toggle highlight for pie chart slice

[gaimanjing]

Pie chart should toggle highlight state if user taps the same slice, same as bar chart and line chart.

code in PieRadarChartViewBase.swift is:

    @objc fileprivate func tapGestureRecognized(_ recognizer: NSUITapGestureRecognizer)
    {
        if recognizer.state == NSUIGestureRecognizerState.ended
        {
            if !self.isHighLightPerTapEnabled { return }
            
            let location = recognizer.location(in: self)
            
            let high = self.getHighlightByTouchPoint(location)
            self.highlightValue(high, callDelegate: true)
        }
    }

code in BarLineChartViewBase.swift is:

            if h === nil || h!.isEqual(self.lastHighlighted)
            {
                self.highlightValue(nil, callDelegate: true)
                self.lastHighlighted = nil
            }

[liuxuan30]

note the gesture handler is private, so you can provide yours and do whatever you want. Someone just need this and others don't. So it will not change until many people asking.