org.eclipse.emf.ecp.common.ColumnViewerSorter.java Source code

Introduction

Here is the source code for org.eclipse.emf.ecp.common.ColumnViewerSorter.java

Source

/*******************************************************************************
 * Copyright (c) 2008-2011 Chair for Applied Software Engineering,
 * Technische Universitaet Muenchen.
 * 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:
 ******************************************************************************/
package org.eclipse.emf.ecp.common;

import org.eclipse.jface.viewers.ColumnLabelProvider;
import org.eclipse.jface.viewers.ColumnViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerColumn;
import org.eclipse.jface.viewers.ViewerComparator;

/**
 * Super-class for sorting column viewer, with ability to turn sorting on and off.
 * 
 * @author zardosht
 */
public abstract class ColumnViewerSorter extends ViewerComparator {

    /**
     * Direction constant used to show right direction arrow on column header.
     */
    public static final int ASC = 1;
    /**
     * Direction constant used to show right direction arrow on column header.
     */
    public static final int DESC = -1;
    private int direction = 1;
    private ColumnLabelProvider columnLabelProvider;
    private final ColumnViewer viewer;
    private boolean sortingEnabled;

    /**
     * Constructor.
     * 
     * @param viewer ColumnViewer
     * @param columnLabelProvider ColumnLabelProvider
     */
    public ColumnViewerSorter(ColumnViewer viewer, ColumnLabelProvider columnLabelProvider) {
        this.columnLabelProvider = columnLabelProvider;
        this.viewer = viewer;
    }

    /**
     * . This is used to set the right direction arrow at column header and refresh the viewer.
     * 
     * @param sorter sorter
     * @param direction direction
     */
    protected void setSorter(ColumnViewerSorter sorter, int direction) {
        if (!sortingEnabled) {
            sortingEnabled = true;
        }

        this.direction = direction;

        if (viewer.getComparator() == sorter) {
            viewer.refresh();
        } else {
            viewer.setComparator(sorter);
        }

    }

    /**
     * . {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    @Override
    public int compare(Viewer viewer, Object e1, Object e2) {

        if (!sortingEnabled) {
            return 0;
        }

        int cat1 = category(e1);
        int cat2 = category(e2);

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

        String str1 = columnLabelProvider.getText(e1);
        String str2 = columnLabelProvider.getText(e2);

        if (str1 == null) {
            str1 = "";
        }
        if (str2 == null) {
            str2 = "";
        }

        // Handle integers
        if (str1.matches("[0-9]*") || str1.equals("")) {
            if (str2.matches("[0-9]*") || str2.equals("")) {
                return compareIntegers(str1, str2);
            }
        }

        // use the comparator to compare the strings
        if (direction == ASC) {
            return getComparator().compare(str1, str2);
        } else {
            return getComparator().compare(str2, str1);
        }

    }

    private int compareIntegers(String str1, String str2) {
        if (str1.equals("")) {
            str1 = "0";
        }
        if (str2.equals("")) {
            str2 = "0";
        }
        int int1;
        int int2;
        try {
            int1 = Integer.parseInt(str1);
            int2 = Integer.parseInt(str2);
        } catch (NumberFormatException e) {
            return 0;
        }

        if (direction == ASC) {
            return int1 - int2;
        } else {
            return int2 - int1;
        }
    }

    /**
     * @param sortingEnabled the sortingEnabled to set
     */
    public void setSortingEnabled(boolean sortingEnabled) {
        this.sortingEnabled = sortingEnabled;
    }

    /**
     * @return the sortingEnabled
     */
    public boolean isSortingEnabled() {
        return sortingEnabled;
    }

    /**
     * @param direction the direction to set
     */
    public void setDirection(int direction) {
        this.direction = direction;
    }

    /**
     * @return the direction
     */
    public int getDirection() {
        return direction;
    }

    /**
     * @return viewer column
     */
    public abstract ViewerColumn getViewerColumn();

    /**
     * @param columnLabelProvider the columnLabelProvider to set
     */
    public void setColumnLabelProvider(ColumnLabelProvider columnLabelProvider) {
        this.columnLabelProvider = columnLabelProvider;
    }

    /**
     * @return the columnLabelProvider
     */
    public ColumnLabelProvider getColumnLabelProvider() {
        return columnLabelProvider;
    }

    /**
     * @return the viewer
     */
    public ColumnViewer getViewer() {
        return viewer;
    }

}