src/log4net/Layout/RawLayoutConverter.cs

#region Apache License
//
// Licensed to the Apache Software Foundation (ASF) under one or more 
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership. 
// The ASF licenses this file to you 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
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//
#endregion

using System;

using log4net.Util.TypeConverters;

namespace log4net.Layout;

/// <summary>
/// Type converter for the <see cref="IRawLayout"/> interface.
/// </summary>
/// <remarks>
/// <para>
/// Supports converting from the <see cref="ILayout"/> interface to
/// the <see cref="IRawLayout"/> interface using the <see cref="Layout2RawLayoutAdapter"/>.
/// </para>
/// </remarks>
/// <author>Nicko Cadell</author>
/// <author>Gert Driesen</author>
public class RawLayoutConverter : IConvertFrom
{
  /// <summary>
  /// Can the sourceType be converted to an <see cref="IRawLayout"/>
  /// </summary>
  /// <param name="sourceType">the source to be to be converted</param>
  /// <returns><c>true</c> if the source type can be converted to <see cref="IRawLayout"/></returns>
  /// <remarks>
  /// <para>
  /// Test if the <paramref name="sourceType"/> can be converted to a
  /// <see cref="IRawLayout"/>. Only <see cref="ILayout"/> is supported
  /// as the <paramref name="sourceType"/>.
  /// </para>
  /// </remarks>
  public bool CanConvertFrom(Type sourceType) =>
    // Accept an ILayout object
    typeof(ILayout).IsAssignableFrom(sourceType);

  /// <summary>
  /// Converts the value to a <see cref="IRawLayout"/> object.
  /// </summary>
  /// <param name="source">the value to convert</param>
  /// <returns>the <see cref="IRawLayout"/> object</returns>
  /// <remarks>
  /// <para>
  /// If the <paramref name="source"/> object is an <see cref="ILayout"/> then the
  /// <see cref="Layout2RawLayoutAdapter"/> is used to adapt between the two interfaces,
  /// otherwise an exception is thrown.
  /// </para>
  /// </remarks>
  public object ConvertFrom(object source)
  {
    if (source is ILayout layout)
    {
      return new Layout2RawLayoutAdapter(layout);
    }
    throw ConversionNotSupportedException.Create(typeof(IRawLayout), source);
  }
}