wacom: Show distinct entries for Wacom Express Key Remote

If you did not know the Wacom Express Key Remote (or EKR for short),
let me introduce it to you:

fb4143a007/a/c/ack-411050_main_2.jpg

This is a hand-sized standalone pad device, meant to be used together
with drawing tablets, providing additional buttons and a touch sensitive
ring that can be mapped to actions and keypresses.

These pads were so far handled in GNOME, but in a very subtle manner.
As the EKR is implicitly paired to a tablet, it was possible to map
EKR buttons from the paired tablet once the pad OSD UI from GNOME
Shell was shown.

As this device basically just needs a "Map buttons" action to
configure it, it just didn't sit well in the older Settings UI,
it would get a separate page with just a lone button in there. So
its support has been kind of an easter egg so far.

But the new UI can indeed accomodate better a device that is neither
tablet nor stylus, and has few options. This commit adds the EKR
as a separate AdwPreferencesGroup.

panels/wacom/cc-wacom-ekr-page.c

@@ -0,0 +1,195 @@
+/*
+ * Copyright © 2022 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Carlos Garnacho <carlosg@gnome.org>
+ */
+
+#include "config.h"
+
+#include "cc-wacom-ekr-page.h"
+#include "cc-wacom-panel.h"
+
+struct _CcWacomEkrPage
+{
+	GtkBox parent_instance;
+	GtkWidget *ekr_section;
+	GtkWidget *ekr_icon;
+	GtkWidget *ekr_map_buttons;
+	CcWacomPanel *panel;
+	CcWacomDevice *device;
+};
+
+enum {
+	PROP_0,
+	PROP_PANEL,
+	PROP_DEVICE,
+	N_PROPS,
+};
+
+static GParamSpec *props[N_PROPS] = { 0, };
+
+G_DEFINE_TYPE (CcWacomEkrPage, cc_wacom_ekr_page, GTK_TYPE_BOX)
+
+static void
+set_osd_visibility_cb (GObject      *source_object,
+		       GAsyncResult *res,
+		       gpointer      data)
+{
+	g_autoptr(GError) error = NULL;
+	g_autoptr(GVariant) result = NULL;
+
+	result = g_dbus_proxy_call_finish (G_DBUS_PROXY (source_object), res, &error);
+
+	if (error && !g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+		g_warning ("Error invoking pad button mapping OSK: %s\n", error->message);
+}
+
+static void
+set_osd_visibility (CcWacomEkrPage *page)
+{
+	GDBusProxy *proxy;
+	GsdDevice *gsd_device;
+	const gchar *device_path;
+
+	proxy = cc_wacom_panel_get_gsd_wacom_bus_proxy (page->panel);
+
+	if (proxy == NULL) {
+		g_warning ("Wacom D-Bus interface is not available");
+		return;
+	}
+
+	gsd_device = cc_wacom_device_get_device (page->device);
+	device_path = gsd_device_get_device_file (gsd_device);
+
+	g_dbus_proxy_call (proxy,
+			   "Show",
+			   g_variant_new ("(ob)", device_path, TRUE),
+			   G_DBUS_CALL_FLAGS_NONE,
+			   -1,
+			   NULL,
+			   set_osd_visibility_cb,
+			   page);
+}
+
+static void
+on_map_buttons_activated (CcWacomEkrPage *self)
+{
+	set_osd_visibility (self);
+}
+
+static void
+cc_wacom_ekr_page_get_property (GObject    *object,
+				guint       prop_id,
+				GValue     *value,
+				GParamSpec *pspec)
+{
+	CcWacomEkrPage *page = CC_WACOM_EKR_PAGE (object);
+
+	switch (prop_id) {
+	case PROP_PANEL:
+		g_value_set_object (value, page->panel);
+		break;
+	case PROP_DEVICE:
+		g_value_set_object (value, page->device);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+		break;
+	}
+}
+
+static void
+cc_wacom_ekr_page_set_property (GObject      *object,
+				guint         prop_id,
+				const GValue *value,
+				GParamSpec   *pspec)
+{
+	CcWacomEkrPage *page = CC_WACOM_EKR_PAGE (object);
+
+	switch (prop_id) {
+	case PROP_PANEL:
+		page->panel = g_value_get_object (value);
+		break;
+	case PROP_DEVICE:
+		page->device = g_value_get_object (value);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+		break;
+	}
+}
+
+static void
+cc_wacom_ekr_page_constructed (GObject *object)
+{
+	CcWacomEkrPage *page = CC_WACOM_EKR_PAGE (object);
+
+	G_OBJECT_CLASS (cc_wacom_ekr_page_parent_class)->constructed (object);
+
+	adw_preferences_group_set_title (ADW_PREFERENCES_GROUP (page->ekr_section),
+					 cc_wacom_device_get_name (page->device));
+}
+
+static void
+cc_wacom_ekr_page_class_init (CcWacomEkrPageClass *klass)
+{
+	GObjectClass *object_class = G_OBJECT_CLASS (klass);
+	GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
+
+	object_class->get_property = cc_wacom_ekr_page_get_property;
+	object_class->set_property = cc_wacom_ekr_page_set_property;
+	object_class->constructed = cc_wacom_ekr_page_constructed;
+
+	gtk_widget_class_set_template_from_resource (widget_class, "/org/gnome/control-center/wacom/cc-wacom-ekr-page.ui");
+
+	gtk_widget_class_bind_template_child (widget_class, CcWacomEkrPage, ekr_section);
+	gtk_widget_class_bind_template_child (widget_class, CcWacomEkrPage, ekr_icon);
+	gtk_widget_class_bind_template_child (widget_class, CcWacomEkrPage, ekr_map_buttons);
+
+	gtk_widget_class_bind_template_callback (widget_class, on_map_buttons_activated);
+
+	props[PROP_PANEL] = g_param_spec_object ("panel",
+						 "panel",
+						 "panel",
+						 CC_TYPE_WACOM_PANEL,
+						 G_PARAM_READWRITE |
+						 G_PARAM_CONSTRUCT_ONLY);
+
+	props[PROP_DEVICE] = g_param_spec_object ("device",
+						  "device",
+						  "device",
+						  CC_TYPE_WACOM_DEVICE,
+						  G_PARAM_READWRITE |
+						  G_PARAM_CONSTRUCT_ONLY);
+
+	g_object_class_install_properties (object_class, N_PROPS, props);
+}
+
+static void
+cc_wacom_ekr_page_init (CcWacomEkrPage *page)
+{
+	gtk_widget_init_template (GTK_WIDGET (page));
+}
+
+GtkWidget *
+cc_wacom_ekr_page_new (CcWacomPanel  *panel,
+		       CcWacomDevice *ekr)
+{
+	return g_object_new (CC_TYPE_WACOM_EKR_PAGE,
+			     "panel", panel,
+			     "device", ekr,
+			     NULL);
+}

