org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/ExtractConstantAction.java

/*******************************************************************************
 * Copyright (c) 2000, 2006 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.ui.actions;

import org.eclipse.jface.text.ITextSelection;

import org.eclipse.ui.PlatformUI;

import org.eclipse.jdt.core.JavaModelException;

import org.eclipse.jdt.internal.corext.refactoring.RefactoringAvailabilityTester;
import org.eclipse.jdt.internal.corext.refactoring.code.ExtractConstantRefactoring;

import org.eclipse.jdt.internal.ui.IJavaHelpContextIds;
import org.eclipse.jdt.internal.ui.actions.ActionUtil;
import org.eclipse.jdt.internal.ui.actions.SelectionConverter;
import org.eclipse.jdt.internal.ui.javaeditor.CompilationUnitEditor;
import org.eclipse.jdt.internal.ui.javaeditor.JavaTextSelection;
import org.eclipse.jdt.internal.ui.refactoring.ExtractConstantWizard;
import org.eclipse.jdt.internal.ui.refactoring.RefactoringMessages;
import org.eclipse.jdt.internal.ui.refactoring.actions.RefactoringStarter;
import org.eclipse.jdt.internal.ui.util.ExceptionHandler;

/**
 * Extracts an expression into a constant field and replaces all occurrences of
 * the expression with the new constant.
 * 
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * 
 * @since 2.1
 */
public class ExtractConstantAction extends SelectionDispatchAction {

	private static final String DIALOG_MESSAGE_TITLE= RefactoringMessages.ExtractConstantAction_extract_constant; 
	private final CompilationUnitEditor fEditor;
	
	/**
	 * Note: This constructor is for internal use only. Clients should not call this constructor.
	 * @param editor the compilation unit editor
	 */
	public ExtractConstantAction(CompilationUnitEditor editor) {
		super(editor.getEditorSite());
		setText(RefactoringMessages.ExtractConstantAction_label); 
		fEditor= editor;
		setEnabled(SelectionConverter.getInputAsCompilationUnit(fEditor) != null);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(this, IJavaHelpContextIds.EXTRACT_CONSTANT_ACTION);
	}
	
	/* (non-Javadoc)
	 * Method declared on SelectionDispatchAction
	 */		
	public void selectionChanged(ITextSelection selection) {
		setEnabled((fEditor != null && SelectionConverter.getInputAsCompilationUnit(fEditor) != null));
	}
	
	/**
	 * Note: This method is for internal use only. Clients should not call this method.
	 */
	public void selectionChanged(JavaTextSelection selection) {
		setEnabled(RefactoringAvailabilityTester.isExtractConstantAvailable(selection));
	}
	
	/* (non-Javadoc)
	 * Method declared on SelectionDispatchAction
	 */		
	public void run(ITextSelection selection) {
		if (!ActionUtil.isProcessable(getShell(), fEditor))
			return;
		try{
			final ExtractConstantRefactoring refactoring= new ExtractConstantRefactoring(SelectionConverter.getInputAsCompilationUnit(fEditor), selection.getOffset(), selection.getLength());
			new RefactoringStarter().activate(refactoring, new ExtractConstantWizard(refactoring), getShell(), DIALOG_MESSAGE_TITLE, false);
		} catch (JavaModelException e){
			ExceptionHandler.handle(e, DIALOG_MESSAGE_TITLE, RefactoringMessages.NewTextRefactoringAction_exception); 
		}	
	}
}