ViewUtilities.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / cdf / src / NetFx40 / Tools / System.Activities.Presentation / System / Activities / Presentation / View / ViewUtilities.cs / 1407647 / ViewUtilities.cs
                        
                        
                            //---------------------------------------------------------------- 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//---------------------------------------------------------------

namespace System.Activities.Presentation.View 
{
    using System.Activities.Presentation.Model; 
    using System.Activities.Presentation.Services; 

    static class ViewUtilities 
    {
        const string ExpandViewStateKey = "IsExpanded";
        internal static bool DoesParentAlwaysExpandChildren(ModelItem modelItem, EditingContext context)
        { 
            return IsParentOfType(modelItem, typeof(IExpandChild), context);
        } 
 
        internal static bool DoesParentAlwaysCollapseChildren(ModelItem modelItem, EditingContext context)
        { 
            bool parentAlwaysCollapsesChild = false;
            Type parentDesignerType = GetParentDesignerType(modelItem, context);
            if (typeof(WorkflowViewElement).IsAssignableFrom(parentDesignerType))
            { 
                ActivityDesignerOptionsAttribute options = WorkflowViewService.GetAttribute(parentDesignerType);
                parentAlwaysCollapsesChild = (options != null && options.AlwaysCollapseChildren); 
            } 
            return parentAlwaysCollapsesChild;
        } 

        // Determines whether a particular ModelItem's view will be visible for a given breadcrumb root.
        //It depends on whether the intermediate designers are expanded or collapsed.
        internal static bool IsViewVisible(ModelItem child, ModelItem root, EditingContext context) 
        {
            ModelItem parent = child; 
            while (parent != null && !object.Equals(parent, root)) 
            {
                parent = GetParentModelItemWithView(parent, context, false); 
                if (!IsViewExpanded(parent, context))
                {
                    break;
                } 
            }
            return object.Equals(parent, root); 
        } 

 
        // Get the first parent ModelItem that has a view
        internal static ModelItem GetParentModelItemWithView(ModelItem modelItem, EditingContext context, bool allowDrillIn)
        {
            if (modelItem == null) 
            {
                return null; 
            } 
            ModelItem parent = modelItem.Parent;
            WorkflowViewService viewService = GetViewService(context); 
            while (parent != null)
            {
                ActivityDesignerOptionsAttribute options = WorkflowViewService.GetAttribute(parent.ItemType);
                Type viewType = viewService.GetDesignerType(parent.ItemType); 
                if (typeof(WorkflowViewElement).IsAssignableFrom(viewType) && (!allowDrillIn || options == null || options.AllowDrillIn))
                { 
                    break; 
                }
                parent = parent.Parent; 
            }
            return parent;
        }
 
        // Determine whether the view of a ModelItem is expanded without querying the view itself - the view may have not been constructed.
        internal static bool IsViewExpanded(ModelItem modelItem, EditingContext context) 
        { 
            if (modelItem == null)
            { 
                return false;
            }

            bool isDesignerExpanded = true; 
            bool isDesignerPinned = false;
            object isExpandedViewState = GetViewStateService(context).RetrieveViewState(modelItem, ExpandViewStateKey); 
            object isPinnedViewState = GetViewStateService(context).RetrieveViewState(modelItem, WorkflowViewElement.PinnedViewStateKey); 
            if (isExpandedViewState != null)
            { 
                isDesignerExpanded = (bool)isExpandedViewState;
            }
            if (isPinnedViewState != null)
            { 
                isDesignerPinned = (bool)isPinnedViewState;
            } 
 
            DesignerView designerView = context.Services.GetService();
 
            return ShouldShowExpanded(IsBreadcrumbRoot(modelItem, context), DoesParentAlwaysExpandChildren(modelItem, context),
                DoesParentAlwaysCollapseChildren(modelItem, context), isDesignerExpanded, designerView.ShouldExpandAll, designerView.ShouldCollapseAll, isDesignerPinned);
        }
 
        internal static bool IsBreadcrumbRoot(ModelItem modelItem, EditingContext context)
        { 
            DesignerView designerView = context.Services.GetService(); 
            return modelItem != null && modelItem.View != null && modelItem.View.Equals(designerView.RootDesigner);
        } 

        internal static bool ShouldShowExpanded(
            bool isRootDesigner,
            bool parentAlwaysExpandChildren, 
            bool parentAlwaysCollapseChildren,
            bool expandState, 
            bool expandAll, 
            bool collapseAll,
            bool pinState) 
        {
            //ShowExpanded based on ExpandAll, CollapseAll, PinState, ExpandState
            bool showExpanded;
            if (pinState) 
            {
                showExpanded = expandState; 
            } 
            else
            { 
                showExpanded = !collapseAll && (expandAll || expandState);
            }
            //return value based on the position of the element in the workflow tree.
            return (isRootDesigner || parentAlwaysExpandChildren || (!parentAlwaysCollapseChildren && showExpanded)); 
        }
 
        static WorkflowViewService GetViewService(EditingContext context) 
        {
            return context.Services.GetService() as WorkflowViewService; 
        }

        static ViewStateService GetViewStateService(EditingContext context)
        { 
            return context.Services.GetService();
        } 
 
        //Checks to see if the immediate parent WorkflowViewElement is of type "parentType".
        static bool IsParentOfType(ModelItem modelItem, Type parentType, EditingContext context) 
        {
            Type parentDesignerType = GetParentDesignerType(modelItem, context);
            return parentType.IsAssignableFrom(parentDesignerType);
        } 

        static Type GetParentDesignerType(ModelItem modelItem, EditingContext context) 
        { 
            ModelItem parent = GetParentModelItemWithView(modelItem, context, false);
            if (parent != null) 
            {
                return GetViewService(context).GetDesignerType(parent.ItemType);
            }
            return null; 
        }
    } 
} 

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

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