Copyright (c) 2016, 2017 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
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2016, 2017 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
 *
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.core.dom;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

Requires directive AST node type (added in JLS9 API).
RequiresDirective:
    requires { ModuleModifier } Name ;

Since:
3.14
@noinstantiate
This class is not intended to be instantiated by clients.
@noextend
This class is not intended to be subclassed by clients./**
 * Requires directive AST node type (added in JLS9 API).
 * <pre>
 * RequiresDirective:
 *     <b>requires</b> { ModuleModifier } Name <b>;</b>
 * </pre>
 *
 * @since 3.14
 * @noinstantiate This class is not intended to be instantiated by clients.
 * @noextend This class is not intended to be subclassed by clients.
 */
@SuppressWarnings({"rawtypes", "unchecked"})
public class RequiresDirective extends ModuleDirective {

	
The "modifiers" structural property of this node type (element type: ModuleModifier). /**
	 * The "modifiers" structural property of this node type (element type: {@link ModuleModifier}).
	 */
	public static final ChildListPropertyDescriptor MODIFIERS_PROPERTY =
		new ChildListPropertyDescriptor(RequiresDirective.class, "modifiers", ModuleModifier.class, NO_CYCLE_RISK); //$NON-NLS-1$

	
The module structural property of this node type (child type: Name). /**
	 * The module structural property of this node type (child type: {@link Name}).
	 */
	public static final ChildPropertyDescriptor NAME_PROPERTY =
		new ChildPropertyDescriptor(RequiresDirective.class, "name", Name.class, OPTIONAL, NO_CYCLE_RISK); //$NON-NLS-1$

	
A list of property descriptors (element type: StructuralPropertyDescriptor), or null if uninitialized. /**
	 * A list of property descriptors (element type:
	 * {@link StructuralPropertyDescriptor}),
	 * or null if uninitialized.
	 */
	private static final List PROPERTY_DESCRIPTORS_9_0;

	static {
		List propertyList = new ArrayList(3);
		createPropertyList(RequiresDirective.class, propertyList);
		addProperty(MODIFIERS_PROPERTY, propertyList);
		addProperty(NAME_PROPERTY, propertyList);
		PROPERTY_DESCRIPTORS_9_0 = reapPropertyList(propertyList);
	}

	
Returns a list of structural property descriptors for this node type.
Clients must not modify the result.
Params:
apiLevel – the API level; one of the
AST.JLS* constants
Returns:
a list of property descriptors (element type: StructuralPropertyDescriptor)/**
	 * Returns a list of structural property descriptors for this node type.
	 * Clients must not modify the result.
	 *
	 * @param apiLevel the API level; one of the
	 * <code>AST.JLS*</code> constants

	 * @return a list of property descriptors (element type:
	 * {@link StructuralPropertyDescriptor})
	 */
	public static List propertyDescriptors(int apiLevel) {
		return PROPERTY_DESCRIPTORS_9_0;
	}

	
The extended modifiers (element type: ModuleModifier). defaults to an empty list /**
	 * The extended modifiers (element type: {@link ModuleModifier}).
	 * defaults to an empty list
	 */
	private ASTNode.NodeList modifiers = new ASTNode.NodeList(MODIFIERS_PROPERTY);

	
The referenced module name; lazily initialized; defaults to a unspecified,
legal Java identifier.
/**
	 * The referenced module name; lazily initialized; defaults to a unspecified,
	 * legal Java identifier.
	 */
	private Name name = null;

	
Creates a new AST node for an requires directive owned by the
given AST. The requires directive initially is a regular (no modifiers)
requires for an unspecified, but legal, Java module name.

N.B. This constructor is package-private; all subclasses must be
declared in the same package; clients are unable to declare
additional subclasses.

Params:
ast – the AST that is to own this node/**
	 * Creates a new AST node for an requires directive owned by the
	 * given AST. The requires directive initially is a regular (no modifiers)
	 * requires for an unspecified, but legal, Java module name.
	 * <p>
	 * N.B. This constructor is package-private; all subclasses must be
	 * declared in the same package; clients are unable to declare
	 * additional subclasses.
	 * </p>
	 *
	 * @param ast the AST that is to own this node
	 */
	RequiresDirective(AST ast) {
		super(ast);
	}

	@Override
	final List internalStructuralPropertiesForType(int apiLevel) {
		return propertyDescriptors(apiLevel);
	}

