content: /*******************************************************************************
   * 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.wst.jsdt.internal.ui.text.correction;
  
  import org.eclipse.core.runtime.CoreException;
  import org.eclipse.core.runtime.IStatus;
  import org.eclipse.core.runtime.NullProgressMonitor;
  import org.eclipse.core.runtime.Status;
  import org.eclipse.jface.text.IDocument;
  import org.eclipse.jface.text.IRewriteTarget;
  import org.eclipse.jface.text.contentassist.IContextInformation;
  import org.eclipse.jface.text.link.LinkedModeModel;
  import org.eclipse.ltk.core.refactoring.Change;
  import org.eclipse.ltk.core.refactoring.IUndoManager;
  import org.eclipse.ltk.core.refactoring.NullChange;
  import org.eclipse.ltk.core.refactoring.RefactoringCore;
  import org.eclipse.ltk.core.refactoring.RefactoringStatus;
  import org.eclipse.swt.graphics.Image;
  import org.eclipse.swt.graphics.Point;
  import org.eclipse.ui.IEditorPart;
  import org.eclipse.wst.jsdt.internal.corext.util.Messages;
  import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
  import org.eclipse.wst.jsdt.internal.ui.util.ExceptionHandler;
  import org.eclipse.wst.jsdt.ui.text.java.IJavaCompletionProposal;
  
  /**
   * Implementation of a Java completion proposal to be used for quick fix and quick assist
   * proposals that invoke a {@link Change}. The proposal offers a proposal information but no context
   * information.
   * 
   * 
   */
  public class ChangeCorrectionProposal implements IJavaCompletionProposal, ICommandAccess {
  
  	private Change fChange;
  	private String fName;
  	private int fRelevance;
  	private Image fImage;
  	private String fCommandId;
  
  	/**
  	 * Constructs a change correction proposal.
  	 * 
  	 * @param name The name that is displayed in the proposal selection dialog.
  	 * @param change The change that is executed when the proposal is applied or <code>null</code>
  	 * if the change will be created by implementors of {@link #createChange()}.
  	 * @param relevance The relevance of this proposal.
  	 * @param image The image that is displayed for this proposal or <code>null</code> if no
  	 * image is desired.
  	 */
  	public ChangeCorrectionProposal(String name, Change change, int relevance, Image image) {
  		if (name == null) {
  			throw new IllegalArgumentException("Name must not be null"); //$NON-NLS-1$
  		}
  		fName= name;
  		fChange= change;
  		fRelevance= relevance;
  		fImage= image;
  		fCommandId= null;
  	}
  
  	/*
  	 * @see ICompletionProposal#apply(IDocument)
  	 */
  	public void apply(IDocument document) {
  		try {
  			performChange(JavaScriptPlugin.getActivePage().getActiveEditor(), document);
  		} catch (CoreException e) {
  			ExceptionHandler.handle(e, CorrectionMessages.ChangeCorrectionProposal_error_title, CorrectionMessages.ChangeCorrectionProposal_error_message);
  		}
  	}
  
  	/**
  	 * Performs the change associated with this proposal.
  	 * 
  	 * @param activeEditor The editor currently active or <code>null</code> if no
  	 * editor is active.
  	 * @param document The document of the editor currently active or <code>null</code> if
  	 * no editor is visible.
  	 * @throws CoreException Thrown when the invocation of the change failed.
  	 */
  	protected void performChange(IEditorPart activeEditor, IDocument document) throws CoreException {
  		Change change= null;
  		IRewriteTarget rewriteTarget= null;
  		try {
  			change= getChange();
  			if (change != null) {
  				if (document != null) {
  					LinkedModeModel.closeAllModels(document);
  				}
  				if (activeEditor != null) {
  					rewriteTarget= (IRewriteTarget) activeEditor.getAdapter(IRewriteTarget.class);
  					if (rewriteTarget != null) {
  						rewriteTarget.beginCompoundChange();
  					}
  				}
  
  				change.initializeValidationData(new NullProgressMonitor());
  				RefactoringStatus valid= change.isValid(new NullProgressMonitor());
  				if (valid.hasFatalError()) {
  					IStatus status= new Status(IStatus.ERROR, JavaScriptPlugin.getPluginId(), IStatus.ERROR,
  						valid.getMessageMatchingSeverity(RefactoringStatus.FATAL), null);
  					throw new CoreException(status);
  				} else {
  					IUndoManager manager= RefactoringCore.getUndoManager();
  					manager.aboutToPerformChange(change);
  					Change undoChange= change.perform(new NullProgressMonitor());
  					manager.changePerformed(change, true);
  					if (undoChange != null) {
  						undoChange.initializeValidationData(new NullProgressMonitor());
  						manager.addUndo(getName(), undoChange);
  					}
  				}
  			}
  		} finally {
  			if (rewriteTarget != null) {
  				rewriteTarget.endCompoundChange();
  			}
  
