public void setOnValueTouchListener(LineChartOnValueSelectListener touchListener) {
        if (null != touchListener) {
            this.onValueTouchListener = touchListener;
        }
    }
LineChart, supports cubic lines, filled lines, circle and square points. Point radius and stroke width can be
adjusted using LineChartData attributes.

@author Leszek Wach
hellocharts-library/src/lecho/lib/hellocharts/view/LineChartView.java