Here you can find the source of canHScroll(JViewport viewport)
public static boolean canHScroll(JViewport viewport)
//package com.java2s; /**/*from w ww . j a v a 2 s . co m*/ * MySwing: Advanced Swing Utilites * Copyright (C) 2005 Santhosh Kumar T * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. */ import javax.swing.*; import java.awt.*; public class Main { public static boolean canHScroll(JViewport viewport) { JScrollPane scrollPane = (JScrollPane) viewport.getParent(); Rectangle availR = scrollPane.getBounds(); Component view = viewport.getView(); Dimension viewPrefSize = view != null ? view.getPreferredSize() : new Dimension(0, 0); Dimension extentSize = viewport.toViewCoordinates(availR.getSize()); boolean canHScroll = true; if (view instanceof Scrollable) canHScroll = !((Scrollable) view).getScrollableTracksViewportWidth(); if (canHScroll && (viewPrefSize.width <= extentSize.width)) canHScroll = false; return canHScroll; } }