panels/wacom/cc-wacom-ekr-page.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2022 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Carlos Garnacho <carlosg@gnome.org>
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+#include "cc-wacom-panel.h"
+#include "cc-wacom-device.h"
+
+G_BEGIN_DECLS
+
+#define CC_TYPE_WACOM_EKR_PAGE (cc_wacom_ekr_page_get_type ())
+G_DECLARE_FINAL_TYPE (CcWacomEkrPage, cc_wacom_ekr_page, CC, WACOM_EKR_PAGE, GtkBox)
+
+GtkWidget * cc_wacom_ekr_page_new (CcWacomPanel  *panel,
+				   CcWacomDevice *stylus);
+
+G_END_DECLS

panels/wacom/cc-wacom-ekr-page.ui

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <template class="CcWacomEkrPage" parent="GtkBox">
+    <property name="orientation">vertical</property>
+    <property name="spacing">24</property>
+    <child>
+      <object class="AdwPreferencesGroup" id="ekr_section">
+	<property name="description" translatable="yes"
+		  comments="translators: this is a drawing tablet pad, i.e. a collection of buttons and knobs">External pad device</property>
+        <property name="header-suffix">
+          <object class="GtkPicture" id="ekr_icon">
+            <property name="halign">end</property>
+            <property name="valign">start</property>
+            <property name="file">resource:///org/gnome/control-center/wacom/wacom-tablet.svg</property>
+          </object>
+        </property>
+        <child>
+          <object class="AdwActionRow" id="ekr_map_buttons">
+            <property name="title" translatable="yes">Map Buttons</property>
+            <property name="activatable">True</property>
+            <signal name="activated" handler="on_map_buttons_activated" object="CcWacomEkrPage" swapped="yes" />
+            <child type="suffix">
+              <object class="GtkImage">
+                <property name="icon-name">go-next-symbolic</property>
+              </object>
+            </child>
+          </object>
+        </child>
+      </object>
+    </child>
+  </template>
+</interface>