  			if (change != null) {
  				change.dispose();
  			}
  		}
  	}
  
  	/*
  	 * @see ICompletionProposal#getAdditionalProposalInfo()
  	 */
  	public String getAdditionalProposalInfo() {
  		StringBuffer buf= new StringBuffer();
  		buf.append("<p>"); //$NON-NLS-1$
  		try {
  			Change change= getChange();
  			if (change != null) {
  				String name= change.getName();
  				if (name.length() == 0) {
  					return null;
  				}
  				buf.append(name);
  			} else {
  				return null;
  			}
  		} catch (CoreException e) {
  			buf.append("Unexpected error when accessing this proposal:<p><pre>"); //$NON-NLS-1$
  			buf.append(e.getLocalizedMessage());
  			buf.append("</pre>"); //$NON-NLS-1$
  		}
  		buf.append("</p>"); //$NON-NLS-1$
  		return buf.toString();
  	}
  
  	/*
  	 * @see ICompletionProposal#getContextInformation()
  	 */
  	public IContextInformation getContextInformation() {
  		return null;
  	}
  
  	/*
  	 * @see ICompletionProposal#getDisplayString()
  	 */
  	public String getDisplayString() {
  		String shortCutString= CorrectionCommandHandler.getShortCutString(getCommandId());
  		if (shortCutString != null) {
  			return Messages.format(CorrectionMessages.ChangeCorrectionProposal_name_with_shortcut, new String[] { getName(), shortCutString });
  		}
  		return getName();
  	}
  	
  	/** 
  	 * Returns the name of the proposal.
  	 * 
  	 * @return return the name of the proposal
  	 */
  	public String getName() {
  		return fName;
  	}
  	
  	/*
  	 * @see ICompletionProposal#getImage()
  	 */
  	public Image getImage() {
  		return fImage;
  	}
  
  	/*
  	 * @see ICompletionProposal#getSelection(IDocument)
  	 */
  	public Point getSelection(IDocument document) {
  		return null;
  	}
  
  	/**
  	 * Sets the proposal's image or <code>null</code> if no image is desired.
  	 * 
  	 * @param image the desired image.
  	 */
  	public void setImage(Image image) {
  		fImage= image;
  	}
  
  	/**
  	 * Returns the change that will be executed when the proposal is applied.
  	 * 
  	 * @return returns the change for this proposal.
  	 * @throws CoreException thrown when the change could not be created
  	 */
  	public final Change getChange() throws CoreException {
  		if (fChange == null) {
  			fChange= createChange();
  		}
  		return fChange;
  	}
  
  	/**
  	 * Creates the text change for this proposal.
  	 * This method is only called once and only when no text change has been passed in
   	 * {@link #ChangeCorrectionProposal(String, Change, int, Image)}.
   	 * 
  	 * @return returns the created change.
  	 * @throws CoreException thrown if the creation of the change failed.
  	 */
  	protected Change createChange() throws CoreException {
  		return new NullChange();
  	}
  	
  	/**
  	 * Sets the display name.
  	 * 
  	 * @param name the name to set
  	 */
  	public void setDisplayName(String name) {
  		if (name == null) {
  			throw new IllegalArgumentException("Name must not be null"); //$NON-NLS-1$
  		}
  		fName= name;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.ui.text.java.IJavaCompletionProposal#getRelevance()
  	 */
  	public int getRelevance() {
  		return fRelevance;
  	}
  
  	/**
  	 * Sets the relevance.
  	 * @param relevance the relevance to set
  	 */
  	public void setRelevance(int relevance) {
  		fRelevance= relevance;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.wst.jsdt.internal.ui.text.correction.IShortcutProposal#getProposalId()
  	 */
  	public String getCommandId() {
  		return fCommandId;
  	}
  	
  	/**
  	 * Set the proposal id to allow assigning a shortcut to the correction proposal.
  	 * 
  	 * @param commandId The proposal id for this proposal or <code>null</code> if no command
  	 * should be assigned to this proposal.
  	 */
  	public void setCommandId(String commandId) {
  		fCommandId= commandId;
  	}
  
  }
  