| 1 | /******************************************************************************* |
|---|---|
| 2 | * Copyright (c) 2004, 2009 IBM Corporation and others. |
| 3 | * |
| 4 | * This program and the accompanying materials |
| 5 | * are made available under the terms of the Eclipse Public License 2.0 |
| 6 | * which accompanies this distribution, and is available at |
| 7 | * https://www.eclipse.org/legal/epl-2.0/ |
| 8 | * |
| 9 | * SPDX-License-Identifier: EPL-2.0 |
| 10 | * |
| 11 | * Contributors: |
| 12 | * IBM Corporation - initial API and implementation |
| 13 | *******************************************************************************/ |
| 14 | package org.eclipse.jdt.core.dom; |
| 15 | |
| 16 | /** |
| 17 | * A node event handler is an internal mechanism for receiving |
| 18 | * notification of changes to nodes in an AST. |
| 19 | * <p> |
| 20 | * The default implementation serves as the default event handler |
| 21 | * that does nothing. Internal subclasses do all the real work. |
| 22 | * </p> |
| 23 | * |
| 24 | * @see AST#getEventHandler() |
| 25 | */ |
| 26 | class NodeEventHandler { |
| 27 | |
| 28 | /** |
| 29 | * Creates a node event handler. |
| 30 | */ |
| 31 | NodeEventHandler() { |
| 32 | // default implementation: do nothing |
| 33 | } |
| 34 | |
| 35 | /** |
| 36 | * Reports that the given node is about to lose a child. |
| 37 | * The first half of an event pair. The default implementation does nothing. |
| 38 | * |
| 39 | * @param node the node about to be modified |
| 40 | * @param child the node about to be removed |
| 41 | * @param property the child or child list property descriptor |
| 42 | * @see #postRemoveChildEvent(ASTNode, ASTNode, StructuralPropertyDescriptor) |
| 43 | * @since 3.0 |
| 44 | */ |
| 45 | void preRemoveChildEvent(ASTNode node, ASTNode child, StructuralPropertyDescriptor property) { |
| 46 | // do nothing |
| 47 | // System.out.println("DEL1 " + property); |
| 48 | } |
| 49 | |
| 50 | /** |
| 51 | * Reports that the given node has just lose a child. |
| 52 | * The second half of an event pair. The default implementation does nothing. |
| 53 | * |
| 54 | * @param node the node that was modified |
| 55 | * @param child the child that was removed; note that this node is unparented |
| 56 | * @param property the child or child list property descriptor |
| 57 | * @see #preRemoveChildEvent(ASTNode, ASTNode, StructuralPropertyDescriptor) |
| 58 | * @since 3.0 |
| 59 | */ |
| 60 | void postRemoveChildEvent(ASTNode node, ASTNode child, StructuralPropertyDescriptor property) { |
| 61 | // do nothing |
| 62 | // System.out.println("DEL2 " + property); |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Reports that the given node is about to have a child replaced. |
| 67 | * The first half of an event pair. |
| 68 | * The default implementation does nothing. |
| 69 | * |
| 70 | * @param node the node about to be modified |
| 71 | * @param child the node about to be replaced |
| 72 | * @param newChild the replacement child; note that this node is unparented |
| 73 | * @param property the child or child list property descriptor |
| 74 | * @see #preReplaceChildEvent(ASTNode, ASTNode, ASTNode, StructuralPropertyDescriptor) |
| 75 | * @since 3.0 |
| 76 | */ |
| 77 | void preReplaceChildEvent(ASTNode node, ASTNode child, ASTNode newChild, StructuralPropertyDescriptor property) { |
| 78 | // do nothing |
| 79 | // System.out.println("REP1 " + property); |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Reports that the given node has had its child replaced. The second half |
| 84 | * of an event pair. The default implementation does nothing. |
| 85 | * |
| 86 | * @param node the node that was modified |
| 87 | * @param child the node that was replaced; note that this node is unparented |
| 88 | * @param newChild the replacement child |
| 89 | * @param property the child or child list property descriptor |
| 90 | * @see #postReplaceChildEvent(ASTNode, ASTNode, ASTNode, StructuralPropertyDescriptor) |
| 91 | * @since 3.0 |
| 92 | */ |
