/* -*- mode: js2; js2-basic-offset: 4; indent-tabs-mode: nil -*- */

/*
    This file is part of CoverflowAltTab.

    CoverflowAltTab is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    CoverflowAltTab is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with CoverflowAltTab.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
 * Gnome Shell extension specific routines.
 *
 * Create the correct manager and enable/disable it.
 */

import * as Manager from './manager.js';
import * as Platform from './platform.js';
import * as Keybinder from './keybinder.js';
import {Extension} from 'resource:///org/gnome/shell/extensions/extension.js';

let manager = null;

export default class CoverflowAltTabExtension extends Extension {
    constructor(metadata) {
        super(metadata);
    }


    enable() {
        if (!manager) {
            /*  
             * As there are restricted Gnome versions the current extension support (that
             * are specified in metadata.json file), only the API related to those supported
             * versions must be used, not anything else. As a result, performing checks for
             * keeping backward-compatiblity with old unsupported versions is a wrong
             * decision.
             *
             * To support older versions of Gnome, first, add the version to the metadata
             * file, then, if needed, include backward-compatible API here for each
             * version.
             */
            manager = new Manager.Manager(
                new Platform.PlatformGnomeShell(this.getSettings()),
                new Keybinder.Keybinder330Api()
            );
        }   
        manager.enable();
    }


    disable() {
        if (manager) {
            manager.disable();
            manager = null;
        }
    }
}