Reduce number of companion updates

Opening and closing a mutator or clicking a block would result in the
blocks code being resent to the companion because any workspace event
would force a YAIL update. This change adds a isUi method to check
whether a Blockly event is a UI event, which doesn't change the
semantics of the program, and ignores such events for the purpose of
updating the companion.

Change-Id: Id80d1d094e585cc7182fe3987f8e0adc2b45b872

appinventor/appengine/src/com/google/appinventor/client/editor/youngandroid/YaBlocksEditor.java

@@ -296,7 +296,9 @@ public final class YaBlocksEditor extends FileEditor
     if (!EventHelper.isTransient(event)) {
       Ode.getInstance().getEditorManager().scheduleAutoSave(this);
     }
-    sendComponentData();
+    if (!EventHelper.isUi(event)) {
+      sendComponentData();
+    }
   }
 
   @Override

appinventor/appengine/src/com/google/appinventor/client/editor/youngandroid/events/EventHelper.java

@@ -13,7 +13,7 @@ public final class EventHelper {
   }
 
   /**
-   * Determine whether an event from the native JavaScript (e.g., Blockly).
+   * Determine whether an event from the native JavaScript (e.g., Blockly) is transient.
    *
    * @param event Native JavaScript event
    * @return true if the event can be determined to be transient, otherwise false.
@@ -33,4 +33,14 @@ public final class EventHelper {
     }
     return false;
   }-*/;
+
+  /**
+   * Determine whether an event from the native JavaScript (e.g., Blockly) is a UI event.
+   *
+   * @param event Native JavaScript event
+   * @return true if the event can be determined to be user interface event, otherwise false.
+   */
+  public static native boolean isUi(JavaScriptObject event)/*-{
+    return event && event.type === 'ui';
+  }-*/;
 }