/**
 * Copyright (C) 2012-2013 KO GmbH <copyright@kogmbh.com>
 *
 * @licstart
 * This file is part of WebODF.
 *
 * WebODF is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Affero General Public License (GNU AGPL)
 * as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * WebODF 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with WebODF.  If not, see <http://www.gnu.org/licenses/>.
 * @licend
 *
 * @source: http://www.webodf.org/
 * @source: https://github.com/kogmbh/WebODF/
 */

/*global define,require*/

define("webodf/editor/widgets/zoomSlider", [
    "dijit/form/HorizontalSlider",
    "dijit/form/NumberTextBox",
    "webodf/editor/EditorSession"],

    function (HorizontalSlider, NumberTextBox, EditorSession) {
    "use strict";

    // The slider zooms from -1 to +1, which corresponds
    // to zoom levels of 1/extremeZoomFactor to extremeZoomFactor.
    return function ZoomSlider(callback) {
        var self = this,
            editorSession,
            slider,
            extremeZoomFactor = 4;

        function updateSlider(zoomLevel) {
            slider.set('value', Math.log(zoomLevel) / Math.log(extremeZoomFactor), false);
        }

        this.setEditorSession = function(session) {
            var zoomHelper;
            if (editorSession) {
                editorSession.getOdfCanvas().getZoomHelper().unsubscribe(gui.ZoomHelper.signalZoomChanged, updateSlider);
            }

            editorSession = session;
            if (editorSession) {
                zoomHelper = editorSession.getOdfCanvas().getZoomHelper();
                zoomHelper.subscribe(gui.ZoomHelper.signalZoomChanged, updateSlider);
                updateSlider(zoomHelper.getZoomLevel());
            }
            slider.setAttribute('disabled', !editorSession);
        };

        this.onToolDone = function () {};

        // init
        function init() {
            slider = new HorizontalSlider({
                name: 'zoomSlider',
                disabled: true,
                value: 0,
                minimum: -1,
                maximum: 1,
                discreteValues: 0.01,
                intermediateChanges: true,
                style: {
                    width: '150px',
                    height: '25px',
                    float: 'right'
                }
            });

            slider.onChange = function (value) {
                if (editorSession) {
                    editorSession.getOdfCanvas().getZoomHelper().setZoomLevel(Math.pow(extremeZoomFactor, value));
                }
                self.onToolDone();
            };

            return callback(slider);
        }

        init();
    };
});
