Core - IAudioHandler now implements IDisposable

IAudioHandler.Dispose is called when the ChromiumWebBrowser instance is being Disposed.

This is a breaking change.

Resolves #3598

Author: amaitland

CefSharp.OffScreen/ChromiumWebBrowser.cs

@@ -275,7 +275,7 @@ protected virtual void Dispose(bool disposing)
 
                 // Release reference to handlers, except LifeSpanHandler which is done after Disposing
                 // ManagedCefBrowserAdapter otherwise the ILifeSpanHandler.DoClose will not be invoked.
-                this.SetHandlersToNullExceptLifeSpan();
+                FreeHandlersExceptLifeSpan();
 
                 browser = null;
 

CefSharp.WinForms/ChromiumWebBrowser.cs

@@ -407,7 +407,7 @@ private void InternalDispose(bool disposing)
 
                 // Release reference to handlers, except LifeSpanHandler which is done after Disposing
                 // ManagedCefBrowserAdapter otherwise the ILifeSpanHandler.DoClose will not be invoked.
-                this.SetHandlersToNullExceptLifeSpan();
+                FreeHandlersExceptLifeSpan();
 
                 browser = null;
 

CefSharp.Wpf/ChromiumWebBrowser.cs

@@ -637,7 +637,7 @@ private void InternalDispose(bool disposing)
 
                 // Release reference to handlers, except LifeSpanHandler which is done after Disposing
                 // ManagedCefBrowserAdapter otherwise the ILifeSpanHandler.DoClose will not be invoked.
-                this.SetHandlersToNullExceptLifeSpan();
+                this.FreeHandlersExceptLifeSpan();
 
                 browser = null;
 

CefSharp/Handler/AudioHandler.cs

@@ -13,6 +13,17 @@ namespace CefSharp.Handler
     /// </summary>
     public class AudioHandler : IAudioHandler
     {
+        private bool isDisposed;
+
+        /// <summary>
+        /// Gets a value indicating this <see cref="AudioHandler"/> instance
+        /// has been disposed.
+        /// </summary>
+        public bool IsDisposed
+        {
+            get { return isDisposed; }
+        }
+
         /// <inheritdoc/>
         bool IAudioHandler.GetAudioParameters(IWebBrowser chromiumWebBrowser, IBrowser browser, ref AudioParameters parameters)
         {
@@ -117,5 +128,21 @@ protected virtual void OnAudioStreamError(IWebBrowser chromiumWebBrowser, IBrows
         {
 
         }
+
+        /// <summary>
+        /// Releases unmanaged and managed resources
+        /// </summary>
+        /// <param name="disposing"><see langword="true" /> to release both managed and unmanaged resources; <see langword="false" /> to release only unmanaged resources.</param>
+        protected virtual void Dispose(bool disposing)
+        {
+            isDisposed = true;
+        }
+
+        /// <inheritdoc />
+        public void Dispose()
+        {
+            Dispose(disposing: true);
+            GC.SuppressFinalize(this);
+        }
     }
 }

CefSharp/Handler/IAudioHandler.cs

@@ -11,7 +11,7 @@ namespace CefSharp
     /// Implement this interface to handle audio events
     /// All methods will be called on the CEF UI thread
     /// </summary>
-    public interface IAudioHandler
+    public interface IAudioHandler : IDisposable
     {
         /// <summary>
         /// Called on the CEF UI thread to allow configuration of audio stream parameters.

CefSharp/Internals/Partial/ChromiumWebBrowser.Partial.cs

@@ -326,8 +326,13 @@ public Task<LoadUrlAsyncResponse> LoadUrlAsync(string url = null, Synchronizatio
 
         partial void OnAfterBrowserCreated(IBrowser browser);
 
-        private void SetHandlersToNullExceptLifeSpan()
+        /// <summary>
+        /// Sets the handler references to null.
+        /// Where required also calls Dispose().
+        /// </summary>
+        private void FreeHandlersExceptLifeSpan()
         {
+            AudioHandler?.Dispose();
             AudioHandler = null;
             DialogHandler = null;
             FindHandler = null;