Merge pull request #99 from nigel-sampson/feature/triggers

Adds an interface for triggers. Resolves #20

src/BehaviorsSDKManaged/Microsoft.Xaml.Interactions/Core/DataTriggerBehavior.cs

@@ -12,18 +12,8 @@ namespace Microsoft.Xaml.Interactions.Core
     /// A behavior that performs actions when the bound data meets a specified condition.
     /// </summary>
     [ContentPropertyAttribute(Name = "Actions")]
-    public sealed class DataTriggerBehavior : Behavior
+    public sealed class DataTriggerBehavior : Trigger
     {
-        /// <summary> q
-        /// Identifies the <seealso cref="Actions"/> dependency property.
-        /// </summary>
-        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes")]
-        public static readonly DependencyProperty ActionsProperty = DependencyProperty.Register(
-            "Actions",
-            typeof(ActionCollection),
-            typeof(DataTriggerBehavior),
-            new PropertyMetadata(null));
-
         /// <summary>
         /// Identifies the <seealso cref="Binding"/> dependency property.
         /// </summary>
@@ -55,24 +45,6 @@ public sealed class DataTriggerBehavior : Behavior
             typeof(DataTriggerBehavior),
             new PropertyMetadata(null, new PropertyChangedCallback(DataTriggerBehavior.OnValueChanged)));
 
-        /// <summary>
-        /// Gets the collection of actions associated with the behavior. This is a dependency property.
-        /// </summary>
-        public ActionCollection Actions
-        {
-            get
-            {
-                ActionCollection actionCollection = (ActionCollection)this.GetValue(DataTriggerBehavior.ActionsProperty);
-                if (actionCollection == null)
-                {
-                    actionCollection = new ActionCollection();
-                    this.SetValue(DataTriggerBehavior.ActionsProperty, actionCollection);
-                }
-
-                return actionCollection;
-            }
-        }
-
         /// <summary>
         /// Gets or sets the bound object that the <see cref="DataTriggerBehavior"/> will listen to. This is a dependency property.
         /// </summary>

src/BehaviorsSDKManaged/Microsoft.Xaml.Interactions/Core/EventTriggerBehavior.cs

@@ -15,18 +15,8 @@ namespace Microsoft.Xaml.Interactions.Core
     /// A behavior that listens for a specified event on its source and executes its actions when that event is fired.
     /// </summary>
     [ContentPropertyAttribute(Name = "Actions")]
-    public sealed class EventTriggerBehavior : Behavior
+    public sealed class EventTriggerBehavior : Trigger
     {
-        /// <summary>
-        /// Identifies the <seealso cref="Actions"/> dependency property.
-        /// </summary>
-        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes")]
-        public static readonly DependencyProperty ActionsProperty = DependencyProperty.Register(
-            "Actions",
-            typeof(ActionCollection),
-            typeof(EventTriggerBehavior),
-            new PropertyMetadata(null));
-
         /// <summary>
         /// Identifies the <seealso cref="EventName"/> dependency property.
         /// </summary>
@@ -61,24 +51,6 @@ public EventTriggerBehavior()
         {
         }
 
-        /// <summary>
-        /// Gets the collection of actions associated with the behavior. This is a dependency property.
-        /// </summary>
-        public ActionCollection Actions
-        {
-            get
-            {
-                ActionCollection actionCollection = (ActionCollection)this.GetValue(EventTriggerBehavior.ActionsProperty);
-                if (actionCollection == null)
-                {
-                    actionCollection = new ActionCollection();
-                    this.SetValue(EventTriggerBehavior.ActionsProperty, actionCollection);
-                }
-
-                return actionCollection;
-            }
-        }
-
         /// <summary>
         /// Gets or sets the name of the event to listen for. This is a dependency property.
         /// </summary>

src/BehaviorsSDKManaged/Microsoft.Xaml.Interactivity/ITrigger.cs

@@ -0,0 +1,15 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+namespace Microsoft.Xaml.Interactivity
+{
+    /// <summary>
+    /// Interface implemented by all custom triggers.
+    /// </summary>
+    public interface ITrigger : IBehavior
+    {
+        /// <summary>
+        /// Gets the collection of actions associated with the behavior.
+        /// </summary>
+        ActionCollection Actions { get; }
+    }
+}

src/BehaviorsSDKManaged/Microsoft.Xaml.Interactivity/Microsoft.Xaml.Interactivity.csproj

