File: src\Framework\System\Windows\Automation\Peers\RadioButtonAutomationPeer.cs
Project: wpf\PresentationFramework.csproj (PresentationFramework)
using System;
using System.Runtime.InteropServices;
using System.Security;
using System.Text;
using System.Windows;
using System.Windows.Automation.Provider;
using System.Windows.Controls;
using System.Windows.Interop;
using System.Windows.Media;
 
using MS.Internal;
using MS.Win32;
 
namespace System.Windows.Automation.Peers
{
 
    ///
    public class RadioButtonAutomationPeer : ToggleButtonAutomationPeer, ISelectionItemProvider
    {
        ///
        public RadioButtonAutomationPeer(RadioButton owner): base(owner)
        {}
 
        ///
        override protected string GetClassNameCore()
        {
            return "RadioButton";
        }
 
        ///
        override protected AutomationControlType GetAutomationControlTypeCore()
        {
            return AutomationControlType.RadioButton;
        }
 
        ///
        override public object GetPattern(PatternInterface patternInterface)
        {
            if (patternInterface == PatternInterface.SelectionItem)
            {
                return this;
            }
            else if(patternInterface == PatternInterface.SynchronizedInput)
            {
                return base.GetPattern(patternInterface);
            }
            else
            {
                return null;
            }
        }
 
        /// <summary>
        /// Sets the current element as the selection
        /// This clears the selection from other elements in the container
        /// </summary>
        void ISelectionItemProvider.Select()
        {
            if (!IsEnabled())
                throw new ElementNotEnabledException();
 
            ((RadioButton)Owner).SetCurrentValueInternal(RadioButton.IsCheckedProperty, MS.Internal.KnownBoxes.BooleanBoxes.TrueBox);
        }
 
 
        /// <summary>
        /// Adds current element to selection
        /// </summary>
        void ISelectionItemProvider.AddToSelection()
        {
            if (((RadioButton)Owner).IsChecked != true)
                throw new InvalidOperationException(SR.Get(SRID.UIA_OperationCannotBePerformed));
        }
 
 
        /// <summary>
        /// Removes current element from selection
        /// </summary>
        void ISelectionItemProvider.RemoveFromSelection()
        {
            // If RadioButton is checked - RemoveFromSelection is invalid operation
            if (((RadioButton)Owner).IsChecked == true)
                throw new InvalidOperationException(SR.Get(SRID.UIA_OperationCannotBePerformed));
        }
 
 
        /// <summary>
        /// Check whether an element is selected
        /// </summary>
        /// <value>returns true if the element is selected</value>
        bool ISelectionItemProvider.IsSelected
        {
            get
            {
                return ((RadioButton)Owner).IsChecked == true;
            }
        }
 
 
        /// <summary>
        /// The logical element that supports the SelectionPattern for this Item
        /// </summary>
        /// <value>returns an IRawElementProviderSimple</value>
        IRawElementProviderSimple ISelectionItemProvider.SelectionContainer
        {
            get
            {
                return null;
            }
        }
 
        // 
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)]
        internal override void RaiseToggleStatePropertyChangedEvent(bool? oldValue, bool? newValue)
        {
            RaisePropertyChangedEvent(
                SelectionItemPatternIdentifiers.IsSelectedProperty,
                oldValue == true,
                newValue == true);
        }
 
    }
}