/*******************************************************************************
 * Copyright (c) 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.part;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResourceChangeEvent;
import org.eclipse.core.resources.IResourceChangeListener;
import org.eclipse.core.resources.IResourceDelta;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;

import org.eclipse.ui.IInPlaceEditor;
import org.eclipse.ui.IInPlaceEditorInput;

/**
 * Adapter for making a file resource a suitable input for an in-place editor.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * 
 * @since 3.0
 */
public class FileInPlaceEditorInput extends FileEditorInput implements IInPlaceEditorInput {
	IInPlaceEditor embeddedEditor;

	/**
	 * A resource listener to update the input and in-place
	 * editor if the input's file resource changes.
	 */
	private IResourceChangeListener resourceListener = new IResourceChangeListener() {
		public void resourceChanged(IResourceChangeEvent event) {
			IResourceDelta mainDelta = event.getDelta();
			if (mainDelta != null && embeddedEditor != null) {
				IResourceDelta affectedElement = mainDelta.findMember(getFile().getFullPath());
				if (affectedElement != null) {
					try {
						processDelta(affectedElement);
					} catch (CoreException exception) {
						// Failed so close the receiver
						if (embeddedEditor != null) {
							embeddedEditor.getSite().getPage().closeEditor(embeddedEditor, true);
						}
					}
				}
			}
		}

		private boolean processDelta(final IResourceDelta delta) throws CoreException {
			Runnable changeRunnable = null;

			switch (delta.getKind()) {
				case IResourceDelta.REMOVED :
					if ((IResourceDelta.MOVED_TO & delta.getFlags()) != 0) {
						changeRunnable = new Runnable() {
							public void run() {
								IPath path = delta.getMovedToPath();
								IFile newFile = delta.getResource().getWorkspace().getRoot().getFile(path);
								if (newFile != null && embeddedEditor != null) {
									embeddedEditor.sourceChanged(new FileInPlaceEditorInput(newFile));
								}
							}
						};
					} else {
						changeRunnable = new Runnable() {
							public void run() {
								if (embeddedEditor != null) {
									embeddedEditor.sourceDeleted();
									embeddedEditor.getSite().getPage().closeEditor(embeddedEditor, true);
								}
							}
						};

					}

					break;
			}

			if (changeRunnable != null && embeddedEditor != null) {
				embeddedEditor.getSite().getShell().getDisplay().asyncExec(changeRunnable);
			}

			return true; // because we are sitting on files anyway
		}
	};

	/**
	 * Creates an in-place editor input based on a file resource.
	 *
	 * @param file the file resource
	 */
	public FileInPlaceEditorInput(IFile file) {
		super(file);
	}

	/* (non-Javadoc)
	 * @see org.eclipse.ui.IInPlaceEditorInput#setInPlaceEditor(org.eclipse.ui.IInPlaceEditor)
	 */
	public void setInPlaceEditor(IInPlaceEditor editor) {
		if (embeddedEditor != editor) {
			if (embeddedEditor != null) {
				getFile().getWorkspace().removeResourceChangeListener(resourceListener);
			}
			
			embeddedEditor = editor;
			
			if (embeddedEditor != null) {
				getFile().getWorkspace().addResourceChangeListener(resourceListener);
			}
		}
	}
}