org.spotter.eclipse.ui.navigator.FixedOrderViewerComparator.java Source code

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Here is the source code for org.spotter.eclipse.ui.navigator.FixedOrderViewerComparator.java

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/**
 * Copyright 2014 SAP AG
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.spotter.eclipse.ui.navigator;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.jface.viewers.ContentViewer;
import org.eclipse.jface.viewers.IBaseLabelProvider;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;

/**
 * An implementation of a viewer comparator that sorts the elements in a
 * predetermined order. Elements not included in this predefinition are sorted
 * using the default comparator, thus are sorted in lexicographical order.
 * 
 * @author Denis Knoepfle
 * 
 */
public class FixedOrderViewerComparator extends ViewerComparator {

    // The order in which the elements appear in the navigator viewer. Elements
    // which are not listed here receive the default category id 0 and are
    // sorted using the default comparator (lexicographically).
    private static final Class<?>[] ELEMENT_ORDER = { SpotterProjectParent.class, SpotterProjectConfig.class,
            SpotterProjectHierarchy.class, SpotterProjectResults.class, SpotterProjectConfigFile.class,
            SpotterProjectConfigInstrumentation.class, SpotterProjectConfigMeasurement.class,
            SpotterProjectConfigWorkload.class };

    private static final Map<String, Integer> CATEGORY_MAP = initCategories();

    @Override
    public int category(Object element) {
        Integer cat = CATEGORY_MAP.get(element.getClass().getName());
        return cat == null ? 0 : cat;
    }

    @SuppressWarnings("unchecked")
    @Override
    public int compare(Viewer viewer, Object e1, Object e2) {
        int cat1 = category(e1);
        int cat2 = category(e2);

        if (cat1 != cat2) {
            return cat1 - cat2;
        }

        String name1 = getLabel(viewer, e1);
        String name2 = getLabel(viewer, e2);

        // use the comparator to compare the strings
        return getComparator().compare(name1, name2);
    }

    private String getLabel(Viewer viewer, Object e1) {
        String name1;
        if (viewer == null || !(viewer instanceof ContentViewer)) {
            name1 = e1.toString();
        } else {
            IBaseLabelProvider prov = ((ContentViewer) viewer).getLabelProvider();
            if (prov instanceof ILabelProvider) {
                ILabelProvider lprov = (ILabelProvider) prov;
                // TODO: convert between timestamp and nice date representation
                // for SpotterProjectRunResult elements
                name1 = lprov.getText(e1);
            } else {
                name1 = e1.toString();
            }
        }
        if (name1 == null) {
            name1 = ""; //$NON-NLS-1$
        }
        return name1;
    }

    private static Map<String, Integer> initCategories() {
        Map<String, Integer> map = new HashMap<>();
        int category = 0;
        for (Class<?> clazz : ELEMENT_ORDER) {
            map.put(clazz.getName(), category++);
        }

        return map;
    }

}