| 93 | void postReplaceChildEvent(ASTNode node, ASTNode child, ASTNode newChild, StructuralPropertyDescriptor property) { |
| 94 | // do nothing |
| 95 | // System.out.println("REP2 " + property); |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Reports that the given node is about to gain a child. |
| 100 | * The first half of an event pair. The default implementation does nothing. |
| 101 | * |
| 102 | * @param node the node that to be modified |
| 103 | * @param child the node that is to be added as a child; note that this |
| 104 | * node is unparented; in the case of a child list property, the exact |
| 105 | * location of insertion is not supplied (but is known on the |
| 106 | * corresponding <code>postAddChildEvent</code> to |
| 107 | * follow) |
| 108 | * @param property the child or child list property descriptor |
| 109 | * @see #postAddChildEvent(ASTNode, ASTNode, StructuralPropertyDescriptor) |
| 110 | * @since 3.0 |
| 111 | */ |
| 112 | void preAddChildEvent(ASTNode node, ASTNode child, StructuralPropertyDescriptor property) { |
| 113 | // do nothing |
| 114 | // System.out.println("ADD1 " + property); |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Reports that the given node has just gained a child. |
| 119 | * The second half of an event pair. The default implementation does nothing. |
| 120 | * |
| 121 | * @param node the node that was modified |
| 122 | * @param child the node that was added as a child |
| 123 | * @param property the child or child list property descriptor |
| 124 | * @see #preAddChildEvent(ASTNode, ASTNode, StructuralPropertyDescriptor) |
| 125 | * @since 3.0 |
| 126 | */ |
| 127 | void postAddChildEvent(ASTNode node, ASTNode child, StructuralPropertyDescriptor property) { |
| 128 | // do nothing |
| 129 | // System.out.println("ADD2 " + property); |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Reports that the given node is about to change the value of a |
| 134 | * non-child property. The first half of an event pair. |
| 135 | * The default implementation does nothing. |
| 136 | * |
| 137 | * @param node the node to be modified |
| 138 | * @param property the property descriptor |
| 139 | * @see #postValueChangeEvent(ASTNode, SimplePropertyDescriptor) |
| 140 | * @since 3.0 |
| 141 | */ |
| 142 | void preValueChangeEvent(ASTNode node, SimplePropertyDescriptor property) { |
| 143 | // do nothing |
| 144 | // System.out.println("MOD1 " + property); |
| 145 | } |
| 146 | |
| 147 | /** |
| 148 | * Reports that the given node has just changed the value of a |
| 149 | * non-child property. The second half of an event pair. |
| 150 | * The default implementation does nothing. |
| 151 | * |
| 152 | * @param node the node that was modified |
| 153 | * @param property the property descriptor |
| 154 | * @see #preValueChangeEvent(ASTNode, SimplePropertyDescriptor) |
| 155 | * @since 3.0 |
| 156 | */ |
| 157 | void postValueChangeEvent(ASTNode node, SimplePropertyDescriptor property) { |
| 158 | // do nothing |
| 159 | // System.out.println("MOD2 " + property); |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * Reports that the given node is about to be cloned. |
| 164 | * The first half of an event pair. |
| 165 | * The default implementation does nothing. |
| 166 | * |
| 167 | * @param node the node to be modified |
| 168 | * @see #postCloneNodeEvent(ASTNode, ASTNode) |
| 169 | * @since 3.0 |
| 170 | */ |
| 171 | void preCloneNodeEvent(ASTNode node) { |
| 172 | // do nothing |
| 173 | // System.out.println("CLONE1"); |
| 174 | } |
| 175 | |
| 176 | /** |
| 177 | * Reports that the given node has just been cloned. |
| 178 | * The second half of an event pair. |
| 179 | * The default implementation does nothing. |
| 180 | * |
| 181 | * @param node the node that was modified |
| 182 | * @param clone the clone of <code>node</code> |
| 183 | * @see #preCloneNodeEvent(ASTNode) |
| 184 | * @since 3.0 |
| 185 | */ |
| 186 | void postCloneNodeEvent(ASTNode node, ASTNode clone) { |
| 187 | // do nothing |
| 188 | // System.out.println("CLONE2"); |
| 189 | } |
| 190 | |
| 191 | } |
| 192 |
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