extension.js

/* 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 2 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/>.
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

"use strict";

const { St, Gio, Clutter, Soup, GLib } = imports.gi;
const ExtensionUtils = imports.misc.extensionUtils;
const Me = ExtensionUtils.getCurrentExtension();
const Main = imports.ui.main;
const PanelMenu = imports.ui.panelMenu;

let panelButton;
let panelButtonText;
let session;
let sourceId = null;

// Start application
function init() {
  // Initialization if needed
}

// Add the button to the panel
function enable() {
  panelButton = new St.Bin({
    style_class: "panel-button",
  });

  handle_request_dollar_api();
  Main.panel._centerBox.insert_child_at_index(panelButton, 0);
  sourceId = GLib.timeout_add_seconds(GLib.PRIORITY_DEFAULT, 30, () => {
    handle_request_dollar_api();
    return GLib.SOURCE_CONTINUE;
  });
}

// Remove the added button from panel
function disable() {
  panelButtonText = null;
  session = null;
  Main.panel._centerBox.remove_child(panelButton);

  if (panelButton) {
    panelButton.destroy();
    panelButton = null;
  }

  if (sourceId) {
    GLib.Source.remove(sourceId);
    sourceId = null;
  }
}

// Handle Requests API Dollar
async function handle_request_dollar_api() {
  let dollarQuotation = null;
  let upDown = null;
  let upDownIcon = null;

  try {
    // Create a new Soup Session
    if (!session) {
      session = new Soup.Session({ timeout: 10 });
    }

    // Create body of Soup request
    let message = Soup.Message.new_from_encoded_form(
      "GET",
      "https://economia.awesomeapi.com.br/last/USD-BRL",
      Soup.form_encode_hash({})
    );

    // Send Soup request to API Server
    await session.send_and_read_async(
      message,
      GLib.PRIORITY_DEFAULT,
      null,
      (_, r0) => {
        let text = session.send_and_read_finish(r0);
        let response = new TextDecoder().decode(text.get_data());
        const body_response = JSON.parse(response);

        // Get the value of Dollar Quotation
        upDown = body_response["USDBRL"]["varBid"];
        dollarQuotation = body_response["USDBRL"]["bid"];
        dollarQuotation = dollarQuotation.split(".");
        dollarQuotation =
          dollarQuotation[0] + "." + dollarQuotation[1].substring(0, 2);

        parseFloat(upDown) > 0 ? (upDownIcon = "⬆") : (upDownIcon = "⬇");
        let rateDisplay = "BRL: $" + dollarQuotation + " ";
        let iconDisplay = upDownIcon;
        let iconColor = upDown > 0 ? "darkgreen" : "darkred";

        let label1 = new St.Label({
          text: rateDisplay,
          y_align: Clutter.ActorAlign.CENTER,
        });

        let label2 = new St.Label({
          text: iconDisplay,
          y_align: Clutter.ActorAlign.CENTER,
          style: `color: ${iconColor};`,
        });

        panelButtonText = new St.BoxLayout();
        panelButtonText.add_child(label1);
        panelButtonText.add_child(label2);

        panelButton.set_child(panelButtonText);
        // Finish Soup Session
        session.abort();
        text = undefined;
        response = undefined;
      }
    );
  } catch (error) {
    log(`Traceback Error in [handle_request_dollar_api]: ${error}`);
    panelButtonText = new St.Label({
      text: "BRL: $" + _dollarQuotation + " * ",
      y_align: Clutter.ActorAlign.CENTER,
    });
    panelButton.set_child(panelButtonText);
    session.abort();
  }
}