Display conditions - Some work on inputs supporting multiple types

src/Artemis.UI.Shared/DataModelVisualization/DataModelInputViewModel.cs

@@ -1,9 +1,12 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Data;
 using System.Windows.Input;
 using Artemis.Core.Plugins.Abstract.DataModels.Attributes;
+using Artemis.UI.Shared.Exceptions;
 using Stylet;
 
 namespace Artemis.UI.Shared.DataModelVisualization
@@ -38,11 +41,29 @@ namespace Artemis.UI.Shared.DataModelVisualization
         }
 
         /// <inheritdoc />
-        public sealed  override void Cancel()
+        public sealed override void Cancel()
         {
             OnCancel();
             UpdateCallback(InputValue, false);
         }
+
+        /// <summary>
+        ///     May be called to convert an object to one of the types defined in CompatibleConversionTypes
+        /// </summary>
+        /// <param name="source">The object to convert, will always be of a type contained in CompatibleConversionTypes</param>
+        /// <returns>The converted value</returns>
+        protected virtual T ConvertToSupportedType(object source)
+        {
+            return default;
+        }
+
+        internal override object InternalConvertToSupportedType(object source)
+        {
+            if (CompatibleConversionTypes != null && CompatibleConversionTypes.Contains(source.GetType()))
+                return ConvertToSupportedType(source);
+
+            throw new ArtemisSharedUIException($"Cannot convert source of type {source.GetType().Name} because the data model input view model does not support it.");
+        }
     }
 
     /// <summary>
@@ -58,6 +79,11 @@ namespace Artemis.UI.Shared.DataModelVisualization
 
         internal Action<object, bool> UpdateCallback { get; set; }
 
+        /// <summary>
+        ///     Gets the types this input view model can support through type conversion
+        /// </summary>
+        internal IReadOnlyCollection<Type> CompatibleConversionTypes { get; set; }
+
         public void AttachView(UIElement view)
         {
             if (View != null)
@@ -98,5 +124,7 @@ namespace Artemis.UI.Shared.DataModelVisualization
         protected virtual void OnCancel()
         {
         }
+
+        internal abstract object InternalConvertToSupportedType(object source);
     }
 }

src/Artemis.UI.Shared/DataModelVisualization/DataModelVisualizationRegistration.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using Artemis.Core;
 using Artemis.Core.Plugins.Models;
 using Artemis.UI.Shared.Services;
@@ -30,6 +31,8 @@ namespace Artemis.UI.Shared.DataModelVisualization
         public Type SupportedType { get; }
         public Type ViewModelType { get; }
 
+        public IReadOnlyCollection<Type> CompatibleConversionTypes { get; internal set; }
+
         internal void Unsubscribe()
         {
             if (PluginInfo != Constants.CorePluginInfo)

src/Artemis.UI.Shared/Services/DataModelVisualizationService.cs

@@ -64,7 +64,7 @@ namespace Artemis.UI.Shared.Services
             return _dataModelService.GetPluginExtendsDataModel(plugin);
         }
 
-        public DataModelVisualizationRegistration RegisterDataModelInput<T>(PluginInfo pluginInfo) where T : DataModelInputViewModel
+        public DataModelVisualizationRegistration RegisterDataModelInput<T>(PluginInfo pluginInfo, IReadOnlyCollection<Type> compatibleConversionTypes) where T : DataModelInputViewModel
         {
             var viewModelType = typeof(T);
             lock (_registeredDataModelEditors)
@@ -80,7 +80,14 @@ namespace Artemis.UI.Shared.Services
                 }
 
                 _kernel.Bind(viewModelType).ToSelf();
-                var registration = new DataModelVisualizationRegistration(this, RegistrationType.Input, pluginInfo, supportedType, viewModelType);
+
+                // Create the registration
+                var registration = new DataModelVisualizationRegistration(this, RegistrationType.Input, pluginInfo, supportedType, viewModelType)
+                {
+                    // Apply the compatible conversion types to the registration
+                    CompatibleConversionTypes = compatibleConversionTypes
+                };
+
                 _registeredDataModelEditors.Add(registration);
                 return registration;
             }
@@ -154,16 +161,7 @@ namespace Artemis.UI.Shared.Services
                 var match = _registeredDataModelEditors.FirstOrDefault(d => d.SupportedType == propertyType);
                 if (match != null)
                 {
-                    // The view models expecting value types shouldn't be given null, avoid that
-                    if (initialValue == null && propertyType.IsValueType)
-                        initialValue = Activator.CreateInstance(propertyType);
-
-                    var parameters = new IParameter[]
-                    {
-                        new ConstructorArgument("description", description),
-                        new ConstructorArgument("initialValue", initialValue)
-                    };
-                    var viewModel = (DataModelInputViewModel) _kernel.Get(match.ViewModelType, parameters);
+                    var viewModel = InstantiateDataModelInputViewModel(match, description, initialValue);
                     viewModel.UpdateCallback = updateCallback;
                     return viewModel;
                 }
@@ -171,6 +169,22 @@ namespace Artemis.UI.Shared.Services
                 return null;
             }
         }
+
+        private DataModelInputViewModel InstantiateDataModelInputViewModel(DataModelVisualizationRegistration registration, DataModelPropertyAttribute description, object initialValue)
+        {
+            // The view models expecting value types shouldn't be given null, avoid that
+            if (initialValue == null && registration.SupportedType.IsValueType)
+                initialValue = Activator.CreateInstance(registration.SupportedType);
+
+            var parameters = new IParameter[]
+            {
+                new ConstructorArgument("description", description),
+                new ConstructorArgument("initialValue", initialValue)
+            };
+            var viewModel = (DataModelInputViewModel) _kernel.Get(registration.ViewModelType, parameters);
+            viewModel.CompatibleConversionTypes = registration.CompatibleConversionTypes;
+            return viewModel;
+        }
     }
 
     public interface IDataModelVisualizationService : IArtemisSharedUIService
@@ -185,7 +199,7 @@ namespace Artemis.UI.Shared.Services
         /// <returns></returns>
         bool GetPluginExtendsDataModel(Plugin plugin);
 
-        DataModelVisualizationRegistration RegisterDataModelInput<T>(PluginInfo pluginInfo) where T : DataModelInputViewModel;
+        DataModelVisualizationRegistration RegisterDataModelInput<T>(PluginInfo pluginInfo, IReadOnlyCollection<Type> compatibleConversionTypes) where T : DataModelInputViewModel;
         DataModelVisualizationRegistration RegisterDataModelDisplay<T>(PluginInfo pluginInfo) where T : DataModelDisplayViewModel;
         void RemoveDataModelInput(DataModelVisualizationRegistration registration);
         void RemoveDataModelDisplay(DataModelVisualizationRegistration registration);