[gnome-control-center/wip/carlosg/ekr-loves-27qhd: 2/4] wacom: Cater for multiple pads in the CcWacomPage

[Carlos Garnacho <carlosg src gnome org>]

commit 47d6892d8fa37f1494bbc6f2a4bccaa2a61e7dea
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Dec 5 15:36:03 2019 +0100

    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

 panels/wacom/cc-wacom-page.c | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)
---
diff --git a/panels/wacom/cc-wacom-page.c b/panels/wacom/cc-wacom-page.c
index 70f7383ff..10521b302 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;
@@ -376,15 +376,17 @@ 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;
 
@@ -470,7 +472,9 @@ 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);
 
@@ -720,7 +724,8 @@ 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;
 
@@ -916,7 +921,7 @@ 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
@@ -938,7 +943,7 @@ check_add_pad (CcWacomPage *page,
                return;
        }
 
-       g_set_object (&page->pad, wacom_device);
+       page->pads = g_list_prepend (page->pads, wacom_device);
        update_pad_availability (page);
 }
 
@@ -946,11 +951,19 @@ 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);
 }