public void zoomOut() {
		if (null == linesData || linesData.size() <= 0) {
			return;
		}
		if (maxPointNum < linesData.get(0).getLineData().size() - 1 - ZOOM_STEP) {
			maxPointNum = maxPointNum + ZOOM_STEP;
		}
		
		this.postInvalidate();
		
//		//Listener
//		if (onZoomGestureListener != null) {
//			onZoomGestureListener.onZoom(ZOOM_OUT, 0, maxPointNum);
//		}
	}
@param linesData
           the linesData to set
src/src/cn/limc/androidcharts/view/LineChart.java