	@Override
	final ASTNode internalGetSetChildProperty(ChildPropertyDescriptor property, boolean get, ASTNode child) {
		if (property == NAME_PROPERTY) {
			if (get) {
				return getName();
			} else {
				setName((Name) child);
				return null;
			}
		}

		// allow default implementation to flag the error
		return super.internalGetSetChildProperty(property, get, child);
	}

	@Override
	final List internalGetChildListProperty(ChildListPropertyDescriptor property) {
		if (property == MODIFIERS_PROPERTY) {
			return modifiers();
		}

		// allow default implementation to flag the error
		return super.internalGetChildListProperty(property);
	}

	@Override
	final int getNodeType0() {
		return REQUIRES_DIRECTIVE;
	}

	@Override
	ASTNode clone0(AST target) {
		RequiresDirective result = new RequiresDirective(target);
		result.modifiers().addAll(ASTNode.copySubtrees(target, modifiers()));
		result.setName((Name) getName().clone(target));
		return result;
	}

	@Override
	final boolean subtreeMatch0(ASTMatcher matcher, Object other) {
		// dispatch to correct overloaded match method
		return matcher.match(this, other);
	}

	@Override
	void accept0(ASTVisitor visitor) {
		boolean visitChildren = visitor.visit(this);
		if (visitChildren) {
			acceptChildren(visitor, this.modifiers);
			acceptChild(visitor, getName());
		}
		visitor.endVisit(this);
	}

	
Returns the live ordered list of modifiers
of this declaration.

Note that the not all modifiers are legal.

Returns:
the live list of module modifiers (element type: ModuleModifier)/**
	 * Returns the live ordered list of modifiers
	 * of this declaration.
	 * <p>
	 * Note that the not all modifiers are legal.
	 * </p>
	 *
	 * @return the live list of module modifiers
	 *    (element type: {@link ModuleModifier})
	 */
	public List modifiers() {
		return this.modifiers;
	}

	
Returns the module modifiers explicitly specified on this declaration.

This method is a convenience method that
computes these flags from modifiers().

See Also:
ModuleModifier
Returns:
the bit-wise or of ModuleModifier constants/**
	 * Returns the module modifiers explicitly specified on this declaration.
	 * <p>
	 * This method is a convenience method that
	 * computes these flags from <code>modifiers()</code>.
	 * </p>
	 *
	 * @return the bit-wise or of <code>ModuleModifier</code> constants
	 * @see ModuleModifier
	 */
	public int getModifiers() {
		// do not cache - performance could be improved by caching computed flags
		// but this would require tracking changes to this.modifiers
		int computedModifierFlags = ModuleModifier.NONE;
		for (Iterator it = modifiers().iterator(); it.hasNext(); ) {
			Object x = it.next();
			if (x instanceof ModuleModifier) {
				computedModifierFlags |= ((ModuleModifier) x).getKeyword().toFlagValue();
			}
		}
		return computedModifierFlags;
	}

	
Returns the module name referenced by this declaration.
Returns:
the module referenced/**
	 * Returns the module name referenced by this declaration.
	 *
	 * @return the module referenced
	 */
	public Name getName()  {
		if (this.name == null) {
			// lazy init must be thread-safe for readers
			synchronized (this) {
				if (this.name == null) {
					preLazyInit();
					this.name =this.ast.newQualifiedName(
							new SimpleName(this.ast), new SimpleName(this.ast));
					postLazyInit(this.name, NAME_PROPERTY);
				}
			}
		}
		return this.name;
	}

	
Sets the module name in requires directive to the given name.
Params:
name – the new module name
Throws:
IllegalArgumentException – if:

the node belongs to a different AST
the node already has a parent
/**
	 * Sets the module name in requires directive to the given name.
	 *
	 * @param name the new module name
	 * @exception IllegalArgumentException if:
	 * <ul>
	 * <li>the node belongs to a different AST</li>
	 * <li>the node already has a parent</li>
	 * </ul>
	 */
	public void setName(Name name) {
		if (name == null) {
			throw new IllegalArgumentException();
		}
		ASTNode oldChild = this.name;
		preReplaceChild(oldChild, name, NAME_PROPERTY);
		this.name = name;
		postReplaceChild(oldChild, name, NAME_PROPERTY);
	}

	@Override
	int memSize() {
		return BASE_NODE_SIZE + 2 * 4;
	}

	@Override
	int treeSize() {
		return
			memSize()
			+ (this.modifiers == null ? 0 : this.modifiers.listSize())
			+ (this.name == null ? 0 : getName().treeSize());
	}

}