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.refactoring.contentassist;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  
  import org.eclipse.core.runtime.Assert;
  import org.eclipse.jface.contentassist.IContentAssistSubjectControl;
  import org.eclipse.jface.contentassist.ISubjectControlContentAssistProcessor;
  import org.eclipse.jface.preference.IPreferenceStore;
  import org.eclipse.jface.text.ITextViewer;
  import org.eclipse.jface.text.contentassist.ICompletionProposal;
  import org.eclipse.jface.text.contentassist.IContentAssistProcessor;
  import org.eclipse.jface.text.contentassist.IContextInformation;
  import org.eclipse.jface.text.contentassist.IContextInformationValidator;
  import org.eclipse.jface.viewers.ILabelProvider;
  import org.eclipse.swt.graphics.Image;
  import org.eclipse.wst.jsdt.core.IJavaScriptElement;
  import org.eclipse.wst.jsdt.core.IPackageFragment;
  import org.eclipse.wst.jsdt.core.IPackageFragmentRoot;
  import org.eclipse.wst.jsdt.core.JavaScriptModelException;
  import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
  import org.eclipse.wst.jsdt.internal.ui.text.java.JavaCompletionProposal;
  import org.eclipse.wst.jsdt.ui.JavaScriptElementLabelProvider;
  import org.eclipse.wst.jsdt.ui.PreferenceConstants;
  import org.eclipse.wst.jsdt.ui.text.java.CompletionProposalComparator;
  
  public class JavaPackageCompletionProcessor implements IContentAssistProcessor, ISubjectControlContentAssistProcessor {
  	
  	private IPackageFragmentRoot fPackageFragmentRoot;
  	private CompletionProposalComparator fComparator;
  	private ILabelProvider fLabelProvider;
  
  	private char[] fProposalAutoActivationSet;
  
  	/**
  	 * Creates a <code>JavaPackageCompletionProcessor</code>.
  	 * The completion context must be set via {@link #setPackageFragmentRoot(IPackageFragmentRoot)}.
  	 */
  	public JavaPackageCompletionProcessor() {
  	    this(new JavaScriptElementLabelProvider(JavaScriptElementLabelProvider.SHOW_SMALL_ICONS));
  	}
  	
      /**
       * Creates a <code>JavaPackageCompletionProcessor</code>.
       * The Processor uses the given <code>ILabelProvider</code> to show text and icons for the 
       * possible completions.
       * @param labelProvider Used for the popups.
       */
  	public JavaPackageCompletionProcessor(ILabelProvider labelProvider) {
  		fComparator= new CompletionProposalComparator();
  		fLabelProvider= labelProvider;
  
  		IPreferenceStore preferenceStore= JavaScriptPlugin.getDefault().getPreferenceStore();
  		String triggers= preferenceStore.getString(PreferenceConstants.CODEASSIST_AUTOACTIVATION_TRIGGERS_JAVA);
  		fProposalAutoActivationSet = triggers.toCharArray();
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeCompletionProposals(org.eclipse.jface.text.ITextViewer, int)
  	 */
  	public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int documentOffset) {
  		Assert.isTrue(false, "ITextViewer not supported"); //$NON-NLS-1$
  		return null;
  	}
  
  	/* (non-Javadoc)
  	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeContextInformation(org.eclipse.jface.text.ITextViewer, int)
  	 */
  	public IContextInformation[] computeContextInformation(ITextViewer viewer, int documentOffset) {
  		Assert.isTrue(false, "ITextViewer not supported"); //$NON-NLS-1$
  		return null;
  	}
  
  	/*
  	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
  	 */
  	public char[] getCompletionProposalAutoActivationCharacters() {
  		return fProposalAutoActivationSet;
  	}
  
  	/*
  	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationAutoActivationCharacters()
  	 */
  	public char[] getContextInformationAutoActivationCharacters() {
  		return null;
  	}
  
  	/*
  	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getErrorMessage()
  	 */
  	public String getErrorMessage() {
  		return null;
  	}
  
  	/*
  	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationValidator()
  	 */
  	public IContextInformationValidator getContextInformationValidator() {
  		return null; //no context
  	}
  
  	/*
  	 * @see ISubjectControlContentAssistProcessor#computeContextInformation(IContentAssistSubjectControl, int)
  	 */
  	public IContextInformation[] computeContextInformation(IContentAssistSubjectControl contentAssistSubjectControl,
  			int documentOffset) {
  		return null;
  	}
  
  	/*
  	 * @see ISubjectControlContentAssistProcessor#computeCompletionProposals(IContentAssistSubjectControl, int)
  	 */
  	public ICompletionProposal[] computeCompletionProposals(IContentAssistSubjectControl contentAssistSubjectControl, int documentOffset) {
  		if (fPackageFragmentRoot == null)
  			return null;
  		String input= contentAssistSubjectControl.getDocument().get();
  		ICompletionProposal[] proposals= createPackagesProposals(documentOffset, input);
  		Arrays.sort(proposals, fComparator);
  		return proposals;
  	}
  	
  	public void setPackageFragmentRoot(IPackageFragmentRoot packageFragmentRoot) {
  		fPackageFragmentRoot= packageFragmentRoot;
  	}
  
  	private ICompletionProposal[] createPackagesProposals(int documentOffset, String input) {
  		ArrayList proposals= new ArrayList();
  		String prefix= input.substring(0, documentOffset);
  		try {
  			IJavaScriptElement[] packageFragments= fPackageFragmentRoot.getChildren();
  			for (int i= 0; i < packageFragments.length; i++) {
  				IPackageFragment pack= (IPackageFragment) packageFragments[i];
  				String packName= pack.getElementName();
  				if (packName.length() == 0 || ! packName.startsWith(prefix))
  					continue;
  				Image image= fLabelProvider.getImage(pack);
  				JavaCompletionProposal proposal= new JavaCompletionProposal(packName, 0, input.length(), image, fLabelProvider.getText(pack), 0);
  				proposals.add(proposal);
  			}
  		} catch (JavaScriptModelException e) {
  			//fPackageFragmentRoot is not a proper root -> no proposals
  		}
  		return (ICompletionProposal[]) proposals.toArray(new ICompletionProposal[proposals.size()]);
  	}
  }
  