extension.js

// This program 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.
//
// This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

"use strict";

const Clutter = imports.gi.Clutter;
const St = imports.gi.St;
const Meta = imports.gi.Meta;
const Shell = imports.gi.Shell;
const Main = imports.ui.main;
const ExtensionUtils = imports.misc.extensionUtils;

let button;
let extension_icon;
let color_effect;

const Keybindings = {
  SchemaId: "org.gnome.shell.extensions.desaturate-all.keybindings",
  Keys: { TOGGLE: "toggle" },
  enable: () => {
    const settings = ExtensionUtils.getSettings(Keybindings.SchemaId);

    Main.wm.addKeybinding(
      Keybindings.Keys.TOGGLE,
      settings,
      Meta.KeyBindingFlags.NONE,
      Shell.ActionMode.ALL,
      _toggleEffect
    );
  },
  disable: () => {
    Main.wm.removeKeybinding(Keybindings.Keys.TOGGLE);
  },
};

function _toggleEffect() {
  if (Main.uiGroup.has_effects(color_effect)) {
    Main.uiGroup.remove_effect(color_effect);
  } else {
    Main.uiGroup.add_effect(color_effect);
  }
}

function init() {
  //Creation of effect
  color_effect = new Clutter.DesaturateEffect();
}

function enable() {
  Keybindings.enable();
}

function disable() {
  Keybindings.disable();
}