Google图表中的动画柱形图

Question

I'm having trouble coming up with a function that will animate a single column bar inside of my chart when I use a slider going back and forth..left and right.. I have read the animation docs on the Google Charts API documentation, but I am having a hard time understanding what I need to do.

Here is my code so far. Where would I start in figuring out how to animate just one of my bars using a slider I have made in titanium? I call the function updateChart() from my app.js file using the evalJS function. I have verified it works, by doing a console.log when my slider goes back and forth. I just can't seem to wrap my head around it how to apply this to animating a single column bar. Any thoughts are appreciated.

Set up Google Charts on my html page.

    <script type="text/javascript" src ="https://www.google.com/jsapi" > </script>
    <script type="text/javascript ">
        google.load("visualization", "1", {packages:["corechart"]});
        google.setOnLoadCallback(drawChart);
        function drawChart() {
            var data = new google.visualization.DataTable();
            data.addColumn('string', 'Importance');
            data.addColumn('number', 'Earning');
            data.addColumn({type: 'string', role: 'style'});

            data.addRows([['',5,'#000000'], ['',5,'#ffffff'],['',5,'#666666'],['', 5,'#cccccc']]); 

        var options = 
        {
            width: 200, 
            height: 240, 
            legend: {
                position: 'none'
            }, 
            chartArea: {
                backgroundColor: 'none'
            }, 
            bar: {
                groupWidth: '100%'
            },
            animation: {
                duration: 1000,
                easing: 'out'
            }
        };

        function updateChart() {

        }

        var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
            chart.draw(data, options);
        }

EDITED CODE:

    <script type="text/javascript" src ="https://www.google.com/jsapi" > </script>
    <script type="text/javascript ">
        google.load("visualization", "1", {packages:["corechart"]});
        google.setOnLoadCallback(drawChart);
        function drawChart() {
            var data = new google.visualization.DataTable();
            data.addColumn('string', 'Importance');
            data.addColumn('number', 'Earning');
            data.addColumn({type: 'string', role: 'style'});

            data.addRows([['',5,'#000000'], ['',5,'#ffffff'],['',5,'#666666'],['', 5,'#cccccc']]); 

                var options = {
                width: 200, 
                height: 240, 
                legend: {
                    position: 'none'
                }, 
                chartArea: {
                    backgroundColor: 'none'
                }, 
                bar: {
                    groupWidth: '100%'
                },
                animation: {
                    duration: 1000,
                    easing: 'out'
                }
        };

        function updateChart(value) {
            data.setValue(0, 1, value);
            chart.draw(data, options);
        }

        var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
            chart.draw(data, options);
        }

Slider Hook Code in separate file (app.js) Titanium Platform

var sliderBarOne = Titanium.UI.createSlider({
    top: '310',
    left: '610',
    min: '0',
    max: '10',
    width: '37%',
    value: '5',
    backgroundImage: 'assets/sliderBar.png'
});
sliderBarOne.addEventListener('change', function(e) {
    chartView.evalJS("updateChart('" + e.value + "');");
});

Answer 1

You need to hook up an event listener for your slider that calls the updateChart function. The updateChart function should get the value from the slider and change the value in the DataTable, then cal the chart's draw method. How you hook up an event listener to the slider is going to depend on the library you are using for the slider. Here's some example code that assumes your slider object has a change method to set a change event handler and a `getValue method to get the value of the slider:

[edit: added in your slider code]

function drawChart() {
    var data = new google.visualization.DataTable();
    data.addColumn('string', 'Importance');
    data.addColumn('number', 'Earning');
    data.addColumn({type: 'string', role: 'style'});

    data.addRows([
        ['',5,'#000000'],
        ['',5,'#ffffff'],
        ['',5,'#666666'],
        ['', 5,'#cccccc']
    ]); 

    var options = {
        width: 200, 
        height: 240, 
        legend: {
            position: 'none'
        }, 
        chartArea: {
            backgroundColor: 'none'
        }, 
        bar: {
            groupWidth: '100%'
        },
        animation: {
            duration: 1000,
            easing: 'out'
        }
    };

    var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));

    function updateChart(value) {
        data.setValue(0, 1, value);
        chart.draw(data, options);
    }

    // create slider
    var sliderBarOne = Titanium.UI.createSlider({
        top: '310',
        left: '610',
        min: '0',
        max: '10',
        width: '37%',
        value: '5',
        backgroundImage: 'assets/sliderBar.png'
    });

    sliderBarOne.addEventListener('change', function(e) {
        updateChart(e.value);
    });

    chart.draw(data, options);
}