Added a "plug-in can do" callback to the VSTCallbackHandler interface

modules/juce_audio_plugin_client/VST/juce_VSTCallbackHandler.h

@@ -36,6 +36,18 @@ struct VSTCallbackHandler
 {
     virtual ~VSTCallbackHandler() {}
 
+    /** This is called by the VST plug-in wrapper when it receives unhandled
+        plug-in "can do" calls from the host.
+    */
+    virtual pointer_sized_int handleVstPluginCanDo (int32 index,
+                                                    pointer_sized_int value,
+                                                    void* ptr,
+                                                    float opt)
+    {
+        ignoreUnused (index, value, ptr, opt);
+        return 0;
+    }
+
     /** This is called by the VST plug-in wrapper when it receives unhandled
         vendor specific calls from the host.
     */

modules/juce_audio_plugin_client/VST/juce_VST_Wrapper.cpp

@@ -2037,6 +2037,9 @@ private:
         if (matches ("hasCockosExtensions"))
             return (int32) 0xbeef0000;
 
+        if (auto callbackHandler = dynamic_cast<VSTCallbackHandler*> (processor))
+            return callbackHandler->handleVstPluginCanDo (args.index, args.value, args.ptr, args.opt);
+
         return 0;
     }