CreatePackageDeclarationOperation.java

/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core;

import org.eclipse.core.runtime.IStatus;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IImportDeclaration;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaModelStatus;
import org.eclipse.jdt.core.IJavaModelStatusConstants;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.core.JavaConventions;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.core.dom.Name;
import org.eclipse.jdt.core.dom.PackageDeclaration;
import org.eclipse.jdt.core.dom.StructuralPropertyDescriptor;
import org.eclipse.jdt.core.dom.rewrite.ASTRewrite;
import org.eclipse.jdt.internal.core.util.Messages;

/**
 * <p>
 * This operation adds/replaces a package declaration in an existing compilation unit. If the
 * compilation unit already includes the specified package declaration, it is not generated (it does
 * not generate duplicates).
 * 
 * <p>
 * Required Attributes:
 * <ul>
 * <li>Compilation unit element
 * <li>Package name
 * </ul>
 */
public class CreatePackageDeclarationOperation extends CreateElementInCUOperation {
	/**
	 * The name of the package declaration being created
	 */
	protected String name= null;

	/**
	 * When executed, this operation will add a package declaration to the given compilation unit.
	 */
	public CreatePackageDeclarationOperation(String name, ICompilationUnit parentElement) {
		super(parentElement);
		this.name= name;
	}

	protected StructuralPropertyDescriptor getChildPropertyDescriptor(ASTNode parent) {
		return CompilationUnit.PACKAGE_PROPERTY;
	}

	protected ASTNode generateElementAST(ASTRewrite rewriter, ICompilationUnit cu) throws JavaModelException {
		//look for an existing package declaration
		IJavaElement[] children= getCompilationUnit().getChildren();
		for (int i= 0; i < children.length; i++) {
			if (children[i].getElementType() == IJavaElement.PACKAGE_DECLARATION && this.name.equals(children[i].getElementName())) {
				//equivalent package declaration already exists
				this.creationOccurred= false;
				return null;
			}
		}
		AST ast= this.cuAST.getAST();
		PackageDeclaration pkgDeclaration= ast.newPackageDeclaration();
		Name astName= ast.newName(this.name);
		pkgDeclaration.setName(astName);
		return pkgDeclaration;
	}

	/**
	 * Creates and returns the handle for the element this operation created.
	 */
	protected IJavaElement generateResultHandle() {
		return getCompilationUnit().getPackageDeclaration(this.name);
	}

	/**
	 * @see CreateElementInCUOperation#getMainTaskName()
	 */
	public String getMainTaskName() {
		return Messages.operation_createPackageProgress;
	}

	/**
	 * Sets the correct position for new package declaration:
	 * <ul>
	 * <li>before the first import
	 * <li>if no imports, before the first type
	 * <li>if no type - first thing in the CU
	 * <li>
	 */
	protected void initializeDefaultPosition() {
		try {
			ICompilationUnit cu= getCompilationUnit();
			IImportDeclaration[] imports= cu.getImports();
			if (imports.length > 0) {
				createBefore(imports[0]);
				return;
			}
			IType[] types= cu.getTypes();
			if (types.length > 0) {
				createBefore(types[0]);
				return;
			}
		} catch (JavaModelException e) {
			// cu doesn't exist: ignore
		}
	}

	/**
	 * Possible failures:
	 * <ul>
	 * <li>NO_ELEMENTS_TO_PROCESS - no compilation unit was supplied to the operation
	 * <li>INVALID_NAME - a name supplied to the operation was not a valid package declaration name.
	 * </ul>
	 * 
	 * @see IJavaModelStatus
	 * @see JavaConventions
	 */
	public IJavaModelStatus verify() {
		IJavaModelStatus status= super.verify();
		if (!status.isOK()) {
			return status;
		}
		IJavaProject project= getParentElement().getJavaProject();
		if (JavaConventions.validatePackageName(this.name, project.getOption(JavaCore.COMPILER_SOURCE, true), project.getOption(JavaCore.COMPILER_COMPLIANCE, true)).getSeverity() == IStatus.ERROR) {
			return new JavaModelStatus(IJavaModelStatusConstants.INVALID_NAME, this.name);
		}
		return JavaModelStatus.VERIFIED_OK;
	}
}