extension.js

/* -*- coding: UTF-8; mode: js2; js2-basic-offset: 4 -*- */
/*
 * Copyright (C) 2012, 2013 Victor Aurélio Santos <victoraur.santos@gmail.com>
 * 
 * This file is part of Alsa-Mixer.
 *
 * Alsa Mixer 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.
 * 
 * Alsa Mixer 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/>.
 */

const St = imports.gi.St;
const Lang = imports.lang;
const Main = imports.ui.main;
const PanelMenu = imports.ui.panelMenu;
const PopupMenu = imports.ui.popupMenu;
const Clutter = imports.gi.Clutter;
const GLib = imports.gi.GLib;
const Util = imports.misc.util;
const Mainloop = imports.mainloop;

// Step on scroll, and olny on scroll
const VOLUME_STEP = 5; 
// Mixer element to control, for example 'Master Surround'
const MIXER_ELEMENT = 'Master';

const AlsaMixer = new Lang.Class({
    Name: 'AlsaMixer',
    Extends: PanelMenu.SystemStatusButton,
    
    _init: function() {
        this.parent('audio-volume-medium', _('Volume'));
        
        this.statusIcon = new St.Icon({
            icon_name: 'audio-volume-medium',
            style_class: 'status-icon'
        });
        this.actor.add_actor(this.statusIcon);
        
        this._onScrollId = this.actor.connect('scroll-event',
            Lang.bind(this, this._onScroll));
        
        this._cVolume = this._getVolume();
        this._muted = this._cVolume < 1 ? true : false;
        this._updateIcon(this._cVolume);
        
        this.pup = new PopupMenu.PopupSliderMenuItem(this._cVolume / 100);
        this._onSliderId = this.pup.connect('value-changed',
                Lang.bind(this, this._onSlider));
        this.menu.addMenuItem(this.pup);
        
        this._timeoutId = Mainloop.timeout_add_seconds(1,
                Lang.bind(this, this._onUpdate));
    },
    
    _getVolume: function() {
        let cmd = GLib.spawn_command_line_sync(
                'env LANG=C amixer get %s'.format(MIXER_ELEMENT));
        let re = /\[(\d{1,2})\%\]/m;
        let values = re.exec(cmd[1]);

        return values[1];
    },
    
    _setVolume: function(value) {
        let cmd = GLib.spawn_command_line_async(
                'amixer -q set %s %s %%'.format(MIXER_ELEMENT, value));
        
        this._cVolume = value;
        
        this._updateIcon(value);
    },
    
    _updateIcon: function(value) {
        if (this.statusIcon.get_icon_name() != this._getIcon(value)) {
            let icon = this._getIcon(value);
            this.statusIcon.set_icon_name(icon);
            this.setIcon(icon);
        }
    },
    
    _getIcon: function(volume) {
        let rvalue = 'audio-volume-muted';
        if (volume < 1) {
            rvalue = 'audio-volume-muted';
        } else {
            let num = Math.floor(3 * volume / 100) + 1;

            if (num >= 3)
                rvalue = 'audio-volume-high';
            else if(num < 2)
                rvalue = 'audio-volume-low';
            else
                rvalue = 'audio-volume-medium';
        }
        return rvalue;
    },
    
    _onScroll: function(widget, event) {
        let di = event.get_scroll_direction();
        
        if (di == Clutter.ScrollDirection.DOWN
                && Number(this._cVolume) > VOLUME_STEP) {
            this._setVolume(Number(this._cVolume) - VOLUME_STEP);
        } else if (di == Clutter.ScrollDirection.DOWN
                && Number(this._cVolume) <= VOLUME_STEP) {
            this._setVolume(0);
        } else if(di == Clutter.ScrollDirection.UP
                && Number(this._cVolume) < 100 - VOLUME_STEP) {
            this._setVolume(Number(this._cVolume) + VOLUME_STEP);
        } else if(di == Clutter.ScrollDirection.UP
                && Number(this._cVolume) >= 100 - VOLUME_STEP) {
            this._setVolume(100);
        }
        this.pup.setValue(Number(this._cVolume) / 100);
    },
    
    _onSlider: function(slider, value) {
        let volume = value * 100;
        this._setVolume(volume);
    },
    
    _onUpdate: function() {
        this._cVolume = this._getVolume();
        this._updateIcon(this._cVolume);
        this.pup.setValue(Number(this._cVolume) / 100);
        return true;
    },
    
    destroy: function() {
        this.parent();
        Mainloop.source_remove(this._timeoutId);
        this.actor.disconnect(this._onScrollId);
        this.pup.disconnect(this._onSliderId);
    },
});

function init() {
    // pass
}

var AM;

function enable() {
    AM = new AlsaMixer();
    Main.panel.addToStatusArea('AlsaMixer', AM);
}

function disable() {
    AM.destroy();
    AM = null;
}