moodle/lib/yuilib/3.17.2/event-contextmenu/event-contextmenu.js

/*
YUI 3.17.2 (build 9c3c78e)
Copyright 2014 Yahoo! Inc. All rights reserved.
Licensed under the BSD License.
http://yuilibrary.com/license/
*/

YUI.add('event-contextmenu', function (Y, NAME) {

/**
 * Provides extended keyboard support for the "contextmenu" event such that:
 * <ul>
 * <li>The browser's default context menu is suppressed regardless of how the event is triggered.</li>
 * <li>On Windows the "contextmenu" event is fired consistently regardless of whether the user
 * pressed the Menu key or Shift + F10.</li>
 * <li>When the "contextmenu" event is fired via the keyboard, the pageX, pageY, clientX and clientY
 * properties reference the center of the event target. This makes it easy for "contextmenu" event listeners
 * to position an overlay in response to the event by not having to worry about special handling of the x
 * and y coordinates based on the device that fired the event.</li>
 * <li>For Webkit and Gecko on the Mac it enables the use of the Shift + Control + Option + M keyboard
 * shortcut to fire the "contextmenu" event, which (by default) is only available when VoiceOver
 * (the screen reader on the Mac) is enabled.</li>
 * <li>For Opera on the Mac it ensures the "contextmenu" event is fired when the user presses
 * Shift + Command + M (Opera's context menu keyboard shortcut).</li>
 * </ul>
 * @module event-contextmenu
 * @requires event
 */

var Event = Y.Event,
    DOM = Y.DOM,
    UA = Y.UA,
    OS = Y.UA.os,

    ie = UA.ie,
    gecko = UA.gecko,
    webkit = UA.webkit,
    opera = UA.opera,

    isWin = (OS === "windows"),
    isMac = (OS === "macintosh"),

    eventData = {},

    conf = {

        on: function (node, subscription, notifier, filter) {

            var handles = [];

            handles.push(Event._attach(["contextmenu", function (e) {

                // Any developer listening for the "contextmenu" event is likely
                // going to call preventDefault() to prevent the display of
                // the browser's context menu. So, you know, save them a step.
                e.preventDefault();

                var id = Y.stamp(node),
                    data = eventData[id];

                if (data) {
                    e.clientX = data.clientX;
                    e.clientY = data.clientY;
                    e.pageX = data.pageX;
                    e.pageY = data.pageY;
                    delete eventData[id];
                }

                notifier.fire(e);

            }, node]));


            handles.push(node[filter ? "delegate" : "on"]("keydown", function (e) {

                var target = this.getDOMNode(),
                    shiftKey = e.shiftKey,
                    keyCode = e.keyCode,
                    shiftF10 = (shiftKey && keyCode == 121),
                    menuKey = (isWin && keyCode == 93),
                    ctrlKey = e.ctrlKey,
                    mKey = (keyCode === 77),
                    macWebkitAndGeckoShortcut = (isMac && (webkit || gecko) && ctrlKey && shiftKey && e.altKey && mKey),

                    // Note: The context menu keyboard shortcut for Opera on the Mac is Shift + Cmd (metaKey) + M,
                    // but e.metaKey is false for Opera, and Opera sets e.ctrlKey to true instead.
                    macOperaShortcut = (isMac && opera && ctrlKey && shiftKey && mKey),

                    clientX = 0,
                    clientY = 0,
                    scrollX,
                    scrollY,
                    pageX,
                    pageY,
                    xy,
                    x,
                    y;


                if ((isWin && (shiftF10 || menuKey)) ||
                        (macWebkitAndGeckoShortcut || macOperaShortcut)) {

                    // Need to call preventDefault() here b/c:
                    // 1) To prevent IE's menubar from gaining focus when the
                    // user presses Shift + F10
                    // 2) In Firefox and Opera for Win, Shift + F10 will display a
                    // context menu, but won't fire the "contextmenu" event. So, need
                    // to call preventDefault() to prevent the display of the
                    // browser's context menu
                    // 3) For Opera on the Mac the context menu keyboard shortcut
                    // (Shift + Cmd + M) will display a context menu, but like Firefox
                    // and Opera on windows, Opera doesn't fire a "contextmenu" event,
                    // so preventDefault() is just used to supress Opera's
                    // default context menu.
                    if (((ie || (isWin && (gecko || opera))) && shiftF10) || macOperaShortcut) {
                        e.preventDefault();
                    }

                    xy = DOM.getXY(target);
                    x = xy[0];
                    y = xy[1];
                    scrollX = DOM.docScrollX();
                    scrollY = DOM.docScrollY();

                    // Protect against instances where xy and might not be returned,
                    // for example if the target is the document.
                    if (!Y.Lang.isUndefined(x)) {
                        clientX = (x + (target.offsetWidth/2)) - scrollX;
                        clientY = (y + (target.offsetHeight/2)) - scrollY;
                    }

                    pageX = clientX + scrollX;
                    pageY = clientY + scrollY;

                    // When the "contextmenu" event is fired from the keyboard
                    // clientX, clientY, pageX or pageY aren't set to useful
                    // values. So, we follow Safari's model here of setting
                    // the x & x coords to the center of the event target.

                    if (menuKey || (isWin && webkit && shiftF10)) {
                        eventData[Y.stamp(node)] = {
                            clientX: clientX,
                            clientY: clientY,
                            pageX: pageX,
                            pageY: pageY
                        };
                    }

                    // Don't need to call notifier.fire(e) when the Menu key
                    // is pressed as it fires the "contextmenu" event by default.
                    //
                    // In IE the call to preventDefault() for Shift + F10
                    // prevents the "contextmenu" event from firing, so we need
                    // to call notifier.fire(e)
                    //
                    // Need to also call notifier.fire(e) for Gecko and Opera since
                    // neither Shift + F10 or Shift + Cmd + M fire the "contextmenu" event.
                    //
                    // Lastly, also need to call notifier.fire(e) for all Mac browsers
                    // since neither Shift + Ctrl + Option + M (Webkit and Gecko) or
                    // Shift + Command + M (Opera) fire the "contextmenu" event.

                    if (((ie || (isWin && (gecko || opera))) && shiftF10) || isMac) {

                        e.clientX = clientX;
                        e.clientY = clientY;
                        e.pageX = pageX;
                        e.pageY = pageY;

                        notifier.fire(e);
                    }

                }

            }, filter));

            subscription._handles = handles;

        },

        detach: function (node, subscription, notifier) {

            Y.each(subscription._handles, function (handle) {
                handle.detach();
            });

        }

    };


conf.delegate = conf.on;
conf.detachDelegate = conf.detach;


Event.define("contextmenu", conf, true);


}, '3.17.2', {"requires": ["event-synthetic", "dom-screen"]});