ActivityLocationReferenceEnvironment.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / System.Activities / System / Activities / ActivityLocationReferenceEnvironment.cs / 1305376 / ActivityLocationReferenceEnvironment.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------

namespace System.Activities 
{
    using System.Activities.Validation; 
    using System.Collections.Generic; 
    using System.Runtime;
 
    [Fx.Tag.XamlVisible(false)]
    sealed class ActivityLocationReferenceEnvironment : LocationReferenceEnvironment
    {
        Dictionary declarations; 
        List unnamedDeclarations;
 
        public ActivityLocationReferenceEnvironment() 
        {
        } 

        public ActivityLocationReferenceEnvironment(LocationReferenceEnvironment parent)
        {
            this.Parent = parent; 

            if (this.Parent != null) 
            { 
                this.InternalRoot = parent.Root;
            } 
        }

        public override Activity Root
        { 
            get
            { 
                return this.InternalRoot; 
            }
        } 

        public Activity InternalRoot
        {
            get; 
            set;
        } 
 
        Dictionary Declarations
        { 
            get
            {
                if (this.declarations == null)
                { 
                    this.declarations = new Dictionary();
                } 
 
                return this.declarations;
            } 
        }

        public override bool IsVisible(LocationReference locationReference)
        { 
            if (locationReference == null)
            { 
                throw FxTrace.Exception.ArgumentNull("locationReference"); 
            }
 
            LocationReferenceEnvironment currentScope = this;

            while (currentScope != null)
            { 
                ActivityLocationReferenceEnvironment activityEnvironment = currentScope as ActivityLocationReferenceEnvironment;
 
                if (activityEnvironment != null) 
                {
                    if (activityEnvironment.declarations != null) 
                    {
                        foreach (LocationReference declaration in activityEnvironment.declarations.Values)
                        {
                            if (locationReference == declaration) 
                            {
                                return true; 
                            } 
                        }
                    } 

                    if (activityEnvironment.unnamedDeclarations != null)
                    {
                        for (int i = 0; i < activityEnvironment.unnamedDeclarations.Count; i++) 
                        {
                            if (locationReference == activityEnvironment.unnamedDeclarations[i]) 
                            { 
                                return true;
                            } 
                        }
                    }
                }
                else 
                {
                    return currentScope.IsVisible(locationReference); 
                } 

                currentScope = currentScope.Parent; 
            }

            return false;
        } 

        public void Declare(LocationReference locationReference, Activity owner, ref IList validationErrors) 
        { 
            Fx.Assert(locationReference != null, "Must not be null");
 
            if (locationReference.Name == null)
            {
                if (this.unnamedDeclarations == null)
                { 
                    this.unnamedDeclarations = new List();
                } 
 
                this.unnamedDeclarations.Add(locationReference);
            } 
            else
            {
                if (this.Declarations.ContainsKey(locationReference.Name))
                { 
                    string id = null;
 
                    if (owner != null) 
                    {
                        id = owner.Id; 
                    }

                    ValidationError validationError = new ValidationError(SR.SymbolNamesMustBeUnique(locationReference.Name))
                    { 
                        Source = owner,
                        Id = id 
                    }; 

                    ActivityUtilities.Add(ref validationErrors, validationError); 
                }
                else
                {
                    this.Declarations.Add(locationReference.Name, locationReference); 
                }
            } 
        } 

        public override bool TryGetLocationReference(string name, out LocationReference result) 
        {
            if (name == null)
            {
                // We don't allow null names in our LocationReferenceEnvironment but 
                // a custom declared environment might.  We need to walk up
                // to the root and see if it chains to a 
                // non-ActivityLocationReferenceEnvironment implementation 
                LocationReferenceEnvironment currentEnvironment = this.Parent;
 
                while (currentEnvironment is ActivityLocationReferenceEnvironment)
                {
                    currentEnvironment = currentEnvironment.Parent;
                } 

                if (currentEnvironment != null) 
                { 
                    Fx.Assert(!(currentEnvironment is ActivityLocationReferenceEnvironment), "We must be at a non-ActivityLocationReferenceEnvironment implementation.");
 
                    return currentEnvironment.TryGetLocationReference(name, out result);
                }
            }
            else 
            {
                if (this.declarations != null && this.declarations.TryGetValue(name, out result)) 
                { 
                    return true;
                } 

                bool found = false;
                LocationReferenceEnvironment currentEnvironment = this.Parent;
                LocationReferenceEnvironment rootEnvironment = this; 

                // Loop through all of the ActivityLocationReferenceEnvironments we have chained together 
                while (currentEnvironment != null && currentEnvironment is ActivityLocationReferenceEnvironment) 
                {
                    ActivityLocationReferenceEnvironment activityEnvironment = (ActivityLocationReferenceEnvironment)currentEnvironment; 
                    if (activityEnvironment.declarations != null && activityEnvironment.declarations.TryGetValue(name, out result))
                    {
                        return true;
                    } 

                    rootEnvironment = currentEnvironment; 
                    currentEnvironment = currentEnvironment.Parent; 
                }
 
                if (!found)
                {
                    if (currentEnvironment != null)
                    { 
                        // Looks like we have a non-ActivityLocationReferenceEnvironment at the root
                        Fx.Assert(!(currentEnvironment is ActivityLocationReferenceEnvironment), "We should have some other host environment at this point."); 
                        if (currentEnvironment.TryGetLocationReference(name, out result)) 
                        {
                            return true; 
                        }
                    }
                }
            } 

            result = null; 
            return false; 
        }
 
        public override IEnumerable GetLocationReferences()
        {
            return this.Declarations.Values;
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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ActivityLocationReferenceEnvironment.cs source code in C# .NET

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