annotate libraries/jquery.hoverIntent/jquery.hoverIntent.js @ 19:fa3358dc1485 tip

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author Chris Cannam
date Wed, 28 Aug 2019 13:14:47 +0100
parents c69a71b4f40f
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Chris@5 1 /*!
Chris@5 2 * hoverIntent v1.9.0 // 2017.09.01 // jQuery v1.7.0+
Chris@5 3 * http://briancherne.github.io/jquery-hoverIntent/
Chris@5 4 *
Chris@5 5 * You may use hoverIntent under the terms of the MIT license. Basically that
Chris@5 6 * means you are free to use hoverIntent as long as this header is left intact.
Chris@5 7 * Copyright 2007-2017 Brian Cherne
Chris@5 8 */
Chris@5 9
Chris@5 10 /* hoverIntent is similar to jQuery's built-in "hover" method except that
Chris@5 11 * instead of firing the handlerIn function immediately, hoverIntent checks
Chris@5 12 * to see if the user's mouse has slowed down (beneath the sensitivity
Chris@5 13 * threshold) before firing the event. The handlerOut function is only
Chris@5 14 * called after a matching handlerIn.
Chris@5 15 *
Chris@5 16 * // basic usage ... just like .hover()
Chris@5 17 * .hoverIntent( handlerIn, handlerOut )
Chris@5 18 * .hoverIntent( handlerInOut )
Chris@5 19 *
Chris@5 20 * // basic usage ... with event delegation!
Chris@5 21 * .hoverIntent( handlerIn, handlerOut, selector )
Chris@5 22 * .hoverIntent( handlerInOut, selector )
Chris@5 23 *
Chris@5 24 * // using a basic configuration object
Chris@5 25 * .hoverIntent( config )
Chris@5 26 *
Chris@5 27 * @param handlerIn function OR configuration object
Chris@5 28 * @param handlerOut function OR selector for delegation OR undefined
Chris@5 29 * @param selector selector OR undefined
Chris@5 30 * @author Brian Cherne <brian(at)cherne(dot)net>
Chris@5 31 */
Chris@5 32
Chris@5 33 ;(function(factory) {
Chris@5 34 'use strict';
Chris@5 35 if (typeof define === 'function' && define.amd) {
Chris@5 36 define(['jquery'], factory);
Chris@5 37 } else if (jQuery && !jQuery.fn.hoverIntent) {
Chris@5 38 factory(jQuery);
Chris@5 39 }
Chris@5 40 })(function($) {
Chris@5 41 'use strict';
Chris@5 42
Chris@5 43 // default configuration values
Chris@5 44 var _cfg = {
Chris@5 45 interval: 100,
Chris@5 46 sensitivity: 6,
Chris@5 47 timeout: 0
Chris@5 48 };
Chris@5 49
Chris@5 50 // counter used to generate an ID for each instance
Chris@5 51 var INSTANCE_COUNT = 0;
Chris@5 52
Chris@5 53 // current X and Y position of mouse, updated during mousemove tracking (shared across instances)
Chris@5 54 var cX, cY;
Chris@5 55
Chris@5 56 // saves the current pointer position coordinates based on the given mousemove event
Chris@5 57 var track = function(ev) {
Chris@5 58 cX = ev.pageX;
Chris@5 59 cY = ev.pageY;
Chris@5 60 };
Chris@5 61
Chris@5 62 // compares current and previous mouse positions
Chris@5 63 var compare = function(ev,$el,s,cfg) {
Chris@5 64 // compare mouse positions to see if pointer has slowed enough to trigger `over` function
Chris@5 65 if ( Math.sqrt( (s.pX-cX)*(s.pX-cX) + (s.pY-cY)*(s.pY-cY) ) < cfg.sensitivity ) {
Chris@5 66 $el.off(s.event,track);
Chris@5 67 delete s.timeoutId;
Chris@5 68 // set hoverIntent state as active for this element (permits `out` handler to trigger)
Chris@5 69 s.isActive = true;
Chris@5 70 // overwrite old mouseenter event coordinates with most recent pointer position
Chris@5 71 ev.pageX = cX; ev.pageY = cY;
Chris@5 72 // clear coordinate data from state object
Chris@5 73 delete s.pX; delete s.pY;
Chris@5 74 return cfg.over.apply($el[0],[ev]);
Chris@5 75 } else {
Chris@5 76 // set previous coordinates for next comparison
Chris@5 77 s.pX = cX; s.pY = cY;
Chris@5 78 // use self-calling timeout, guarantees intervals are spaced out properly (avoids JavaScript timer bugs)
Chris@5 79 s.timeoutId = setTimeout( function(){compare(ev, $el, s, cfg);} , cfg.interval );
Chris@5 80 }
Chris@5 81 };
Chris@5 82
Chris@5 83 // triggers given `out` function at configured `timeout` after a mouseleave and clears state
