org.eclipse.net4j.util.ui.ComboAutoCompleter.java Source code

Introduction

Here is the source code for org.eclipse.net4j.util.ui.ComboAutoCompleter.java

Source

/*
 * Copyright (c) 2007, 2011, 2012, 2015 Eike Stepper (Berlin, Germany) 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:
 *    Eike Stepper - initial API and implementation
 */
package org.eclipse.net4j.util.ui;

import org.eclipse.jface.viewers.ComboViewer;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;

/**
 * @author Eike Stepper
 */
public class ComboAutoCompleter implements ModifyListener {
    private ComboViewer viewer;

    public ComboAutoCompleter(ComboViewer viewer) {
        this.viewer = viewer;
    }

    public final ComboViewer getViewer() {
        return viewer;
    }

    public final void modifyText(ModifyEvent e) {
        String text = getText();
        Object foundElement = findShortestLabel(text);
        if (foundElement != null) {
            setSelection(new StructuredSelection(foundElement));
        } else {
            // setSelection(StructuredSelection.EMPTY);
        }
    }

    protected void setSelection(StructuredSelection selection) {
        viewer.setSelection(selection);
    }

    private Object findShortestLabel(String prefix) {
        Object foundElement = null;
        String shortestLabel = null;
        ILabelProvider labelProvider = (ILabelProvider) viewer.getLabelProvider();
        IStructuredContentProvider contentProvider = (IStructuredContentProvider) viewer.getContentProvider();
        for (Object element : contentProvider.getElements(viewer.getInput())) {
            String label = labelProvider.getText(element);
            if (label.startsWith(prefix)) {
                if (shortestLabel == null || label.length() < shortestLabel.length()) {
                    shortestLabel = label;
                    foundElement = element;
                }
            }
        }

        return foundElement;
    }

    private String getText() {
        return viewer.getCombo().getText();
    }

    public static void attach(ComboViewer viewer, ComboAutoCompleter completer) {
        viewer.getCombo().addModifyListener(completer);
    }

    public static void attach(ComboViewer viewer) {
        viewer.getCombo().addModifyListener(new ComboAutoCompleter(viewer));
    }
}