Add server-side expand and collapse to TreeGrid (#9021)

* Add server-side expand and collapse to TreeGrid

* Add javadocs

* Fix variable naming in TreeGridHugeTreeTest

* Fix review comments

* Merge remote-tracking branch 'github/master' into 8759-server-expand

* Clear pending expands when all data is dropped

* Add documentation

2 files changed, 50 insertions, 1 deletions

diff --git a/shared/src/main/java/com/vaadin/shared/ui/treegrid/NodeCollapseRpc.java b/shared/src/main/java/com/vaadin/shared/ui/treegrid/NodeCollapseRpc.java
index 1b16203648..f0748a9b88 100644
--- a/shared/src/main/java/com/vaadin/shared/ui/treegrid/NodeCollapseRpc.java
+++ b/shared/src/main/java/com/vaadin/shared/ui/treegrid/NodeCollapseRpc.java
@@ -36,6 +36,10 @@ public interface NodeCollapseRpc extends ServerRpc {
      *            index where the row is in grid (all rows)
      * @param collapse
      *            {@code true} to collapse, {@code false} to expand
+     * @param userOriginated
+     *            {@code true} if this RPC was triggered by a user interaction,
+     *            {@code false} otherwise
      */
-    void setNodeCollapsed(String rowKey, int rowIndex, boolean collapse);
+    void setNodeCollapsed(String rowKey, int rowIndex, boolean collapse,
+            boolean userOriginated);
 }
diff --git a/shared/src/main/java/com/vaadin/shared/ui/treegrid/TreeGridClientRpc.java b/shared/src/main/java/com/vaadin/shared/ui/treegrid/TreeGridClientRpc.java
new file mode 100644
index 0000000000..a07a2d4885
--- /dev/null
+++ b/shared/src/main/java/com/vaadin/shared/ui/treegrid/TreeGridClientRpc.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2000-2016 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.treegrid;
+
+import com.vaadin.shared.communication.ClientRpc;
+
+/**
+ * Server-to-client RPC interface for the TreeGrid component.
+ *
+ * @since 8.1
+ * @author Vaadin Ltd
+ */
+public interface TreeGridClientRpc extends ClientRpc {
+
+    /**
+     * Inform the client that an item with the given key has been expanded by
+     * the server.
+     *
+     * @param key
+     *            the communication key of the expanded item
+     */
+    public void setExpanded(String key);
+
+    /**
+     * Inform the client that an item with the given key has been collapsed by
+     * the server.
+     *
+     * @param key
+     *            the communication key of the collapsed item
+     */
+    public void setCollapsed(String key);
+}