import Clutter from "gi://Clutter";
import GObject from "gi://GObject";
import Gio from "gi://Gio";
import GLib from "gi://GLib";
import Meta from "gi://Meta";
import Shell from "gi://Shell";
import St from "gi://St";

import {
  Extension,
  gettext as _,
} from "resource:///org/gnome/shell/extensions/extension.js";
import * as Main from "resource:///org/gnome/shell/ui/main.js";
import * as PanelMenu from "resource:///org/gnome/shell/ui/panelMenu.js";
import * as PopupMenu from "resource:///org/gnome/shell/ui/popupMenu.js";
import * as QuickSettings from "resource:///org/gnome/shell/ui/quickSettings.js";

import Gdk from "gi://Gdk?version=4.0";
import Gtk from "gi://Gtk?version=4.0";
import Adw from "gi://Adw";
import Gio from "gi://Gio";

import {
  ExtensionPreferences,
  gettext as _,
} from "resource:///org/gnome/Shell/Extensions/js/extensions/prefs.js";

import { Extension } from "resource:///org/gnome/shell/extensions/extension.js";

export default class MyExtension extends Extension {
  enable() {
    // Create objects, connect signals, add UI
  }

  disable() {
    // MUST undo everything done in enable():
    // - Destroy all created widgets
    // - Disconnect all signals
    // - Remove all GLib.timeout/idle sources
    // - Null out all references
  }
}

{
  "uuid": "my-extension@example.com",
  "name": "My Extension",
  "description": "Does something useful",
  "shell-version": ["47", "48", "49"],
  "url": "https://github.com/user/my-extension"
}

import St from "gi://St";

import { Extension } from "resource:///org/gnome/shell/extensions/extension.js";
import * as Main from "resource:///org/gnome/shell/ui/main.js";
import * as PanelMenu from "resource:///org/gnome/shell/ui/panelMenu.js";

export default class MyExtension extends Extension {
  enable() {
    this._indicator = new PanelMenu.Button(0.0, this.metadata.name, false);

    const icon = new St.Icon({
      icon_name: "face-laugh-symbolic",
      style_class: "system-status-icon",
    });
    this._indicator.add_child(icon);

    Main.panel.addToStatusArea(this.uuid, this._indicator);
  }

  disable() {
    this._indicator?.destroy();
    this._indicator = null;
  }
}

# Create extension directory
mkdir -p ~/.local/share/gnome-shell/extensions/my-extension@example.com
# Copy files there, then:

# Wayland: run nested session
dbus-run-session gnome-shell --devkit --wayland   # GNOME 49+
dbus-run-session gnome-shell --nested --wayland    # GNOME 48 and earlier

# Enable extension in nested session
gnome-extensions enable my-extension@example.com

# Watch logs
journalctl -f -o cat /usr/bin/gnome-shell

enable() {
    this._handlerId = someObject.connect('some-signal', () => { /* ... */ });
}
disable() {
    if (this._handlerId) {
        someObject.disconnect(this._handlerId);
        this._handlerId = null;
    }
}

enable() {
    this._timeoutId = GLib.timeout_add_seconds(GLib.PRIORITY_DEFAULT, 5, () => {
        // do work
        return GLib.SOURCE_CONTINUE; // or GLib.SOURCE_REMOVE
    });
}
disable() {
    if (this._timeoutId) {
        GLib.Source.remove(this._timeoutId);
        this._timeoutId = null;
    }
}

enable() {
    this._settings = this.getSettings(); // uses metadata settings-schema
    this._settings.bind('show-indicator', this._indicator, 'visible',
        Gio.SettingsBindFlags.DEFAULT);
}
disable() {
    this._settings = null;
}

import {
  Extension,
  InjectionManager,
} from "resource:///org/gnome/shell/extensions/extension.js";
import { Panel } from "resource:///org/gnome/shell/ui/panel.js";

export default class MyExtension extends Extension {
  enable() {
    this._injectionManager = new InjectionManager();
    this._injectionManager.overrideMethod(
      Panel.prototype,
      "toggleCalendar",
      (originalMethod) => {
        return function (...args) {
          console.debug("Calendar toggled!");
          originalMethod.call(this, ...args);
        };
      },
    );
  }
  disable() {
    this._injectionManager.clear();
    this._injectionManager = null;
  }
}

cd ~/.local/share/gnome-shell/extensions/my-extension@example.com
gnome-extensions pack --podir=po --extra-source=utils.js .

# GNOME 49+: upload directly
gnome-extensions upload --accept-tos