printers: Move "Add Printer" button to header bar

This patch introduces a change to the Lock/Unlock logic. From now
on, unlocking the panel causes the "Lock" button to turn into the
"Add Printer" button.

https://bugzilla.gnome.org/show_bug.cgi?id=767600

panels/printers/cc-printers-panel.c

@@ -99,6 +99,7 @@ struct _CcPrintersPanelPrivate
   guint            cups_status_check_id;
   guint            dbus_subscription_id;
 
+  GtkWidget    *headerbar_buttons;
   GtkWidget    *popup_menu;
   GList        *driver_change_list;
   GCancellable *get_ppd_name_cancellable;
@@ -119,6 +120,9 @@ struct _CcPrintersPanelPrivate
   gpointer dummy;
 };
 
+#define PAGE_LOCK "_lock"
+#define PAGE_ADDPRINTER "_addprinter"
+
 typedef struct
 {
   gchar        *printer_name;
@@ -159,6 +163,24 @@ cc_printers_panel_set_property (GObject      *object,
     }
 }
 
+static void
+cc_printers_panel_constructed (GObject *object)
+{
+  CcPrintersPanel *self = CC_PRINTERS_PANEL (object);
+  CcPrintersPanelPrivate *priv = self->priv;
+  GtkLockButton *button;
+  CcShell *shell;
+
+  G_OBJECT_CLASS (cc_printers_panel_parent_class)->constructed (object);
+
+  shell = cc_panel_get_shell (CC_PANEL (self));
+  cc_shell_embed_widget_in_header (shell, priv->headerbar_buttons);
+
+  button = (GtkLockButton*)
+    gtk_builder_get_object (priv->builder, "lock-button");
+  gtk_lock_button_set_permission (button, priv->permission);
+}
+
 static void
 cc_printers_panel_dispose (GObject *object)
 {
@@ -250,14 +272,6 @@ cc_printers_panel_finalize (GObject *object)
   G_OBJECT_CLASS (cc_printers_panel_parent_class)->finalize (object);
 }
 
-static GPermission *
-cc_printers_panel_get_permission (CcPanel *panel)
-{
-  CcPrintersPanelPrivate *priv = CC_PRINTERS_PANEL (panel)->priv;
-
-  return priv->permission;
-}
-
 static const char *
 cc_printers_panel_get_help_uri (CcPanel *panel)
 {
@@ -274,10 +288,10 @@ cc_printers_panel_class_init (CcPrintersPanelClass *klass)
 
   object_class->get_property = cc_printers_panel_get_property;
   object_class->set_property = cc_printers_panel_set_property;
+  object_class->constructed = cc_printers_panel_constructed;
   object_class->dispose = cc_printers_panel_dispose;
   object_class->finalize = cc_printers_panel_finalize;
 
-  panel_class->get_permission = cc_printers_panel_get_permission;
   panel_class->get_help_uri = cc_printers_panel_get_help_uri;
 }
 
@@ -2698,6 +2712,9 @@ update_sensitivity (gpointer user_data)
     priv->lockdown_settings &&
     !g_settings_get_boolean (priv->lockdown_settings, "disable-print-setup");
 
+  gtk_stack_set_visible_child_name (GTK_STACK (priv->headerbar_buttons),
+    is_authorized ? PAGE_ADDPRINTER : PAGE_LOCK);
+
   printer_selected = priv->current_dest >= 0 &&
                      priv->current_dest < priv->num_dests &&
                      priv->dests != NULL;
@@ -3061,7 +3078,7 @@ cc_printers_panel_init (CcPrintersPanel *self)
   GtkWidget              *widget;
   PpCups                 *cups;
   GError                 *error = NULL;
-  gchar                  *objects[] = { "main-vbox", NULL };
+  gchar                  *objects[] = { "main-vbox", "headerbar-buttons", NULL };
   GtkStyleContext        *context;
   guint                   builder_result;
 
@@ -3118,6 +3135,10 @@ cc_printers_panel_init (CcPrintersPanel *self)
       return;
     }
 
+  widget = (GtkWidget*)
+    gtk_builder_get_object (priv->builder, "headerbar-buttons");
+  priv->headerbar_buttons = widget;
+
   /* add the top level widget */
   top_widget = (GtkWidget*)
     gtk_builder_get_object (priv->builder, "main-vbox");

panels/printers/printers.ui

@@ -2,6 +2,31 @@
 <interface>
   <requires lib="gtk+" version="3.12"/>
   <!-- interface-naming-policy project-wide -->
+  <object class="GtkStack" id="headerbar-buttons">
+    <property name="visible">True</property>
+    <child>
+      <object class="GtkLockButton" id="lock-button">
+        <property name="visible">True</property>
+      </object>
+      <packing>
+        <property name="name">_lock</property>
+      </packing>
+    </child>
+    <child>
+      <object class="GtkButton" id="printer-add-button">
+        <property name="visible">True</property>
+        <property name="sensitive">True</property>
+        <property name="use_underline">True</property>
+        <property name="label" translatable="yes">Add Printer</property>
+        <style>
+          <class name="suggested-action"/>
+        </style>
+      </object>
+      <packing>
+        <property name="name">_addprinter</property>
+      </packing>
+    </child>
+  </object>
   <object class="GtkStack" id="main-vbox">
     <property name="margin-start">6</property>
     <property name="margin-end">6</property>
@@ -61,19 +86,6 @@
                 <style>
                   <class name="inline-toolbar"/>
                 </style>
-                <child>
-                  <object class="GtkToolButton" id="printer-add-button">
-                    <property name="visible">True</property>
-                    <property name="sensitive">True</property>
-                    <property name="use_underline">True</property>
-                    <property name="icon_name">list-add-symbolic</property>
-                    <property name="label" translatable="yes">Add Printer</property>
-                  </object>
-                  <packing>
-                    <property name="expand">False</property>
-                    <property name="homogeneous">True</property>
-                  </packing>
-                </child>
                 <child>
                   <object class="GtkToolButton" id="printer-remove-button">
                     <property name="visible">True</property>