private int calculateContentRectInternalMargin() {
        int contentAreaMargin = 0;
        final LineChartData data = dataProvider.getLineChartData();
        for (Line line : data.getLines()) {
            if (checkIfShouldDrawPoints(line)) {
                int margin = line.getPointRadius() + DEFAULT_TOUCH_TOLERANCE_MARGIN_DP;
                if (margin > contentAreaMargin) {
                    contentAreaMargin = margin;
                }
            }
        }
        return ChartUtils.dp2px(density, contentAreaMargin);
    }
Renderer for line chart. Can draw lines, cubic lines, filled area chart and scattered chart.
hellocharts-library/src/lecho/lib/hellocharts/renderer/LineChartRenderer.java