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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package jdk.javadoc.internal.doclets.toolkit.taglets;
import javax.lang.model.element.Element;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.util.Elements;
import com.sun.source.doctree.DocTree;
import jdk.javadoc.internal.doclets.toolkit.Configuration;
import jdk.javadoc.internal.doclets.toolkit.Content;
import jdk.javadoc.internal.doclets.toolkit.Messages;
import jdk.javadoc.internal.doclets.toolkit.util.CommentHelper;
import jdk.javadoc.internal.doclets.toolkit.util.Utils;
import static com.sun.source.doctree.DocTree.Kind.*;
An inline Taglet representing the value tag. This tag should only be used with
constant fields that have a value. It is used to access the value of constant
fields. This inline tag has an optional field name parameter. If the name is
specified, the constant value is retrieved from the specified field. A link
is also created to the specified field. If a name is not specified, the value
is retrieved for the field that the inline tag appears on. The name is specifed
in the following format: [fully qualified class name]#[constant field name].
This is NOT part of any supported API.
If you write code that depends on this, you do so at your own risk.
This code and its internal interfaces are subject to change or
deletion without notice.
Author: Jamie Ho
/**
* An inline Taglet representing the value tag. This tag should only be used with
* constant fields that have a value. It is used to access the value of constant
* fields. This inline tag has an optional field name parameter. If the name is
* specified, the constant value is retrieved from the specified field. A link
* is also created to the specified field. If a name is not specified, the value
* is retrieved for the field that the inline tag appears on. The name is specifed
* in the following format: [fully qualified class name]#[constant field name].
*
* <p><b>This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*
* @author Jamie Ho
*/
public class ValueTaglet extends BaseInlineTaglet {
Construct a new ValueTaglet.
/**
* Construct a new ValueTaglet.
*/
public ValueTaglet() {
name = VALUE.tagName;
}
Will return false because this inline tag may
only appear in Fields.
Returns: false since this is not a method.
/**
* Will return false because this inline tag may
* only appear in Fields.
* @return false since this is not a method.
*/
public boolean inMethod() {
return true;
}
Will return false because this inline tag may
only appear in Fields.
Returns: false since this is not a method.
/**
* Will return false because this inline tag may
* only appear in Fields.
* @return false since this is not a method.
*/
public boolean inConstructor() {
return true;
}
Will return false because this inline tag may
only appear in Fields.
Returns: false since this is not a method.
/**
* Will return false because this inline tag may
* only appear in Fields.
* @return false since this is not a method.
*/
public boolean inOverview() {
return true;
}
Will return false because this inline tag may
only appear in Fields.
Returns: false since this is not a field.
/**
* Will return false because this inline tag may
* only appear in Fields.
* @return false since this is not a field.
*/
public boolean inModule() {
return false;
}
Will return false because this inline tag may
only appear in Fields.
Returns: false since this is not a method.
/**
* Will return false because this inline tag may
* only appear in Fields.
* @return false since this is not a method.
*/
public boolean inPackage() {
return true;
}
Will return false because this inline tag may
only appear in Fields.
Returns: false since this is not a method.
/**
* Will return false because this inline tag may
* only appear in Fields.
* @return false since this is not a method.
*/
public boolean inType() {
return true;
}
Given the name of the field, return the corresponding VariableElement. Return null
due to invalid use of value tag if the name is null or empty string and if
the value tag is not used on a field.
Params: - holder – the element holding the tag
- config – the current configuration of the doclet.
- tag – the value tag.
Returns: the corresponding VariableElement. If the name is null or empty string,
return field that the value tag was used in. Return null if the name is null
or empty string and if the value tag is not used on a field.
/**
* Given the name of the field, return the corresponding VariableElement. Return null
* due to invalid use of value tag if the name is null or empty string and if
* the value tag is not used on a field.
*
* @param holder the element holding the tag
* @param config the current configuration of the doclet.
* @param tag the value tag.
*
* @return the corresponding VariableElement. If the name is null or empty string,
* return field that the value tag was used in. Return null if the name is null
* or empty string and if the value tag is not used on a field.
*/
private VariableElement getVariableElement(Element holder, Configuration config, DocTree tag) {
Utils utils = config.utils;
CommentHelper ch = utils.getCommentHelper(holder);
String signature = ch.getReferencedSignature(tag);
if (signature == null) { // no reference
//Base case: no label.
if (utils.isVariableElement(holder)) {
return (VariableElement)(holder);
} else {
// If the value tag does not specify a parameter which is a valid field and
// it is not used within the comments of a valid field, return null.
return null;
}
}
String[] sigValues = signature.split("#");
String memberName = null;
TypeElement te = null;
if (sigValues.length == 1) {
//Case 2: @value in same class.
if (utils.isExecutableElement(holder) || utils.isVariableElement(holder)) {
te = utils.getEnclosingTypeElement(holder);
} else if (utils.isTypeElement(holder)) {
te = utils.getTopMostContainingTypeElement(holder);
}
memberName = sigValues[0];
} else {
//Case 3: @value in different class.
Elements elements = config.docEnv.getElementUtils();
te = elements.getTypeElement(sigValues[0]);
memberName = sigValues[1];
}
if (te == null) {
return null;
}
for (Element field : utils.getFields(te)) {
if (utils.getSimpleName(field).equals(memberName)) {
return (VariableElement)field;
}
}
return null;
}
{@inheritDoc}
/**
* {@inheritDoc}
*/
public Content getTagletOutput(Element holder, DocTree tag, TagletWriter writer) {
Utils utils = writer.configuration().utils;
Messages messages = writer.configuration().getMessages();
VariableElement field = getVariableElement(holder, writer.configuration(), tag);
if (field == null) {
if (tag.toString().isEmpty()) {
//Invalid use of @value
messages.warning(holder,
"doclet.value_tag_invalid_use");
} else {
//Reference is unknown.
messages.warning(holder,
"doclet.value_tag_invalid_reference", tag.toString());
}
} else if (field.getConstantValue() != null) {
return writer.valueTagOutput(field,
utils.constantValueExpresion(field),
// TODO: investigate and cleanup
// in the j.l.m world, equals will not be accurate
// !field.equals(tag.holder())
!utils.elementsEqual(field, holder)
);
} else {
//Referenced field is not a constant.
messages.warning(holder,
"doclet.value_tag_invalid_constant", utils.getSimpleName(field));
}
return writer.getOutputInstance();
}
}