ComboBoxAutomationPeer.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Framework / System / Windows / Automation / Peers / ComboBoxAutomationPeer.cs / 1305600 / ComboBoxAutomationPeer.cs
                        
                        
                            using System; 
using System.Collections;
using System.Collections.Generic;
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.Controls.Primitives; 
using System.Windows.Interop;
using System.Windows.Media;
using System.Windows.Threading;
 
using MS.Internal;
using MS.Win32; 
 
namespace System.Windows.Automation.Peers
{ 

    ///
    public class ComboBoxAutomationPeer: SelectorAutomationPeer, IValueProvider, IExpandCollapseProvider
    { 
        ///
        public ComboBoxAutomationPeer(ComboBox owner): base(owner) 
        {} 

        /// 
        override protected ItemAutomationPeer CreateItemAutomationPeer(object item)
        {
            // Use the same peer as ListBox
            return new ListBoxItemAutomationPeer(item, this); 
        }
 
        /// 
        override protected AutomationControlType GetAutomationControlTypeCore()
        { 
            return AutomationControlType.ComboBox;
        }

        /// 
        override protected string GetClassNameCore()
        { 
            return "ComboBox"; 
        }
 
        ///
        override public object GetPattern(PatternInterface pattern)
        {
            object iface = null; 

            if (pattern == PatternInterface.Value) 
            { 
                ComboBox owner = (ComboBox)Owner;
                if (owner.IsEditable) iface = this; 
            }
            else if(pattern == PatternInterface.ExpandCollapse)
            {
                iface = this; 
            }
            else 
            { 
                iface = base.GetPattern(pattern);
            } 

            return iface;
        }
 
        ///
        protected override List GetChildrenCore() 
        { 
            List children = base.GetChildrenCore();
 
            //  include text box part into children collection
            ComboBox owner = (ComboBox)Owner;
            TextBox textBox = owner.EditableTextBoxSite;
            if (textBox != null) 
            {
                AutomationPeer peer = UIElementAutomationPeer.CreatePeerForElement(textBox); 
                if (peer != null) 
                {
                    if (children == null) 
                        children = new List();

                    children.Insert(0, peer);
                } 
            }
 
            return children; 
        }
 
        ///
        protected override void SetFocusCore()
        {
            ComboBox owner = (ComboBox)Owner; 
            if (owner.Focusable)
            { 
                if (!owner.Focus()) 
                {
                    //The fox might have went to the TextBox inside Combobox if it is editable. 
                    if (owner.IsEditable)
                    {
                        TextBox tb = owner.EditableTextBoxSite;
                        if (tb == null || !tb.IsKeyboardFocused) 
                            throw new InvalidOperationException(SR.Get(SRID.SetFocusFailed));
                    } 
                    else 
                        throw new InvalidOperationException(SR.Get(SRID.SetFocusFailed));
                } 
            }
            else
            {
                throw new InvalidOperationException(SR.Get(SRID.SetFocusFailed)); 
            }
 
        } 

        /// 
        internal void ScrollItemIntoView(object item)
        {
            // Item can be scrolled into view only when the Combo is expanded.
            // 

            if(((IExpandCollapseProvider)this).ExpandCollapseState == ExpandCollapseState.Expanded) 
            { 
                ComboBox owner = (ComboBox)Owner;
                if (owner.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated) 
                {
                    owner.OnBringItemIntoView(item);
                }
                else 
                {
                    // The items aren't generated, try at a later time 
                    Dispatcher.BeginInvoke(DispatcherPriority.Loaded, new DispatcherOperationCallback(owner.OnBringItemIntoView), item); 
                }
            } 
        }

        #region Value
 
        /// 
        /// Request to set the value that this UI element is representing 
        ///  
        /// Value to set the UI to, as an object
        /// true if the UI element was successfully set to the specified value 
        //[CodeAnalysis("AptcaMethodsShouldOnlyCallAptcaMethods")] //Tracking Bug: 29647
        void IValueProvider.SetValue(string val)
        {
            if (val == null) 
                throw new ArgumentNullException("val");
 
            ComboBox owner = (ComboBox)Owner; 

            if (!owner.IsEnabled) 
                throw new ElementNotEnabledException();

            owner.SetCurrentValueInternal(ComboBox.TextProperty, val);
        } 

        ///Value of a value control, as a a string. 
        string IValueProvider.Value 
        {
            get 
            {
                return ((ComboBox)(((ComboBoxAutomationPeer)this).Owner)).Text;
            }
        } 

 
        ///Indicates that the value can only be read, not modified. 
        ///returns True if the control is read-only
        bool IValueProvider.IsReadOnly 
        {
            get
            {
                ComboBox owner = (ComboBox)Owner; 
                return !owner.IsEnabled || owner.IsReadOnly;
            } 
        } 

        // 
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)]
        internal void RaiseValuePropertyChangedEvent(string oldValue, string newValue)
        {
            if (oldValue != newValue) 
            {
                RaisePropertyChangedEvent(ValuePatternIdentifiers.ValueProperty, oldValue, newValue); 
            } 
        }
 
        #endregion Value

        #region ExpandCollapse
        ///  
        /// Blocking method that returns after the element has been expanded.
        ///  
        /// true if the node was successfully expanded 
        void IExpandCollapseProvider.Expand()
        { 
            if(!IsEnabled())
                throw new ElementNotEnabledException();

            ComboBox owner = (ComboBox)((ComboBoxAutomationPeer)this).Owner; 
            owner.SetCurrentValueInternal(ComboBox.IsDropDownOpenProperty, MS.Internal.KnownBoxes.BooleanBoxes.TrueBox);
        } 
 

        ///  
        /// Blocking method that returns after the element has been collapsed.
        /// 
        /// true if the node was successfully collapsed
        void IExpandCollapseProvider.Collapse() 
        {
            if(!IsEnabled()) 
                throw new ElementNotEnabledException(); 

            ComboBox owner = (ComboBox)((ComboBoxAutomationPeer)this).Owner; 
            owner.SetCurrentValueInternal(ComboBox.IsDropDownOpenProperty, MS.Internal.KnownBoxes.BooleanBoxes.FalseBox);
        }

 
        ///indicates an element's current Collapsed or Expanded state
        ExpandCollapseState IExpandCollapseProvider.ExpandCollapseState 
        { 
            get
            { 
                ComboBox owner = (ComboBox)((ComboBoxAutomationPeer)this).Owner;
                return owner.IsDropDownOpen ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed;
            }
        } 

        // 
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)] 
        internal void RaiseExpandCollapseAutomationEvent(bool oldValue, bool newValue)
        { 
            RaisePropertyChangedEvent(
                ExpandCollapsePatternIdentifiers.ExpandCollapseStateProperty,
                oldValue ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed,
                newValue ? ExpandCollapseState.Expanded : ExpandCollapseState.Collapsed); 
        }
 
 
        #endregion ExpandCollapse
 

    }
}
 

 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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ComboBoxAutomationPeer.cs source code in C# .NET

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