Here you can find the source of rememberOldHeightRatio (JSplitPane splitPane)
static public float rememberOldHeightRatio (JSplitPane splitPane)
//package com.java2s; import javax.swing.*; public class Main { static public float rememberOldHeightRatio(JSplitPane splitPane) { int oldHeight = splitPane.getHeight(); float oldFraction = ((oldHeight == 0) ? 0 : ((float) splitPane.getDividerLocation()) / oldHeight); return oldFraction; }//from w w w. j a v a 2 s . c o m }