Implement programmatic scrolling (#13327)

Further changes required for this, included in the same patch: 
- created GridClientRpc interface
- created test case UI for server-side controlled Grid programmatic
scrolling
- refactored getScrollPos logic into Escalator and moved
ScrollDestination enum to shared package

Change-Id: Ibf72a4f75831807d83fb5941597a6ce3fda08e17

2 files changed, 86 insertions, 0 deletions

diff --git a/shared/src/com/vaadin/shared/ui/grid/GridClientRpc.java b/shared/src/com/vaadin/shared/ui/grid/GridClientRpc.java
new file mode 100644
index 0000000000..00cc93d371
--- /dev/null
+++ b/shared/src/com/vaadin/shared/ui/grid/GridClientRpc.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2000-2013 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.grid;
+
+import com.vaadin.shared.communication.ClientRpc;
+
+/**
+ * Server-to-client RPC interface for the Grid component.
+ * 
+ * @since 7.2
+ * @author Vaadin Ltd
+ */
+public interface GridClientRpc extends ClientRpc {
+
+    /**
+     * Command client Grid to scroll to a specific data row.
+     * 
+     * @param row
+     *            zero-based row index. If the row index is below zero or above
+     *            the row count of the client-side data source, a client-side
+     *            exception will be triggered. Since this exception has no
+     *            handling by default, an out-of-bounds value will cause a
+     *            client-side crash.
+     * @param destination
+     *            desired placement of scrolled-to row. See the documentation
+     *            for {@link ScrollDestination} for more information.
+     */
+    public void scrollToRow(int row, ScrollDestination destination);
+
+    /**
+     * Command client Grid to scroll to the first row.
+     */
+    public void scrollToStart();
+
+    /**
+     * Command client Grid to scroll to the last row.
+     */
+    public void scrollToEnd();
+
+}
diff --git a/shared/src/com/vaadin/shared/ui/grid/GridConstants.java b/shared/src/com/vaadin/shared/ui/grid/GridConstants.java
new file mode 100644
index 0000000000..5b88fad5a8
--- /dev/null
+++ b/shared/src/com/vaadin/shared/ui/grid/GridConstants.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2000-2013 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.grid;
+
+/**
+ * Container class for common constants and default values used by the Grid
+ * component.
+ * 
+ * @since 7.2
+ * @author Vaadin Ltd
+ */
+public final class GridConstants {
+
+    /**
+     * Default padding in pixels when scrolling programmatically, without an
+     * explicitly defined padding value.
+     */
+    public static final int DEFAULT_PADDING = 0;
+
+}