TableColumnSortListener.java

/*
 * DBeaver - Universal Database Manager
 * Copyright (C) 2010-2017 Serge Rider (serge@jkiss.org)
 *
 * 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.jkiss.dbeaver.ui.controls;

import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.*;
import org.jkiss.dbeaver.ui.UIUtils;

import java.text.Collator;
import java.util.Comparator;
import java.util.Locale;

/**
 * TableColumnSortListener
 */
public class TableColumnSortListener implements Listener {
    private final Table table;
    private final int columnIndex;
    private int sortDirection = SWT.DOWN;
    private TableColumn prevColumn = null;

    public TableColumnSortListener(Table table, int columnIndex) {
        this.table = table;
        this.columnIndex = columnIndex;
    }

    @Override
    public void handleEvent(Event e) {
        final Collator collator = Collator.getInstance(Locale.getDefault());
        TableColumn column = (TableColumn) e.widget;
        if (prevColumn == column) {
            // Set reverse order
            sortDirection = (sortDirection == SWT.UP ? SWT.DOWN : SWT.UP);
        }
        prevColumn = column;
        this.table.setSortColumn(column);
        this.table.setSortDirection(sortDirection);
        UIUtils.sortTable(this.table, new Comparator<TableItem>() {
            @Override
            public int compare(TableItem e1, TableItem e2) {
                int mul = (sortDirection == SWT.UP ? 1 : -1);
                String text1 = e1.getText(columnIndex);
                String text2 = e2.getText(columnIndex);
                try {
                    Double num1 = getNumberFromString(text1);
                    if (num1 != null) {
                        Double num2 = getNumberFromString(text2);
                        if (num2 != null) {
                            return (int)(num1 - num2) * mul;
                        }
                    }
                } catch (NumberFormatException e3) {
                    // Ignore
                }
                return collator.compare(text1, text2) * mul;
            }
        });
    }

    private static Double getNumberFromString(String str) {
        if (str.isEmpty()) return null;
        if (!Character.isDigit(str.charAt(0))) return null;
        int numLength = 1;
        for (; numLength < str.length(); numLength++) {
            if (Character.isWhitespace(str.charAt(numLength))) {
                break;
            }
        }
        if (numLength == str.length()) {
            return Double.parseDouble(str);
        } else {
            return Double.parseDouble(str.substring(0, numLength));
        }
    }
}