Fix built in plugins and some UI issues

src/DesktopMagicPluginAPI/Plugin.cs

@@ -11,7 +11,13 @@ namespace DesktopMagic.Api;
 /// </summary>
 public abstract class Plugin
 {
-    private IPluginData application = null;
+    [Setting("horizontalAlignment", "Horizontal Alignment", -999)]
+    internal ComboBox horizontalAlignment = new ComboBox("Center", "Left", "Right");
+
+    [Setting("verticalAlignment", "Vertical Alignment", -998)]
+    internal ComboBox verticalAlignment = new ComboBox("Center", "Top", "Bottom");
+
+    private IPluginData application = null!;
 
     /// <summary>
     /// Informations about the main application.

src/DesktopMagicPluginAPI/Settings/ComboBox.cs

@@ -1,5 +1,4 @@
 using System.Collections.ObjectModel;
-using System.Text.Json;
 
 namespace DesktopMagic.Api.Settings;
 
@@ -8,7 +7,7 @@ namespace DesktopMagic.Api.Settings;
 /// </summary>
 public class ComboBox : Setting
 {
-    private string _value;
+    private string _value = string.Empty;
 
     /// <summary>
     /// Gets the collection used to generate the content of the <see cref="ComboBox"/>.
@@ -38,6 +37,8 @@ public class ComboBox : Setting
     /// <param name="items"></param>
     public ComboBox(params string[] items)
     {
+        Value = items[0];
+
         foreach (string item in items)
         {
             Items.Add(item);
@@ -46,7 +47,7 @@ public class ComboBox : Setting
 
     internal override string GetJsonValue()
     {
-        return JsonSerializer.Serialize(new { Value, Items });
+        return Value;
     }
 
     internal override void SetJsonValue(string value)
@@ -56,12 +57,6 @@ public class ComboBox : Setting
             return;
         }
 
-        JsonElement json = JsonSerializer.Deserialize<JsonElement>(value);
-        Items.Clear();
-        foreach (JsonElement item in json.GetProperty(nameof(Items)).EnumerateArray())
-        {
-            Items.Add(item.GetString() ?? string.Empty);
-        }
-        Value = json.GetProperty(nameof(Value)).GetString() ?? string.Empty;
+        Value = value;
     }
 }

src/DesktopMagicPluginAPI/Settings/SettingAttribute.cs

@@ -5,13 +5,13 @@ namespace DesktopMagic.Api.Settings;
 /// <summary>
 /// Marks a Property as element.
 /// </summary>
-[AttributeUsage(AttributeTargets.Field)]
+[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
 public class SettingAttribute : Attribute
 {
     /// <summary>
     /// The name of the element.
     /// </summary>
-    public string Name { get; set; }
+    public string Name { get; set; } = string.Empty;
 
     /// <summary>
     /// The order index of the element.