org.eclipse.ui.examples.javaeditor/Eclipse Java Editor Example/org/eclipse/ui/examples/javaeditor/JavaTextHover.java

/*******************************************************************************
 * Copyright (c) 2000, 2005 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.ui.examples.javaeditor;


import org.eclipse.swt.graphics.Point;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextHover;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.Region;

/**
 * Example implementation for an <code>ITextHover</code> which hovers over Java code.
 */
public class JavaTextHover implements ITextHover {

	/* (non-Javadoc)
	 * Method declared on ITextHover
	 */
	public String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion) {
		if (hoverRegion != null) {
			try {
				if (hoverRegion.getLength() > -1)
					return textViewer.getDocument().get(hoverRegion.getOffset(), hoverRegion.getLength());
			} catch (BadLocationException x) {
			}
		}
		return JavaEditorMessages.getString("JavaTextHover.emptySelection"); //$NON-NLS-1$
	}

	/* (non-Javadoc)
	 * Method declared on ITextHover
	 */
	public IRegion getHoverRegion(ITextViewer textViewer, int offset) {
		Point selection= textViewer.getSelectedRange();
		if (selection.x <= offset && offset < selection.x + selection.y)
			return new Region(selection.x, selection.y);
		return new Region(offset, 0);
	}
}