title: How to change width of bar in bar charts in charts_flutter?
body: <p>Trying to use <code>charts_flutter</code> for bar charts but couldn't find a property to reduce the width of bars in simple bar charts.</p>
  
  <p>Following is my mock:
  <a href="https://i.stack.imgur.com/kk3hg.png" rel="noreferrer"><img src="https://i.stack.imgur.com/kk3hg.png" alt="charts"></a></p>
  
  <p>Also, don't know how to:</p>
  
  <p>-add below indexes in this package</p>
  
  <p>-add values inside the bars like shown in mock.</p>
  
  <p>Following is my Code:</p>
  
  <pre><code>class HiddenTicksAndLabelsAxis extends StatelessWidget {
    final List&lt;charts.Series&gt; seriesList;
    final bool animate;
  
    HiddenTicksAndLabelsAxis(this.seriesList, {this.animate});
  
    factory HiddenTicksAndLabelsAxis.withSampleData() {
      return new HiddenTicksAndLabelsAxis(
        _createSampleData(),
        // Disable animations for image tests.
        animate: true,
      );
    }
  
  
    @override
    Widget build(BuildContext context) {
      return new charts.BarChart(
        seriesList,
        animate: animate,
  
        /// Assign a custom style for the measure axis.
        ///
        /// The NoneRenderSpec can still draw an axis line with
        /// showAxisLine=true.
        primaryMeasureAxis:
            new charts.NumericAxisSpec(renderSpec: new charts.NoneRenderSpec()),
  
        /// This is an OrdinalAxisSpec to match up with BarChart's default
        /// ordinal domain axis (use NumericAxisSpec or DateTimeAxisSpec for
        /// other charts).
        domainAxis: new charts.OrdinalAxisSpec(
            // Make sure that we draw the domain axis line.
            showAxisLine: true,
            // But don't draw anything else.
            renderSpec: new charts.NoneRenderSpec()),
      );
    }
  
    /// Create series list with single series
    static List&lt;charts.Series&lt;OrdinalSales, String&gt;&gt; _createSampleData() {
      final globalSalesData = [
        new OrdinalSales('2014', 3, Colors.lightGreen),
        new OrdinalSales('2015', 6,Colors.lightBlue),
        new OrdinalSales('2016', 0.5,Colors.red),
        // new OrdinalSales('2017', 750000),
      ];
  
      return [
        new charts.Series&lt;OrdinalSales, String&gt;(
          id: 'Global Revenue',
          domainFn: (OrdinalSales sales, _) =&gt; sales.year,
          measureFn: (OrdinalSales sales, _) =&gt; sales.sales,
          colorFn: (OrdinalSales sales, _) =&gt; sales.color,
  
          data: globalSalesData,
        ),
      ];
    }
  }
  
  /// Sample ordinal data type.
  class OrdinalSales {
    final String year;
    final double sales;
  
    final charts.Color color;
  
    OrdinalSales(this.year, this.sales, Color color)
        : this.color = new charts.Color(
              r: color.red, g: color.green, b: color.blue, a: color.alpha);
  }
  </code></pre>
  
  <p>I being a newbie to flutter, please excuse if any problem. </p>