0readme.md

mouseenter / leave

Get the mouseenter / mouseleave events for an elem

Example

var fold = require("reducers/fold")
var Stream = require("stream-reduce/stream")
var mouseleave = require("mouseleave")
// var mouseenter = require("mouseenter")

var elem = document.getElementById("my-element")

var leaves = mouseleave(elem)

// consume leaves an handle each mouseleave event
fold(leaves, function (event) {
  
})

// or convert to stream and handle as stream
var leaves = Stream(mouseleave(elem))

leaves.on("data", function (event) {
  
})

contains.js

var DOCUMENT_POSITION_CONTAINED_BY = 16

module.exports = contains

function contains(container, elem) {
    if (container.contains) {
        return container.contains(elem)
    }

    var comparison = container.compareDocumentPosition(elem)

    return comparison === 0 || comparison & DOCUMENT_POSITION_CONTAINED_BY
}

mouseenter.js

var events = require("dom-reduce/event")
var filter = require("reducers/filter")
var map = require("reducers/map")

var contains = require("./contains")

module.exports = mouseenter

function mouseenter(elem) {
    var overs = events(elem, "mouseover")

    var correctElems = filter(overs, function isCorrectElement(event) {
        var target = event.target
        var elem = event.currentTarget

        return target === elem || contains(elem, target)
    })

    var correctMoves = filter(correctElems, function notMovedFromChild(event) {
        var related = event.relatedTarget || event.fromElement

        return !contains(event.currentTarget, related)
    })
    
    var withType = map(correctMoves, function mouseenter(event) {
        event.type = "mouseenter"
        return event
    })

    return withType
}

mouseleave.js

var events = require("dom-reduce/event")
var synthesize = require("synthesize")
var filter = require("reducers/filter")
var map = require("reducers/map")

var contains = require("./contains")

module.exports = (synthesize)
    (events, "mouseout")
    (filter, function isCorrectElement(event) {
        var target = event.target
        var elem = event.currentTarget

        return target === elem || contains(elem, target)
    })
    (filter, function notLeftFromChild(event) {
        var related = event.relatedTarget || event.toElement

        return !contains(event.currentTarget, related)
    })
    (map, function mouseleave(event) {
        event.type = "mouseleave"
        return event
    })