Chris@5 84 var delay = function(ev,$el,s,out) {
Chris@5 85 delete $el.data('hoverIntent')[s.id];
Chris@5 86 return out.apply($el[0],[ev]);
Chris@5 87 };
Chris@5 88
Chris@5 89 $.fn.hoverIntent = function(handlerIn,handlerOut,selector) {
Chris@5 90 // instance ID, used as a key to store and retrieve state information on an element
Chris@5 91 var instanceId = INSTANCE_COUNT++;
Chris@5 92
Chris@5 93 // extend the default configuration and parse parameters
Chris@5 94 var cfg = $.extend({}, _cfg);
Chris@5 95 if ( $.isPlainObject(handlerIn) ) {
Chris@5 96 cfg = $.extend(cfg, handlerIn);
Chris@5 97 if ( !$.isFunction(cfg.out) ) {
Chris@5 98 cfg.out = cfg.over;
Chris@5 99 }
Chris@5 100 } else if ( $.isFunction(handlerOut) ) {
Chris@5 101 cfg = $.extend(cfg, { over: handlerIn, out: handlerOut, selector: selector } );
Chris@5 102 } else {
Chris@5 103 cfg = $.extend(cfg, { over: handlerIn, out: handlerIn, selector: handlerOut } );
Chris@5 104 }
Chris@5 105
Chris@5 106 // A private function for handling mouse 'hovering'
Chris@5 107 var handleHover = function(e) {
Chris@5 108 // cloned event to pass to handlers (copy required for event object to be passed in IE)
Chris@5 109 var ev = $.extend({},e);
Chris@5 110
Chris@5 111 // the current target of the mouse event, wrapped in a jQuery object
Chris@5 112 var $el = $(this);
Chris@5 113
Chris@5 114 // read hoverIntent data from element (or initialize if not present)
Chris@5 115 var hoverIntentData = $el.data('hoverIntent');
Chris@5 116 if (!hoverIntentData) { $el.data('hoverIntent', (hoverIntentData = {})); }
Chris@5 117
Chris@5 118 // read per-instance state from element (or initialize if not present)
Chris@5 119 var state = hoverIntentData[instanceId];
Chris@5 120 if (!state) { hoverIntentData[instanceId] = state = { id: instanceId }; }
Chris@5 121
Chris@5 122 // state properties:
Chris@5 123 // id = instance ID, used to clean up data
Chris@5 124 // timeoutId = timeout ID, reused for tracking mouse position and delaying "out" handler
Chris@5 125 // isActive = plugin state, true after `over` is called just until `out` is called
Chris@5 126 // pX, pY = previously-measured pointer coordinates, updated at each polling interval
Chris@5 127 // event = string representing the namespaced event used for mouse tracking
Chris@5 128
Chris@5 129 // clear any existing timeout
Chris@5 130 if (state.timeoutId) { state.timeoutId = clearTimeout(state.timeoutId); }
Chris@5 131
Chris@5 132 // namespaced event used to register and unregister mousemove tracking
Chris@5 133 var mousemove = state.event = 'mousemove.hoverIntent.hoverIntent'+instanceId;
Chris@5 134
Chris@5 135 // handle the event, based on its type
Chris@5 136 if (e.type === 'mouseenter') {
Chris@5 137 // do nothing if already active
Chris@5 138 if (state.isActive) { return; }
Chris@5 139 // set "previous" X and Y position based on initial entry point
Chris@5 140 state.pX = ev.pageX; state.pY = ev.pageY;
Chris@5 141 // update "current" X and Y position based on mousemove
Chris@5 142 $el.off(mousemove,track).on(mousemove,track);
Chris@5 143 // start polling interval (self-calling timeout) to compare mouse coordinates over time
Chris@5 144 state.timeoutId = setTimeout( function(){compare(ev,$el,state,cfg);} , cfg.interval );
Chris@5 145 } else { // "mouseleave"
Chris@5 146 // do nothing if not already active
Chris@5 147 if (!state.isActive) { return; }
Chris@5 148 // unbind expensive mousemove event
Chris@5 149 $el.off(mousemove,track);
Chris@5 150 // if hoverIntent state is true, then call the mouseOut function after the specified delay
Chris@5 151 state.timeoutId = setTimeout( function(){delay(ev,$el,state,cfg.out);} , cfg.timeout );
Chris@5 152 }
Chris@5 153 };
Chris@5 154
Chris@5 155 // listen for mouseenter and mouseleave
Chris@5 156 return this.on({'mouseenter.hoverIntent':handleHover,'mouseleave.hoverIntent':handleHover}, cfg.selector);
Chris@5 157 };
Chris@5 158 });