Fix DragAndDropWrapper update after file upload (#19616)

After a file has been uploaded VDragAndDropWrapper tries to pull changes
from the server by calling
ApplicationConnection.sendPendingVariableChanges() which has no effect.

This change replaces the
ApplicationConnection.sendPendingVariableChanges() call with an RPC.

Change-Id: If8abc662d4761969e5aa8e6327bfd4bdd7f5e905

4 files changed, 73 insertions, 4 deletions

diff --git a/client/src/com/vaadin/client/ui/VDragAndDropWrapper.java b/client/src/com/vaadin/client/ui/VDragAndDropWrapper.java
index f3905f9e46..a4cdd6e70f 100644
--- a/client/src/com/vaadin/client/ui/VDragAndDropWrapper.java
+++ b/client/src/com/vaadin/client/ui/VDragAndDropWrapper.java
@@ -196,6 +196,9 @@ public class VDragAndDropWrapper extends VCustomComponent implements
     /** For internal use only. May be removed or replaced in the future. */
     public VAbstractDropHandler dropHandler;
 
+    /** For internal use only. May be removed or replaced in the future. */
+    public UploadHandler uploadHandler;
+
     private VDragEvent vaadinDragEvent;
 
     int filecounter = 0;
@@ -239,9 +242,9 @@ public class VDragAndDropWrapper extends VCustomComponent implements
         @Override
         public void onReadyStateChange(XMLHttpRequest xhr) {
             if (xhr.getReadyState() == XMLHttpRequest.DONE) {
-                // visit server for possible
-                // variable changes
-                client.sendPendingVariableChanges();
+                // #19616 Notify the upload handler that the request is complete
+                // and let it poll the server for changes.
+                uploadHandler.uploadDone();
                 uploading = false;
                 startNextUpload();
                 xhr.clearOnReadyStateChange();
@@ -727,4 +730,10 @@ public class VDragAndDropWrapper extends VCustomComponent implements
         return dragImageWidget;
     }
 
+    public interface UploadHandler {
+
+        public void uploadDone();
+
+    }
+
 }
diff --git a/client/src/com/vaadin/client/ui/draganddropwrapper/DragAndDropWrapperConnector.java b/client/src/com/vaadin/client/ui/draganddropwrapper/DragAndDropWrapperConnector.java
index f222721e24..7ea9596809 100644
--- a/client/src/com/vaadin/client/ui/draganddropwrapper/DragAndDropWrapperConnector.java
+++ b/client/src/com/vaadin/client/ui/draganddropwrapper/DragAndDropWrapperConnector.java
@@ -30,11 +30,18 @@ import com.vaadin.client.ui.VDragAndDropWrapper;
 import com.vaadin.client.ui.customcomponent.CustomComponentConnector;
 import com.vaadin.shared.ui.Connect;
 import com.vaadin.shared.ui.draganddropwrapper.DragAndDropWrapperConstants;
+import com.vaadin.shared.ui.draganddropwrapper.DragAndDropWrapperServerRpc;
 import com.vaadin.ui.DragAndDropWrapper;
 
 @Connect(DragAndDropWrapper.class)
 public class DragAndDropWrapperConnector extends CustomComponentConnector
-        implements Paintable {
+        implements Paintable, VDragAndDropWrapper.UploadHandler {
+
+    @Override
+    protected void init() {
+        super.init();
+        getWidget().uploadHandler = this;
+    }
 
     @Override
     public void updateFromUIDL(UIDL uidl, ApplicationConnection client) {
@@ -121,4 +128,11 @@ public class DragAndDropWrapperConnector extends CustomComponentConnector
     private static Logger getLogger() {
         return Logger.getLogger(DragAndDropWrapperConnector.class.getName());
     }
+
+    @Override
+    public void uploadDone() {
+        // #19616 RPC to poll the server for changes
+        getRpcProxy(DragAndDropWrapperServerRpc.class).poll();
+    }
+
 }
diff --git a/server/src/com/vaadin/ui/DragAndDropWrapper.java b/server/src/com/vaadin/ui/DragAndDropWrapper.java
index 90b3b56ef6..29179ddca7 100644
--- a/server/src/com/vaadin/ui/DragAndDropWrapper.java
+++ b/server/src/com/vaadin/ui/DragAndDropWrapper.java
@@ -40,6 +40,7 @@ import com.vaadin.shared.MouseEventDetails;
 import com.vaadin.shared.ui.dd.HorizontalDropLocation;
 import com.vaadin.shared.ui.dd.VerticalDropLocation;
 import com.vaadin.shared.ui.draganddropwrapper.DragAndDropWrapperConstants;
+import com.vaadin.shared.ui.draganddropwrapper.DragAndDropWrapperServerRpc;
 import com.vaadin.ui.declarative.DesignContext;
 
 @SuppressWarnings("serial")
@@ -111,6 +112,14 @@ public class DragAndDropWrapper extends CustomComponent implements DropTarget,
 
     }
 
+    private final DragAndDropWrapperServerRpc rpc = new DragAndDropWrapperServerRpc() {
+
+        @Override
+        public void poll() {
+            // #19616 RPC to poll the server for changes
+        }
+    };
+
     private Map<String, ProxyReceiver> receivers = new HashMap<String, ProxyReceiver>();
 
     public class WrapperTargetDetails extends TargetDetailsImpl {
@@ -197,6 +206,7 @@ public class DragAndDropWrapper extends CustomComponent implements DropTarget,
     @Deprecated
     public DragAndDropWrapper() {
         super();
+        registerRpc(rpc);
     }
 
     /**
diff --git a/shared/src/com/vaadin/shared/ui/draganddropwrapper/DragAndDropWrapperServerRpc.java b/shared/src/com/vaadin/shared/ui/draganddropwrapper/DragAndDropWrapperServerRpc.java
new file mode 100644
index 0000000000..d5100aba3f
--- /dev/null
+++ b/shared/src/com/vaadin/shared/ui/draganddropwrapper/DragAndDropWrapperServerRpc.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2000-2014 Vaadin Ltd.
+ * 
+ * Licensed 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 com.vaadin.shared.ui.draganddropwrapper;
+
+import com.vaadin.shared.communication.ServerRpc;
+
+/**
+ * RPC interface for calls from client to server.
+ * 
+ * @since
+ * @author Vaadin Ltd
+ */
+public interface DragAndDropWrapperServerRpc extends ServerRpc {
+
+    /**
+     * Called to poll the server to see if any changes have been made e.g. when
+     * the upload is complete.
+     * 
+     * @since
+     */
+    public void poll();
+
+}