mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/ExpandButtonVisibilityConverter.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4
   5 namespace System.Activities.Presentation
   6 {
   7     using System.Diagnostics;
   8     using System.Globalization;
   9     using System.Windows.Data;
  10     using System.Activities.Presentation.Model;
  11     using System.Activities.Presentation.Internal.PropertyEditing.Model;
  12     using System.Windows;
  13     using System.Activities.Presentation.View;
  14     using System.Runtime;
  15
  16     internal class ExpandButtonVisibilityConverter : IMultiValueConverter
  17     {
  18
  19         public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
  20         {
  21             bool isRootDesigner = true;
  22             if (values[0] is bool)
  23             {
  24                 isRootDesigner = (bool)values[0];
  25             }
  26             ModelItem modelItem = values[1] as ModelItem;
  27             WorkflowViewElement viewElement = values[2] as WorkflowViewElement;
  28             Fx.Assert(viewElement != null, "TemplatedParent should be of type WorkflowViewElement");
  29             return GetExpandCollapseButtonVisibility(viewElement);
  30         }
  31
  32         public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
  33         {
  34             throw FxTrace.Exception.AsError(new NotSupportedException());
  35         }
  36
  37         public static Visibility GetExpandCollapseButtonVisibility(WorkflowViewElement viewElement)
  38         {
  39             ActivityDesigner designer = viewElement as ActivityDesigner;
  40             bool hasDelegates = (designer != null) && designer.HasActivityDelegates;
  41
  42             Visibility visibility = Visibility.Visible;
  43             if (viewElement == null || viewElement.IsRootDesigner || viewElement.DoesParentAlwaysExpandChild() ||
  44                 viewElement.DoesParentAlwaysCollapseChildren() || (viewElement.Content == null && !hasDelegates) ||
  45                 !viewElement.Collapsible || !(viewElement is ActivityDesigner))
  46             {
  47                 visibility = Visibility.Collapsed;
  48             }
  49             return visibility;
  50         }
  51
  52     }
  53 }