TexCompletionProposal.java

/*
 * $Id$
 *
 * Copyright (c) 2006 by the TeXlipse team.
 * 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
 */
package net.sourceforge.texlipse.editor;

import net.sourceforge.texlipse.TexlipsePlugin;
import net.sourceforge.texlipse.model.TexCommandEntry;
import net.sourceforge.texlipse.properties.TexlipseProperties;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.link.LinkedModeModel;
import org.eclipse.jface.text.link.LinkedModeUI;
import org.eclipse.jface.text.link.LinkedPosition;
import org.eclipse.jface.text.link.LinkedPositionGroup;
import org.eclipse.jface.text.link.LinkedModeUI.ExitFlags;
import org.eclipse.jface.text.link.LinkedModeUI.IExitPolicy;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.swt.events.VerifyEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.ui.texteditor.link.EditorLinkedModeUI;

/**
 * This class is a wrapper class to create an ICompletionProposal
 * from a TexCommandEntry. It also creates "smart" braces.
 * 
 * @author Boris von Loesch
 * @author Oskar Ojala
 *
 */
public class TexCompletionProposal implements ICompletionProposal {
    private TexCommandEntry fentry;
    private int fReplacementOffset;
    private int fReplacementLength;
    private ISourceViewer fviewer;
    
    /**
     * Constructs a new completion proposal for a (La)TeX command
     * 
     * @param entry The command entry
     * @param replacementOffset Offset of where it is to be replaced
     * @param replacementLength The length of the replacement
     * @param viewer The current viewer
     */
    public TexCompletionProposal(TexCommandEntry entry, int replacementOffset, int replacementLength, ISourceViewer viewer) {
        fentry = entry;
        fReplacementLength = replacementLength;
        fReplacementOffset = replacementOffset;
        fviewer = viewer;
    }
    
    /* (non-Javadoc)
     * @see org.eclipse.jface.text.contentassist.ICompletionProposal#apply(org.eclipse.jface.text.IDocument)
     */
    public void apply(IDocument document) {
        try {
            if (fentry.arguments > 0) {
                StringBuffer displayKey = new StringBuffer(fentry.key);
                for (int j=0; j < fentry.arguments; j++)
                    displayKey.append("{}");
                document.replace(fReplacementOffset, fReplacementLength, displayKey.toString());
                if (TexlipsePlugin.getDefault().getPreferenceStore()
                        .getBoolean(TexlipseProperties.SMART_PARENS)){
                    LinkedModeModel model= new LinkedModeModel();
                    for (int j=0; j < fentry.arguments; j++){
                        int newOffset = fReplacementOffset + fentry.key.length() + j*2 + 1;
                        LinkedPositionGroup group = new LinkedPositionGroup();
                        group.addPosition(new LinkedPosition(document, newOffset, 0, LinkedPositionGroup.NO_STOP));
                        model.addGroup(group);
                    }
                    model.forceInstall();
                    LinkedModeUI ui = new EditorLinkedModeUI(model, fviewer);
                    ui.setSimpleMode(false);
                    ui.setExitPolicy(new ExitPolicy('}', fviewer));
                    ui.setExitPosition(fviewer, fReplacementOffset + displayKey.length(),
                            0, Integer.MAX_VALUE);
                    ui.setCyclingMode(LinkedModeUI.CYCLE_NEVER);
                    ui.enter();
                }
            } else {
                document.replace(fReplacementOffset, fReplacementLength, fentry.key);
            }
        } catch (BadLocationException x) {
        }
    }
    
    /* (non-Javadoc)
     * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getSelection(org.eclipse.jface.text.IDocument)
     */
    public Point getSelection(IDocument document) {
        if (fentry.arguments > 0) 
            return new Point(fReplacementOffset + fentry.key.length()+1, 0);
        return new Point(fReplacementOffset + fentry.key.length(), 0);
    }
    
    /* (non-Javadoc)
     * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getAdditionalProposalInfo()
     */
    public String getAdditionalProposalInfo() {
        return (fentry.info.length() > TexCompletionProcessor.assistLineLength ?
                TexCompletionProcessor.wrapString(fentry.info, TexCompletionProcessor.assistLineLength)
                : fentry.info);
    }
    
    /* (non-Javadoc)
     * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getDisplayString()
     */
    public String getDisplayString() {
        return fentry.key;
    }
    
    /* (non-Javadoc)
     * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getImage()
     */
    public Image getImage() {
        return fentry.getImage();
    }
    
    /* (non-Javadoc)
     * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getContextInformation()
     */
    public IContextInformation getContextInformation() {
        return null;
    }
    
    protected static class ExitPolicy implements IExitPolicy {
        
        final char fExitCharacter;
        ISourceViewer fviewer;
        
        public ExitPolicy(char exitCharacter, ISourceViewer viewer) {
            fExitCharacter= exitCharacter;
            fviewer = viewer;
        }
        
        /*
         * @see org.eclipse.jdt.internal.ui.text.link.LinkedPositionUI.ExitPolicy#doExit(org.eclipse.jdt.internal.ui.text.link.LinkedPositionManager, org.eclipse.swt.events.VerifyEvent, int, int)
         */
        public ExitFlags doExit(LinkedModeModel environment, VerifyEvent event, int offset, int length) {
            if (event.character == fExitCharacter) {
                try {
                    if (fviewer.getDocument().getChar(offset) == fExitCharacter) {
                        event.doit = false;
                    }
                    try {
                        if (fviewer.getDocument().getChar(offset + 1) == '{') {
                            fviewer.setSelectedRange(offset + 2, 0);
                        } else {
                            fviewer.setSelectedRange(offset + 1, 0);
                        }
                        return null;
                    } catch (BadLocationException e) {
                    }
                    fviewer.setSelectedRange(offset + 1, 0);
                } catch (BadLocationException e1) {
                    // Should not happen
                }
            } else if (event.character == '{') {
                try {
                    if (fviewer.getDocument().getChar(offset - 1) == '{')
                        event.doit = false;
                } catch (BadLocationException e) {
                }
            }
            return null;
        }
    }
    
}