1 /* 2 * Copyright (c) 2010, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.javafx.scene.control.skin; 27 28 import javafx.scene.control.IndexedCell; 29 import javafx.scene.control.ScrollBar; 30 31 import com.sun.javafx.util.Utils; 32 33 /** 34 * This custom ScrollBar is used to map the increment & decrement features 35 * to pixel based scrolling rather than thumb/track based scrolling, if the 36 * "virtual" attribute is true. 37 */ 38 public class VirtualScrollBar extends ScrollBar { 39 private final VirtualFlow flow; 40 41 private boolean virtual; 42 43 private boolean adjusting; 44 45 public VirtualScrollBar(final VirtualFlow flow) { 46 this.flow = flow; 47 48 super.valueProperty().addListener(valueModel -> { 49 if (isVirtual()/* && oldValue != newValue*/) { 50 if (adjusting) { 51 // no-op 52 } else { 53 flow.setPosition(getValue()); 54 } 55 } 56 }); 57 } 58 59 public void setVirtual(boolean virtual) { 60 this.virtual = virtual; 61 } 62 63 public boolean isVirtual() { 64 return this.virtual; 65 } 66 67 @Override public void decrement() { 68 if (isVirtual()) { 69 flow.adjustPixels(-10); 70 } else { 71 super.decrement(); 72 } 73 } 74 75 @Override public void increment() { 76 if (isVirtual()) { 77 flow.adjustPixels(10); 78 } else { 79 super.increment(); 80 } 81 } 82 83 // private double lastAdjustValue = 0.0; 84 85 // this method is called when the user clicks in the scrollbar track, so 86 // we special-case it to allow for page-up and page-down clicking to work 87 // as expected. 88 @Override public void adjustValue(double pos) { 89 if (isVirtual()) { 90 // if (pos == lastAdjustValue) { 91 // return; 92 // } 93 94 adjusting = true; 95 double oldValue = flow.getPosition(); 96 97 double newValue = ((getMax() - getMin()) * Utils.clamp(0, pos, 1))+getMin(); 98 if (newValue < oldValue) { 99 IndexedCell cell = flow.getFirstVisibleCell(); 100 if (cell == null) return; 101 flow.showAsLast(cell); 102 } else if (newValue > oldValue) { 103 IndexedCell cell = flow.getLastVisibleCell(); 104 if (cell == null) return; 105 flow.showAsFirst(cell); 106 } 107 // lastAdjustValue = pos; 108 109 adjusting = false; 110 } else { 111 super.adjustValue(pos); 112 } 113 } 114 }