- Add ComboBox element to the API

src/DesktopMagicPluginAPI/DesktopMagicPluginAPI.md

@@ -10,6 +10,10 @@
 - [CheckBox](#T-DesktopMagicPluginAPI-Inputs-CheckBox 'DesktopMagicPluginAPI.Inputs.CheckBox')
   - [#ctor(value)](#M-DesktopMagicPluginAPI-Inputs-CheckBox-#ctor-System-Boolean- 'DesktopMagicPluginAPI.Inputs.CheckBox.#ctor(System.Boolean)')
   - [Value](#P-DesktopMagicPluginAPI-Inputs-CheckBox-Value 'DesktopMagicPluginAPI.Inputs.CheckBox.Value')
+- [ComboBox](#T-DesktopMagicPluginAPI-Inputs-ComboBox 'DesktopMagicPluginAPI.Inputs.ComboBox')
+  - [#ctor(items)](#M-DesktopMagicPluginAPI-Inputs-ComboBox-#ctor-System-String[]- 'DesktopMagicPluginAPI.Inputs.ComboBox.#ctor(System.String[])')
+  - [Items](#P-DesktopMagicPluginAPI-Inputs-ComboBox-Items 'DesktopMagicPluginAPI.Inputs.ComboBox.Items')
+  - [Value](#P-DesktopMagicPluginAPI-Inputs-ComboBox-Value 'DesktopMagicPluginAPI.Inputs.ComboBox.Value')
 - [Element](#T-DesktopMagicPluginAPI-Inputs-Element 'DesktopMagicPluginAPI.Inputs.Element')
   - [ValueChanged()](#M-DesktopMagicPluginAPI-Inputs-Element-ValueChanged 'DesktopMagicPluginAPI.Inputs.Element.ValueChanged')
 - [ElementAttribute](#T-DesktopMagicPluginAPI-Inputs-ElementAttribute 'DesktopMagicPluginAPI.Inputs.ElementAttribute')
@@ -151,6 +155,48 @@ Initializes a new instance of the [CheckBox](#T-DesktopMagicPluginAPI-Inputs-Che
 
 Gets or set a value indicating whether the [CheckBox](#T-DesktopMagicPluginAPI-Inputs-CheckBox 'DesktopMagicPluginAPI.Inputs.CheckBox') is in the checked state.
 
+<a name='T-DesktopMagicPluginAPI-Inputs-ComboBox'></a>
+## ComboBox `type`
+
+##### Namespace
+
+DesktopMagicPluginAPI.Inputs
+
+##### Summary
+
+Represents a selection control with a drop-down list.
+
+<a name='M-DesktopMagicPluginAPI-Inputs-ComboBox-#ctor-System-String[]-'></a>
+### #ctor(items) `constructor`
+
+##### Summary
+
+Initializes a new instance of the [Label](#T-DesktopMagicPluginAPI-Inputs-Label 'DesktopMagicPluginAPI.Inputs.Label') class with the provided `items`.
+
+##### Parameters
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| items | [System.String[]](http://msdn.microsoft.com/query/dev14.query?appId=Dev14IDEF1&l=EN-US&k=k:System.String[] 'System.String[]') |  |
+
+<a name='P-DesktopMagicPluginAPI-Inputs-ComboBox-Items'></a>
+### Items `property`
+
+##### Summary
+
+Gets the collection used to generate the content of the [ComboBox](#T-DesktopMagicPluginAPI-Inputs-ComboBox 'DesktopMagicPluginAPI.Inputs.ComboBox').
+
+<a name='P-DesktopMagicPluginAPI-Inputs-ComboBox-Value'></a>
+### Value `property`
+
+##### Summary
+
+Gets the currently selected item associated with this [ComboBox](#T-DesktopMagicPluginAPI-Inputs-ComboBox 'DesktopMagicPluginAPI.Inputs.ComboBox').
+
+##### Remarks
+
+If you assign a value to this property, the displayed text in the user interface will not be changed.
+
 <a name='T-DesktopMagicPluginAPI-Inputs-Element'></a>
 ## Element `type`
 

src/DesktopMagicPluginAPI/DesktopMagicPluginAPI.xml

@@ -145,6 +145,28 @@
             </summary>
             <param name="value">A value indicating whether the <see cref="T:DesktopMagicPluginAPI.Inputs.CheckBox"/> is in the checked state.</param>
         </member>
+        <member name="T:DesktopMagicPluginAPI.Inputs.ComboBox">
+            <summary>
+            Represents a selection control with a drop-down list.
+            </summary>
+        </member>
+        <member name="P:DesktopMagicPluginAPI.Inputs.ComboBox.Items">
+            <summary>
+            Gets the collection used to generate the content of the <see cref="T:DesktopMagicPluginAPI.Inputs.ComboBox"/>.
+            </summary>
+        </member>
+        <member name="P:DesktopMagicPluginAPI.Inputs.ComboBox.Value">
+            <summary>
+            Gets the currently selected item associated with this <see cref="T:DesktopMagicPluginAPI.Inputs.ComboBox"/>.
+            </summary>
+            <remarks>If you assign a value to this property, the displayed text in the user interface will not be changed.</remarks>
+        </member>
+        <member name="M:DesktopMagicPluginAPI.Inputs.ComboBox.#ctor(System.String[])">
+            <summary>
+            Initializes a new instance of the <see cref="T:DesktopMagicPluginAPI.Inputs.Label"/> class with the provided <paramref name="items"/>.
+            </summary>
+            <param name="items"></param>
+        </member>
         <member name="T:DesktopMagicPluginAPI.Inputs.Element">
             <summary>
             The element base class.

src/DesktopMagicPluginAPI/Inputs/ComboBox.cs

@@ -0,0 +1,46 @@
+using System.Collections.ObjectModel;
+
+namespace DesktopMagicPluginAPI.Inputs
+{
+    /// <summary>
+    /// Represents a selection control with a drop-down list.
+    /// </summary>
+    public class ComboBox : Element
+    {
+        private string _value;
+
+        /// <summary>
+        /// Gets the collection used to generate the content of the <see cref="ComboBox"/>.
+        /// </summary>
+        public ObservableCollection<string> Items { get; } = new ObservableCollection<string>();
+
+        /// <summary>
+        /// Gets the currently selected item associated with this <see cref="ComboBox"/>.
+        /// </summary>
+        /// <remarks>If you assign a value to this property, the displayed text in the user interface will not be changed.</remarks>
+        public string Value
+        {
+            get => _value;
+            set
+            {
+                if (_value != value)
+                {
+                    _value = value;
+                    ValueChanged();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Label"/> class with the provided <paramref name="items"/>.
+        /// </summary>
+        /// <param name="items"></param>
+        public ComboBox(params string[] items)
+        {
+            foreach (string item in items)
+            {
+                Items.Add(item);
+            }
+        }
+    }
+}

src/DesktopMagicPluginAPI/Plugin.cs

@@ -19,17 +19,7 @@ namespace DesktopMagicPluginAPI
         public IPluginData Application
         {
             get => application;
-            set
-            {
-                if (application is null)
-                {
-                    application = value;
-                }
-                else
-                {
-                    throw new InvalidOperationException($"You cannot set the value of the {nameof(Application)} property");
-                }
-            }
+            set => application = application is null ? value : throw new InvalidOperationException($"You cannot set the value of the {nameof(Application)} property");
         }
 
         /// <summary>