Github user andruhon commented on a diff in the pull request:
https://github.com/apache/wicket/pull/256#discussion_r161936292
--- Diff:
wicket-extensions/src/main/java/org/apache/wicket/extensions/ajax/markup/html/AjaxFileUploadBehavior.java
---
@@ -0,0 +1,156 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.wicket.extensions.ajax.markup.html;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.fileupload.FileItem;
+import org.apache.commons.fileupload.FileUploadException;
+import org.apache.wicket.Component;
+import org.apache.wicket.ajax.AjaxEventBehavior;
+import org.apache.wicket.ajax.AjaxRequestTarget;
+import org.apache.wicket.ajax.attributes.AjaxRequestAttributes;
+import org.apache.wicket.ajax.attributes.AjaxRequestAttributes.Method;
+import org.apache.wicket.markup.head.IHeaderResponse;
+import org.apache.wicket.markup.head.JavaScriptHeaderItem;
+import org.apache.wicket.markup.head.OnDomReadyHeaderItem;
+import org.apache.wicket.markup.html.form.upload.FileUpload;
+import org.apache.wicket.protocol.http.servlet.MultipartServletWebRequest;
+import org.apache.wicket.protocol.http.servlet.ServletWebRequest;
+import org.apache.wicket.request.resource.PackageResourceReference;
+import org.apache.wicket.request.resource.ResourceReference;
+import org.apache.wicket.util.lang.Args;
+import org.apache.wicket.util.lang.Bytes;
+
+/**
+ * Uploads files from a drop event.
+ *
+ * @author svenmeier
+ */
+public class AjaxFileUploadBehavior extends AjaxEventBehavior
--- End diff --
I think the name of this particular class should somehow point that this
one handles drop event, because we might need to ajax upload with some other
cause event (such as `change` of file select field). So most of functionality
can go into some superclass, probably with `AjaxFileUploadBehavior` name and
two subclasses this drag-n-drop one and another one for file input change.
---
