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Viewing changes to src/Main/ICSharpCode.SharpDevelop.Widgets/Project/ListViewSorting/ListViewMultipleColumnsComparer.cs

  • Committer: sk
  • Date: 2011-09-10 05:17:57 UTC
  • Revision ID: halega@halega.com-20110910051757-qfouz1llya9m6boy
4.1.0.7915 Release Candidate 1

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src/Main/ICSharpCode.SharpDevelop.Widgets/Project/ListViewSorting/ListViewMultipleColumnsComparer.cs
 
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// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
 
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// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
 
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using System;
 
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using System.Collections.Generic;
 
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using System.Windows.Forms;
 
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namespace ICSharpCode.SharpDevelop.Widgets.ListViewSorting
 
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{
 
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        /// <summary>
 
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        /// Compares ListViewItems by comparing multiple columns,
 
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        /// using an object that implements <see cref="IListViewItemComparer"/>
 
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        /// for every column to compare.
 
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        /// </summary>
 
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        public class ListViewMultipleColumnsComparer : IListViewItemComparer
 
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        {
 
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                readonly List<IListViewItemComparer> comparers = new List<IListViewItemComparer>(2);
 
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                readonly List<int> columns = new List<int>(2);
 
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                /// <summary>
 
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                /// Initializes a new instance of the <see cref="ListViewMultipleColumnsComparer"/> class.
 
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                /// </summary>
 
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                /// <param name="firstComparer">The <see cref="IListViewItemComparer"/> to use to compare the first column.</param>
 
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                /// <param name="firstColumn">The 0-based index of the first column to compare.</param>
 
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                /// <param name="secondComparer">The <see cref="IListViewItemComparer"/> to use to compare the second column.</param>
 
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                /// <param name="secondColumn">The 0-based index of the second column to compare.</param>
 
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                /// <remarks>
 
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                /// You can add more columns to compare by using the <see cref="AddComparer"/> method.
 
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                /// </remarks>
 
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                public ListViewMultipleColumnsComparer(IListViewItemComparer firstComparer, int firstColumn, IListViewItemComparer secondComparer, int secondColumn)
 
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                {
 
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                        if (firstComparer == null) {
 
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                                throw new ArgumentNullException("firstComparer");
 
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                        }
 
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                        if (secondComparer == null) {
 
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                                throw new ArgumentNullException("secondComparer");
 
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                        }
 
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                        this.AddComparer(firstComparer, firstColumn);
 
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                        this.AddComparer(secondComparer, secondColumn);
 
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                }
 
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                /// <summary>
 
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                /// Adds another column to compare.
 
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                /// </summary>
 
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                /// <param name="comparer">The <see cref="IListViewItemComparer"/> to use to compare this column.</param>
 
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                /// <param name="column">The 0-based index of the column to compare.</param>
 
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                public void AddComparer(IListViewItemComparer comparer, int column)
 
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                {
 
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                        if (comparer == null) {
 
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                                throw new ArgumentNullException("comparer");
 
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                        }
 
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                        this.comparers.Add(comparer);
 
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                        this.columns.Add(column);
 
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                }
 
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                public int Compare(ListViewItem lhs, ListViewItem rhs, int column)
 
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                {
 
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                        int compareResult;
 
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                        for (int i = 0; i < this.comparers.Count; i++) {
 
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                                if ((compareResult = this.comparers[i].Compare(lhs, rhs, this.columns[i])) != 0) {
 
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                                        return compareResult;
 
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                                }
 
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                        }
 
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                        return 0;
 
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                }
 
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        }
 
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}