// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
//
// Description: Defines DisplayMemberTemplateSelector class.
//
 
using System;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using MS.Internal;
 
namespace MS.Internal.Data
{
    // Selects template appropriate for CLR/XML item in order to
    // display string property at DisplayMemberPath on the item.
    internal sealed class DisplayMemberTemplateSelector : DataTemplateSelector
    {
        /// <summary>
        /// Constructor
        /// </summary>
        /// <param name="displayMemberPath">path to the member to display</param>
        public DisplayMemberTemplateSelector(string displayMemberPath, string stringFormat)
        {
            Debug.Assert(!(String.IsNullOrEmpty(displayMemberPath) && String.IsNullOrEmpty(stringFormat)));
            _displayMemberPath = displayMemberPath;
            _stringFormat = stringFormat;
        }
 
        /// <summary>
        /// Override this method to return an app specific <seealso cref="DataTemplate"/>.
        /// </summary>
        /// <param name="item">The data content</param>
        /// <param name="container">The container in which the content is to be displayed</param>
        /// <returns>a app specific template to apply.</returns>
        public override DataTemplate SelectTemplate(object item, DependencyObject container)
        {
            if (SystemXmlHelper.IsXmlNode(item))
            {
                if (_xmlNodeContentTemplate == null)
                {
                    _xmlNodeContentTemplate = new DataTemplate();
                    FrameworkElementFactory text = ContentPresenter.CreateTextBlockFactory();
                    Binding binding = new Binding();
                    binding.XPath = _displayMemberPath;
                    binding.StringFormat = _stringFormat;
                    text.SetBinding(TextBlock.TextProperty, binding);
                    _xmlNodeContentTemplate.VisualTree = text;
                    _xmlNodeContentTemplate.Seal();
                }
                return _xmlNodeContentTemplate;
            }
            else
            {
                if (_clrNodeContentTemplate == null)
                {
                    _clrNodeContentTemplate = new DataTemplate();
                    FrameworkElementFactory text = ContentPresenter.CreateTextBlockFactory();
                    Binding binding = new Binding();
                    binding.Path = new PropertyPath(_displayMemberPath);
                    binding.StringFormat = _stringFormat;
                    text.SetBinding(TextBlock.TextProperty, binding);
                    _clrNodeContentTemplate.VisualTree = text;
                    _clrNodeContentTemplate.Seal();
                }
                return _clrNodeContentTemplate;
            }
        }
 
        private string _displayMemberPath;
        private string _stringFormat;
        private DataTemplate _xmlNodeContentTemplate;
        private DataTemplate _clrNodeContentTemplate;
    }
}