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.java.hover;
  
  import java.util.Iterator;
  
  import org.eclipse.core.filebuffers.FileBuffers;
  import org.eclipse.core.filebuffers.ITextFileBufferManager;
  import org.eclipse.core.filebuffers.LocationKind;
  import org.eclipse.core.runtime.CoreException;
  import org.eclipse.core.runtime.IPath;
  import org.eclipse.wst.jsdt.internal.ui.text.html.HTMLPrinter;
  import org.eclipse.jface.preference.IPreferenceStore;
  import org.eclipse.jface.text.IRegion;
  import org.eclipse.jface.text.ITextViewer;
  import org.eclipse.jface.text.Position;
  import org.eclipse.jface.text.source.Annotation;
  import org.eclipse.jface.text.source.IAnnotationModel;
  import org.eclipse.jface.text.source.ISourceViewer;
  import org.eclipse.ui.IEditorInput;
  import org.eclipse.ui.IStorageEditorInput;
  import org.eclipse.ui.editors.text.EditorsUI;
  import org.eclipse.ui.texteditor.AnnotationPreference;
  import org.eclipse.ui.texteditor.DefaultMarkerAnnotationAccess;
  import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
  import org.eclipse.wst.jsdt.internal.ui.javaeditor.JavaAnnotationIterator;
  
  
  /**
   * Abstract super class for annotation hovers.
   *
   * 
   */
  public abstract class AbstractAnnotationHover extends AbstractJavaEditorTextHover {
  
  	private IPreferenceStore fStore= JavaScriptPlugin.getDefault().getCombinedPreferenceStore();
  	private DefaultMarkerAnnotationAccess fAnnotationAccess= new DefaultMarkerAnnotationAccess();
  	private boolean fAllAnnotations;
  
  
  	public AbstractAnnotationHover(boolean allAnnotations) {
  		fAllAnnotations= allAnnotations;
  	}
  
  	/*
  	 * Formats a message as HTML text.
  	 */
  	private String formatMessage(String message) {
  		StringBuffer buffer= new StringBuffer();
  		HTMLPrinter.insertPageProlog(buffer, 0, getStyleSheet());
  		buffer.append(HTMLPrinter.convertToHTMLContent(message));
  		HTMLPrinter.addPageEpilog(buffer);
  		return buffer.toString();
  	}
  
  	/*
  	 * @see ITextHover#getHoverInfo(ITextViewer, IRegion)
  	 */
  	public String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion) {
  		IPath path;
  		IAnnotationModel model;
  		if (textViewer instanceof ISourceViewer) {
  			path= null;
  			model= ((ISourceViewer)textViewer).getAnnotationModel();
  		} else {
  			// Get annotation model from file buffer manager
  			path= getEditorInputPath();
  			model= getAnnotationModel(path);
  		}
  		if (model == null)
  			return null;
  
  		try {
  			Iterator e= new JavaAnnotationIterator(model, true, fAllAnnotations);
  			int layer= -1;
  			String message= null;
  			while (e.hasNext()) {
  				Annotation a= (Annotation) e.next();
  
  				AnnotationPreference preference= getAnnotationPreference(a);
  				if (preference == null || !(preference.getTextPreferenceKey() != null && fStore.getBoolean(preference.getTextPreferenceKey()) || (preference.getHighlightPreferenceKey() != null && fStore.getBoolean(preference.getHighlightPreferenceKey()))))
  					continue;
  
  				Position p= model.getPosition(a);
  
  				int l= fAnnotationAccess.getLayer(a);
  
  				if (l > layer && p != null && p.overlapsWith(hoverRegion.getOffset(), hoverRegion.getLength())) {
  					String msg= a.getText();
  					if (msg != null && msg.trim().length() > 0) {
  						message= msg;
  						layer= l;
  					}
  				}
  			}
  			if (layer > -1)
  				return formatMessage(message);
  
  		} finally {
  			try {
  				if (path != null) {
  					ITextFileBufferManager manager= FileBuffers.getTextFileBufferManager();
  					manager.disconnect(path, LocationKind.NORMALIZE, null);
  				}
  			} catch (CoreException ex) {
  				JavaScriptPlugin.log(ex.getStatus());
  			}
  		}
  
  		return null;
  	}
  
  	private IPath getEditorInputPath() {
  		if (getEditor() == null)
  			return null;
  
  		IEditorInput input= getEditor().getEditorInput();
  		if (input instanceof IStorageEditorInput) {
  			try {
  				return ((IStorageEditorInput)input).getStorage().getFullPath();
  			} catch (CoreException ex) {
  				JavaScriptPlugin.log(ex.getStatus());
  			}
  		}
  		return null;
  	}
  
  	private IAnnotationModel getAnnotationModel(IPath path) {
  		if (path == null)
  			return null;
  
  		ITextFileBufferManager manager= FileBuffers.getTextFileBufferManager();
  		try {
  			manager.connect(path, LocationKind.NORMALIZE, null);
  		} catch (CoreException ex) {
  			JavaScriptPlugin.log(ex.getStatus());
  			return null;
  		}
  
  		IAnnotationModel model= null;
  		try {
  			model= manager.getTextFileBuffer(path, LocationKind.NORMALIZE).getAnnotationModel();
  			return model;
  		} finally {
  			if (model == null) {
  				try {
  					manager.disconnect(path, LocationKind.NORMALIZE, null);
  				} catch (CoreException ex) {
  					JavaScriptPlugin.log(ex.getStatus());
  				}
  			}
  		}
  	}
  
  	/**
  	 * Returns the annotation preference for the given annotation.
  	 *
  	 * @param annotation the annotation
  	 * @return the annotation preference or <code>null</code> if none
  	 */
  	private AnnotationPreference getAnnotationPreference(Annotation annotation) {
  
  		if (annotation.isMarkedDeleted())
  			return null;
  		return EditorsUI.getAnnotationPreferenceLookup().getAnnotationPreference(annotation);
  	}
  }
  