/*******************************************************************************
* Copyright (c) 2005, 2010 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.core.dom;
import org.eclipse.jdt.core.ICompilationUnit;
/**
* An AST requestor handles ASTs for compilation units passed to
* {@link ASTParser#createASTs(ICompilationUnit[], String[], ASTRequestor, org.eclipse.core.runtime.IProgressMonitor) ASTParser.createASTs}.
* <p>
* {@link #acceptAST(ICompilationUnit, CompilationUnit) ASTRequestor.acceptAST} is called for each of the
* compilation units passed to {@link ASTParser#createASTs(ICompilationUnit[], String[], ASTRequestor, org.eclipse.core.runtime.IProgressMonitor) ASTParser.createASTs}.
* After all the compilation units have been processed,
* {@link #acceptBinding(String, IBinding) ASTRequestor.acceptBindings} is called for each
* of the binding keys passed to {@link ASTParser#createASTs(ICompilationUnit[], String[], ASTRequestor, org.eclipse.core.runtime.IProgressMonitor) ASTParser.createASTs}.
* </p>
* <p>
* This class is intended to be subclassed by clients.
* AST requestors are serially reusable, but neither reentrant nor thread-safe.
* </p>
*
* @see ASTParser#createASTs(ICompilationUnit[], String[], ASTRequestor, org.eclipse.core.runtime.IProgressMonitor)
* @since 3.1
*/
public abstract class ASTRequestor {
/**
* The compilation unit resolver used to resolve bindings, or
* <code>null</code> if none. Note that this field is non-null
* only within the dynamic scope of a call to
* <code>ASTParser.createASTs</code>.
*/
CompilationUnitResolver compilationUnitResolver = null;
/**
* Creates a new instance.
*/
protected ASTRequestor() {
// do nothing
}
/**
* Accepts an AST corresponding to the compilation unit.
* That is, <code>ast</code> is an AST for <code>source</code>.
* <p>
* The default implementation of this method does nothing.
* Clients should override to process the resulting AST.
* </p>
*
* @param source the compilation unit the ast is coming from
* @param ast the requested abtract syntax tree
*/
public void acceptAST(ICompilationUnit source, CompilationUnit ast) {
// do nothing
}
/**
* Accepts a binding corresponding to the binding key.
* That is, <code>binding</code> is the binding for
* <code>bindingKey</code>; <code>binding</code> is <code>null</code>
* if the key cannot be resolved.
* <p>
* The default implementation of this method does nothing.
* Clients should override to process the resulting binding.
* </p>
*
* @param bindingKey the key of the requested binding
* @param binding the requested binding, or <code>null</code> if none
*/
public void acceptBinding(String bindingKey, IBinding binding) {
// do nothing
}
/**
* Resolves bindings for the given binding keys.
* The given binding keys must have been obtained earlier
* using {@link IBinding#getKey()}.
* <p>
* If a binding key cannot be resolved, <code>null</code> is put in the resulting array.
* Bindings can only be resolved in the dynamic scope of a <code>ASTParser.createASTs</code>,
* and only if <code>ASTParser.resolveBindings(true)</code> was specified.
* </p>
* <p>
* Caveat: During an <code>acceptAST</code> callback, there are implementation
* limitations concerning the look up of binding keys representing local elements.
* In some cases, the binding is unavailable, and <code>null</code> will be returned.
* This is only an issue during an <code>acceptAST</code> callback, and only
* when the binding key represents a local element (e.g., local variable,
* local class, method declared in anonymous class). There is no such limitation
* outside of <code>acceptAST</code> callbacks, or for top-level types and their
* members even within <code>acceptAST</code> callbacks.
* </p>
*
* @param bindingKeys the binding keys to look up
* @return a list of bindings paralleling the <code>bindingKeys</code> parameter,
* with <code>null</code> entries for keys that could not be resolved
*/
public final IBinding[] createBindings(String[] bindingKeys) {
int length = bindingKeys.length;
IBinding[] result = new IBinding[length];
for (int i = 0; i < length; i++) {
result[i] = null;
if (this.compilationUnitResolver != null) {
result[i] = this.compilationUnitResolver.createBinding(bindingKeys[i]);
}
}
return result;
}
}
