// 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.
 
/***************************************************************************\
*
*
*  ServiceProvider class that is passed into MarkupExtensions.ProvideValue method
*  that understands the ParserContext.
*
*
\***************************************************************************/
using System;
using System.Windows;
using System.Windows.Media;
using System.Diagnostics;
 
namespace System.Windows.Markup
{
    /// <summary>
    ///  Base class for all Xaml markup extensions.
    /// </summary>
 
    internal class ProvideValueServiceProvider : IServiceProvider, IProvideValueTarget, IXamlTypeResolver, IUriContext, IFreezeFreezables
    {
        // Construction
        
        internal ProvideValueServiceProvider(ParserContext context)
        {
            _context = context;
        }
 
        internal ProvideValueServiceProvider()
        {
        }
 
        // Set the TargetObject/Property (for use by IProvideValueTarget).
        
        internal void SetData(object targetObject, object targetProperty)
        {
            _targetObject = targetObject;
            _targetProperty = targetProperty;
        }
 
        // Clear the TargetObject/Property (after a call to ProvideValue)
        
        internal void ClearData()
        {
            _targetObject = _targetProperty = null;
        }
 
 
        // IXamlTypeResolver implementation
        
        Type IXamlTypeResolver.Resolve(string qualifiedTypeName) // E.g. foo:Class
        {
            return _context.XamlTypeMapper.GetTypeFromBaseString(qualifiedTypeName, _context, true);
        }
 
        // IProvideValueTarget implementation
        
        object IProvideValueTarget.TargetObject
        {
            get { return _targetObject; }
        }
        object IProvideValueTarget.TargetProperty
        {
            get { return _targetProperty; }
        }
 
        // IUriContext implementation
        
        Uri IUriContext.BaseUri
        {
            get { return _context.BaseUri; }
            set { throw new NotSupportedException(SR.ParserProvideValueCantSetUri); }
        }
 
        bool IFreezeFreezables.FreezeFreezables
        {
            get
            {
                return _context.FreezeFreezables;
            }
        }
 
        bool IFreezeFreezables.TryFreeze(string value, Freezable freezable)
        {
            return _context.TryCacheFreezable(value, freezable);
        }
 
        Freezable IFreezeFreezables.TryGetFreezable(string value)
        {
            return _context.TryGetFreezable(value);
        }
 
 
        // IServiceProvider implementation (this is the way to get to the
        // above interface implementations).
        
        public object GetService(Type service)
        {
            // IProvideValueTarget is the only implementation that
            // doesn't need the ParserContext
            
            if( service == typeof(IProvideValueTarget))
            {
                return this as IProvideValueTarget;
            }
 
            if( _context != null )
            {
                if( service == typeof(IXamlTypeResolver))
                {
                    return this as IXamlTypeResolver;
                }
 
                else if( service == typeof(IUriContext))
                {
                    return this as IUriContext;
                }
 
                else if (service == typeof(IFreezeFreezables))
                {
                    return this as IFreezeFreezables;
                }
            }
 
 
            return null;
        }
 
 
        // Data
 
        private ParserContext _context = null;
        private object _targetObject = null;
        private object _targetProperty = null;
    }
}