Theme aware plugin (#4499)

* Migrate theme manager to infrastructure and added it as input to public API instance

* Working event-delegate for PublicAPIInstance

* Theme aware UWP applications

* Theme aware program plugin

* Update query icon on theme change

* Theme aware calculator plugin

* Fix issue with query running before theme change

* Theme based changes in ImageLoader

* Removed ErrorIcon direct references and added references from ImageLoader

* Nit fixes

* Removed unnecessary TODO in UWP.cs

* Added preference to theme based icons

* Added IDisposable interfaces to unsubscribe events

src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Main.cs

@@ -1,4 +1,6 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
+using System.Drawing;
 using System.Runtime.InteropServices;
 using System.Text.RegularExpressions;
 using System.Threading;
@@ -8,7 +10,7 @@ using Wox.Plugin;
 
 namespace Microsoft.Plugin.Calculator
 {
-    public class Main : IPlugin, IPluginI18n
+    public class Main : IPlugin, IPluginI18n, IDisposable
     {
         private static readonly Regex RegValidExpressChar = new Regex(
                         @"^(" +
@@ -22,6 +24,8 @@ namespace Microsoft.Plugin.Calculator
         private static readonly Regex RegBrackets = new Regex(@"[\(\)\[\]]", RegexOptions.Compiled);
         private static readonly Engine MagesEngine;
         private PluginInitContext Context { get; set; }
+        private string IconPath { get; set; }
+        private bool _disposed = false;
 
         static Main()
         {
@@ -58,7 +62,7 @@ namespace Microsoft.Plugin.Calculator
                         new Result
                         {
                             Title = result.ToString(),
-                            IcoPath = "Images/calculator.png",
+                            IcoPath = IconPath,
                             Score = 300,
                             SubTitle = Context.API.GetTranslation("wox_plugin_calculator_copy_number_to_clipboard"),
                             Action = c =>
@@ -115,6 +119,26 @@ namespace Microsoft.Plugin.Calculator
         public void Init(PluginInitContext context)
         {
             Context = context;
+            Context.API.ThemeChanged += OnThemeChanged;
+            UpdateIconPath(Context.API.GetCurrentTheme());
+        }
+
+        // Todo : Update with theme based IconPath
+        private void UpdateIconPath(Theme theme)
+        {
+            if (theme == Theme.Light || theme == Theme.HighContrastWhite)
+            {
+                IconPath = "Images/calculator_light.png";
+            }
+            else
+            {
+                IconPath = "Images/calculator_dark.png";
+            }
+        }
+
+        private void OnThemeChanged(Theme _, Theme newTheme)
+        {
+            UpdateIconPath(newTheme);
         }
 
         public string GetTranslatedPluginTitle()
@@ -126,5 +150,23 @@ namespace Microsoft.Plugin.Calculator
         {
             return Context.API.GetTranslation("wox_plugin_calculator_plugin_description");
         }
+
+        public void Dispose()
+        {
+            Dispose(disposing: true);
+            GC.SuppressFinalize(this);
+        }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!_disposed)
+            {
+                if (disposing)
+                {
+                    Context.API.ThemeChanged -= OnThemeChanged;
+                    _disposed = true;
+                }
+            }
+        }
     }
 }

src/modules/launcher/Plugins/Microsoft.Plugin.Calculator/Microsoft.Plugin.Calculator.csproj

@@ -49,7 +49,7 @@
   </ItemGroup>
   
   <ItemGroup>
-    <None Include="Images\calculator.png">
+    <None Include="Images\calculator_light.png">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
   </ItemGroup>
@@ -107,5 +107,11 @@
     <PackageReference Include="Mages" Version="1.6.0" />
     <PackageReference Include="System.Runtime" Version="4.3.1" />
   </ItemGroup>
+  
+  <ItemGroup>
+    <None Update="Images\calculator_dark.png">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
 
 </Project>