javax.lang.model.util.ElementScanner7 Maven / Gradle / Ivy
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package javax.lang.model.util;
import javax.lang.model.element.*;
import javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;
import static javax.lang.model.SourceVersion.*;
/**
* A scanning visitor of program elements with default behavior
* appropriate for the {@link SourceVersion#RELEASE_7 RELEASE_7}
* source version. The visitXyz methods in this
* class scan their component elements by calling {@code scan} on
* their {@linkplain Element#getEnclosedElements enclosed elements},
* {@linkplain ExecutableElement#getParameters parameters}, etc., as
* indicated in the individual method specifications. A subclass can
* control the order elements are visited by overriding the
* visitXyz methods. Note that clients of a scanner
* may get the desired behavior be invoking {@code v.scan(e, p)} rather
* than {@code v.visit(e, p)} on the root objects of interest.
*
* When a subclass overrides a visitXyz method, the
* new method can cause the enclosed elements to be scanned in the
* default way by calling super.visitXyz. In this
* fashion, the concrete visitor can control the ordering of traversal
* over the component elements with respect to the additional
* processing; for example, consistently calling
* super.visitXyz at the start of the overridden
* methods will yield a preorder traversal, etc. If the component
* elements should be traversed in some other order, instead of
* calling super.visitXyz, an overriding visit method
* should call {@code scan} with the elements in the desired order.
*
*
Methods in this class may be overridden subject to their
* general contract. Note that annotating methods in concrete
* subclasses with {@link java.lang.Override @Override} will help
* ensure that methods are overridden as intended.
*
*
WARNING: The {@code ElementVisitor} interface
* implemented by this class may have methods added to it in the
* future to accommodate new, currently unknown, language structures
* added to future versions of the Java™ programming language.
* Therefore, methods whose names begin with {@code "visit"} may be
* added to this class in the future; to avoid incompatibilities,
* classes which extend this class should not declare any instance
* methods with names beginning with {@code "visit"}.
*
*
When such a new visit method is added, the default
* implementation in this class will be to call the {@link
* #visitUnknown visitUnknown} method. A new element scanner visitor
* class will also be introduced to correspond to the new language
* level; this visitor will have different default behavior for the
* visit method in question. When the new visitor is introduced, all
* or portions of this visitor may be deprecated.
*
* @param the return type of this visitor's methods. Use {@link
* Void} for visitors that do not need to return results.
* @param the type of the additional parameter to this visitor's
* methods. Use {@code Void} for visitors that do not need an
* additional parameter.
*
* @see ElementScanner6
* @see ElementScanner8
* @see ElementScanner9
* @since 1.7
*/
@SupportedSourceVersion(RELEASE_7)
public class ElementScanner7 extends ElementScanner6 {
/**
* Constructor for concrete subclasses; uses {@code null} for the
* default value.
*/
@SuppressWarnings("deprecation") // Superclass constructor deprecated
protected ElementScanner7(){
super(null);
}
/**
* Constructor for concrete subclasses; uses the argument for the
* default value.
*
* @param defaultValue the default value
*/
@SuppressWarnings("deprecation") // Superclass constructor deprecated
protected ElementScanner7(R defaultValue){
super(defaultValue);
}
/**
* This implementation scans the enclosed elements.
*
* @param e {@inheritDoc}
* @param p {@inheritDoc}
* @return the result of scanning
*/
@Override
public R visitVariable(VariableElement e, P p) {
return scan(e.getEnclosedElements(), p);
}
}