| 1 | /******************************************************************************* |
|---|---|
| 2 | * Copyright (c) 2005, 2010 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 | import org.eclipse.jdt.core.ICompilationUnit; |
| 17 | |
| 18 | /** |
| 19 | * An AST requestor handles ASTs for compilation units passed to |
| 20 | * {@link ASTParser#createASTs(ICompilationUnit[], String[], ASTRequestor, org.eclipse.core.runtime.IProgressMonitor) ASTParser.createASTs}. |
| 21 | * <p> |
| 22 | * {@link #acceptAST(ICompilationUnit, CompilationUnit) ASTRequestor.acceptAST} is called for each of the |
| 23 | * compilation units passed to {@link ASTParser#createASTs(ICompilationUnit[], String[], ASTRequestor, org.eclipse.core.runtime.IProgressMonitor) ASTParser.createASTs}. |
| 24 | * After all the compilation units have been processed, |
| 25 | * {@link #acceptBinding(String, IBinding) ASTRequestor.acceptBindings} is called for each |
| 26 | * of the binding keys passed to {@link ASTParser#createASTs(ICompilationUnit[], String[], ASTRequestor, org.eclipse.core.runtime.IProgressMonitor) ASTParser.createASTs}. |
| 27 | * </p> |
| 28 | * <p> |
| 29 | * This class is intended to be subclassed by clients. |
| 30 | * AST requestors are serially reusable, but neither reentrant nor thread-safe. |
| 31 | * </p> |
| 32 | * |
| 33 | * @see ASTParser#createASTs(ICompilationUnit[], String[], ASTRequestor, org.eclipse.core.runtime.IProgressMonitor) |
| 34 | * @since 3.1 |
| 35 | */ |
| 36 | public abstract class ASTRequestor { |
| 37 | |
| 38 | /** |
| 39 | * The compilation unit resolver used to resolve bindings, or |
| 40 | * <code>null</code> if none. Note that this field is non-null |
| 41 | * only within the dynamic scope of a call to |
| 42 | * <code>ASTParser.createASTs</code>. |
| 43 | */ |
| 44 | CompilationUnitResolver compilationUnitResolver = null; |
| 45 | |
| 46 | /** |
| 47 | * Creates a new instance. |
| 48 | */ |
| 49 | protected ASTRequestor() { |
| 50 | // do nothing |
| 51 | } |
| 52 | |
| 53 | /** |
| 54 | * Accepts an AST corresponding to the compilation unit. |
| 55 | * That is, <code>ast</code> is an AST for <code>source</code>. |
| 56 | * <p> |
| 57 | * The default implementation of this method does nothing. |
| 58 | * Clients should override to process the resulting AST. |
| 59 | * </p> |
| 60 | * |
| 61 | * @param source the compilation unit the ast is coming from |
| 62 | * @param ast the requested abtract syntax tree |
| 63 | */ |
| 64 | public void acceptAST(ICompilationUnit source, CompilationUnit ast) { |
| 65 | // do nothing |
| 66 | } |
| 67 | |
| 68 | /** |
| 69 | * Accepts a binding corresponding to the binding key. |
| 70 | * That is, <code>binding</code> is the binding for |
| 71 | * <code>bindingKey</code>; <code>binding</code> is <code>null</code> |
| 72 | * if the key cannot be resolved. |
| 73 | * <p> |
| 74 | * The default implementation of this method does nothing. |
| 75 | * Clients should override to process the resulting binding. |
| 76 | * </p> |
| 77 | * |
| 78 | * @param bindingKey the key of the requested binding |
| 79 | * @param binding the requested binding, or <code>null</code> if none |
| 80 | */ |
| 81 | public void acceptBinding(String bindingKey, IBinding binding) { |
| 82 | // do nothing |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * Resolves bindings for the given binding keys. |
| 87 | * The given binding keys must have been obtained earlier |
| 88 | * using {@link IBinding#getKey()}. |
| 89 | * <p> |
| 90 | * If a binding key cannot be resolved, <code>null</code> is put in the resulting array. |
| 91 | * Bindings can only be resolved in the dynamic scope of a <code>ASTParser.createASTs</code>, |
| 92 | * and only if <code>ASTParser.resolveBindings(true)</code> was specified. |
| 93 | * </p> |
| 94 | * <p> |
| 95 | * Caveat: During an <code>acceptAST</code> callback, there are implementation |
| 96 | * limitations concerning the look up of binding keys representing local elements. |
| 97 | * In some cases, the binding is unavailable, and <code>null</code> will be returned. |
| 98 | * This is only an issue during an <code>acceptAST</code> callback, and only |
| 99 | * when the binding key represents a local element (e.g., local variable, |
| 100 | * local class, method declared in anonymous class). There is no such limitation |
| 101 | * outside of <code>acceptAST</code> callbacks, or for top-level types and their |
| 102 | * members even within <code>acceptAST</code> callbacks. |
| 103 | * </p> |
| 104 | * |
| 105 | * @param bindingKeys the binding keys to look up |
| 106 | * @return a list of bindings paralleling the <code>bindingKeys</code> parameter, |
| 107 | * with <code>null</code> entries for keys that could not be resolved |
| 108 | */ |
| 109 | public final IBinding[] createBindings(String[] bindingKeys) { |
| 110 | int length = bindingKeys.length; |
| 111 | IBinding[] result = new IBinding[length]; |
| 112 | for (int i = 0; i < length; i++) { |
| 113 | result[i] = null; |
| 114 | if (this.compilationUnitResolver != null) { |
| 115 | result[i] = this.compilationUnitResolver.createBinding(bindingKeys[i]); |
| 116 | } |
| 117 | } |
| 118 | return result; |
| 119 | } |
| 120 | } |
| 121 |
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