1 /* 2 * Copyright (c) 2014, 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 package hello.dialog.wizard; 26 27 import java.lang.reflect.Method; 28 import java.util.Collections; 29 import java.util.List; 30 31 import javafx.collections.FXCollections; 32 import javafx.collections.ObservableList; 33 import javafx.scene.Group; 34 import javafx.scene.Node; 35 import javafx.scene.Parent; 36 import javafx.scene.control.Control; 37 import javafx.scene.control.Skin; 38 import javafx.scene.control.SkinBase; 39 import javafx.scene.layout.Pane; 40 41 public class ImplUtils { 42 43 private ImplUtils() { 44 // no-op 45 } 46 47 public static List<Node> getChildren(Node n, boolean useReflection) { 48 return n instanceof Parent ? getChildren((Parent)n, useReflection) : Collections.emptyList(); 49 } 50 51 @SuppressWarnings("unchecked") 52 public static ObservableList<Node> getChildren(Parent p, boolean useReflection) { 53 ObservableList<Node> children = null; 54 55 // previously we used reflection immediately, now we try to avoid reflection 56 // by checking the type of the Parent. Still not great... 57 if (p instanceof Pane) { 58 // This should cover the majority of layout containers, including 59 // AnchorPane, FlowPane, GridPane, HBox, Pane, StackPane, TilePane, VBox 60 children = ((Pane)p).getChildren(); 61 } else if (p instanceof Group) { 62 children = ((Group)p).getChildren(); 63 } else if (p instanceof Control) { 64 Control c = (Control) p; 65 Skin<?> s = c.getSkin(); 66 children = s instanceof SkinBase ? ((SkinBase<?>)s).getChildren() : null; 67 } else if (useReflection) { 68 // we really want to avoid using this!!!! 69 try { 70 Method getChildrenMethod = Parent.class.getDeclaredMethod("getChildren"); //$NON-NLS-1$ 71 72 if (getChildrenMethod != null) { 73 if (! getChildrenMethod.isAccessible()) { 74 getChildrenMethod.setAccessible(true); 75 } 76 children = (ObservableList<Node>) getChildrenMethod.invoke(p); 77 } else { 78 // uh oh, trouble 79 } 80 } catch (ReflectiveOperationException | IllegalArgumentException e) { 81 throw new RuntimeException("Unable to get children for Parent of type " + p.getClass(), e); 82 } 83 } 84 85 if (useReflection && children == null) { 86 throw new RuntimeException("Unable to get children for Parent of type " + p.getClass() + 87 ". useReflection is set to true"); 88 } 89 90 return children == null ? FXCollections.emptyObservableList() : children; 91 } 92 }