wacom: Cater for multiple pads in the CcWacomPage

We don't need to track them much specifically, as we delegate pad
button mapping UI on GNOME Shell. It is however possible to have
tablets with 0 to N pads (upper bound within sanity = 2), so we
must at least reflect that in the "Map Buttons..." button visibility.

This distinction is most important for the combination of EKR plus
Cintiq 27QHD, as this is a pad-less tablet, for which we wouldn't
usually show the "Map buttons..." action.

https://gitlab.gnome.org/GNOME/gnome-control-center/issues/415

1 files changed, 22 insertions, 9 deletions

diff --git a/panels/wacom/cc-wacom-page.c b/panels/wacom/cc-wacom-page.c
index 64e51f809..2ab4b6125 100644
--- a/panels/wacom/cc-wacom-page.c
+++ b/panels/wacom/cc-wacom-page.c
@@ -68,7 +68,7 @@ struct _CcWacomPage
 
 	CcWacomPanel   *panel;
 	CcWacomDevice  *stylus;
-	CcWacomDevice  *pad;
+	GList          *pads;
 	GtkBuilder     *builder;
 	GtkWidget      *nav;
 	GtkWidget      *notebook;
@@ -375,15 +375,17 @@ static void
 setup_button_mapping (CcWacomPage *page)
 {
 	GDesktopPadButtonAction action;
+	CcWacomDevice *pad;
 	GtkWidget *list_box;
 	guint i, n_buttons;
 	GSettings *settings;
 
 	list_box = MWID ("shortcuts_list");
-	n_buttons = cc_wacom_device_get_num_buttons (page->pad);
+	pad = page->pads->data;
+	n_buttons = cc_wacom_device_get_num_buttons (pad);
 
 	for (i = 0; i < n_buttons; i++) {
-		settings = cc_wacom_device_get_button_settings (page->pad, i);
+		settings = cc_wacom_device_get_button_settings (pad, i);
 		if (!settings)
 			continue;
 
@@ -467,7 +469,9 @@ set_osd_visibility (CcWacomPage *page)
 	const gchar        *device_path;
 
 	proxy = cc_wacom_panel_get_gsd_wacom_bus_proxy (page->panel);
-	gsd_device = cc_wacom_device_get_device (page->pad);
+
+	/* Pick the first device, the OSD may change later between them */
+	gsd_device = cc_wacom_device_get_device (page->pads->data);
 
 	device_path = gsd_device_get_device_file (gsd_device);
 
@@ -707,7 +711,8 @@ cc_wacom_page_dispose (GObject *object)
 	g_clear_pointer (&self->dialog, gtk_widget_destroy);
 	g_clear_object (&self->builder);
 	g_clear_object (&self->header_group);
-	g_clear_object (&self->pad);
+	g_list_free_full (self->pads, g_object_unref);
+	self->pads = NULL;
 
 	self->panel = NULL;
 
@@ -901,7 +906,7 @@ set_page_layout (CcWacomPage *page,
 static void
 update_pad_availability (CcWacomPage *page)
 {
-	gtk_widget_set_visible (WID ("map-buttons-button"), page->pad != NULL);
+	gtk_widget_set_visible (WID ("map-buttons-button"), page->pads != NULL);
 }
 
 static void
@@ -921,7 +926,7 @@ check_add_pad (CcWacomPage *page,
 		       cc_wacom_device_get_name (wacom_device)) != 0)
 		return;
 
-	g_set_object (&page->pad, wacom_device);
+	page->pads = g_list_prepend (page->pads, g_steal_pointer (&wacom_device));
 	update_pad_availability (page);
 }
 
@@ -929,11 +934,19 @@ static void
 check_remove_pad (CcWacomPage *page,
 		  GsdDevice   *gsd_device)
 {
+	GList *l;
+
 	if ((gsd_device_get_device_type (gsd_device) & GSD_DEVICE_TYPE_PAD) == 0)
 		return;
 
-	if (page->pad && cc_wacom_device_get_device (page->pad) == gsd_device)
-		page->pad = NULL;
+	for (l = page->pads; l; l = l->next) {
+		CcWacomDevice *wacom_device = l->data;
+		if (cc_wacom_device_get_device (wacom_device) == gsd_device) {
+			page->pads = g_list_delete_link (page->pads, l);
+			g_object_unref (wacom_device);
+		}
+	}
+
 	update_pad_availability (page);
 }