core changes required for UX Analytics plugin

Docstring, remove unused imports

re-add imports which were necessary at compile time

Author: daykin

app/display/representation/src/main/java/org/csstudio/display/builder/representation/ToolkitListener.java

@@ -45,6 +45,11 @@ public interface ToolkitListener
      */
     default public void handleWrite(Widget widget, Object value) {};
 
+    /**
+     * A method was called from the UI that other listeners might be interested in.
+     * @param user_args Zero or more objects relevant to what was called.
+     *      Case-specific Implementations should expect and check these.
+     */
     default public void handleMethodCalled(Object... user_args) {};
 
 }

app/display/runtime/src/main/java/org/csstudio/display/builder/runtime/app/DisplayRuntimeInstance.java

@@ -11,6 +11,7 @@
 
 
 import java.awt.geom.Rectangle2D;
+import java.util.ArrayList;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.Callable;
@@ -286,9 +287,12 @@ public DisplayInfo getDisplayInfo()
      */
     public void loadDisplayFile(final DisplayInfo info)
     {
+        DisplayInfo old_info = display_info.orElse(null);
         // If already executing another display, shut it down
         disposeModel();
 
+        ArrayList<DisplayInfo> dst_src = new ArrayList<>();
+
         // Set input ASAP so that other requests to open this
         // resource will find this instance and not start
         // another instance
@@ -324,7 +328,9 @@ public void loadDisplayFile(final DisplayInfo info)
                 {
                     representation.awaitRepresentation(30, TimeUnit.SECONDS);
                     representation_init.run();
-                    representation.fireMethodCall(info, applicationThreadStackTrace);
+                    dst_src.add(info);
+                    dst_src.add(old_info);
+                    representation.fireMethodCall(dst_src, applicationThreadStackTrace);
                     logger.log(Level.FINE, "Done with representing model of " + info.getPath());
                 }
                 catch (TimeoutException | InterruptedException ex)