@@ -140,9 +140,12 @@
     <Compile Include="IAction.cs" />
     <Compile Include="IBehavior.cs" />
     <Compile Include="Interaction.cs" />
+    <Compile Include="ITrigger.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="..\Version\Version.cs" />
     <Compile Include="ResourceHelper.cs" />
+    <Compile Include="Trigger.cs" />
+    <Compile Include="TriggerOfT.cs" />
     <Compile Include="TypeConstraintAttribute.cs" />
     <Compile Include="VisualStateUtilities.cs" />
     <EmbeddedResource Include="Properties\Microsoft.Xaml.Interactivity.rd.xml" />

src/BehaviorsSDKManaged/Microsoft.Xaml.Interactivity/Trigger.cs

@@ -0,0 +1,43 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using Windows.UI.Xaml;
+
+namespace Microsoft.Xaml.Interactivity
+{
+    /// <summary>
+    /// A base class for behaviors, implementing the basic plumbing of ITrigger
+    /// </summary>
+    /// <typeparam name="T">The object type to attach to</typeparam>
+    public abstract class Trigger : Behavior, ITrigger
+    {
+        /// <summary>
+        /// Identifies the <seealso cref="Actions"/> dependency property.
+        /// </summary>
+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2104:DoNotDeclareReadOnlyMutableReferenceTypes")]
+        public static readonly DependencyProperty ActionsProperty = DependencyProperty.Register(
+            "Actions",
+            typeof(ActionCollection),
+            typeof(Trigger),
+            new PropertyMetadata(null));
+
+        /// <summary>
+        /// Gets the collection of actions associated with the behavior. This is a dependency property.
+        /// </summary>
+        public ActionCollection Actions
+        {
+            get
+            {
+                ActionCollection actionCollection = (ActionCollection)this.GetValue(Trigger.ActionsProperty);
+                if (actionCollection == null)
+                {
+                    actionCollection = new ActionCollection();
+                    this.SetValue(Trigger.ActionsProperty, actionCollection);
+                }
+
+                return actionCollection;
+            }
+        }
+    }
+}

src/BehaviorsSDKManaged/Microsoft.Xaml.Interactivity/TriggerOfT.cs

@@ -0,0 +1,42 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using Windows.UI.Xaml;
+
+namespace Microsoft.Xaml.Interactivity
+{
+    /// <summary>
+    /// A base class for behaviors, implementing the basic plumbing of ITrigger
+    /// </summary>
+    public abstract class Trigger<T> : Trigger where T : DependencyObject
+    {
+        /// <summary>
+        /// Gets the object to which this behavior is attached.
+        /// </summary>
+        [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
+        public new T AssociatedObject
+        {
+            get { return base.AssociatedObject as T; }
+        }
+
+        /// <summary>
+        /// Called after the behavior is attached to the <see cref="Microsoft.Xaml.Interactivity.Behavior.AssociatedObject"/>.
+        /// </summary>
+        /// <remarks>
+        /// Override this to hook up functionality to the <see cref="Microsoft.Xaml.Interactivity.Behavior.AssociatedObject"/>
+        /// </remarks>
+        protected override void OnAttached()
+        {
+            base.OnAttached();
+
+            if (this.AssociatedObject == null)
+            {
+                string actualType = base.AssociatedObject.GetType().FullName;
+                string expectedType = typeof(T).FullName;
+                string message = string.Format(ResourceHelper.GetString("InvalidAssociatedObjectExceptionMessage"), actualType, expectedType);
+                throw new InvalidOperationException(message);
+            }
+        }
+    }
+}