status-icons: Add new extension

Based on an original "top-icons" extension by Adel Gadllah that
is no longer maintained.

The code has been heavily simplified and modernised, and adapted
to integrate into the top bar more seemlessly.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/merge_requests/194>

extensions/status-icons/extension.js

@@ -0,0 +1,91 @@
+// SPDX-FileCopyrightText: 2018 Adel Gadllah <adel.gadllah@gmail.com>
+// SPDX-FileCopyrightText: 2018 Florian Müllner <fmuellner@gnome.org>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+import Clutter from 'gi://Clutter';
+import Shell from 'gi://Shell';
+import St from 'gi://St';
+
+import * as Main from 'resource:///org/gnome/shell/ui/main.js';
+import {Button as PanelButton} from 'resource:///org/gnome/shell/ui/panelMenu.js';
+
+const PANEL_ICON_SIZE = 16;
+
+const STANDARD_TRAY_ICON_IMPLEMENTATIONS = [
+    'bluetooth-applet',
+    'gnome-sound-applet',
+    'nm-applet',
+    'gnome-power-manager',
+    'keyboard',
+    'a11y-keyboard',
+    'kbd-scrolllock',
+    'kbd-numlock',
+    'kbd-capslock',
+    'ibus-ui-gtk',
+];
+
+export default class SysTray {
+    constructor() {
+        this._icons = new Map();
+        this._tray = null;
+    }
+
+    _onTrayIconAdded(o, icon) {
+        let wmClass = icon.wm_class ? icon.wm_class.toLowerCase() : '';
+        if (STANDARD_TRAY_ICON_IMPLEMENTATIONS.includes(wmClass))
+            return;
+
+        let button = new PanelButton(0.5, null, true);
+
+        let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
+        let iconSize = PANEL_ICON_SIZE * scaleFactor;
+
+        icon.set({
+            width: iconSize,
+            height: iconSize,
+            x_align: Clutter.ActorAlign.CENTER,
+            y_align: Clutter.ActorAlign.CENTER,
+        });
+
+        let iconBin = new St.Widget({
+            layout_manager: new Clutter.BinLayout(),
+            style_class: 'system-status-icon',
+        });
+        iconBin.add_child(icon);
+        button.add_child(iconBin);
+
+        this._icons.set(icon, button);
+
+        button.connect('button-release-event',
+            (actor, event) => icon.click(event));
+        button.connect('key-press-event',
+            (actor, event) => icon.click(event));
+
+        const role = `${icon}`;
+        Main.panel.addToStatusArea(role, button);
+    }
+
+    _onTrayIconRemoved(o, icon) {
+        const button = this._icons.get(icon);
+        button?.destroy();
+        this._icons.delete(icon);
+    }
+
+    enable() {
+        this._tray = new Shell.TrayManager();
+        this._tray.connect('tray-icon-added',
+            this._onTrayIconAdded.bind(this));
+        this._tray.connect('tray-icon-removed',
+            this._onTrayIconRemoved.bind(this));
+        this._tray.manage_screen(Main.panel);
+    }
+
+    disable() {
+        this._icons.forEach(button => button.destroy());
+        this._icons.clear();
+
+        this._tray.unmanage_screen();
+        this._tray = null;
+    }
+}

extensions/status-icons/meson.build

@@ -0,0 +1,9 @@
+# SPDX-FileCopyrightText: 2018 Florian Müllner <fmuellner@gnome.org>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+extension_data += configure_file(
+  input: metadata_name + '.in',
+  output: metadata_name,
+  configuration: metadata_conf
+)

extensions/status-icons/metadata.json.in

@@ -0,0 +1,10 @@
+{
+"extension-id": "@extension_id@",
+"uuid": "@uuid@",
+"settings-schema": "@gschemaname@",
+"gettext-domain": "@gettext_domain@",
+"name": "Status Icons",
+"description": "Show status icons in the top bar",
+"shell-version": [ "@shell_current@" ],
+"url": "@url@"
+}

meson.build

@@ -42,6 +42,7 @@ default_extensions += [
   'drive-menu',
   'light-style',
   'screenshot-window-sizer',
+  'status-icons',
   'system-monitor',
   'windowsNavigator',
   'workspace-indicator'