highcharts: fire animation when visible instead of

问题:

i have a page separated out into sections that are accessed via anchors. is there a way to have the highcharts animation fire when its particular section becomes visible instead of on page load?

http://jsfiddle.net/YFMSb/2/ (the chart is under 'skills', so would like its initial animation to occur when that section of the page is brought up. does not need to re-animate during subsequent visits to/through the section)

$(function () {
$('#container').highcharts({
    chart: {
            type: 'bar',
            spacingTop: 0
        },

        title: {
            text: ''
        },

        xAxis: {
            labels: {
                enabled: false
            }
        },

        yAxis: {
            min: 0,
            max: 100,
            title: {
                text: ''
            },
            labels: {
                enabled: false
            }
        },

        plotOptions: {
            series: {
                stacking: 'normal'
            }
        },


        tooltip: {
            formatter: function() {
               return '<b>'+ this.series.name +'</b>';
            }
        },

        series: [{
            name: 'clean',
            data: [10],
        }, {
            name: 'eat',
            data: [10]
        }, {
            name: 'sleep',
            data: [40]
        }, {
            name: 'work',
            data: [30]
        }, {
            name: 'play',
            data: [10]
        }]

    });
});

回答1:

Attach a scroll event listener to the window that detects when you get close to the skills section. When you create the chart, remove the scroll listener to ensure that the chart is only created once. This will also help with performance: no reason to listen to an event that we aren't going to respond to anymore.

This approach also works if the user clicks the skills link at the top.

You want to be careful with the scroll event as it can be a real performance bottleneck. I took the approach suggested by John Resig to check the scroll position at regular intervals.

Working Demo

$(function () {
    var $window = $(window),
        didScroll = false,
        skillsTop = $('#skills').offset().top - 40; //the point at which we will create the chart

    $window.on('scroll', function () {
        //detected a scroll event, you want to minimize the code here because this event can be thrown A LOT!
        didScroll = true;
    });

    //check every 250ms if user has scrolled to the skills section
    setInterval(function () {
        if (didScroll) {
            didScroll = false;
            if ($window.scrollTop() >= skillsTop) {
                createChart();
            }
        }
    }, 250);

    function createChart() {
        $window.off('scroll'); //remove listener that will create chart, this ensures the chart will be created only once

        $('#container').highcharts({
            //chart configuration here
        });
    };
});

回答2:

I'm supposing with "section becomes visible" you meant a scroll event.

This is the most basic code to make it work:

var target = $('#container');
var targetHeight = target.get(0).offsetTop;
var printed = false;
var printChart = function(){ 
    if(printed) return;
    printed = true;
    target.highcharts({
        chart: type: 'bar',
        /* all chart code */
    });
};
$('[href="#skills"]').on('click', printChart);
$(window).on('scroll',function(e){
    var st = $(window).scrollTop();
    if(st > targetHeight) printChart();
});

http://jsfiddle.net/YFMSb/12/

回答3:

You have to create the chart on click of 'skills'. jsfiddle below. http://jsfiddle.net/YFMSb/6/

$("#your skills link").click(function(){
         createChart();  
    });

createChart() basically defines your chart.