevicemanager.c			\
 	gdkdisplay.c				\

gdk/gdk.h

@@ -33,6 +33,7 @@
 #include <gdk/gdkcairo.h>
 #include <gdk/gdkcursor.h>
 #include <gdk/gdkdevice.h>
+#include <gdk/gdkdevicepad.h>
 #include <gdk/gdkdevicetool.h>
 #include <gdk/gdkdevicemanager.h>
 #include <gdk/gdkdisplay.h>

gdk/gdkdevicepad.c

+/* GDK - The GIMP Drawing Kit
+ * Copyright (C) 2016 Red Hat
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Carlos Garnacho <carlosg@gnome.org>
+ */
+
+/**
+ * SECTION:gdkdevicepad
+ * @Short_description: Pad device interface
+ * @Title: GtkDevicePad
+ *
+ * #GdkDevicePad is an interface implemented by devices of type
+ * %GDK_SOURCE_TABLET_PAD, it allows querying the features provided
+ * by the pad device.
+ *
+ * Tablet pads may contain one or more groups, each containing a subset
+ * of the buttons/rings/strips available. gdk_device_pad_get_n_groups()
+ * can be used to obtain the number of groups, gdk_device_pad_get_n_features()
+ * and gdk_device_pad_get_feature_group() can be combined to find out the
+ * number of buttons/rings/strips the device has, and how are they grouped.
+ *
+ * Each of those groups have different modes, which may be used to map
+ * each individual pad feature to multiple actions. Only one mode is
+ * effective (current) for each given group, different groups may have
+ * different current modes. The number of available modes in a group can
+ * be found out through gdk_device_pad_get_group_n_modes(), and the current
+ * mode for a given group will be notified through the #GdkEventPadGroupMode
+ * event.
+ *
+ */
+
+#include "config.h"
+
+#include "gdkdevicepad.h"
+#include "gdkdevicepadprivate.h"
+#include "gdkdeviceprivate.h"
+
+G_DEFINE_INTERFACE (GdkDevicePad, gdk_device_pad, GDK_TYPE_DEVICE)
+
+static void
+gdk_device_pad_default_init (GdkDevicePadInterface *pad)
+{
+}
+
+/**
+ * gdk_device_pad_get_n_groups:
+ * @pad: a #GdkDevicePad
+ *
+ * Returns the number of groups this pad device has. Pads have
+ * at least one group. A pad group is a subcollection of
+ * buttons/strip/rings that is affected collectively by a same
+ * current mode.
+ *
+ * Returns: The number of button/ring/strip groups in the pad.
+ *
+ * Since: 3.22
+ **/
+gint
+gdk_device_pad_get_n_groups (GdkDevicePad *pad)
+{
+  GdkDevicePadInterface *iface = GDK_DEVICE_PAD_GET_IFACE (pad);
+
+  g_return_val_if_fail (GDK_IS_DEVICE_PAD (pad), 0);
+
+  return iface->get_n_groups (pad);
+}
+
+/**
+ * gdk_device_pad_get_group_n_modes:
+ * @pad: a #GdkDevicePad
+ * @group_idx: group to get the number of available modes from
+ *
+ * Returns the number of modes that @group may have.
+ *
+ * Returns: The number of modes available in @group.
+ *
+ * Since: 3.22
+ **/
+gint
+gdk_device_pad_get_group_n_modes (GdkDevicePad *pad,
+                                  gint          group_idx)
+{
+  GdkDevicePadInterface *iface = GDK_DEVICE_PAD_GET_IFACE (pad);
+
+  g_return_val_if_fail (GDK_IS_DEVICE_PAD (pad), 0);
+  g_return_val_if_fail (group_idx >= 0, 0);
+
+  return iface->get_group_n_modes (pad, group_idx);
+}
+
+/**
+ * gdk_device_pad_get_n_features:
+ * @pad: a #GdkDevicePad
+ * @feature: a pad feature
+ *
+ * Returns the number of features a tablet pad has.
+ *
+ * Returns: The amount of elements of type @feature that this pad has.
+ *
+ * Since: 3.22
+ **/
+gint
+gdk_device_pad_get_n_features (GdkDevicePad        *pad,
+                               GdkDevicePadFeature  feature)
+{
+  GdkDevicePadInterface *iface = GDK_DEVICE_PAD_GET_IFACE (pad);
+
+  g_return_val_if_fail (GDK_IS_DEVICE_PAD (pad), 0);
+
+  return iface->get_n_features (pad, feature);
+}
+
+/**
+ * gdk_device_pad_get_feature_group:
+ * @pad: a #GdkDevicePad
+ * @feature: the feature type to get the group from
+ * @feature_idx: the index of the feature to get the group from
+ *
+ * Returns the group the given @feature and @idx belong to,
+ * or -1 if feature/index do not exist in @pad.
+ *
+ * Returns: The group number of the queried pad feature.
+ *
+ * Since: 3.22
+ **/
+gint
+gdk_device_pad_get_feature_group (GdkDevicePad        *pad,
+                                  GdkDevicePadFeature  feature,
+                                  gint                 idx)
+{
+  GdkDevicePadInterface *iface = GDK_DEVICE_PAD_GET_IFACE (pad);
+
+  g_return_val_if_fail (GDK_IS_DEVICE_PAD (pad), -1);
+  g_return_val_if_fail (idx >= 0, -1);
+
+  return iface->get_feature_group (pad, feature, idx);
+}

