BestMatchHover.java

/*******************************************************************************
 * 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.imp.editor.internal.hover;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.imp.editor.UniversalEditor;
import org.eclipse.imp.editor.hover.AbstractTextHover;
import org.eclipse.jface.text.IInformationControlCreator;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextHover;
import org.eclipse.jface.text.ITextHoverExtension;
import org.eclipse.jface.text.ITextHoverExtension2;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.information.IInformationProviderExtension2;



/**
 * Caution: this implementation is a layer breaker and contains some "shortcuts"
 */
@SuppressWarnings({"unchecked", "deprecation"})
public class BestMatchHover extends AbstractTextHover {

	private List fTextHoverSpecifications;
	private List fInstantiatedTextHovers;
	private ITextHover fBestHover;

	public BestMatchHover() {
		installTextHovers();
	}

	public BestMatchHover(UniversalEditor editor) {
		this();
		setEditor(editor);
	}

	/**
	 * Installs all text hovers.
	 */
	private void installTextHovers() {

		// initialize lists - indicates that the initialization happened
		fTextHoverSpecifications= new ArrayList(2);
		fInstantiatedTextHovers= new ArrayList(2);
		
		fInstantiatedTextHovers.add(new ProblemHover());

		// populate list
//		JavaEditorTextHoverDescriptor[] hoverDescs= JavaPlugin.getDefault().getJavaEditorTextHoverDescriptors();
//		for (int i= 0; i < hoverDescs.length; i++) {
//			// ensure that we don't add ourselves to the list
//			if (!PreferenceConstants.ID_BESTMATCH_HOVER.equals(hoverDescs[i].getId()))
//				fTextHoverSpecifications.add(hoverDescs[i]);
//		}
		
		//fTextHoverSpecifications.add(new ProblemHover());
	}

	private void checkTextHovers() {
		if (fTextHoverSpecifications.size() == 0)
			return;

//		for (Iterator iterator= new ArrayList(fTextHoverSpecifications).iterator(); iterator.hasNext(); ) {
//			JavaEditorTextHoverDescriptor spec= (JavaEditorTextHoverDescriptor) iterator.next();
//
//			IJavaEditorTextHover hover= spec.createTextHover();
//			if (hover != null) {
//				hover.setEditor(getEditor());
//				addTextHover(hover);
//				fTextHoverSpecifications.remove(spec);
//			}
//		}
	}

	protected void addTextHover(ITextHover hover) {
		if (!fInstantiatedTextHovers.contains(hover))
			fInstantiatedTextHovers.add(hover);
	}

	/*
	 * @see ITextHover#getHoverInfo(ITextViewer, IRegion)
	 */
	public String getHoverInfo(ITextViewer textViewer, IRegion hoverRegion) {

		checkTextHovers();
		fBestHover= null;

		if (fInstantiatedTextHovers == null)
			return null;

		for (Iterator iterator= fInstantiatedTextHovers.iterator(); iterator.hasNext(); ) {
			ITextHover hover= (ITextHover)iterator.next();

			String s= hover.getHoverInfo(textViewer, hoverRegion);
			if (s != null && s.trim().length() > 0) {
				fBestHover= hover;
				return s;
			}
		}

		return null;
	}

	/*
	 * @see org.eclipse.jface.text.ITextHoverExtension2#getHoverInfo2(org.eclipse.jface.text.ITextViewer, org.eclipse.jface.text.IRegion)
	 */
	
	public Object getHoverInfo2(ITextViewer textViewer, IRegion hoverRegion) {

		checkTextHovers();
		fBestHover= null;

		if (fInstantiatedTextHovers == null)
			return null;

		for (Iterator iterator= fInstantiatedTextHovers.iterator(); iterator.hasNext(); ) {
			ITextHover hover= (ITextHover)iterator.next();

			if (hover instanceof ITextHoverExtension2) {
				Object info= ((ITextHoverExtension2) hover).getHoverInfo2(textViewer, hoverRegion);
				if (info != null) {
					fBestHover= hover;
					return info;
				}
			} else {
				String s= hover.getHoverInfo(textViewer, hoverRegion);
				if (s != null && s.trim().length() > 0) {
					fBestHover= hover;
					return s;
				}
			}
		}

		return null;
	}

	/*
	 * @see org.eclipse.jface.text.ITextHoverExtension#getHoverControlCreator()
	 * @since 3.0
	 */
	public IInformationControlCreator getHoverControlCreator() {
		if (fBestHover instanceof ITextHoverExtension)
			return ((ITextHoverExtension)fBestHover).getHoverControlCreator();

		return null;
	}

	/*
	 * @see org.eclipse.jface.text.information.IInformationProviderExtension2#getInformationPresenterControlCreator()
	 * @since 3.0
	 */
	public IInformationControlCreator getInformationPresenterControlCreator() {
		if (fBestHover instanceof IInformationProviderExtension2) // this is wrong, but left here for backwards compatibility
			return ((IInformationProviderExtension2)fBestHover).getInformationPresenterControlCreator();

		return null;
	}
}