Send battery notification instead of infobar

src/Application.vala

@@ -33,6 +33,35 @@ public class Installer.App : Gtk.Application {
         base.startup ();
 
         Granite.init ();
+
+        try {
+            UPower upower = Bus.get_proxy_sync (BusType.SYSTEM, "org.freedesktop.UPower", "/org/freedesktop/UPower", GLib.DBusProxyFlags.GET_INVALIDATED_PROPERTIES);
+
+            send_withdraw_battery_notification (upower.on_battery);
+
+            ((DBusProxy) upower).g_properties_changed.connect ((changed, invalid) => {
+                var _on_battery = changed.lookup_value ("OnBattery", GLib.VariantType.BOOLEAN);
+                if (_on_battery != null) {
+                    send_withdraw_battery_notification (upower.on_battery);
+                }
+            });
+        } catch (Error e) {
+            critical ("Can't connect to UPower; unable to send battery notifications: %s", e.message);
+        }
+    }
+
+    private void send_withdraw_battery_notification (bool on_battery) {
+        if (!on_battery) {
+            withdraw_notification ("on-battery");
+            return;
+        }
+
+        var notification = new GLib.Notification (_("Connect to a Power Source"));
+        notification.set_body (_("Installation will not succeed if this device loses power."));
+        notification.set_icon (new ThemedIcon ("battery-ac-adapter"));
+        notification.set_priority (NotificationPriority.URGENT);
+
+        send_notification ("on-battery", notification);
     }
 
     public override void activate () {

src/MainWindow.vala

@@ -28,7 +28,6 @@ public class Installer.MainWindow : Gtk.ApplicationWindow {
     // Minimum 15 GB
     private const uint64 MINIMUM_SPACE = 15 * ONE_GB;
 
-    private Gtk.Label infobar_label;
     private Adw.NavigationView navigation_view;
     private LanguageView language_view;
     private TryInstallView try_install_view;
@@ -42,29 +41,7 @@ public class Installer.MainWindow : Gtk.ApplicationWindow {
         navigation_view = new Adw.NavigationView ();
         navigation_view.add (language_view);
 
-        infobar_label = new Gtk.Label ("") {
-            use_markup = true
-        };
-        set_infobar_string ();
-
-        var battery_infobar = new Gtk.InfoBar () {
-            message_type = Gtk.MessageType.WARNING,
-            margin_end = 7,
-            margin_bottom = 7,
-            margin_start = 7,
-            show_close_button = true,
-            halign = Gtk.Align.START, // Can't cover action area; need to select language
-            valign = Gtk.Align.END
-        };
-        battery_infobar.add_child (infobar_label);
-        battery_infobar.add_css_class (Granite.STYLE_CLASS_FRAME);
-
-        var overlay = new Gtk.Overlay () {
-            child = navigation_view
-        };
-        overlay.add_overlay (battery_infobar);
-
-        child = overlay;
+        child = navigation_view;
         titlebar = new Gtk.Grid () { visible = false };
 
         var back_action = new SimpleAction ("back", null);
@@ -80,31 +57,9 @@ public class Installer.MainWindow : Gtk.ApplicationWindow {
                 Source.remove (orca_timeout_id);
             }
 
-            // Reset when language selection changes
-            set_infobar_string ();
             load_keyboard_view ();
         });
 
-        try {
-            UPower upower = Bus.get_proxy_sync (BusType.SYSTEM, "org.freedesktop.UPower", "/org/freedesktop/UPower", GLib.DBusProxyFlags.GET_INVALIDATED_PROPERTIES);
-
-            battery_infobar.revealed = upower.on_battery;
-
-            ((DBusProxy) upower).g_properties_changed.connect ((changed, invalid) => {
-                var _on_battery = changed.lookup_value ("OnBattery", GLib.VariantType.BOOLEAN);
-                if (_on_battery != null) {
-                    battery_infobar.revealed = upower.on_battery;
-                }
-            });
-        } catch (Error e) {
-            warning (e.message);
-            battery_infobar.revealed = false;
-        }
-
-        battery_infobar.response.connect (() => {
-            battery_infobar.revealed = false;
-        });
-
         var mediakeys_settings = new Settings ("org.gnome.settings-daemon.plugins.media-keys");
         var a11y_settings = new Settings ("org.gnome.desktop.a11y.applications");
 
@@ -263,13 +218,4 @@ public class Installer.MainWindow : Gtk.ApplicationWindow {
 
         navigation_view.push (error_view);
     }
-
-    private void set_infobar_string () {
-        var infobar_string = "%s\n%s".printf (
-            _("Connect to a Power Source"),
-            Granite.TOOLTIP_SECONDARY_TEXT_MARKUP.printf (_("Your device is running on battery power. It's recommended to be plugged in while installing."))
-        );
-
-        infobar_label.label = infobar_string;
-    }
 }