org.eclipse.jface.text/projection/org/eclipse/jface/text/source/projection/ProjectionAnnotationHover.java

/*******************************************************************************
 * Copyright (c) 2000, 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.jface.text.source.projection;

import java.util.Iterator;

import org.eclipse.swt.widgets.Shell;

import org.eclipse.jface.resource.JFaceResources;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IInformationControl;
import org.eclipse.jface.text.IInformationControlCreator;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.Position;
import org.eclipse.jface.text.source.IAnnotationHover;
import org.eclipse.jface.text.source.IAnnotationHoverExtension;
import org.eclipse.jface.text.source.IAnnotationModel;
import org.eclipse.jface.text.source.IAnnotationModelExtension;
import org.eclipse.jface.text.source.ILineRange;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.text.source.ISourceViewerExtension2;
import org.eclipse.jface.text.source.LineRange;

/**
 * Annotation hover for projection annotations.
 * <p>
 * Internal class. Do not use. Public for testing purposes only.
 * 
 * @since 3.0
 */
class ProjectionAnnotationHover implements IAnnotationHover, IAnnotationHoverExtension {
	
	private IInformationControlCreator fInformationControlCreator;
	
	/**
	 * Sets the hover control creator for this projection annotation hover.
	 * 
	 * @param creator the creator
	 */
	public void setHoverControlCreator(IInformationControlCreator creator) {
		fInformationControlCreator= creator;
	}
	
	/*
	 * @see org.eclipse.jface.text.source.IAnnotationHover#getHoverInfo(org.eclipse.jface.text.source.ISourceViewer, int)
	 */
	public String getHoverInfo(ISourceViewer sourceViewer, int lineNumber) {
		// this is a no-op as semantics is defined by the implementation of the annotation hover extension
		return null;
	}

	private int compareRulerLine(Position position, IDocument document, int line) {
		if (position.getOffset() > -1 && position.getLength() > -1) {
			try {
				int startLine= document.getLineOfOffset(position.getOffset());
				if (line == startLine)
					return 1;
				if (startLine <= line && line <= document.getLineOfOffset(position.getOffset() + position.getLength()))
					return 2;
			} catch (BadLocationException x) {
			}
		}
		return 0;
	}
	
	private String getProjectionTextAtLine(ISourceViewer viewer, int line, int numberOfLines) {
				
		IAnnotationModel model= null;
		if (viewer instanceof ISourceViewerExtension2) {
			ISourceViewerExtension2 viewerExtension= (ISourceViewerExtension2) viewer;
			IAnnotationModel visual= viewerExtension.getVisualAnnotationModel();
			if (visual instanceof IAnnotationModelExtension) {
				IAnnotationModelExtension modelExtension= (IAnnotationModelExtension) visual;
				model= modelExtension.getAnnotationModel(ProjectionSupport.PROJECTION);
			}
		}
		
		if (model != null) {
			try {
				IDocument document= viewer.getDocument();
				Iterator e= model.getAnnotationIterator();
				while (e.hasNext()) {
					ProjectionAnnotation annotation= (ProjectionAnnotation) e.next();
					if (!annotation.isCollapsed())
						continue;
					
					Position position= model.getPosition(annotation);
					if (position == null)
						continue;
					
					if (1 == compareRulerLine(position, document, line))
						return getText(document, position.getOffset(), position.getLength(), numberOfLines);
						
				}
			} catch (BadLocationException x) {
			}
		}
		
		return null;
	}

	private String getText(IDocument document, int offset, int length, int numberOfLines) throws BadLocationException {
		int endOffset= offset + length;
		
		try {
			int endLine= document.getLineOfOffset(offset) + Math.max(0, numberOfLines -1);
			IRegion lineInfo= document.getLineInformation(endLine);
			endOffset= Math.min(endOffset, lineInfo.getOffset() + lineInfo.getLength());
		} catch (BadLocationException x) {
		}
		
		return document.get(offset, endOffset - offset);
	}

	/*
	 * @see org.eclipse.jface.text.source.IAnnotationHoverExtension#getHoverInfo(org.eclipse.jface.text.source.ISourceViewer, org.eclipse.jface.text.source.ILineRange, int)
	 */
	public Object getHoverInfo(ISourceViewer sourceViewer, ILineRange lineRange, int visibleLines) {
		return getProjectionTextAtLine(sourceViewer, lineRange.getStartLine(), visibleLines);	
	}

	/*
	 * @see org.eclipse.jface.text.source.IAnnotationHoverExtension#getHoverLineRange(org.eclipse.jface.text.source.ISourceViewer, int)
	 */
	public ILineRange getHoverLineRange(ISourceViewer viewer, int lineNumber) {
		return new LineRange(lineNumber, 1);
	}

	/*
	 * @see org.eclipse.jface.text.source.IAnnotationHoverExtension#canHandleMouseCursor()
	 */
	public boolean canHandleMouseCursor() {
		return false;
	}
	
	/*
	 * @see org.eclipse.jface.text.source.IAnnotationHoverExtension#getHoverControlCreator()
	 */
	public IInformationControlCreator getHoverControlCreator() {
		
		if (fInformationControlCreator != null)
			return fInformationControlCreator;
		
		return new IInformationControlCreator() {
			public IInformationControl createInformationControl(Shell parent) {
				return new SourceViewerInformationControl(parent, JFaceResources.TEXT_FONT);
			}
		};
	}
}