wacom: Bring back empty state view

This went mistakenly missing in the recent UI updates. Since this
panel is still accessible through search despite tablet availability,
we should have a proper empty state view when moving to the panel
with no tablets available.

Fixes: https://gitlab.gnome.org/GNOME/gnome-control-center/-/issues/1684

2 files changed, 50 insertions, 20 deletions

diff --git a/panels/wacom/cc-wacom-panel.c b/panels/wacom/cc-wacom-panel.c
index 0c808c24b..05592f3ea 100644
--- a/panels/wacom/cc-wacom-panel.c
+++ b/panels/wacom/cc-wacom-panel.c
@@ -49,6 +49,9 @@ struct _CcWacomPanel
 	GtkWidget        *scrollable;
 	GtkWidget        *tablets;
 	GtkWidget        *styli;
+	GtkWidget        *initial_state_stack;
+	GtkWidget        *panel_view;
+	GtkWidget        *panel_empty_state;
 	GHashTable       *devices; /* key=GsdDevice, value=CcWacomDevice */
 	GHashTable       *pages; /* key=CcWacomDevice, value=GtkWidget */
 	GHashTable       *stylus_pages; /* key=CcWacomTool, value=GtkWidget */
@@ -349,6 +352,15 @@ update_test_button (CcWacomPanel *self)
 }
 
 static void
+update_initial_state (CcWacomPanel *self)
+{
+	gtk_stack_set_visible_child (GTK_STACK (self->initial_state_stack),
+				     g_hash_table_size (self->devices) == 0 ?
+				     self->panel_empty_state :
+				     self->panel_view);
+}
+
+static void
 update_highlighted_stylus (CcWacomPanel *panel,
 			   CcWacomTool  *stylus)
 {
@@ -520,6 +532,9 @@ cc_wacom_panel_class_init (CcWacomPanelClass *klass)
 	gtk_widget_class_bind_template_child (widget_class, CcWacomPanel, test_draw_area);
 	gtk_widget_class_bind_template_child (widget_class, CcWacomPanel, tablets);
 	gtk_widget_class_bind_template_child (widget_class, CcWacomPanel, styli);
+	gtk_widget_class_bind_template_child (widget_class, CcWacomPanel, initial_state_stack);
+	gtk_widget_class_bind_template_child (widget_class, CcWacomPanel, panel_empty_state);
+	gtk_widget_class_bind_template_child (widget_class, CcWacomPanel, panel_view);
 	gtk_widget_class_bind_template_child (widget_class, CcWacomPanel, vadjustment);
 }
 
@@ -582,6 +597,7 @@ device_removed_cb (CcWacomPanel     *self,
 	g_hash_table_remove (self->devices, gsd_device);
 	check_remove_stylus_pages (self);
 	update_test_button (self);
+	update_initial_state (self);
 }
 
 static void
@@ -590,6 +606,7 @@ device_added_cb (CcWacomPanel *self,
 {
 	add_known_device (self, device);
 	update_test_button (self);
+	update_initial_state (self);
 }
 
 void
@@ -663,6 +680,7 @@ cc_wacom_panel_init (CcWacomPanel *self)
 		add_known_device (self, l->data);
 
 	update_test_button (self);
+	update_initial_state (self);
 }
 
 GDBusProxy *
diff --git a/panels/wacom/cc-wacom-panel.ui b/panels/wacom/cc-wacom-panel.ui
index 28a9d79b6..77e7e16a9 100644
--- a/panels/wacom/cc-wacom-panel.ui
+++ b/panels/wacom/cc-wacom-panel.ui
@@ -15,34 +15,46 @@
     </child>
 
     <child type="content">
-      <object class="GtkScrolledWindow">
-        <property name="hscrollbar-policy">never</property>
-        <property name="vadjustment">vadjustment</property>
+      <object class="GtkStack" id="initial_state_stack">
+        <property name="transition_duration">0</property>
         <child>
-          <object class="AdwClamp" id="scrollable">
-            <property name="margin_top">32</property>
-            <property name="margin_bottom">32</property>
-            <property name="margin_start">12</property>
-            <property name="margin_end">12</property>
-
+          <object class="GtkScrolledWindow" id="panel_view">
+            <property name="hscrollbar-policy">never</property>
+            <property name="vadjustment">vadjustment</property>
             <child>
-              <object class="GtkBox">
-                <property name="spacing">48</property>
-                <property name="orientation">vertical</property>
+              <object class="AdwClamp" id="scrollable">
+                <property name="margin_top">32</property>
+                <property name="margin_bottom">32</property>
+                <property name="margin_start">12</property>
+                <property name="margin_end">12</property>
+
                 <child>
-                  <object class="GtkBox" id="tablets">
-                    <property name="orientation">vertical</property>
+                  <object class="GtkBox">
                     <property name="spacing">48</property>
-	          </object>
-                </child>
-                <child>
-                  <object class="GtkBox" id="styli">
                     <property name="orientation">vertical</property>
-                    <property name="spacing">48</property>
-	          </object>
+                    <child>
+                      <object class="GtkBox" id="tablets">
+                        <property name="orientation">vertical</property>
+                        <property name="spacing">48</property>
+                      </object>
+                    </child>
+                    <child>
+                      <object class="GtkBox" id="styli">
+                        <property name="orientation">vertical</property>
+                        <property name="spacing">48</property>
+                      </object>
+                    </child>
+                  </object>
                 </child>
               </object>
             </child>
+	  </object>
+	</child>
+	<child>
+          <object class="AdwStatusPage" id="panel_empty_state">
+            <property name="icon-name">input-tablet-symbolic</property>
+            <property name="title" translatable="yes">No tablet detected</property>
+            <property name="description" translatable="yes">Please plug in or turn on your Wacom tablet.</property>
           </object>
         </child>
       </object>