window: Warn about development builds

With this commit, a message dialog pops up whenever a
development build runs. This is meant to actually annoy,
so that we're always reminded that things may not work
as expected.

Since the dialog can be dismissed with a single button
press, it is not the end of the world. But people still
should be aware that Settings is ~not~ meant to run with
Flatpak, and that this is a development tool only.

meson.build

@@ -282,4 +282,4 @@ output += '     NetworkManager (Network panel) ............. ' + host_is_linux.t
 output += '     Wacom (Wacom tablet panel) ................. ' + host_is_linux_not_s390.to_string() + '\n'
 output += '     Wayland .................................... ' + enable_wayland.to_string() + '\n'
 
-message(output)
+message(output)

meson_options.txt

@@ -3,4 +3,4 @@ option('documentation', type: 'boolean', value: false, description: 'build docum
 option('gnome_session_libexecdir', type: 'string', value: '', description: 'Directory for gnome-session\'s libexecdir')
 option('ibus', type: 'boolean', value: true, description: 'build with IBus support')
 option('tracing', type: 'boolean', value: false, description: 'add extra debugging information')
-option('wayland', type: 'boolean', value: true, description: 'build with Wayland support')
+option('wayland', type: 'boolean', value: true, description: 'build with Wayland support')

shell/cc-window.c

@@ -65,6 +65,7 @@ struct _CcWindow
   GtkWidget  *search_entry;
   GtkWidget  *lock_button;
   GtkWidget  *current_panel_box;
+  GtkWidget  *development_warning_dialog;
   GtkWidget  *current_panel;
   char       *current_panel_id;
   GQueue     *previous_panels;
@@ -91,6 +92,47 @@ enum
 };
 
 /* Auxiliary methods */
+static gboolean
+in_flatpak_sandbox (void)
+{
+  return g_file_test ("/.flatpak-info", G_FILE_TEST_EXISTS);
+}
+
+static void
+add_development_build_css (CcWindow *self)
+{
+  g_autoptr(GtkCssProvider) provider = NULL;
+  g_autoptr(GError) error = NULL;
+
+  /* This CSS snipped is added on development builds of GNOME Settings. It is
+   * not meant to be beautiful (althout it is) and is only supposed to integrate
+   * with Adwaita light (although it integrates well with dark too).
+   */
+
+  const gchar *development_build_css =
+  "window.development-version headerbar {\n"
+   "  background: @theme_bg_color linear-gradient(to top,\n"
+   "                                              alpha(@theme_selected_bg_color, 0.34),\n"
+   "                                              alpha(@theme_selected_bg_color, 0.27) 2px,\n"
+   "                                              alpha(@theme_selected_bg_color, 0.20) 3px);\n"
+   "}";
+
+  gtk_style_context_add_class (gtk_widget_get_style_context (GTK_WIDGET (self)), "development-version");
+
+  provider = gtk_css_provider_new ();
+  gtk_css_provider_load_from_data (provider, development_build_css, -1, &error);
+
+  if (error)
+    {
+      g_error ("Failed to load CSS: %s", error->message);
+      return;
+    }
+
+  gtk_style_context_add_provider_for_screen (gtk_widget_get_screen (GTK_WIDGET (self)),
+                                             GTK_STYLE_PROVIDER (provider),
+                                             GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+}
+
 static gchar *
 get_symbolic_icon_name_from_g_icon (GIcon *gicon)
 {
@@ -580,6 +622,17 @@ split_decorations_cb (GtkSettings *settings,
   gtk_header_bar_set_decoration_layout (GTK_HEADER_BAR (self->panel_headerbar), layout_end);
 }
 
+static void
+on_development_warning_dialog_responded_cb (GtkWidget *dialog,
+                                            gint       response,
+                                            CcWindow  *self)
+{
+  g_debug ("Disabling development build warning dialog");
+  g_settings_set_boolean (self->settings, "show-development-warning", FALSE);
+
+  gtk_widget_hide (dialog);
+}
+
 /* CcShell implementation */
 static gboolean
 cc_window_set_active_panel_from_id (CcShell      *shell,
@@ -618,6 +671,19 @@ cc_shell_iface_init (CcShellInterface *iface)
   iface->get_toplevel = cc_window_get_toplevel;
 }
 
