fix not displaying all lines in graph

[kscheff]

Issue Link 🔗

#4662

Goals ⚽

When multiple lines with different xMin and xMax values are present and the view port includes all lines then all of the lines should be drawn.

Implementation Details 🚧

Calculating Xbounds for the "shorter" line fails, due to not finding a valid index for highestVisibleX or lowestVisibleX.
Modifying the low and high marks for .entryForXValue() solves the issue.

Testing Details 🔍

Observing to display lines that
a) have a higher xMin value than the lowestVisibleXValue
b) have a lower xMax value than the highestVisbleXValue

[peacedudes]

This works for me, and I need it too. It may be clearer to write:

            let low = Swift.max(chart.lowestVisibleX, dataSet.xMin)
            let high = Swift.min(chart.highestVisibleX, dataSet.xMax)

[schusterlich]

Please merge this, it works and the bug breaks our product 🥲

[schusterlich]

@danielgindi 🙏

[SarahHassaine]

@danielgindi Please merge this 🙏 we can't update to the latest version as it breaks our line charts

[zygoat]

This solution is also duplicated by #4730 (#4710).

I too am waiting on this; stuck on Charts 3.x until resolved.

[developforapple]

@danielgindi
Please merge this.

Here's my workaround:
Using a subclass of LineChartDataSet, override the entryForXValue(_, rounding:) method. In this method, xValue is recalculated by xMin and xMax constraints. Where the LineChartDataSet is used previously, use this subclass instead.

class CustomLineChartDataSet: LineChartDataSet {
    override func entryForXValue(_ xValue: Double, closestToY yValue: Double, rounding: ChartDataSetRounding) -> ChartDataEntry? {
        let newXValue = Swift.min(Swift.max(xValue, xMin), xMax)
        return super.entryForXValue(newXValue, closestToY: yValue, rounding: rounding)
    }
}

[mortenkleveland]

Hi, is it possible to merge this in? I am also stuck at version 3 because of charts with multiple LineChartDataSets aren't working.