TableViewerSorter.java 文件源码

/**
 * Performs a default column-wise comparison of two elements. This method is
 * called after checking for any {@link Comparator} set through
 * {@link #setComparator(int, Comparator)}. Subclasses may override. The
 * base class implementation uses this sorter's {@link Collator} to compare
 * the column text for each element provided by the viewer's label provider.
 *
 * @param columnIndex
 *        the index of the column being sorted by
 * @param viewer
 *        the {@link Viewer} we are sorting for
 * @param e1
 *        the first element
 * @param e2
 *        the second element
 * @return a comparison value
 */
protected int defaultColumnCompare(final int columnIndex, final Viewer viewer, final Object e1, final Object e2) {
    final ITableLabelProvider labelProvider = (ITableLabelProvider) ((StructuredViewer) viewer).getLabelProvider();

    String s1 = labelProvider.getColumnText(e1, columnIndex);
    String s2 = labelProvider.getColumnText(e2, columnIndex);

    if (s1 == null) {
        s1 = ""; //$NON-NLS-1$
    }
    if (s2 == null) {
        s2 = ""; //$NON-NLS-1$
    }

    return getCollator().compare(s1, s2);
}