panels/wacom/cc-wacom-panel.c

@@ -29,6 +29,7 @@
 #include "shell/cc-debug.h"
 #include "cc-wacom-panel.h"
 #include "cc-wacom-page.h"
+#include "cc-wacom-ekr-page.h"
 #include "cc-wacom-stylus-page.h"
 #include "cc-wacom-resources.h"
 #include "cc-drawing-area.h"
@@ -39,6 +40,9 @@
 #include <gdk/wayland/gdkwayland.h>
 #endif
 
+#define EKR_VENDOR "056a"
+#define EKR_PRODUCT "0331"
+
 struct _CcWacomPanel
 {
 	CcPanel           parent_instance;
@@ -546,6 +550,7 @@ add_known_device (CcWacomPanel *self,
 	GsdDeviceType device_type;
 	g_autoptr(GList) tools = NULL;
 	GtkWidget *page;
+	gboolean is_ekr = FALSE;
 	GList *l;
 
 	device_type = gsd_device_get_device_type (gsd_device);
@@ -554,12 +559,27 @@ add_known_device (CcWacomPanel *self,
 		return;
 
 	if ((device_type &
-	     (GSD_DEVICE_TYPE_PAD |
+	     (GSD_DEVICE_TYPE_TOUCHSCREEN |
-	      GSD_DEVICE_TYPE_TOUCHSCREEN |
 	      GSD_DEVICE_TYPE_TOUCHPAD)) != 0) {
 		return;
 	}
 
+	if ((device_type & GSD_DEVICE_TYPE_PAD) != 0) {
+		const char *vendor, *product;
+
+		gsd_device_get_device_ids (gsd_device, &vendor, &product);
+		is_ekr = (g_strcmp0 (vendor, EKR_VENDOR) == 0 &&
+			  g_strcmp0 (product, EKR_PRODUCT) == 0);
+
+		/* Express key remote is an special case, as it is an
+		 * external pad device, we want to distinctly show it
+		 * in the list. Other pads are mounted on a tablet, which
+		 * get their own entries.
+		 */
+		if (!is_ekr)
+			return;
+	}
+
 	device = cc_wacom_device_new (gsd_device);
 	if (!device)
 		return;
@@ -572,7 +592,11 @@ add_known_device (CcWacomPanel *self,
 		add_stylus (self, l->data);
 	}
 
-	page = cc_wacom_page_new (self, device);
+	if (is_ekr)
+		page = cc_wacom_ekr_page_new (self, device);
+	else
+		page = cc_wacom_page_new (self, device);
+
 	gtk_box_append (GTK_BOX (self->tablets), page);
 	g_hash_table_insert (self->pages, device, page);
 }

panels/wacom/meson.build

@@ -70,7 +70,8 @@ common_sources += wacom_gresource
 
 sources = common_sources + files(
   'cc-' + cappletname + '-panel.c',
-  'cc-drawing-area.c'
+  'cc-drawing-area.c',
+  'cc-wacom-ekr-page.c',
 )
 
 deps += libdevice_dep

panels/wacom/wacom.gresource.xml

@@ -3,6 +3,7 @@
   <gresource prefix="/org/gnome/control-center/wacom">
     <file preprocess="xml-stripblanks">cc-wacom-panel.ui</file>
     <file preprocess="xml-stripblanks">cc-wacom-page.ui</file>
+    <file preprocess="xml-stripblanks">cc-wacom-ekr-page.ui</file>
     <file preprocess="xml-stripblanks">cc-wacom-stylus-page.ui</file>
     <file preprocess="xml-stripblanks">button-mapping.ui</file>
     <file preprocess="xml-stripblanks">calibrator/calibrator.ui</file>