ABCpdf .NET PDF Component Documentation

// ===========================================================================
//  ©2013-2026 WebSupergoo. All rights reserved.
//
//  This source code is for use exclusively with the ABCpdf product with
//  which it is distributed, under the terms of the license for that
//  product. Details can be found at
//
//    http://www.websupergoo.com/
//
//  This copyright notice must not be deleted and must be reproduced alongside
//  any sections of code extracted from this module.
// ===========================================================================

using System;
using System.Collections;
using System.Windows.Forms;
using System.Globalization;


namespace WebSupergoo.PDFSurgeon
{
  /// <summary>
  /// Summary description for ListViewItemComparer.
  /// </summary>
  public class ListViewItemComparer: IComparer
  {
    private int _column;
    private SortOrder _order;
    private IComparer _stringComparer;

    public ListViewItemComparer(){
      _column = 0;
      _order = SortOrder.None;
      _stringComparer = new CaseInsensitiveComparer(
        CultureInfo.InvariantCulture);
    }

    public int Column{
      get{ return _column; }
      set{ _column = value; }
    }

    public SortOrder Order{
      get{ return _order; }
      set{ _order = value; }
    }

    public int Compare(object x, object y){
      if(_order==SortOrder.None)
        return 0;

      ListViewItem itemX = (ListViewItem)x;
      ListViewItem itemY = (ListViewItem)y;

      int v = 0;
      if(_column==0 && TryCompareID(ref v, itemX, itemY))
        return v;

      return CompareStringColumn(itemX, itemY);
    }

    private bool TryCompareID(ref int outV, ListViewItem x, ListViewItem y){
      if(_order==SortOrder.None){
        outV = 0;
        return true;
      }

      ObjectExtractor xExtractor = x.Tag as ObjectExtractor;
      if(xExtractor==null)
        return false;

      ObjectExtractor yExtractor = y.Tag as ObjectExtractor;
      if(yExtractor==null)
        return false;

      outV = Comparer.DefaultInvariant.Compare(
        xExtractor.Object.ID, yExtractor.Object.ID);
      if(_order==SortOrder.Descending)
        outV = -outV;
      return true;
    }

    private int CompareStringColumn(ListViewItem x, ListViewItem y){
      if(_order==SortOrder.None)
        return 0;

      ListViewItem.ListViewSubItem sitemX = _column>=x.SubItems.Count?
        null: x.SubItems[_column];
      ListViewItem.ListViewSubItem sitemY = _column>=y.SubItems.Count?
        null: y.SubItems[_column];

      if(sitemX==sitemY)
        return 0;

      string xText = sitemX==null? "": sitemX.Text;
      string yText = sitemY==null? "": sitemY.Text;

      return xText=="" && yText==""? 0: xText==""? 1: yText==""? -1:
        _stringComparer.Compare(sitemX.Text, sitemY.Text);
    }
  }
}