+/* GtkWidget overrides */
+static void
+cc_window_map (GtkWidget *widget)
+{
+  CcWindow *self = (CcWindow *) widget;
+
+  GTK_WIDGET_CLASS (cc_window_parent_class)->map (widget);
+
+  /* Show a warning for Flatpak builds */
+  if (in_flatpak_sandbox () && g_settings_get_boolean (self->settings, "show-development-warning"))
+    gtk_window_present (GTK_WINDOW (self->development_warning_dialog));
+}
+
 /* GObject Implementation */
 static void
 cc_window_get_property (GObject    *object,
@@ -695,10 +761,13 @@ cc_window_class_init (CcWindowClass *klass)
   object_class->dispose = cc_window_dispose;
   object_class->finalize = cc_window_finalize;
 
+  widget_class->map = cc_window_map;
+
   g_object_class_override_property (object_class, PROP_ACTIVE_PANEL, "active-panel");
 
   gtk_widget_class_set_template_from_resource (widget_class, "/org/gnome/ControlCenter/gtk/window.ui");
 
+  gtk_widget_class_bind_template_child (widget_class, CcWindow, development_warning_dialog);
   gtk_widget_class_bind_template_child (widget_class, CcWindow, header);
   gtk_widget_class_bind_template_child (widget_class, CcWindow, header_box);
   gtk_widget_class_bind_template_child (widget_class, CcWindow, header_sizegroup);
@@ -714,6 +783,7 @@ cc_window_class_init (CcWindowClass *klass)
   gtk_widget_class_bind_template_child (widget_class, CcWindow, top_right_box);
 
   gtk_widget_class_bind_template_callback (widget_class, gdk_window_set_cb);
+  gtk_widget_class_bind_template_callback (widget_class, on_development_warning_dialog_responded_cb);
   gtk_widget_class_bind_template_callback (widget_class, panel_list_view_changed_cb);
   gtk_widget_class_bind_template_callback (widget_class, previous_button_clicked_cb);
   gtk_widget_class_bind_template_callback (widget_class, search_entry_activate_cb);
@@ -760,6 +830,10 @@ cc_window_init (CcWindow *self)
     cc_panel_list_set_active_panel (CC_PANEL_LIST (self->panel_list), id);
   else
     cc_panel_list_activate (CC_PANEL_LIST (self->panel_list));
+
+  /* Add a custom CSS class on development builds */
+  if (in_flatpak_sandbox ())
+    add_development_build_css (self);
 }
 
 CcWindow *

shell/org.gnome.ControlCenter.gschema.xml

@@ -8,5 +8,12 @@
         will be ignored and the first panel in the list selected.
       </description>
     </key>
+    <key name="show-development-warning" type="b">
+      <default>true</default>
+      <summary>Show warning when running a development build of Settings</summary>
+      <description>
+        Whether Settings should show a warning when running a development build.
+      </description>
+    </key>
   </schema>
 </schemalist>

shell/window.ui

@@ -224,4 +224,17 @@
       <widget name="sidebar_box"/>
     </widgets>
   </object>
+
+  <!-- Warning dialog for development builds -->
+  <object class="GtkMessageDialog" id="development_warning_dialog">
+    <property name="message-type">warning</property>
+    <property name="transient-for">CcWindow</property>
+    <property name="resizable">false</property>
+    <property name="modal">true</property>
+    <property name="buttons">ok</property>
+    <property name="text" translatable="yes">Warning: Development Version</property>
+    <property name="secondary-text" translatable="yes">This version of Settings should only be used for development purposes. You may experience incorrect system behavior, data loss, and other unexpected issues. </property>
+    <signal name="response" handler="on_development_warning_dialog_responded_cb" object="CcWindow" swapped="no" />
+  </object>
+
 </interface>