x轴多行文本，无法显示全

```swift
let barData = BarChartData(dataSets: sets)
barData.barWidth = 0.5
barData.setValueFont(.sys(8))

let count = data.charts.max(by: { $0.datas.count < $1.datas.count })?.datas.count ?? 1

let axisMinimum: Double = 0
let groupSpace: Double = 0.8
let barSpace: Double = 0.1

let axisMaximum: Double = axisMinimum + barData.groupWidth(groupSpace: groupSpace, barSpace: barSpace) * Double(count)
chartView.xAxis.valueFormatter = IndexAxisValueFormatter(values: data.xVals)
chartView.xAxis.axisMinimum = axisMinimum
chartView.xAxis.axisMaximum = axisMaximum
// chartView.xAxis.labelRotationAngle = 30
chartView.animate(yAxisDuration: 1)

chartView.data = barData
// chartView.notifyDataSetChanged()
chartView.setVisibleXRangeMaximum(10)
chartView.barData?.groupBars(fromX: axisMinimum, groupSpace: groupSpace, barSpace: barSpace)
```