File: Core\CSharp\MS\Internal\Automation\RangeValueProviderWrapper.cs
Project: wpf\src\PresentationCore.csproj (PresentationCore)
//---------------------------------------------------------------------------
//
// <copyright file="RangeValueProviderWrapper.cs" company="Microsoft">
//    Copyright (C) Microsoft Corporation.  All rights reserved.
// </copyright>
// 
//
// Description: Range Value pattern provider wrapper for WCP
//
// History:  
//  07/21/2003 : BrendanM Ported to WCP
//
//---------------------------------------------------------------------------
 
using System;
using System.Windows.Threading;
 
using System.Windows.Media;
using System.Windows.Automation;
using System.Windows.Automation.Provider;
using System.Windows.Automation.Peers;
 
namespace MS.Internal.Automation
{
    // Automation/WCP Wrapper class: Implements that UIAutomation I...Provider
    // interface, and calls through to a WCP AutomationPeer which implements the corresponding
    // I...Provider inteface. Marshalls the call from the RPC thread onto the
    // target AutomationPeer's context.
    //
    // Class has two major parts to it:
    // * Implementation of the I...Provider, which uses Dispatcher.Invoke
    //   to call a private method (lives in second half of the class) via a delegate,
    //   if necessary, packages any params into an object param. Return type of Invoke
    //   must be cast from object to appropriate type.
    // * private methods - one for each interface entry point - which get called back
    //   on the right context. These call through to the peer that's actually
    //   implenting the I...Provider version of the interface. 
    internal class RangeValueProviderWrapper: MarshalByRefObject, IRangeValueProvider
    {
        //------------------------------------------------------
        //
        //  Constructors
        //
        //------------------------------------------------------
 
        #region Constructors
 
        private RangeValueProviderWrapper( AutomationPeer peer, IRangeValueProvider iface )
        {
            _peer = peer;
            _iface = iface;
        }
 
        #endregion Constructors
 
 
        //------------------------------------------------------
        //
        //  Interface IRangeValueProvider
        //
        //------------------------------------------------------
 
        #region Interface IRangeValueProvider
 
        public void SetValue( double val )
        {
            ElementUtil.Invoke( _peer, new DispatcherOperationCallback( SetValueInternal ), val );
        }
 
        public double Value
        {
            get
            {
                return (double) ElementUtil.Invoke( _peer, new DispatcherOperationCallback( GetValue ), null );
            }
        }
 
        public bool IsReadOnly
        {
            get
            {
                return (bool) ElementUtil.Invoke( _peer, new DispatcherOperationCallback( GetIsReadOnly ), null );
            }
        }
 
        public double Maximum
        {
            get
            {
                return (double) ElementUtil.Invoke( _peer, new DispatcherOperationCallback( GetMaximum ), null );
            }
        }
 
        public double Minimum
        {
            get
            {
                return (double) ElementUtil.Invoke( _peer, new DispatcherOperationCallback( GetMinimum ), null );
            }
        }
 
        public double LargeChange
        {
            get
            {
                return (double) ElementUtil.Invoke( _peer, new DispatcherOperationCallback( GetLargeChange ), null );
            }
        }
 
        public double SmallChange
        {
            get
            {
                return (double) ElementUtil.Invoke( _peer, new DispatcherOperationCallback( GetSmallChange ), null );
            }
        }
 
        #endregion Interface IRangeValueProvider
 
 
        //------------------------------------------------------
        //
        //  Internal Methods
        //
        //------------------------------------------------------
 
        #region Internal Methods
 
        internal static object Wrap( AutomationPeer peer, object iface )
        {
            return new RangeValueProviderWrapper( peer, (IRangeValueProvider) iface );
        }
 
        #endregion Internal Methods
 
        //------------------------------------------------------
        //
        //  Private Methods
        //
        //------------------------------------------------------
 
        #region Private Methods
 
        private object SetValueInternal( object arg )
        {
            _iface.SetValue( (double)arg );
            return null;
        }
 
        private object GetValue( object unused )
        {
            return _iface.Value;
        }
 
        private object GetIsReadOnly( object unused )
        {
            return _iface.IsReadOnly;
        }
 
        private object GetMaximum( object unused )
        {
            return _iface.Maximum;
        }
 
        private object GetMinimum( object unused )
        {
            return _iface.Minimum;
        }
 
        private object GetLargeChange( object unused )
        {
            return _iface.LargeChange;
        }
 
        private object GetSmallChange( object unused )
        {
            return _iface.SmallChange;
        }
 
        #endregion Private Methods
 
 
        //------------------------------------------------------
        //
        //  Private Fields
        //
        //------------------------------------------------------
 
        #region Private Fields
 
        private AutomationPeer _peer;
        private IRangeValueProvider _iface;
 
        #endregion Private Fields
    }
}