Crash when calling func highlightValue(x: Double, dataSetIndex: Int, callDelegate: Bool)

[everlof]

I use charts version 3.0.2.

I call highlightValue like this:
highlightValue(x: 2, dataSetIndex: 0, callDelegate: true).

I then get a crash here:

When following the code stack trace from the crash:

Stack trace step 5:
Row 522 in ChartViewBase.swift
The Highlight object is created with x=2, y=Nan, dataSetIndex=0 .

Step trace step 4:
The Highlight object is then passed to entryForHighlight on row 547 in ChartViewBase.swift.

Then it crashes with Index out of range on row 278 in CombinedChartData:
let data = dataObjects[highlight.dataIndex]

Because highlight.dataIndex is -1, since it's not set from the constructor. The constructor that is used is:

    /// - parameter x: the x-value of the highlighted value
    /// - parameter y: the y-value of the highlighted value
    /// - parameter dataSetIndex: the index of the DataSet the highlighted value belongs to
    public init(x: Double, y: Double, dataSetIndex: Int)
    {
        _x = x
        _y = y
        _dataSetIndex = dataSetIndex
    }

Where highlight.dataIndex is not initialized.

[liuxuan30]

You can pass dataIndex to

@objc open func highlightValue(_ highlight: Highlight?, callDelegate: Bool)

Before that you create the highlight object you need to calculate dataIndex carefully when you manually call it.

[liuxuan30]

Or we add a new method to pass dataIndex into.

[everlof]

Not sure how this is an enhancement, when calling a public API (highlightValue) causes a crash.

However, seems like the fixes you've created would solve it.

[liuxuan30]

@everlof because you use the wrong API as they don't have dataIndex setup. Use @objc open func highlightValue(_ highlight: Highlight?, callDelegate: Bool) and manually create the highlight object and setup your correct dataIndex first.

[jjatie]

@liuxuan30 I agree. This sounds like a problem with documentation more than anything else, but your #2852 also works ; )