gdk/gdkdevicepad.h

+/* GDK - The GIMP Drawing Kit
+ * Copyright (C) 2016 Red Hat
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Carlos Garnacho <carlosg@gnome.org>
+ */
+
+#ifndef __GDK_DEVICE_PAD_H__
+#define __GDK_DEVICE_PAD_H__
+
+#if !defined (__GDK_H_INSIDE__) && !defined (GDK_COMPILATION)
+#error "Only <gdk/gdk.h> can be included directly."
+#endif
+
+#include <gdk/gdkversionmacros.h>
+#include <gdk/gdktypes.h>
+
+G_BEGIN_DECLS
+
+#define GDK_TYPE_DEVICE_PAD         (gdk_device_pad_get_type ())
+#define GDK_DEVICE_PAD(o)           (G_TYPE_CHECK_INSTANCE_CAST ((o), GDK_TYPE_DEVICE_PAD, GdkDevicePad))
+#define GDK_IS_DEVICE_PAD(o)        (G_TYPE_CHECK_INSTANCE_TYPE ((o), GDK_TYPE_DEVICE_PAD))
+
+typedef struct _GdkDevicePad GdkDevicePad;
+typedef struct _GdkDevicePadInterface GdkDevicePadInterface;
+
+/**
+ * GdkDevicePadFeature:
+ * @GDK_DEVICE_PAD_FEATURE_BUTTON: a button
+ * @GDK_DEVICE_PAD_FEATURE_RING: a ring-shaped interactive area
+ * @GDK_DEVICE_PAD_FEATURE_STRIP: a straight interactive area
+ *
+ * A pad feature.
+ */
+typedef enum {
+  GDK_DEVICE_PAD_FEATURE_BUTTON,
+  GDK_DEVICE_PAD_FEATURE_RING,
+  GDK_DEVICE_PAD_FEATURE_STRIP
+} GdkDevicePadFeature;
+
+GDK_AVAILABLE_IN_3_22
+GType gdk_device_pad_get_type          (void) G_GNUC_CONST;
+
+GDK_AVAILABLE_IN_3_22
+gint  gdk_device_pad_get_n_groups      (GdkDevicePad *pad);
+
+GDK_AVAILABLE_IN_3_22
+gint  gdk_device_pad_get_group_n_modes (GdkDevicePad *pad,
+                                        gint          group_idx);
+
+GDK_AVAILABLE_IN_3_22
+gint  gdk_device_pad_get_n_features    (GdkDevicePad        *pad,
+                                        GdkDevicePadFeature  feature);
+
+GDK_AVAILABLE_IN_3_22
+gint  gdk_device_pad_get_feature_group (GdkDevicePad        *pad,
+                                        GdkDevicePadFeature  feature,
+                                        gint                 feature_idx);
+
+G_END_DECLS
+
+#endif /* __GDK_DEVICE_PAD_H__ */

gdk/gdkdevicepadprivate.h

+/* GDK - The GIMP Drawing Kit
+ * Copyright (C) 2016 Red Hat
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Carlos Garnacho <carlosg@gnome.org>
+ */
+
+#ifndef __GDK_DEVICE_PAD_PRIVATE_H__
+#define __GDK_DEVICE_PAD_PRIVATE_H__
+
+#include "gdkdevicepad.h"
+
+G_BEGIN_DECLS
+
+#define GDK_DEVICE_PAD_GET_IFACE(obj)  (G_TYPE_INSTANCE_GET_INTERFACE ((obj), GDK_TYPE_DEVICE_PAD, GdkDevicePadInterface))
+
+struct _GdkDevicePadInterface {
+  GTypeInterface parent_interface;
+
+  gint (* get_n_groups)      (GdkDevicePad        *pad);
+
+  gint (* get_group_n_modes) (GdkDevicePad        *pad,
+                              gint                 group);
+  gint (* get_n_features)    (GdkDevicePad        *pad,
+                              GdkDevicePadFeature  feature);
+  gint (* get_feature_group) (GdkDevicePad        *pad,
+                              GdkDevicePadFeature  feature,
+                              gint                 idx);
+};
+
+G_END_DECLS
+
+#endif /* __GDK_DEVICE_PAD_PRIVATE_H__ */