VisualBasicSettingsHandler.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / Tools / System.Activities.Presentation / System / Activities / Presentation / VisualBasicSettingsHandler.cs / 1305376 / VisualBasicSettingsHandler.cs
                        

                        
                            //---------------------------------------------------------------- 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//---------------------------------------------------------------

 
namespace System.Activities.Presentation
{ 
    using System.ComponentModel; 
    using Microsoft.VisualBasic.Activities;
    using System.Activities.Debugger; 
    using System.Activities.Presentation.Model;
    using System.Runtime;
    using System.Linq;
 
    //the class does several things:
    //1. make sure a special property "Imports" (implemented using VisualBasicSettings attached properties) is added to the root object before it's loaded into ModelTree 
    //2. make sure the "root workflow" of the root object always have the same VisualBasicSettings 
    static class VisualBasicSettingsHandler
    { 
        static public void PreviewLoadRoot(object sender, WorkflowDesigner.PreviewLoadEventArgs args)
        {
            VisualBasicSettings settings = VisualBasic.GetSettings(args.Instance);
            if (settings == null) 
            {
                settings = new VisualBasicSettings(); 
                VisualBasic.SetSettings(args.Instance, settings); 
            }
 
            IDebuggableWorkflowTree root = args.Instance as IDebuggableWorkflowTree;
            if (root != null)
            {
                Activity rootActivity = root.GetWorkflowRoot(); 
                if (rootActivity != null)
                { 
                    VisualBasic.SetSettings(rootActivity, settings); 
                }
 
                args.Context.Services.Subscribe(manager => manager.Root.PropertyChanged += new PropertyChangedEventHandler(OnRootPropertyChanged));
            }

            TypeDescriptor.AddProvider(new RootModelTypeDescriptionProvider(args.Instance), args.Instance); 

        } 
 
        static void OnRootPropertyChanged(object sender, PropertyChangedEventArgs e)
        { 
            ModelItem rootModel = sender as ModelItem;
            Fx.Assert(rootModel != null, "sender item could not be null");
            ModelProperty changedProperty = rootModel.Properties[e.PropertyName];
            if (changedProperty == null) 
            {
                return; 
            } 

            object changedPropertyValue = changedProperty.ComputedValue; 
            if (changedPropertyValue == null)
            {
                return;
            } 

            IDebuggableWorkflowTree root = rootModel.GetCurrentValue() as IDebuggableWorkflowTree; 
            Fx.Assert(root != null, "root must be a IDebuggableWorkflowTree"); 
            if (root.GetWorkflowRoot() == changedPropertyValue)
            { 
                VisualBasicSettings settings = VisualBasic.GetSettings(root);
                VisualBasic.SetSettings(changedPropertyValue, settings);
            }
        } 
    }
 
 

    class RootModelTypeDescriptionProvider : TypeDescriptionProvider 
    {
        public RootModelTypeDescriptionProvider(object instance)
            : base(TypeDescriptor.GetProvider(instance))
        { 
        }
 
        public override ICustomTypeDescriptor GetTypeDescriptor(Type objectType, object instance) 
        {
            ICustomTypeDescriptor defaultDescriptor = base.GetTypeDescriptor(objectType, instance); 
            return new RootModelTypeDescriptor(defaultDescriptor, instance);
        }
    }
 
    class RootModelTypeDescriptor : CustomTypeDescriptor
    { 
        object root; 
        NamespaceListPropertyDescriptor importDescriptor;
 
        public RootModelTypeDescriptor(ICustomTypeDescriptor parent, object root)
            : base(parent)
        {
            this.root = root; 
        }
 
        PropertyDescriptor ImportDescriptor 
        {
            get 
            {
                if (this.importDescriptor == null)
                {
                    this.importDescriptor = new NamespaceListPropertyDescriptor(this.root); 
                }
 
                return this.importDescriptor; 
            }
        } 

        public override PropertyDescriptorCollection GetProperties()
        {
            return GetProperties(null); 
        }
 
        public override PropertyDescriptorCollection GetProperties(Attribute[] attributes) 
        {
            return new PropertyDescriptorCollection(base.GetProperties(attributes).Cast() 
                .Union(new PropertyDescriptor[] { this.ImportDescriptor }).ToArray());
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

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