DependencyPropertyHelper.cs source code in C# .NET

                        Code:
                         / DotNET / DotNET / 8.0 / untmp / WIN_WINDOWS / lh_tools_devdiv_wpf / Windows / wcp / Framework / System / Windows / DependencyPropertyHelper.cs / 1 / DependencyPropertyHelper.cs
                        
                        
                            //---------------------------------------------------------------------------- 
//
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved.
//  
//
// Description: Helper class for miscellaneous framework-level features related 
// to DependencyProperties. 
//
// See spec at [....]/sites/Avalon/Specs/GetValueSource.mht 
//
//---------------------------------------------------------------------------

using System; 

namespace System.Windows 
{ 
    /// 
    /// Source of a DependencyProperty value. 
    /// 
    public enum BaseValueSource
    {
        ///  The source is not known by the Framework.  
        Unknown                 = BaseValueSourceInternal.Unknown,
        ///  Default value, as defined by property metadata.  
        Default                 = BaseValueSourceInternal.Default, 
        ///  Inherited from an ancestor. 
        Inherited               = BaseValueSourceInternal.Inherited, 
        ///  Default Style for the current theme. 
        DefaultStyle            = BaseValueSourceInternal.ThemeStyle,
        ///  Trigger in the default Style for the current theme. 
        DefaultStyleTrigger     = BaseValueSourceInternal.ThemeStyleTrigger, 
        ///  Style setter. 
        Style                   = BaseValueSourceInternal.Style, 
        ///  Trigger in the Template.  
        TemplateTrigger         = BaseValueSourceInternal.TemplateTrigger,
        ///  Trigger in the Style.  
        StyleTrigger            = BaseValueSourceInternal.StyleTrigger,
        ///  Implicit Style reference. 
        ImplicitStyleReference  = BaseValueSourceInternal.ImplicitReference,
        ///  Template that created the element.  
        ParentTemplate          = BaseValueSourceInternal.ParentTemplate,
        ///  Trigger in the Template that created the element.  
        ParentTemplateTrigger   = BaseValueSourceInternal.ParentTemplateTrigger, 
        ///  Local value. 
        Local                   = BaseValueSourceInternal.Local, 
    }

    /// 
    /// This struct contains the information returned from 
    /// DependencyPropertyHelper.GetValueSource.
    ///  
    public struct ValueSource 
    {
        internal ValueSource(BaseValueSourceInternal source, bool isExpression, bool isAnimated, bool isCoerced) 
        {
            // this cast is justified because the public BaseValueSource enum
            // values agree with the internal BaseValueSourceInternal enum values.
            _baseValueSource = (BaseValueSource)source; 

            _isExpression = isExpression; 
            _isAnimated = isAnimated; 
            _isCoerced = isCoerced;
        } 

        /// 
        /// The base value source.
        ///  
        public BaseValueSource BaseValueSource
        { 
            get { return _baseValueSource; } 
        }
 
        /// 
        /// True if the value came from an Expression.
        /// 
        public bool IsExpression 
        {
            get { return _isExpression; } 
        } 

        ///  
        /// True if the value came from an animation.
        /// 
        public bool IsAnimated
        { 
            get { return _isAnimated; }
        } 
 
        /// 
        /// True if the value was coerced. 
        /// 
        public bool IsCoerced
        {
            get { return _isCoerced; } 
        }
 
        #region Object overrides - required by FxCop 

        ///  
        /// Return the hash code for this ValueSource.
        /// 
        public override int GetHashCode()
        { 
            return _baseValueSource.GetHashCode();
        } 
 
        /// 
        /// True if this ValueSource equals the argument. 
        /// 
        public override bool Equals(object o)
        {
            if (o is ValueSource) 
            {
                ValueSource that = (ValueSource)o; 
 
                return  this._baseValueSource == that._baseValueSource &&
                        this._isExpression == that._isExpression && 
                        this._isAnimated == that._isAnimated &&
                        this._isCoerced == that._isCoerced;
            }
            else 
            {
                return false; 
            } 
        }
 
        /// 
        /// True if the two arguments are equal.
        /// 
        public static bool operator==(ValueSource vs1, ValueSource vs2) 
        {
            return vs1.Equals(vs2); 
        } 

        ///  
        /// True if the two arguments are unequal.
        /// 
        public static bool operator!=(ValueSource vs1, ValueSource vs2)
        { 
            return !vs1.Equals(vs2);
        } 
 
        #endregion Object overrides - required by FxCop
 
        BaseValueSource _baseValueSource;
        bool            _isExpression;
        bool            _isAnimated;
        bool            _isCoerced; 
    }
 
    ///  
    /// Helper class for miscellaneous framework-level features related
    /// to DependencyProperties. 
    /// 
    public static class DependencyPropertyHelper
    {
        ///  
        /// Return the source of the value for the given property.
        ///  
        public static ValueSource GetValueSource(DependencyObject dependencyObject, DependencyProperty dependencyProperty) 
        {
            if (dependencyObject == null) 
                throw new ArgumentNullException("dependencyObject");
            if (dependencyProperty == null)
                throw new ArgumentNullException("dependencyProperty");
 
            dependencyObject.VerifyAccess();
 
            bool hasModifiers, isExpression, isAnimated, isCoerced; 
            BaseValueSourceInternal source = dependencyObject.GetValueSource(dependencyProperty, null, out hasModifiers, out isExpression, out isAnimated, out isCoerced);
 
            return new ValueSource(source, isExpression, isAnimated, isCoerced);
        }
    }
} 

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

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